December 2019

Authors
David Sandalow
Center on Global Energy Policy,
Columbia University
Chair, ICEF Innova on Roadmap
Project
Julio Friedmann
Center on Global Energy Policy,
Columbia University
Roger Aines
Lawrence Livermore Na onal
Laboratory
Colin McCormick
Walsh School of Foreign Service,
Georgetown University
Sean McCoy
Department of Chemical andPetroleum Engineering, Universityof Calgary
Joshuah Stolaroﬀ
Lawrence Livermore Na onal
Laboratory
Roger Aines and Joshuah Stolaroﬀ
contributed to the technicalevalua ons but not the policy
recommenda ons in this document.

This roadmap was prepared to facilitate dialogue at the Sixth Innova on for Cool Earth
Forum (Tokyo October 2019), for ﬁnal release at COP-25 (Madrid December 2019).
We are deeply grateful to the Ministry of Economy, Trade and Industry (METI) and
New Energy and Industrial Technology Development Organiza on (NEDO), Japan, forlaunching and suppor ng the ICEF Innova on Roadmap Project of which this is a part.

Contents
EXECUTIVE SUMMARY
1
1 CHAPTERINTRODUCTION
2
5 CHAPTERTECHNOLOGY OPTIONS FOR LOW-CARBON
INDUSTRIAL HEAT
5 Hydrogen
11 Biomass
16 Electriﬁcation
21 Carbon Capture, Use and Storage
3
25 CHAPTERSECTORAL STUDIES
25 Cement
34 Iron and Steel
43 Chemicals
453 CHAPTERINNOVATION PATHWAYS
560 CHAPTERPOLICY6
66 CHAPTER
FINDINGS AND RECOMMENDATIONS
iii

December 2019

EXECUTIVE
SUMMARY
INTRODUCTION
Roughly 10% of global greenhouse gas (GHG)
emissions come from the produc on of heat forindustrial processes—more than cars and planes
combined. Decarbonizing industrial heat produc on
will be essen al to mee ng the Paris Agreement
goals. This topic has received far less a en on thandecarboniza on of the power, transport or building
sectors.
Most heavy industries require enormous quan es ofheat. In many cases (including the cement, iron andsteel, and chemical industries), core processes involve
smel ng ore, breaking strong chemical bonds and/or
increasing the energy content of products.
Today, almost all industrial heat is provided by
combus on of coal, oil or natural gas. These fossil fuels
provide the high temperatures, con nuous opera on
and reliability many industrial processes require. Any
op ons for decarbonizing industrial heat must matchthese capabili es or be part of a broader change inindustrial processes.
Op ons to provide low-carbon heat for industry includehydrogen; biomass; electriﬁca on; carbon capture, use
and storage (CCUS); nuclear power; and concentrated
solar power (CSP). Few if any of these op ons are welldeveloped in the context of industrial heat produc on.
Several characteris cs of heavy industries create
challenges in decarbonizing industrial heat produc on.
First, industrial facili es are long-lived capital stock,las ng decades. Second, many industrial products areglobally traded commodi es, subject to signiﬁcant lossof market share due to small increases in produc on
costs. Third, many industrial facili es are far fromrenewable resources such as biomass or abundant solar
radia on, limi ng decarboniza on op ons. Fourth, many
governments view these industries as core na onal
assets, aﬀec ng na onal security and the balance oftrade.
This Roadmap explores the challenge of industrial
heat decarboniza on. It is intended to be an ini al,
iv“1.0” analysis of the topic. A er providing generalbackground, we discuss four technological approaches
for providing low-carbon industrial heat: hydrogen,biomass, electriﬁca on and CCUS. We next examine
decarbonizing heat produc on in the cement, ironand steel, and chemical industries. We then turn topolicy op ons and an innova on agenda. We close withﬁndings and recommenda ons.

TECHNOLOGYOPTIONS FOR LOWCARBON INDUSTRIAL
HEAT
Hydrogen.
Hydrogen combus on produces heat without carbon
dioxide (CO2) emissions. Hydrogen can subs tute forcoal, oil and gas as a fuel in some industrial processes,
reducing on-site emissions. However the produc onof hydrogen may involve substan al CO2 emissions,
reducing or elimina ng the CO2 beneﬁts of switching tohydrogen. Low-carbon produc on of hydrogen is thus
essen al for hydrogen to play a role in decarbonizing
industrial heat.
The most common hydrogen produc on process today
is steam methane reforming (“gray” hydrogen), which
has signiﬁcant CO2 emissions. This can be substan ally
decarbonized by adding CCUS (“blue” hydrogen),reducing the carbon footprint by 55-90% or more. Lowcarbon hydrogen can also be made through electrolysis
using zero-carbon power (“green” hydrogen).
Hydrogen could be used in many exis ng industrial
hea ng systems with small changes, especially forchemical synthesis. Issues such as sensors, controls,
corrosion and embri lement appear resolvable withminor costs and system modiﬁca ons. Blue hydrogen
would add modest costs to produc on of hydrogenand raw industrial products (20-50% increase). Greenhydrogen would add substan al costs (200-400%
increase). As costs for ﬁrm renewable power decrease in
the future, green hydrogen may become more a rac ve
and could take advantage of infrastructure originallyinstalled to use blue hydrogen.

Biomass.
Biomass provides considerable heat when burned.
Biomass can be converted to useful intermediates suchas biomethane, biodiesel and bio-char, and provides
a carbon source and chemical reductant important insome industries. Biomass has the poten al to deliver net
low-carbon heat, since biomass can regrow, absorbing
CO2 released during combus on. However land usechanges related to biomass harves ng can reduce or
eliminate these CO2 beneﬁts. Transport and processingof biomass, as well as use of fer lizer, can also reduce
the GHG beneﬁts of biomass combus on.
Approximately 200-500 EJ/y of sustainably produced
biomass can be available by 2050, similar to theprojected global industrial energy demand of 330 EJ/y
in 2040. Nevertheless, scaling biomass suﬃciently toplay a signiﬁcant role in industrial heat produc on
would be a challenge. Biomass is more geographicallydiverse and expensive to collect and transport thanfossil fuels. Woody biomass has about half the energy
density and considerably lower bulk density (before
grinding) than coal. There are compe ng demands forbiomass in a low-carbon future, including as vehicle
fuel, dispatchable electricity and means of nega veemissions. Despite these challenges, biomass has thepoten al to contribute to low-carbon heat for industry insome applica ons.

Electrification.
A wide variety of exis ng and emerging electrical
technologies can provide high-temperature industrial
process heat, including resistance hea ng, microwaves,
induc on and electric arc furnaces. Electrical hea ng has
high controllability of temperature and dura on of heatapplica on, rela vely low maintenance, and inherently
low emissions when powered by low-carbon electricity.
However, reliable electricity in industrially relevant
quan es is not always available and in general is higher
cost than combus on-based technologies.
The installa on of electric process heat systems o en
requires more changes to exis ng equipment thanswitching to alternate combus on-based fuels (such ashydrogen or biomass). It may also require substan alplant redesign. The use of electricity in industrial
process heat applica ons can place major burdens
on the electric grid. While some op miza on suchas par cipa on in demand-side management (DSM)
systems is possible, this is limited in prac ce and majorv

grid infrastructure upgrades are needed for large-scaleindustrial electriﬁca on.

Carbon capture, use and storage (CCUS).
CCUS has an important role to play in reducing emissions
from produc on of industrial heat. The building blocks
of CCUS include separa on of CO2 from combus on
products or hydrocarbon fuels, transporta on of CO2
to a suitable storage site (or loca on where it is used),
and geologic storage of CO2 or conversion of CO2 into a
range of products (e.g., carbonate minerals, chemicals
and fuels). CCUS is a rac ve because it usually does not
require wholesale changes to the underlying industrial
processes.
Experience with CCUS has grown considerably since
1996, when the ﬁrst “purpose built” project beganstoring CO2 captured from a gas processing pla orm
deep under the North Sea. Today, CCUS projects
are capturing CO2 that would have otherwise been
emi ed from power genera on, ethanol fermenta on,gas separa on, iron and steelmaking, and hydrogenproduc on. CO2 capture for industrial processes—
par cularly cement and steel—requires further
development through demonstra on projects at scale.
Infrastructure is needed to transport and geologicallystore large volumes of CO2.

SECTORAL STUDIES
Cement.
Cement provides the founda on for the built
environment. Currently, over 4 Gt of cement are
produced annually, resul ng in more than 2 Gt per
year of CO2 emissions. CO2 emissions from cement
manufacturing result not only from high-temperature
heat—nearly 1,500 °C in the cement kiln—but also fromdecomposi on of limestone (CaCO3). Many strategies
for reducing these emissions have been considered,including fuel switching in conven onal cement making,fundamental changes in the composi on of cement andmore eﬃcient use of concrete in design.
Subs tu on of lower-carbon-intensity fuels for coalis already having a substan al impact in the cement
sector. This could be furthered by increased useof biomass-based wastes and sustainable biofuels.
However, given the limited supply of sustainable biomass
and compe on that may emerge for its diﬀerent

uses, this may not be cost-eﬀec ve in large quan es.
CCUS appears to be an important op on for reducing
emissions from cement produc on.

Iron and steel.
The iron and steel sector is one of the largest in theworld, responsible for 7-9% of global direct emissions
from fossil fuel. New steel produc on primarily uses a
blast furnace to convert iron ore to pig iron, followed
by a basic oxygen furnace to convert pig iron to steel.
This process is emissions-intensive, with most emissions
coming from the blast furnace. Electric arc furnaces
convert recycled steel and iron from other processes toliquid steel in a far less emissions-intensive manner but
are limited by availability of recycled material.
In blast furnaces, process heat is provided by
combus on of coke. Coke also provides carbon as a
reductant, acts as structural support to hold the oreburden, and provides porosity for rising hot gas andsinking molten iron. Because of these mul ple roles,
directly replacing coke combus on with an alterna vesource of process heat is not prac cal. Op ons for
reducing process-heat-related emissions from blast
furnaces include reducing coke through hydrogenco-injec on and plasma torch super-hea ng of hot blast
air. Direct-reduced iron (DRI) and smel ng reduc oniron can also be used in blast or arc furnaces to reduce
emissions. Biomass-nugget smel ng, hydrogenreduc on iron making, and electroly c steel produc on
also oﬀer alterna ves. CCUS can signiﬁcantly reduce
process-heat-related emissions when applied to ﬂue gas
at an integrated steel mill, blast furnace gas, or DRI andsmel ng reduc on processes.

Chemicals.
The global chemical industry is roughly 3% of global
CO2 emissions. Energy demand for chemicals is greaterthan for either cement or steel, reﬂec ng enormous
heat consump on. Chemical facili es use a wide set offeedstocks and fuels, consuming natural gas, natural gas
liquids, heavy hydrocarbons (e.g., bitumen, asphalt), coaland hydrogen. Facili es are highly complex with a wide
range of chemical-produc on processes. Many reac ons
require ﬁt-for-purpose reactors that cannot readily be
replaced. A concern speciﬁc to the chemical industry is
the broad distribu on of heat sources, which can include
dozens or hundreds of small emissions sources such as
burners, furnaces and boilers.
vi

Hydrogen (blue or green) appears to be the most readysubs tute for current fossil fuel heat sources, in largepart because many chemical facili es use predominantly
gaseous fuels for heat produc on. CCUS retroﬁts may
cost less than switching to hydrogen in some instances,although capturing CO2 from many distributed heatsources may prove challenging. Eﬃciency improvements
provide near-term opportuni es to reduce emissions.
In the future, electriﬁca on may prove workable,
especially for straigh orward subs tu ons such as
steam produc on. To achieve widespread electriﬁca on,
low-carbon electric power would need to be muchcheaper and more readily available, and novel systemsof heat deposi on would require development anddemonstra on.

INNOVATION
The greatest challenge in innova on for industrial
heat is the extreme diversity of processes that require
carbon-free energy. Systema c changes across the
economy, such as switching from methane to hydrogenin gas pipelines, will be important op ons, but there
is currently no analy cal basis on which to compare
op ons. Detailed and cross-cu ng analysis of the
beneﬁts and costs of zero-carbon fuels, biomass, andhybrid systems involving CCUS and direct air capture
are needed before na ons can commit to wholesaleindustrial changes.
The most immediate pathway to decarbonizing industrial
heat is likely to be one that incrementally reduces
emissions, with rela vely small changes from op ons
like more eﬃcient heat applica on, reduced carbon
footprint of fuels, and hybrids involving par al carbon
capture and storage (CCS). It is important to evaluate
and develop these par al pathways in concert withthose that completely transform industrial processes.
Zero-carbon fuels are likely to be an important elementof such transi ons. Global transport of hydrogen andbiomass needs to be evaluated for both economic andclimate impacts to determine if that is an approach thatcan overcome regional shortages in those two fuels. The
safety and opera onal issues of zero-carbon fuels (ﬂamevisibility for hydrogen, methane leakage for renewable
natural gas and food/ecosystem tradeoﬀs for biofuels)need to be carefully evaluated.
High capital costs are likely to be a major barrier to thetransi on to zero-carbon industrial heat sources. Finally,

the costs of completely decarbonizing by u lizing direct
air capture need to be evaluated for industries that haveachieved par al decarboniza on but face massive capital
expenditures to completely eliminate their carbon
emissions.

POLICY
Policy tools are essen al for decarbonizing industrial
heat, both in the short- and long-term.
Market forces alone are insuﬃcient, since CO2 emi ers
do not bear the full costs of their emissions. Government
policies are essen al. Many policy tools are available tohelp with decarbonizing industrial heat. These include:
1. Government support for research anddevelopment (R&D). Na onal governments spend
roughly $15 billion annually on R&D for clean energy
technologies. These programs have played importantroles in the development of countless technologies
in recent decades. Increased R&D funding on
industrial heat decarboniza on is essen al.
2. Government procurement. Governments are majorpurchasers of steel, cement, chemicals and otherproducts that require heat in the manufacturing
process. Procurement standards that give
preferences to products with the lowest embedded
carbon content could drive signiﬁcant changes inindustrial behavior.
3. Fiscal subsidies. Decarbonizing industrial heat will
impose costs on aﬀected businesses. Government
policies can help to reduce those costs with ﬁscal
subsidies. These can take several forms, including tax
incen ves, grants, loan guarantees, feed-in-tariﬀsand contracts for diﬀerences.
4. Infrastructure development. The transi on
to low carbon industrial heat may require new
infrastructure (such as electric transmission lines
or hydrogen pipelines). Governments can play acentral role in facilita ng the development of suchinfrastructure through permi ng, ﬁnancing andother measures.
5. Carbon prices. A price on CO2 emissions, whether
through an emissions-trading program or tax
mechanism, provides emi ers with an important
incen ve to cut emissions. The carbon prices thatmight be needed to induce a transi on from fossil
fuels for industrial heat produc on are unclear.
vii

6. Carbon tariﬀs. Carbon tariﬀs (some mes called“carbon border-tax adjustments”) are a tool for
addressing interna onal compe veness concerns. A
country that requires its manufacturers to transi on
to low-carbon industrial heat could tax imports ofrelevant products from countries that fail to do so.
7. Mandates. Governments could prohibit the useof fossil fuels or require the use of low-carbon
technologies for genera ng heat in certain industrial
sectors.
8. Voluntary industry associa ons. Industry
associa ons such as World Steel Associa on, WorldPetroleum Council, World Cement Associa on andWorld Business Council on Sustainable Development
can help develop methods and standards for
decarbonizing industrial heat. They can play animportant role in informa on-sharing on such topics.
9. Clean Energy Ministerial. The Clean Energy
Ministerial is a global forum where major economies
work together to share best prac ces and promote
policies and programs that encourage and facilitate
the transi on to a global clean energy economy. A
Clean Energy Ministerial ini a ve on industrial heat
decarboniza on could help to share best prac ces
and accelerate their adop on.

FINDINGS AND
RECOMMENDATIONS
Decarbonizing industrial heat produc on will requireinnova ng in mul ple sectors. Our key ﬁndings andrecommenda ons include:■ Finding 1: Emissions from industrial heat produc onlimit progress on climate goals.
■ Finding 2: The opera onal requirements andcommercial reali es of many industries limit
opportuni es for decarboniza on.
■ Finding 3: There are few op ons today for low-carbon
heat genera on for industry.
■ Finding 4: Exis ng op ons face challenges based on
price, performance and viability.
■ Finding 5: There appear to be many pathways toimproving cost, performance and viability of lowcarbon industrial heat op ons.
■ Finding 6: Many policy op ons exist that could
improve the speed and magnitude of industrialdecarboniza on and deployment of low-carbon
alterna ve heat systems.
■ Recommendation 1: Key stakeholders should

priori ze industrial heat produc on as a key elementof any climate mi ga on strategy.
■ Recommendation 2: Industry-speciﬁc analy cal
frameworks and innova on agendas are essen al.
Governments and companies together should
develop new ini a ves and R&D programs to focus
on industrial sector decarboniza on with a focus onheat supplies.
■ Recommendation 3: Governments should iden fy
and implement a set of policy ac ons to accelerateand support industrial decarboniza on, star ng with“buy clean” procurement.

Final thoughts
This Roadmap is an ini al foray into this extremely
important and complex topic. One core ﬁnding of thisRoadmap is that more work is needed on this topic. The
urgency of climate change requires profound and rapid
ac on. More data, input and technology op ons for
decarbonizing industrial heat are urgently needed.

viii

CHAPTER 1
INTRODUCTION
Roughly 10% of global greenhouse gas (GHG) emissions
come from the produc on of heat for industrial
processes. This is more than GHG emissions from cars
and planes combined.1,2 Decarbonizing industrial heatproduc on will be essen al to mee ng the goals set
forth in the Paris Agreement, including achieving net
zero emissions in the second half of this century, yet
technological approaches for decarbonizing industrial
heat produc on are far from maturity. This topic hasreceived far less a en on than decarboniza on of thepower, transport and building sectors.
This Roadmap explores the challenge of industrial heat
decarboniza on. A er providing background, we explore
four technological approaches with the poten al for
genera ng industrial heat without GHG emissions:hydrogen; biomass; electriﬁca on; and carbon capture,
use and storage. We next explore the poten al for
decarbonizing heat produc on in three industries:
cement, iron and steel, and chemicals. We then turn topolicy op ons and an innova on agenda. We close withﬁndings and recommenda ons.

Background
Almost a quarter of global GHG emissions come fromthe industrial sector.3,4 The cement, steel and chemicalindustries are the largest contributors. The reﬁning,
fer lizer and glass industries are signiﬁcant contributors
as well. In 2018, global industrial GHG emissions grew at
a rate of 2.7%.5
Recent studies have provided excellent analyses ofseveral strategies for reducing emissions, including
process intensiﬁca on, material subs tu on, overall
demand reduc on and energy eﬃciency.6 Rela vely li lea en on has focused on how industry uses heat.
In many industrial applica ons, high quality heat is themost important input a er primary feedstocks. Heat
produc on, usually through fossil fuel combus on, iseither the largest contributor or the second largest
contributor to industrial sector emissions. Together,industrial heat represents roughly 40% of total industrial
emissions. Even with substan al eﬃciency gains,1demand reduc on and development of a circular
economy, the ambi ous goals of the Paris Agreement
will be diﬃcult or impossible to achieve without
signiﬁcant reduc ons in emissions from industrial heatproduc on.

Requirements
Most heavy industries require enormous quan es ofheat at high temperature. In many cases (including thecement, iron and steel, and chemical industries), thecore industrial processes involve smel ng ore, breaking
strong chemical bonds or increasing a product’s energy
content. These processes produce substan al GHG
emissions. Earlier this century, industrial emissions
growth was driven by high temperature in sectors
including cement and steel (in part to build Chinese
megaci es). Although these sectors s ll produce large
emissions, current growth is from medium temperatureapplica ons including reﬁning and chemicals.
The needs of the speciﬁc industries themselves
vary considerably and are extremely heterogenous(even within one major produc on facility). Three
requirements are key:
■ Temperature: Industrial products are made throughthe applica on of high-grade heat to feedstocks.
Temperature demands vary signiﬁcantly from around
200 °C to nearly 2,000 °C (Table 1.1).
■ Flux: Industrial heat demands must be met with high(and commonly con nuous) heat ﬂux into the system.
The ﬂux must be large enough to sustain reasonableproduc on (Table 1.1).
■ Reliability: Most heavy industrial produc on occurs
at large facili es with high capital costs (e.g., reﬁnery,steel mill). Most of these facili es operate with very
high capacity factors, commonly 60-95%.7 As such,heat supply must be dispatchable and available boththroughout the day and throughout the year.
Any viable op on to replace exis ng sources of industrial
heat must be able to achieve the temperatures,
ﬂuxes and reliability necessary for robust, con nuous
opera on. Approaches or fuels that cannot achieve hightemperatures (e.g., heat pumps) or are intermi ent(e.g., hea ng with variable renewable power) will have
limited u lity as viable subs tutes. Finally, most op ons
must operate in the speciﬁc geography where theseindustries exist and operate (e.g., along the Gulf of
Mexico or Northern European ports).
December 2019

Applica on & process

Temperature
required (°C)

Energy requirements(GJ/ton product)

Glass: Silica mel ng

1,600

≈3

Cement: Clinker produc on

1,450

4

Steel: Blast furnace opera on

1,100

11-14

Hydrogen produc on: Steam methane reforming

820

16

Fer lizer: Ammonia synthesis

450

36

Petrochem: Methanol synthesis

300

33

Table 1.1. Temperature requirements and energy requirements per ton produc on for key industrial processes &applica ons (global averages)

Options
Op ons for providing low-carbon heat of industrial
quality are not well developed. Challenges can bephysical or chemical (e.g., the temperature of steam atconven onal nuclear power plants), geographic (e.g.,
the availability of solar radiance or biomass feedstock)and economic (e.g., the cost of electroly c produc on ofhydrogen).
Unfortunately, no op on exists that can be widely
deployed today. Current op ons include:■ Hydrogen combustion: Burning hydrogen made fromelectrolysis or decarbonized fossil fuels.
■ Biomass combustion: Burning of unreﬁned biomass(e.g., agricultural wastes and wood pellets).
■ Biofuel combustion: Burning of reﬁned biomass (e.g.,biogas, biodiesel and corn ethanol).
■ Electrical heating: Direct and indirect hea ng
approaches such as resis ve hea ng, induc on
hea ng and dielectric hea ng (e.g., microwaves).
■ Carbon capture, use and storage: Capturing COfrom combus on of fossil fuels (or biofuels) andsequestering it underground or in durable products.
■ Concentrated solar power: Large facili es (e.g.,
power towers) and more distributed approaches (e.g.,
small parabolic mirrors).
■ Conventional and advanced nuclear heat: Light
water reactors, emerging small modular reactors andadvanced nuclear processes (e.g., sodium-cooled fast
reactors or nuclear fusion).
In considering these op ons, heat quality, cost,
availability and carbon footprint are all important.
Some of these op ons can serve only a limited numberof industrial applica ons based on temperature
requirements alone (Figure 1.1).
Some low-carbon op ons will only prove viable fora small number of industrial applica ons. Stateddiﬀerently, it is unlikely that one pathway will provesuperior to the others in all contexts. A por olio offuels is likely to serve a range of poten al industrial
applica ons, and individual sectors or plants may selectdiﬀerent op ons based on their geography, policy
framework and asset requirements.

Nature of industrial operations and markets
Several characteris cs of industrial opera ons andmarkets create challenges in decarbonizing industrial
heat produc on.8
First, industrial facili es are long-lived capital stock.
Turnover o en takes place over many decades.
Components such as rotary cement kilns, blast furnaces,
cataly c crackers and hydrogen produc on units can
individually cost $100s of millions and are central to theopera on of mul -billion dollar assets. It may take 30-60
years to replace core components of a large industrial
facility, and some facili es have operated for over 80
years and are s ll making products and revenues. This
creates a high hurdle rate to rebuilding and replacing
high-emi ng units and aﬀects the ability of innova vesolu ons to propagate into the sector.
Second, many industrial products are globally tradedcommodi es (unlike electricity, which serves local orregional markets).a This means that prices of manyindustrial products are set by interna onal trade. Smalla

Cement and concrete markets are excep ons, since they are mostly used
locally (although that has begun to change).

2

December 2019

Figure 1.1. Temperature requirements of key industrial process and the temperature limits provided by some op ons for
low-carbon heat source replacements.8

increases in produc on costs could lead to a drama closs of market share and loss of compe veness overall,which can aﬀect the na onal trade balance and theoverall health of the industry. This has led to narrowmargins9,10 and a reluctance to increase costs.
Third, many industrial facili es are located far fromrenewable resources such biomass or solar radia on
suﬃcient for concentrated solar power. O en, heavy
industrial manufacturing facili es are found in ports tofacilitate trade and delivery of feedstocks. For example,
over 70% of the US reﬁning capacity lies along the Gulf
of Mexico coast in Texas and Louisiana.
Fourth, many governments consider these industries
to be core na onal assets, aﬀec ng na onal security
and the balance of trade. In part for that reason,these industries have some mes received exemp ons
or waivers from carbon pricing and environmental
regula ons. In some cases, this has been a factor
contribu ng to signiﬁcant overcapacity (e.g., in Chineseand Korean steel produc on). While some of thisovercapacity may lead to closures, it may also lead to life
extension for lowest cost assets, which may have a poor
carbon emissions proﬁle.
3Strategies for reducing GHG emissions from industrial
heat produc on will be more likely to succeed if theytake account of these quali es of the key sectors.

Framing for this Roadmap
More and be er op ons for low-carbon industrial heatare essen al to mee ng global climate goals. To improvethe exis ng op ons and develop addi onal pathways
requires informa on and knowledge that is unavailable.
The general lack of knowledge and informa on aroundthe topic of industrial decarboniza on (and industrial
heat in par cular) prevents investors, operators andpolicy makers from considering and implemen ng
alterna ves. This Roadmap explores op ons available
today as an early foray into the subject.
This Roadmap is intended to be an ini al, “1.0” analysis
of op ons for decarbonizing industrial heat. In preparing
this Roadmap, we have priori zed several technologicalpathways (hydrogen, biomass, electriﬁca on and CCUS).
We do not explore other op ons including concentrated
solar power, gene cally modiﬁed organisms and nuclear
heat. Our selec on was based on factors including
geographic availability, technological readiness andDecember 2019public acceptance. We explore several key industries(cement, iron and steel, and chemical) but have not
had the chance to explore others (including pulp andpaper, glass making, and aluminum smel ng). We
recognize that all viable op ons today are challenging,including most of those we have selected for analysis.
The challenges include cost, availability, life-cycle carbon
footprint and engineering viability.
Strategies for decarbonizing the industrial sector mustalso include eﬃciency improvements, material use
reduc on and development of a circular economy.6
Decarbonizing produc on of industrial heat will be an
important part of the solu on set.
1

M. Fischedick et al.,Climate Change 2014: Mi ga onof Climate Change (Fi h Assessment Report), Chapter
10: Industry, Intergovernmental Panel on Climate
Change, at p. 752, h ps://www.ipcc.ch/site/assets/
uploads/2018/02/ipcc_wg3_ar5_chapter10.pdf

2

IEA, Tracking Clean Energy Progress, Transport Page,“Transport sector CO emissions by mode,” h ps://www.iea.org/tcep/transport/ (accessed September 29,
2019)

3

EPA, 2019, “Global Greenhouse Gas Emission Data”,
h ps://www.epa.gov/ghgemissions/global-greenhousegas-emissions-data

4

4

IEA, 2018, “World Energy Outlook 2018”, h ps://www.
iea.org/weo2018/

5

R. Jackson et al., 2018, “Global energy growth isoutpacing decarboniza on”, Environ. Res. Le ., h ps://iopscience.iop.org/ar cle/10.1088/1748-9326/aaf303/
meta

6

Ins tute for European Studies, 2019, “Industrial
Transforma on 2050: Towards and Industrial Strategy
for a Climate Neutral Europe”, h ps://europeanclimate.
org/wp-content/uploads/2019/04/Towards-anIndustrial-Strategy-FULL-REPORT.pdf

7

Material Economics, 2019, “Industrial Transforma on
2050: Pathways to net-zero emissions for European
Heavy Industy”, h ps://europeanclimate.
org/wp-content/uploads/2019/04/IndustrialTransforma on-2050.pdf

8

See J. Friedmann et al., 2019, “Low-carbon heatsolu ons for heavy industry: sources, op ons & costs
today”, Columbia Univ. Center on Global Energy Policy,
h ps://energypolicy.columbia.edu/research/report/
low-carbon-heat-solu ons-heavy-industry-sourcesop ons-and-costs-today

9

Macrotrends, 2019a, U.S. Steel Proﬁt Margin 20062019, h ps://www.macrotrends.net/stocks/charts/X/
united-states-steel/proﬁt-margins

10

Macrotrends, 2019b, U.S. Concrete Proﬁt Margin 20062019, h ps://www.macrotrends.net/stocks/charts/
USCR/u-s-concrete/proﬁt-margins

December 2019

CHAPTER 2TECHNOLOGYOPTIONS FOR LOWCARBON INDUSTRIALHEAT
HYDROGEN
Hydrogen is the most abundant element in the universe
and extremely abundant on Earth. When burned,hydrogen produces high-grade heat without carbon
dioxide (CO2) emissions. Subs tu ng hydrogen forhydrocarbon fuels such as natural gas is one poten al
pathway for decarbonizing industrial heat produc on.
Although hydrogen is extremely abundant, it is usuallybound to other elements in compounds such methane(CH4) and water (H2O). Separa ng hydrogen from thesecompounds requires substan al amounts of energy
to break chemical bonds. The processes for doing so(chemical, electrical, thermal) are readily available today
and used commercially in many industries in whichhydrogen is a feedstock. Pipelines in many countries
currently provide hydrogen as a feedstock to chemical
and reﬁning plants, steel plants and other industrial
facili es.
Hydrogen can be burned in air, producing a 2100 °C
ﬂame. (If burned in oxygen, the heat of hydrogen

combus on is 2800 °C.) Although today it is rare forhydrogen combus on to create an industrial heatsource, some applica ons burn hydrogen in boilers,
stoves and vehicle engines. Hydrogen combus on
systems require special burners and in some cases
require conversion from liquiﬁed hydrogen to gas form.
In most other respects, hydrogen combus on for heat isextremely similar to burning natural gas and is a viable
subs tute for other gaseous fuels.
Roughly half of hydrogen produced today worldwide isfrom natural-gas reforming.1 It is a mature technology
and rela vely energy eﬃcient (65-75% conversion
eﬃciency) and can operate wherever there is a natural
gas supply. Gas reforming itself uses high-temperature
heat (700-1,000 °C) at elevated pressures (15-25 bars),
usually provided from natural gas furnaces. The reac on
occurs in the presence of a catalyst. The fundamental
chemistry of reforma on can be represented in simple
terms:
Steam-methane reforming reaction
CH4 + H2O (+ heat) → CO + 3H2
Water-gas shift reaction
CO + H2O → CO2 + H2 (+ small amount of heat)
Although the fundamental chemistry is straigh orward,
the engineering is more complicated. The key process(reforming) is strongly endothermic and consumes heat(i.e., 206 kJ/mol). It operates at high temperature which
requires high combus on heat. Feedstock coming froma conven onal natural gas pipeline must be puriﬁed,
which requires separa ons of sulfur, nitrogen and othertrace gases. These each have their own heaters, o enprovided by pre-heaters and o en from heat recovery

Figure 2A-1. Hydrogen producƟon processes. A: Steam methane reforming (SMR). B: Electrolysis of water.
5

December 2019

units. The ﬁnal separa ons through the pressure swing
adsorp on unit also require heat and work.

CO2 emissions from a facility (the rest comes from gas
combus on in the hea ng systems).

In addi on to steam-methane reforming (SMR), otherapproaches include autothermal reforming (ATR), par aloxida on and other more exo c methods (see below).
In reﬁneries, oil residues are commonly gasiﬁed andreﬁnery gas streams are reformed. In loca ons where
gas is expensive or supplies are limited (e.g., China,
India, South Africa), coal or petcoke is gasiﬁed as analterna ve feedstock to gas reforming and is commonly
combined with a water-gas shi reac on to maximize
produc on.a The dominant costs are the costs of gas(85% of total) and the heavy industrial equipment usedin reforma on. Importantly, CO2 is a direct chemical
byproduct of reforma on and represents about 55% ofElectrolysis of water is a completely diﬀerent op on forhydrogen produc on, using electricity as the energy
source to break the chemical bonds in water, forminghydrogen and oxygen (Figure 2A-1). The process
requires an electroly c cell and fairly pure watersupplies. Electrolysis is typically more expensive thangas reforming, with costs principally determined by thecosts of electricity and electrolyzers. The electricity forelectrolysis can come from high-carbon or low-carbon
sources. Electrolysis itself produces no greenhouse gases(GHGs).

aCoal or petcoke feedstocks yield addi onal CO , roughly twice thatof natural gas, requiring extra storage. In regions where CO storage
resources are limited, this can cause challenges to decarbonizing
produc on.

Decarboniza on has only recently become importantto hydrogen produc on. Increasingly, scholars,
environmental ac vists and policy makers have begun toclassify hydrogen into three broad categories:

BOX 2 1 Other challenges with hydrogen
Hydrogen’s poten al to contribute to decarboniza on has been extensively studied. This focus has revealed
several physics and chemistry challenges to widespread hydrogen use.
■ Leakage: Because hydrogen is a very small molecule, leakage risks are substanal, especiallyin pre-exis ng pipelines or devices. Special materials and gaskets are o en required to ensure
minimal leakage.
■ Safety: Hydrogen is colorless, odorless and burns invisibly. On that basis, special monitors andsensors are needed to iden fy opera ng hydrogen combus on units and appropriate mi ga onplans are needed to ensure safety.6■ Corrosion and embrittlement: In small frac ons (7-20%), hydrogen can be mixed into exis ng
pipeline networks with minimal consequence. At higher frac ons, hydrogen can corrode
conven onal pipes, providing a leakage or safety concern. Moreover, hydrogen can makeconven onal metal pipes and ﬁxtures bri le through aging and low-level reac ons. Overt steps
are needed to mi gate or counter corrosion and embri lement, poten ally including full
pipeline replacement.
■ Storage: Hydrogen is notoriously challenging to store. Many tank systems areadequate (either compressed, liquiﬁed or cryo-compressed) but require
special materials and systems to avoid leak-oﬀ or other losses, some mes
adding substan al costs to hydrogen systems. Some work has begun on
using engineered salt caverns to store hydrogen in large volumes.
While these issues are straigh orward and manageable, they require a en on toensure safe and cost-eﬀec ve hydrogen deployment in industrial se ngs.

6

December 2019

■ Gray hydrogen: H produc on without2

carbon controls (typically SMR, ven ng
byproduct and combus on related CO2).
■ Blue hydrogen: H produc on with carbon
2
controls (typically carbon capture, use andstorage—CCUS).
■ Green hydrogen: Electrolysis of waterusing only low-carbon electricity sources(e.g., renewables, nuclear).
All three categories of hydrogen produc on
can have a wide range of GHG emissions.
For example, both gray and blue hydrogenproduc on carry the upstream emissions
associated with methane produc on, which
can vary substan ally.2,3Figure 2A-2. Cost of hydrogen produc on ($/kg) of selected hydrogenproduc on methods (unsubsidized). Source: Friedmann et al. 2019For blue hydrogen, CO2 capture can either
be par al (i.e., from only the reforma onunit) or applied to addi onal plant systems at
Conven onal produc on from natural gas without
addi onal costs (see below).4 Today, four units aroundcarbon capture and storage (CCS)(gray hydrogen) is
the world capture CO2 from the reforma on unit,5 whichcheaper than all low-carbon op ons. Par al or full CCS
represents an emissions reduc on of roughly 53-60%(blue hydrogen) increases costs by 20-50% depending on
per unit hydrogen. It is possible to reduce emissions
the degree of decarboniza on. All electroly c hydrogenfrom hydrogen produc on to much higher levels,
is more expensive s ll, with US grid costs producing
commonly up to 90%, although even higher capturehydrogen at roughly twice the cost of gray hydrogen andrates are possible. Blue hydrogen produc on is only
resul ng in only 20-30% carbon footprint reduc ons.
viable at sites that can access CO2 transport and storage
When all power is generated with renewable sources,
infrastructure (i.e., where there are geological storage
costs increase by a factor of 3-10.
sites or pipelines that can move CO2 to them).

For green hydrogen, the footprint of electricity
produc on can vary greatly across regions. This
underscores the need for careful life-cycle analysis
to understand and es mate the carbon footprint of
all forms of produc on. Many low-carbon electricity
systems have low capacity factors, which can add
substan al costs for ﬁrm power genera on.

Estimated costs
Following Collidi et al.,7 Friedmann et al.8 developed a“levelized cost of hydrogen” (LCOH). LCOH es mates
the unit cost of producing hydrogen over its economic
life me, including capital costs, opera ng andmaintenance costs, and capacity factors, as well as
calcula ng diﬀerent costs as a func on of gas costs,
power costs, conversion methodology and degrees ofdecarboniza on.9 These costs and assump ons are
represented in Table 2A-1. and compared in Figure 2A-2.

7

A blue-green transition
Today, it is possible to generate low-carbon hydrogenat a large scale from natural gas and to decarbonize
the produc on with rela vely small increases in cost.
It is likely that as CCUS technologies improve, theincremental cost of decarbonizing blue hydrogenproduc on will drop somewhat as well. However, theprincipal element of blue hydrogen cost is the cost ofnatural gas itself, which is already low in North America,
and it is hard to imagine drama c cost improvements forblue hydrogen.
In contrast, the primary costs of green hydrogen (lowcarbon electricity prices) have decreased drama callyand con nue to drop. While it is unclear how muchcosts can or will decrease for solar or wind, it is plausiblethat capacity factors will increase for some renewablesources and that costs will drop with technology
advances.10 While curtailment today represents rela vely
small percentages of power genera on, many scholars
December 2019

H2 PRODUCTION APPROACH
Natural Gas Reforma on*

Capture Rate

LCOH

Cost of Heat (LHV)

Steam-methane reforming without CCS

0%$1.05-1.5/kga$8.78-12.51/GJ

53%$1.32-1.77/kg$11.02-14.75/GJ

64%$1.46-1.91/kg$12.19-15.91/GJ

89%$1.71-2.15/kg$14.22-17.92/GJ

Electrolysis of Water#

Cost of PowerLCOH

Cost of Heat (lower
hea ng value)

US average grid + PEM (90% capacity factor)$60-90/MWh$4.50-6.04/kg$37.52-50.34/GJ

Solar PEV (20% capacity factor)$36-46/MWh$7.1-8.3/kg$59.2-69.2/GJ

Wind unsubsidized (35% capacity factor)$29-56/MWh$6.02-7.25/kg$50.17-60.46/GJ

Hydropower unsubsidized(40% capacity factor)$30-60/MWh$4.80-6.34/kg$40.01-52.83/GJ

Steam-methane reforming with CCS* All natural gas capture cases assume 90% capacity factor, $3.5/million BTU and $20/ton costs for CO2 compression,transporta on and storage.
# All electrolysis cases assume $1,000,000/MW electrolyzer cost.
a

Even for ﬁxed gas prices and capacity factors, the range of costs reﬂects choice of conversion technology (e.g., SMR vs. autothermal
reformers).

Table 2A-1: Es mated costs for hydrogen produc on (normalized to natural gas).

have posited that overgenera on of renewables will
prove cost eﬀec ve. If so, costs for green hydrogen
could drop substan ally. They would drop further with
substan al capital cost reduc ons for electrolyzers.
It is thus possible to imagine a transi on from blue togreen hydrogen supply. Low-carbon hydrogen systems
could be deployed rela vely quickly using blue hydrogenas a primary fuel, providing the ability to scale quickly
and at modest addi onal cost. Over me, as greenhydrogen became cost-compe ve, it could gain market
share for decarbonized heat and begin to displace bluehydrogen produc on. If so, future LCOH could remain
fairly constant and possibly decrease while the total
frac on of fossil-based hydrogen produc on decreases
over me.

Potential to improve
To date, only four facili es in the world produce bluehydrogen. It is likely that as more carbon capturesystems are deployed on exis ng facili es, engineers
and innovators will ﬁnd opportuni es to decrease8

costs. Improvements could come from novel CO2
capture systems that have lower costs themselves,from incremental learning-by-doing improvements incapital cost (e.g., reduc on in steel, lower cost materialsubs tu on) or opera ng cost (e.g., improved heatrecovery, more eﬃcient systems). Similarly, for newhydrogen produc on facili es using conven onal
technology (e.g., SMRs, ATRs, gasiﬁers), costs andeﬃciencies could improve through integrated design.
Many groups have studied approaches to improve thecost and performance of electrolyzers.9 These include
discovery and func onaliza on of new materials, mostnotably metal anodes. Research to improve corrosion
resistance and seal performance and to extend thecapital life and longevity of components and integrated
systems remains important. Ul mately, the largest
cost element will remain the cost of electric power.
Overall research to con nue reducing the total costfor renewable power systems would help. In the nearterm, research should iden fy and map loca ons
where a combina on of features (e.g., high capacity

December 2019

BOX 2 2 Alterna ve approaches tohydrogen produc onHydrogen can be generated through several other technological pathways. In some cases, these technologies
are in early stages of development (low technical readiness level [TRL]). In other cases, the processes are welldescribed and recognized but have not scaled due to high costs or other reasons.
■ Sulfur-iodine cycle: This thermochemical cycle process generates hydrogen from water and recycles sulfur

and iodine without their consump on. The cycle operates at high temperatures (~950 °C) from any source,
although many consider it to be well-suited to heat from high-temperature nuclear reactors. The Japanese
government and Savannah River Na onal Laboratory have studied the process in depth, and a Japanese test
reactor runs experiments to improve the eﬃciency and performance of the cycle. TRL = 3■ Methane cracking: Methane can be separated directly into carbon and hydrogen by breaking its chemicalbonds. For example, the Kvaerner Carbon Black & Hydrogen Process (KCB&H) was developed by Norwegiancompany Kvaerner and uses a high-temperature plasma burner to directly separate methane into hydrogenand amorphous carbon (carbon black). The ﬁrst plant was built and began opera on in Norway in 1999 but has
not received widespread adop on. This process does not emit substan al greenhouse gases, since all carbon isconverted to solid form. TRL = 5-6■ Biomass gasiﬁcation: Like natural gas, oil residues, coal or petcoke, biomass can be gasiﬁed and combinedwith water-gas shi to produce hydrogen. This has the advantage of a renewable
feedstock (biomass) which could reduce the carbon footprint of produc onrs,
drama cally. This process today is expensive due to the high capital costs of gasiﬁers,
challenges in feed systems and ash handling, and limita ons of biomass supply.
There are substan al ranges and uncertain es in carbon footprint. (See Biomass
sec on, chapter 2B.) TRL = 8
Because low-carbon hydrogen will remain an important decarboniza on op on forindustry and other applica ons (including heavy duty transport), research programsaround the world should increase the size and scope of programs to develop new
methods of hydrogen produc on.

factors, regular curtailment) produce extremely low-costgreen power today in proximity to relevant industrial
applica ons.
Finally, and perhaps most importantly, research isurgently needed on how best to implement hydrogen
combus on systems in facili es that currently use otherfuels. In some cases, the changes may prove fairly
modest (e.g., new burner ps, sensors and controls). In
other cases, subs tu on of low-carbon hydrogen may
require new handling and fueling systems, as well as new
designs for retroﬁ ng complex systems and reactors.
In some cases, addi onal NOX control equipment may
be required. For very challenging cases (e.g., cementkilns or blast furnaces) where solid fuel use is closely

9integrated with system opera on, long-lived programs
would help iden fy possibili es for subs tu on that
could prove viable.
1

IRENA, 2018, Hydrogen from renewable power:
Technology outlook for the energy transi on, h ps://www.irena.org/publica ons/2018/Sep/Hydrogen-fromrenewable-power

2

IEA, 2019, “Methane emissions from oil and gas”,
h ps://www.iea.org/tcep/fuelsupply/methane/3

Le Fevre, 2017, “Methane Emissions: from blind spot
to spotlight”, The Oxford Ins tute for Energy Studies,h ps://www.oxfordenergy.org/wpcms/wp-content/
uploads/2017/07/Methane-Emissions-from-blind-spotto-spotlight-NG-122.pdf

December 2019

4

Soltani R, Rosen M.A., Dincer I., 2014, Assessmentof CO capture op ons from various points in steam
methane reforming for hydrogen produc on,
Intl. J. of Hydrogen Energy 39(35) DOI: 10.1016/j.
ijhydene.2014.09.161

5

GCCSI, 2019, Global Status Report, h ps://www.
globalccsins tute.com/resources/global-status-report/

6

NREL, 2008, Hydrogen Conversion Factors and Fact
Card, DOE/GO-102008-2597, h ps://www.nrel.gov/
docs/gen/fy08/43061.pdf

7

G. Collidi, et al., 2017, “Techno-Economic Evalua onof Deploying CCS in SMR Based Merchant H
Produc on with NG as Feedstock and Fuel”, Energy
Procedia, 114:2690-2712, h ps://doi.org/10.1016/j.
egypro.2017.03.1533

108

J. Friedmann et al., 2019, “Low-carbon heat solu ons
for heavy industry: sources, op ons & costs today”,
Columbia Univ. Center on Global Energy Policy

9

DOE, 2015, Quadrennial Technology Review, Chapter
6, Innova ng Clean Energy Technologies in Advanced
Manufacturing, h ps://www.energy.gov/sites/prod/ﬁles/2016/06/f32/QTR2015-6I-Process-Hea ng.pdf

10Gigler J, Weeda M, 2018, Outlines of a Hydrogen
Roadmap, TKI Nieuw Gas, h ps://www.
topsectorenergie.nl/sites/default/ﬁles/uploads/
TKI%20Gas/publica es/20180514%20Roadmap%20
Hydrogen%20TKI%20Nieuw%20Gas%20May%202018.
pdf

December 2019

BIOMASS
Biomass is the oldest source of industrial heat andprovides about 10% of global primary energy.1 Of this,roughly 15% goes to non-electricity industrial uses (7.8
EJ in 2009) with the rest used mainly for cooking, space
hea ng, vehicle fuel and electricity genera on.2
Expanded use of biomass has substan al poten al todecarbonize industrial heat produc on. A wide variety ofbiomass types, from wastes such as manure and almondshells to dedicated energy crops such as sugarcaneand switchgrass, can be used to provide industrial
heat. Exis ng or emerging technologies are available
to convert biomass to many intermediates, such as
biomethane, biodiesel or bio-char. Unlike electricity
or hydrogen, biomass can act as a carbon source andchemical reductant in steelmaking and other processes.

Climate impacts of bioenergy
Although combus on of biomass releases similar
quan es of CO2 as fossil fuels, biomass combus on canhave substan ally lower climate impacts because theCO2 will be recaptured from the atmosphere when thesource of the biomass regrows. For example, combus onof agricultural residues, like rice husks, is generally
considered carbon-neutral because the crops will regrow
the next season. This is also true for short-rota on
woody biomass from sustainably managed forests.
However, use of biomass can result in net land-use
changes, reducing or elimina ng any CO2 emissions
beneﬁts. Transport, processing and use of fer lizer canalso result in CO2 emissions, reducing or elimina ng theCO2 beneﬁts of bioenergy.
If supply of dedicated energy crops is substan ally
expanded, some land must be converted from otheruses to grow the crops. There is typically a net change
in carbon stored in the soil and ﬂora when land usechanges. If the previous use stored more carbon thanthe energy crop, then there will be an ini al release ofcarbon to the atmosphere, followed by a reduc on incarbon emissions to the atmosphere, compared to thescenario where fossil energy was used instead. Thusa “payback period” can be calculated based on thenumber of years it would take to compensate for ini alcarbon release. When conver ng degraded land or othertypes of cropland to energy crops, the payback period
is generally a year or less. But clearing forest or na ve

11grassland to plant energy crops can result in payback
periods of decades or centuries.3
Complica ng the picture, many energy crops, including
corn and sugarcane, can compete with food crops forland, which has ripple eﬀects on the food system and canresult in indirect land-use changes with carbon impacts.
The lifecycle impacts, including the indirect land-use
changes, have been studied extensively, primarily in thecontext of liquid biofuels for transporta on. Some recent
research has indicated that the CO2-emissions impacts
of indirect land-use changes may not be as strong aspreviously thought.4 However, lifecycle impacts are s ll
signiﬁcant, especially for liquid fuels derived from energy
crops. Figure 2B-1 summarizes es mates of the lifecycle
impacts from biofuels and fossil fuels. The greenhousegas emissions impact of genera ng heat from biomass
is generally low, with es mates ranging from negligible
to 30 g CO2eq/MJ.3,5 For comparison, the impacts range
roughly 80-150 g CO2eq/MJ for fossil fuels, as shown in
Figure 2B-1.
Current industrial use of bioenergy is dominated bysolids (93% in the EU), followed by municipal wastes(3%) and biogas (2%).6 To the extent that industrial useof bioenergy con nues to favor solids and gases overliquids, which is reasonable given current demands
and expected sources of biomass, the lifecycle impacts
are somewhat less challenging for industry than fortransporta on. S ll, most use cases of biomass forindustrial heat are not truly carbon neutral. However,bioenergy could be made carbon neutral or carbon
nega ve by addi on of carbon capture and storage (CCS)
to either the industrial process or the biofuel processing
facility, as discussed below.

Biomass availability
Numerous assessments have been made of global
biomass availability. Es mates vary widely, especiallyfor dedicated energy crops, but there is moderately
good agreement in the literature that 200-500 EJ/yof sustainably produced biomass can be available
by 2050.3,5 These values compare favorably with thees mated global industrial energy demand of 230 EJ
in 2012, projected to rise to 330 EJ by 2040.7 However,there are compe ng demands for biomass in a lowcarbon future, including as vehicle fuel, dispatchable
electricity and a means of nega ve emissions throughbioenergy with CCS (BECCS). Most assessments ofDecember 2019

Figure 2B-1. Summary of literature es mates of the lifecycle greenhouse gas impacts of bioenergy. Source: IPCC3 (usedwith permission).

bioenergy as a climate-mi ga on op on have focusedon liquid biofuels for transporta on speciﬁcally. These
compe ng uses will have to be balanced in a policy thatencourages expanded use of biofuels in industry.
Also limi ng its deployment in industry, biomass is moregeographically diverse and more expensive to collect andtransport than fossil fuels. For example, in Australia, biochar suitable for steelmaking was found to cost about 4
mes as much as coal, even though low-cost agriculturalresidues are also abundant there.8 The produc on costfor solid biomass has been es mated to be in the rangeof 11-50 $/GJ using current technologies,3 which makes
it at least four mes as expensive as coal and twice as
expensive as natural gas in current markets.9,10 Thissuggests that much of the poten al biomass discussed
above will be uneconomical to collect without strong
incen ves for industrial decarboniza on.

Processing and transport
Since biomass grows over wide stretches of land,collec on and transport is o en a crucial componentof the cost to use it. Woody biomass has about half
the energy density and considerably lower bulk density(before grinding) than coal.11 However, biomass can beconverted to a variety of forms for easier transport and a12wider range of uses. Common pathways are summarized
in Figure 2B-2.
Most biomass sources, such as forest biomass andagricultural residue, contain up to about 50% water.
Chipping and drying is the most common treatment
for biomass currently used industrially, and thisallows reasonable transport. There is already robustinterna onal trade in wood, which is the 5th mostimportant traded commodity. Only about 10% of
currently traded woodchip goes for bioenergy, but s llpelle zed wood for energy is traded interna onally,
primarily in Europe. With emerging technologies, thesesources can be treated by a handful of other means
to produce fuels for transport or further processing:gasiﬁca on to produce biogas, syngas or hydrogen;pyrolysis to produce bio-oil and bio-char; torrefac on
to produce torreﬁed biomass; and hydrothermalliquefac on to produce bio-oil.
As examples, top-level process diagrams for biomass
gasiﬁca on to hydrogen (Figure 2B-3) and biomass
pyrolysis (Figure 2B-4) are shown below. With
gasiﬁca on, a range of biomass types can be converted
into renewable hydrogen, which in turn can provide
carbon-free heat. Depending on the biomass source,
the CO2 emissions resul ng from the process may be
December 2019

Figure 2B-2. Biomass conversion pathways. (Fire Management refers to forest biomass, such as small-diameter trees andshrubs, removed from a forest to reduce ﬁre risk or ﬁre severity. RNG (renewable natural gas) refers to biogas that has
been puriﬁed to meet natural gas pipeline standards (also known as biomethane).

considered carbon neutral. However, this process is
especially a rac ve because the rela vely pure streamof CO2 from the acid-gas-removal opera on can be
captured and sequestered, resul ng in nega ve CO2
emissions (analogous to BECCS), while also providing a
stream of valuable hydrogen.
In the pyrolysis process, biomass is heated without
oxygen to frac onate the material into gases, liquid fuelsand bio-char. The bio-char and liquids can be used asindustrial fuels. Typically, the gases are combusted to
produce heat for the process, and the resul ng CO2 canop onally be captured to yield reduced or nega ve CO2
emissions for the overall process.
Wet biomass streams, such as manure, wastewater,
landﬁlled municipal solid waste (MSW) and foodwaste are most commonly treated with anaerobic
diges on, crea ng biogas. In some cases, hydrothermalliquefac on can also be used. Biogas via anaerobic

diges on is the least expensive source of bioenergy, withproduc on costs es mated in the range of 1.5-8.7 $/GJ,
some mes less than fossil gas.3 However, the feedstocks
for biogas are limited: manure, MSW, landﬁll gas andagricultural waste made up about 10% of total bioenergy
use in 2007,1 and these are unlikely to grow as muchwith demand as other types of biomass.
For most of the conversion pathways, addi onal reﬁning
can yield a fuel that is a drop-in replacement for a fossil
fuel. Bio-char, depending on the process and biomasssource, has a hea ng value of 30-38 MJ/kg, which is in
the range of many coals.11 Anaerobic diges on generates
a biogas that is roughly half methane and half CO2. If theCO2 and minor impuri es are removed, the remaining
biomethane can meet speciﬁca ons for natural gas
pipelines. Syngas can be converted to desired fuelsusing conven onal Fischer-Tropsch methods. Pyrolysis
oil, although it starts with about half the hea ng valueof crude oil because of its high oxygen content, canFigure 2B-3. Process for biomass gasiﬁca on to hydrogen.

13

December 2019

Figure 2B-4. Process for biomass pyrolysis to liquid fuel and bio-char.

be reﬁned to standard vehicle fuels, depending on thedesired product.
In most cases, reﬁned biomass fuels are more expensive
than compe ng fossil fuels, which has limited the market
for conversion technologies in the same way as forbiomass use. Except for anaerobic diges on, which isrela vely mature, technology development and market
incen ves can s ll substan ally improve the conversion
processes and lower costs.

Specific applications
For certain industrial uses where the process is sensi ve
to fuel composi on, further development is especiallyneeded. As discussed in Chapter 3B, steelmaking is acomplex process with both fuel and process emissions
coming from mul ple units of an integrated plant.
Biomass can be subs tuted in several forms. Bio-cokecan be produced to replace coal-based coke in the
coking opera on. Bio-char can be used in the sintering
process and blast furnace. Bio-chars with higher hea ng
values are more eﬀec ve in the blast furnace. Pyrolyzed
or torriﬁed biomass may also be op ons to fuel the blast
furnace.12
Mul ple full-scale steelmaking plants already operate
on biomass energy in Brazil, with 34% of the energy
consumed by the iron and steel industry in that country
coming from biomass.6 Elsewhere, however, only low
subs tu on rates of biomass have generally beenachieved.8 The composi on and proper es of bio-coke,in par cular, need reﬁnement and innova on—bio-cokedoes not yet perform as well as conven onal coke due
to higher reac vity and lower strength a er reac on.
In general, development of the biomass feedstocks to14

be er func on in exis ng steel mills and developmentof the basic oxygen furnace process to run be er
on biomass fuels are both important pathways todecarbonize steelmaking.
Regional biomass availability appears less of a concern
for steelmaking. In an analysis of biomass availability
compared with the loca ons of the current steelmaking
industry, it was found that several of the top steelproducing countries have high suitability to adopt
biofuels in steelmaking, including China, Russia, the US
and Brazil. Japan, India and Germany had moderate
suitability. Only South Korea, Ukraine and Taiwan had
low suitability to biomass adop on, together accoun ng
for 6.6% of global steel produc on.8
In contrast to steel mills, cement kilns are fairly tolerant
to fuel varia ons and impuri es because of their highcombus on temperature. Although not typical prac ce,many cement plants across the world co-ﬁre wastes andbiomass along with fossil fuels when local condi ons
make this economically a rac ve.13 Addi onally, co-ﬁring
can have beneﬁts for local air pollu on by reducing
emissions of sulfur and nitrogen oxides. Expanded use of
biomass in cement opera ons appears straigh orward,
however it will not address the process CO2 emissions
from calcium carbonate decomposi on.
1

WEC, 2010 Survey of Energy Resources, World Energy
Council, London, UK, 2010.

2

Esa Vakkilainen, Katja Kuparinen, Jussi Heinimö, Large
Industrial Users of Energy Biomass, IEA Bioenergy Task
40, 2013.

3

Helena Chum, Andre Faaij, José Moreira, Göran
Berndes, Parveen Dhamija, Hongmin Dong, Benoît
December 2019

4

5

Gabrielle, Alison Goss Eng, Wolfgang Lucht, Maxwell
Mapako, Omar Masera Ceru , Terry McIntyre, Tomoaki
Minowa, Kim Pingoud, Bioenergy, in: IPCC Spec. Rep.
Renew. Energy Sources Clim. Change Mi g., Cambridge
University Press, Cambridge, UK, 2011. h ps://www.
ipcc.ch/report/renewable-energy-sources-and-climatechange-mi ga on/.

8

H. Mandova, W.F. Gale, A. Williams, A.L. Heyes, P.
Hodgson, K.H. Miah, Global assessment of biomass
suitability for ironmaking – Opportuni es forco-loca on of sustainable biomass, iron and steel
produc on and suppor ve policies, Sustain. Energy
Technol. Assess. 27 (2018) 23–39. doi:10.1016/j.
seta.2018.03.001.

Glaucia Mendes Souza, Reynaldo L. Victoria, Luciano
M. Verdade, Carlos A. Joly, Paulo Eduardo Artaxo
Ne o, Carlos Henrique de Brito Cruz, Heitor Cantarella,
Helena L. Chum, Luis Augusto Barbosa Cortez, Rocio
Diaz-Chavez, Erick Fernandes, et al., SCOPE: Bioenergy
and Sustainability, UNESCO, 2014.

9

EIA, Natural gas prices, (n.d.). (accessed September
21, 2019).

10

EIA, Coal Markets, (n.d.). h ps://www.eia.gov/coal/markets/ (accessed September 21, 2019).

11

K. Raveendran, A. Ganesh, Hea ng value of biomass
and biomass pyrolysis products, Fuel. 75 (1996)
1715–1720. doi:10.1016/S0016-2361(96)00158-5.

12E. Mousa, C. Wang, J. Riesbeck, M. Larsson, Biomass
applica ons in iron and steel industry: An overview
of challenges and opportuni es, Renew. Sustain.
Energy Rev. 65 (2016) 1247–1266. doi:10.1016/j.
rser.2016.07.061.

13

A. Rahman, M.G. Rasul, M.M.K. Khan, S. Sharma,
Recent development on the uses of alterna ve fuelsin cement manufacturing process, Fuel. 145 (2015)
84–99. doi:10.1016/j.fuel.2014.12.029.

F. Creutzig, N.H. Ravindranath, G. Berndes, S. Bolwig, R.
Bright, F. Cherubini, H. Chum, E. Corbera, M. Delucchi,
A. Faaij, J. Fargione, H. Haberl, G. Heath, O. Lucon, R.
Plevin, A. Popp, C. Robledo-Abad, S. Rose, P. Smith, A.
Stromman, S. Suh, O. Masera, Bioenergy and climatechange mi ga on: an assessment, GCB Bioenergy. 7(2015) 916–944. doi:10.1111/gcbb.12205.

6

I. Malico, R. Nepomuceno Pereira, A.C. Gonçalves,
A.M.O. Sousa, Current status and future perspec ves
for energy produc on from solid biomass in theEuropean industry, Renew. Sustain. Energy Rev. 112(2019) 960–977. doi:10.1016/j.rser.2019.06.022.

7

EIA, Chapter 7: Industrial sector energy consump on,
in: Int. Energy Outlook 2016, U.S. Energy Informa on
Administra on, 2017.

15

December 2019

ELECTRIFICATION
Overview
A wide variety of electrical technologies are available
to provide industrial process heat. When powered by
low-carbon electricity, these technologies can provide
process heat with very low greenhouse gas (GHG)
emissions. Although the opera onal principles andcapabili es of these technologies vary, they share
several features because of their use of electricity.
First, electric hea ng systems can be precisely controlled
by varying the electrical current, voltage or otherparameters. This allows precision delivery of heat,minimizing energy waste and enabling automatedprocess control. This feature stands in contrast to
combus on-based process heat, for which the amountof heat delivered is more diﬃcult to control. Similarly,
electrical systems are able to provide heat ﬂexibly ata range of design temperatures. Combus on systems,
in contrast, are constrained by the combus ontemperatures of their fuels.
A second, related feature of electrical hea ng systems istheir ability to rapidly turn on and oﬀ. This allows themto have greater opera onal ﬂexibility, ramping up anddown heat delivery for a range of purposes. These can
include adjus ng processing opera ons based on grid ormarket condi ons or enabling extremely rapid, brief heatapplica on unit opera ons compared with combus on
methods (for example, electron-beam curing).
Third, electrical hea ng systems tend to have rela vely
low maintenance. They are not exposed to combus on
products or ﬂame, and their components are almost
en rely solid-state, with no fuel supply or storage
requirement. These features tend to reduce or
eliminate problems such as corrosion from combus ongases or ﬂame impingement on refractory materials.
Some electrical hea ng systems, such as induc ve
and microwave technologies, can apply heat without
contac ng the workpiece or material being treated,which reduces the poten al for contamina on andenables be er control of the reac on environment
during heat applica on.
The disadvantages of electrical hea ng systems include
the need to provide large amounts of electric power,
which may require addi onal infrastructure (such as

16

distribu on grid build-out and transformer installa on)
and place severe demands on the local electric grid(see below). In markets where natural gas is cheap andelectricity is expensive, electrical hea ng systems will
be at a cost disadvantage. Also, industrial processes thatare op mized for combus on-based process heat areo en highly op mized, taking advantage of waste heatfor combined heat and power or recupera ng it throughheat exchangers or heat pumps. In these cases, replacing
combus on heat with electrical hea ng may require
substan al plant redesign. Unlike approaches to lowcarbon heat treatment that are essen ally low-carbon
fuel replacements, such as hydrogen and biofuels,
electrical hea ng cannot leverage exis ng combus onbased industrial process designs and generally cannot
be retroﬁted into an exis ng process without signiﬁcantequipment modiﬁca on.

Principles of electrical heating
At the most basic level, heat can be transferred to aprocess material in three ways. Convec ve hea ng is
the transfer of heat energy through the mo on of aﬂuid, such as water or air; it is generally constrained byparameters such as ﬂuid ﬂow rate and heat capacity.
Conduc ve hea ng results from direct contact between
the process material and a solid heat source; it is
impacted by the thermal conduc vity of the processmaterial. Radia ve hea ng is caused by electromagne c(EM) waves (such as microwaves) arriving at the processmaterial; it is constrained by both the reﬂec vity andabsorp on of the process material to the wavelengths
used.
In an engineering context, there are two broad
approaches to applying heat energy. Direct hea ng
applies an electric current through the process material
to cause resis ve hea ng, induces an electric current
in the process material using alterna ng magne cﬁelds, or excites molecules within the process material
with electromagne c radia on (microwaves or radio
frequency). In each of these cases the material musthave suitable proper es (such as electrical conduc vity).
Indirect hea ng is used in cases where the processmaterial is not suitable for direct hea ng and instead
uses one of these methods to heat a separate susceptor
or element that is near or in contact with the processmaterial, which then transfers that heat to the processmaterial through conduc on, convec on or radia on.

December 2019

Figure 2C-1. An infrared dryer for automobile paint. Short-wave infrared emi ers can reach ﬁlament temperatures of
2,000°C. (Dmitry Kalinovsky/Shu erstock.com)

Specific electrical heating methods
Direct resistance hea ng is the simplest of all electricalhea ng methods, par cularly for conduc ve material
that can be directly heated by the applica on of electric
current. The material can be clamped to electrodes in
the wall of the furnace in order to apply current. Joulehea ng resul ng from the interac on of the current
and the electrical resistance of the process material canbe highly eﬃcient, par cularly for materials with highresistance (e.g., steel). Temperatures up to 2,000 °C are
possible.1,2
Indirect resistance hea ng uses electrical resistancein a hea ng element, which is commonly made fromgraphite, silicon carbide or nichrome (nickel-chromium
alloy). The heat is transferred by conduc on, convec onor radia on (similar to infrared hea ng, below) to thework material. Various geometries are used; tubular
hea ng elements are common and comprise a nichrome
hea ng coil surrounded by magnesium oxide forelectrical insula on, sheathed in stainless steel. Thesesystems have a maximum temperature of approximately
750 °C and can deliver heat at powers ranging up to 120
Wa s per square inch of surface area. Indirect resistancehea ng is used in electric indirect rotary kiln technology,
in which resis ve heaters are placed outside of a rota ng
high-temperature alloy shell and heat is transferred
to process material inside; these systems can reachtemperatures of 1,200 °C.1,2
17

Infrared hea ng is based on passing an electric current
through a solid resistor to heat it and then direc ng theresul ng infrared radia on to the process material. The
material must have rela vely high absorp on and low
reﬂectance for infrared wavelengths corresponding to
the temperature of the radiator. Short-wave emi ers
reach the highest temperatures, up to approximately
2,000 °C, using evacuated quartz tubes with tungsten
ﬁlaments, back-ﬁlled with argon to prevent oxida on.
Medium- and long-wave emi ers use the tubular
hea ng elements described above or wires embedded in
ceramic panels. Baﬄes and reﬂectors can focus infrared
radia on on the process material, improving eﬃciency.
The heat transfer is mostly conﬁned to the surface of theprocess material and is therefore most appropriate forsurface applica ons like curing and drying.1,2
Microwave hea ng is based on the fact that microwave
radia on (with frequencies in the range of 300 to
300,000 MHz) heats non-conduc ve (dielectric)
materials that are composed of or contain polar
molecules, such as water. Microwaves excite thesemolecules into mo on, which leads to fric on hea ng.
The heat energy can be deposited throughout the bulkof the process material as long as it is not too thick.
However, because microwave radia on is coherent witha wavelength in the range of a millimeter to a meter,
standing waves can develop in hea ng chambers, leading
to local hot and cold spots. Microwaves are generated in
December 2019a magnetron and generally must be guided or contained
to ensure eﬃciency and minimize exposure. Radio
frequency hea ng works on a very similar principle,
although it uses lower frequencies (2 to 100 MHz) withcorrespondingly longer wavelengths. These are able topenetrate farther into process materials, although theytend to deliver heat more slowly.2,3Induc on hea ng is based on an alterna ng magne cﬁeld, generated by passing an AC electric current
through a coil (solenoid). This ﬁeld in turn inducesalterna ng eddy currents in the work material if it iselectrically conduc ng. For op mal eﬃciency, the work
material is placed within the solenoid, or the magne c
ﬂux is coupled into the material in other ways. Induc on
hea ng avoids any physical contact between the hea ng
system and the process material. However, the energy ismostly deposited on the surface of the material (due tothe skin eﬀect). If the work material is not conduc ng, it
can be put in contact with a susceptor, which is heatedinduc vely and transfers heat through conduc on orconvec on. Common applica ons are reﬁning andre-mel ng of metals, including aluminum, copper, brass,bronze, iron, steel and zinc.1,2Electric arc furnaces consist of a refractory vessel withretractable electrodes, o en made from graphite
or carbon. AC or DC current is passed through theelectrodes and forms an electric arc with the processmaterial. This deposits heat both from the direct
resistance of current passing through the material andfrom the radiant energy from the arc. Commercialized
arc furnaces range from a few tons to hundreds oftons of capacity. The electrodes wear out and must be
replaced; suitable electrode materials are important
for the overall economic viability of the technology. An
alternate but less common conﬁgura on is the indirectarc furnace, which draws the arc between electrodes,
applying heat through radiant transfer. Electric arc
furnaces are commonly used in steelmaking, where
they achieve temperatures up to 1,800 °C, as well as in
the produc on of ferronickel in the Rotary Kiln–Electric
Furnace (RKEF) process.2,4,5
Electron beam hea ng uses a focused beam ofelectrons directed onto a process material, usually invacuum. Common uses include cross-linking polymers,
welding, surface hardening for high-wear automo ve
components, and addi ve manufacturing. Electron beam
furnaces are used in mel ng refractory metals such as
tanium. The hea ng is primarily at the surface of thematerial, making bulk treatment more challenging.6,7
Plasma heaters operate by developing an electric arc
across two cooled electrodes; gas (of many diﬀerent
composi ons, including a variety of waste gases) is
directed past the arc, which ionizes it into plasma thatcan reach temperatures from 2,000–20,000 °C. The

Figure 2C-2. Electric arc furnaces use electric current to form an arc between electrodes, providing high-temperature heat
to melt scrap steel and iron. (D.Alimkin/Shu erstock.com)
18

December 2019plasma forms a jet, which is then directed onto the work
material, hea ng it. Plasma processing is commonly usedin the tanium industry, as well as in the disposal of toxic
ash, asbestos and sludge.8,9For low-temperature process hea ng requirements(generally under 200 °C) there are several electrical
technologies available that make use of waste heat,including heat pumps and organic Rankine cycle
turbines. Solar process hea ng is also available fortemperatures up to 250 °C.10 However, these are noteﬀec ve for medium- or high-temperature process heat.

Installation considerations
Combus on-based hea ng for a range of industrial
processes usually involves furnaces whose design
has been op mized for delivering heat from one ormore individual point loca ons (burners) where fuel iscombusted. The furnace is designed to handle the ﬂow
of combus on and reac on gases and may also include
heat integra on to recapture waste heat for other usesin the overall process. While some modiﬁca ons are
required for this design to burn alterna ve fuels suchas hydrogen and biomass, the basic architecture largely
remains the same. However, modifying the design to use
electric sources of heat requires much more substan alchanges.
■ First, electric heat is generally not delivered from point

sources (burners). Direct hea ng methods deposit
heat energy throughout a material or poten ally in asurface layer. Indirect hea ng generally delivers heat
across the surface of a material. This can signiﬁcantly
change the distribu on of temperatures withina furnace and thus the hea ng rates of the work
material, poten ally requiring process redesigns.
■ Second, there is no need to handle combus ongases, as none are generated in the hea ng process.
However, heat-integra on systems will no longer beable to use this waste heat, poten ally leading to acascade of necessary process changes throughout theoverall facility.
■ Third, replacing fuel combus on with electriﬁca on
removes the need to handle fuel delivery to burners,
but it may create the need for managing high-voltage
electric power distribu on through ac ve cooling,
electrical isola on, etc. In general, the architectureand design assump ons of electric process heat arevery diﬀerent from those for fuel-combus on-based
process heat and lead to a far larger need for process
19

redesigns. As a consequence, the capital costs forprocess changes to electriﬁca on are generally higher
than those for switching to alterna ve fuels.

System consideration
Electriﬁca on of process heat can create signiﬁcantdiﬃcul es for local electric-grid opera on. Large power
consumers that func on in a batch mode are par cularly
challenging, since they can rapidly increase or decrease
overall power demand and require genera on to ramp
quickly. In some cases, such as electric arc furnaces forsteel produc on, there may be strategies to harmonize
opera ons with demand-side management (DSM)
systems put in place by grid operators, but this canlead to highly complicated ming decisions.11,12 In othercases, such as electroly c produc on of hydrogen, it
may be possible to add ﬂexibility to a con nuous process
to par cipate in DSM or provide other grid services.13
Ul mately, wide-scale electriﬁca on of process heatwould require more integrated system planning between
industrial customers and grid operators to be er
understand the opportuni es and challenges.

Conclusions■ A wide variety of electrical technologies are available

for delivering process heat. These can achievetemperatures of well over 1,000 °C and, in some cases,
over 10,000 °C.
■ Electriﬁed process hea ng has several advantages
over combus on-based hea ng, including precision
temperature control, high ﬂexibility and low
maintenance costs. However, it requires large amountsof electric power, which may be unavailable or costprohibi ve.
■ Electric hea ng systems can be categorized as direct,
in which a working material is heated directly throughelectric resistance, microwaves or other techniques,or as indirect, in which a separate device such as asusceptor or resistor is used to deliver heat throughconduc on, convec on or radia on.
■ Installa on of electric hea ng systems in facili es
currently using combus on-based hea ng may require
substan al process changes and corresponding capital
investment. It may also eliminate heat integra on
methods that had been in use to recuperate waste
heat, crea ng requirements for installa on ofaddi onal hea ng systems.
■ Electriﬁca on of process heat may also place
December 2019

signiﬁcant strain on the local electric grid, requiring
capital-intensive upgrades to electric transmission anddistribu on facili es. In some cases these systems canpar cipate in demand-reduc on programs to ease
the impact on the grid, but in others this may not be
possible due to the need for con nuous or inﬂexible
process heat delivery.
1

US DOE, “Improving process hea ng system
performance: A sourcebook for industry” (2007),
h ps://www.energy.gov/sites/prod/ﬁles/2014/05/f15/
process_hea ng_sourcebook2.pdf.

2

McMillan, C. et al. “Genera on and use of thermalenergy in the U.S. industrial sector and opportuni es toreduce its carbon emissions”, NREL/INL (2016), h ps://www.nrel.gov/docs/fy17os /66763.pdf.

3

Leonelli, C. et al, 2010, “Microwave and ultrasonicprocessing: Now a realis c op on for industry”, Chem.
Eng. Proc.: Proc. Int. 49(9):885-900, h ps://doi.
org/10.1016/j.cep.2010.05.006.

4

G. Li, et al. 2016, “Ferronickel prepara on fromnickeliferous laterite by rotary kiln-electric arc furnace
process” In: S. Ikhmayies, et al. (eds.) Characteriza onof Minerals, Metals, and Materials 2016. Springer,
Cham, h ps://link.springer.com/content/
pdf/10.1007%2F978-3-319-48210-1_17.pdf.

B. Lee, B. et al., 2014, “Review of Innova ve Energy
Savings Technology for the Electric Arc Furnace”, JOM,
66(9):1581-1594. h ps://doi.org/10.1007/s11837-0141092-y

5

Industrial Hea ng, 2001, “Advancements In
Electron Beam Mel ng and Reﬁning”, h ps://www.
industrialhea ng.com/ar cles/84954-advancements-inelectron-beam-mel ng-and-reﬁning.

20

6

M. Gala , et al. 2018, “A literature review of
powder-based electron beam mel ng focusing on
numerical simula ons”, Add. Man. 19:1-20, h ps://doi.
org/10.1016/j.addma.2017.11.001.

7

N. Venkatramani, 2002, “Industrial plasma torches andapplica ons”, Cur. Sci., 83(3):254-262, h ps://www.
jstor.org/stable/24106883?seq=1#page_scan_tab_
contents

8

L. Rao, et al., 2013, “Thermal Plasma Torches for
Metallurgical Applica ons”, In: 4th Int. Symp. H. Temp.
Met. Proc., TMS Mee ng, San Antonio, TX, h ps://doi.
org/10.1002/9781118663448.ch8.

9

A. Sharma, et al., “2017 Solar industrial process
hea ng: A review.” Renewable and Sustainable Energy
Reviews, 78:124-137, h ps://doi.org/10.1016/j.
rser.2017.04.079.

10

Zhang, X. et al. “Cost-eﬀec ve scheduling of steel
plants with ﬂexible EAFs”, IEEE Transac ons on
Smart Grid (2016), h ps://ieeexplore.ieee.org/
document/7482812.

11

Ave, G. et al. “Demand side management schedulingformula on for a steel plant considering electrodedegrada on”, IFAC-PapersOnline (2019), h ps://www.sciencedirect.com/science/ar cle/pii/
S2405896319302307.

12

Brolin, M. et al. “Industry’s electriﬁca on androle in the future electricity system”, Chalmers
University (2017), h ps://research.chalmers.se/en/
publica on/248528.

December 2019CARBON CAPTURE, USE AND STORAGE
Carbon capture, use and storage (CCUS) is a collec on oftechnologies that result in substan al reduc ons of CO2
emissions.1,2 The building blocks of CCUS include:■ separa on of CO2 from combus on products (such as

ﬂue gas) or hydrocarbon fuels;■ transporta on of CO2 to a suitable geologic storagesite;■ injec on of CO2 into a reservoir where it becomestrapped deep underground; and/or■ use of CO2 in enhanced oil recovery, alkaline minerals(e.g., steel slag), aggregates, chemicals, fuels or otherproducts.3
CCUS does not, strictly speaking, decarbonize produc onof industrial heat—a er all, CCUS is based on thecapture of CO2 that results from use of carboncontaining fuels. However, CCUS is an a rac ve op on
to reduce emissions from industrial heat because CCUS
does not, in principle, require a wholesale change in thedesign of industrial facili es or underlying produc onprocesses. However, as the case studies on cement, ironand steel, and chemicals in this Roadmap illustrate, CCUS
provides maximum beneﬁt when closely integrated
with underlying industrial processes. There are generally
three routes to CO2 capture, all of which have relevancein industrial applica ons: pre-combus on, postcombus on and oxy-combus on.
In pre-combus on CO2 capture, a hydrocarbon fuel isconverted to a mixture composed predominantly of
CO2, hydrogen (H2) and water from which the CO2 isseparated, leaving hydrogen for use as a fuel (Figure2D-1). The hydrocarbon fuel can be natural gas or a solid
fuel—e.g., coal, biomass—that has been gasiﬁed. The
advantage of pre-combus on capture is that the totalpressure of the CO2 and H2 mixture is rela vely high, as is
the concentra on of CO2 therein, making the separa on
process less energe cally intensive and more compact.
Solvent-based separa ons dominate, but membrane andadsorp on processes (e.g., pressure swing adsorp on)
are also increasingly popular in commercial applica ons.
In principle, this is the route used for CO2 capture fromsteam-methane reforming (SMR) in produc on of bluehydrogen—although, it may also be combined with
post-combus on capture to maximize CO2 removals
from SMR.4 Pre-combus on capture for CCUS is usedcommercially today in fer lizer produc on,5 reﬁning6 andSMR.7,8Post-combus on capture is separa on of CO from theproducts of combus on—referred to commonly as ﬂue
gas (Figure 2D-2). Flue gas is composed primarily of
nitrogen, CO , water and lesser amounts of pollutants(e.g., oxides of sulfur and nitrogen), where the nitrogencomes from the atmosphere. Flue gas is typically atclose to atmospheric pressure, with a rela vely low COconcentra on (i.e., typically less than 10% by volume),
making the separa on typically more energy intensive
than for pre-combus on capture. The clear beneﬁt
of post-combus on capture, however, is that it canbe added as an “end-of-pipe” solu on for almost any
sta onary combus on process using any fuel. Solventbased absorp on processes dominate in commercial
applica ons, but advanced solvents, adsorbents andother processes (e.g., calcium looping) are being
developed.2,9 Post-combus on capture for CCS has beencommercially applied in power genera on in two cases.5
The third route to CO2 capture is referred to as oxycombus on (Figure 2D-3). In its most straigh orward
implementa on, a hydrocarbon fuel is burnt in oxygen—typically diluted with recycled CO2 for temperature

Figure 2D-1. Typical pre-combus on capture process for solid fuels (coal, biomass) and natural gas. The water-gas shi
reac on is not illustrated here for the sake of simplicity.
21

December 2019

Figure 2D-2. Typical post-combus on capture process for coal, biomass and natural gas. Cleaning of the ﬂue gas is notillustrated here for the sake of simplicity.

control. The resul ng combus on products are CO2
and water, the la er of which can be easily removed,
leaving CO2.10 Chemical looping processes can also be
considered an oxy-fuel route, but chemical looping
combus on may be less relevant to industrial processes
than the closely related chemical looping reforming,
which could be an alterna ve means to producehydrogen while capturing CO2.11 Similarly, powergenera on cycles based on oxy-combus on of natural
gas are in development,10 but these typically are lessrelevant for industrial-process heat applica ons. The
notable diﬀerence between the oxy-combus on routes
and others is that oxy-combus on does not require CO2
separa on and instead involves separa on of oxygenfrom air. Oxy-fuel CO2 capture has been demonstrated
at industrially relevant scales but has not yet beencommercially applied.
Once CO2 has been captured from an industrial process
via one (or more) of these three routes, the CO2 must betransported to a loca on suitable for geologic storage
and then injected into the storage reservoir. Perhaps
the most well-prac ced component of the CCUS chain
is CO2 transport. In the US, over 7,000 km of pipelinetransport around 70 MtCO /y of CO2, predominantly foruse in enhanced oil recovery (EOR).12 The US pipeline
network extends into Canada as well, delivering CO2 foruse in EOR, and is being extended in Alberta to enablelarge-scale CCS. Na onal and interna onal standards
exist for design and construc on of such pipelinesa, as
do government safety regula ons where such pipelines
existb. Shipping of CO2 is also currently prac ced at small
scales and is being considered as part of a Norwegian
integrated CCS demonstra on projectc. Transport by railor truck may also be an economically viable op on forsmall-scale sources (e.g., less that 100 ktCO2/y) overrela vely short distances.13
Experience with CO2 storage in geological forma ons
has been growing, as EOR projects that inject and store
CO2 have been undertaken since the 1960s and the ﬁrst
dedicated geological storage project began opera ons
in 1996. In addi on, governments have con nued tosupport research to advance tools and methods formeasuring and predic ng the behavior of stored CO2.
This growing knowledge base has been reﬂected indevelopment of standards for geological storage inrecent years.14,15
A suitable geologic storage site must have suﬃcient
capacity to hold the desired quan ty of CO2, while
also being able receive the CO2 at acceptable ratesaE.g., in Canada, CSA Z662; Europe, DNV-RP-J202; and, interna onally, ISO
27913:2016.

bE.g., in the United States, 49 CFR Part 195.

c

See h ps://ccsnorway.com/

Figure 2D-3. Typical oxy-combus on process for solid fuels (e.g., coal, biomass). Natural gas could also be used in such a
process.
22

December 2019

through a reasonable number of wells. It must alsosafely contain this CO2 permanently—or at least for theforeseeable future.16mainly coal, for power genera on
and combus on in industrial processes because they
are rela vely abundant, cheap, available and globally
distributed, thus enhancing the security and stabilityof energy systems. Geological media suitable for CO
storage through various physical and chemical trapping
mechanisms must have the necessary capacity andinjec vity, and must conﬁne the CO and impede its
lateral migra on and/or ver cal leakage to other strata,
shallow potable groundwater, soils and/or atmosphere.
Such geological media are mainly oil and gas reservoirs
and deep saline aquifers that are found in sedimentarybasins. Storage of gases, including CO , in these media
has been demonstrated on a commercial scale byenhanced oil recovery opera ons, natural gas storage
and acid gas disposal. Some of the risks associatedwith CO capture and geological storage are similar
to, and comparable with, any other industrial ac vity
for which extensive safety and regulatory frameworks
are in place. Speciﬁc risks associated with CO storage
relate to the opera onal (injec on The prac cal global
capacity to store CO2 in saline forma ons is believed, on
the basis of geological assessments for select regionsof the world, to be upwards of 4,000 GtCO2. Another
1,000 GtCO2 are es mated to be available in depleted
oil and gas reservoirs.17 While these capacity numbers
are large, they hide the uneven geological distribu onof storage resources and the challenge of characterizing,assessing and developing storage sites, which can behigh risk and take many years to a decade. This meline
can also be complicated by the laws and regula onsthat may—or may not—exist to facilitate safe, eﬀec ve
CO2 storage.182005 Many governments have recognizedthat coordina ng and suppor ng development of CO2
storage sites is as important to future deployment, if not
more so, than support for technology development.5
Consequently, there is growing emphasis on
development of storage-centric and integrated CCUS
projects that are focused around clusters of emi ers(e.g., the Port of Ro erdam, Northern Alberta) andlinked to transport and storage hubs (e.g., in the North
Sea, EOR in Southern Alberta).5,19 Many of these hub andcluster projects involve the cement, iron and steel, andchemical industries.
1

B. Metz, O. Davidson, H. de Coninck, M. Loos and L.
Meyer, Eds., IPCC Special Report on Carbon Dioxide
23

Capture and Storage, Cambridge University Press,
Cambridge, U.K., 2005.
2

M. Bui, C. S. Adjiman, A. Bardow, E. J. Anthony, A.
Boston, S. Brown, P. S. Fennell, S. Fuss, A. Galindo,
L. A. Hacke , J. P. Halle , H. J. Herzog, G. Jackson, J.
Kemper, S. Krevor, G. C. Maitland, M. Matuszewski, I.
S. Metcalfe, C. Pe t, G. Puxty, J. Reimer, D. M. Reiner,
E. S. Rubin, S. A. Sco , N. Shah, B. Smit, J. P. M. Trusler,
P. Webley, J. Wilcox and N. M. Dowell, Energy Environ.
Sci., , DOI:10.1039/C7EE02342A.

3

D. Sandalow, R. Aines, J. S. Friedman, C. McCormickand S. T. McCoy, Carbon Dioxide U liza on (CO U): ICEF
Roadmap 2.0, Innova on for Cool Earth Forum, Tokyo,
Japan, 2017.

4

IEAGHG, Techno-Economic Evalua on of SMR BasedStandalone (Merchant) Hydrogen Plant with CCS, IEA
Greenhouse Gas R&D Program, Cheltenham, UK, 2017.

5

IEA, 20 Years of Carbon Capture and Storage:
Accelera ng Future Deployment, Interna onal Energy
Agency, Paris, France, 2016.

6Enhance Energy Inc. and North West Redwater
Partnership, Alberta Carbon Trunk Line project :knowledge sharing report, 2017, Calgary, Alberta, 2018.

7

Shell, Quest Carbon Capture and Storage Project:
Annual Summary Report- Alberta Department ofEnergy: 2017, Shell Canada Energy, Calgary, Alberta,
2018.

8

IEAGHG, The Carbon Capture Project at Air Products’
Port Arthur Hydrogen Produc on Facility, IEA
Greenhouse Gas R&D Programme, Cheltenham, United
Kingdom, 2018.

9

Z. Liang, W. Rongwong, H. Liu, K. Fu, H. Gao, F. Cao,R. Zhang, T. Sema, A. Henni, K. Sumon, D. Nath, D.
Gelowitz, W. Srisang, C. Saiwan, A. Benamor, M. AlMarri, H. Shi, T. Supap, C. Chan, Q. Zhou, M. Abu-Zahra,
M. Wilson, W. Olson, R. Idem and P. Ton wachwuthikul,
Interna onal Journal of Greenhouse Gas Control, 2015,40, 26–54.

10

R. Stanger, T. Wall, R. Spörl, M. Paneru, S. Grathwohl,
M. Weidmann, G. Sche necht, D. McDonald, K.
Myöhänen, J. Ritvanen, S. Rahiala, T. Hyppänen, J.
Mletzko, A. Kather and S. Santos, Interna onal Journalof Greenhouse Gas Control, 2015, 40, 55–125.

11

J. C. Abanades, B. Arias, A. Lyngfelt, T. Ma sson, D.
E. Wiley, H. Li, M. T. Ho, E. Mangano and S. Brandani,Interna onal Journal of Greenhouse Gas Control, 2015,
40, 126–166.

12

K. [Na onal E. T. Lab. (NETL) Callahan Albany, OR(United States)], L. [Na onal E. T. Lab. (NETL) Goudarzi
Albany, OR (United States)], M. [Na onal E. T. Lab.
December 2019

(NETL) Wallace Albany, OR (United States)] and R. [Booz
A. H. Wallace McLean, VA (United States)], A Reviewof the CO Pipeline Infrastructure in the U.S., UnitedStates, 2015.
13

P. C. Psarras, S. Comello, P. Bains, P. Charoensawadpong,
S. Reichelstein and J. Wilcox, Environ. Sci. Technol.,
2017, 51, 11440–11449.

14

CSA, Geological storage of carbon dioxide, CanadianStandards Associa on, 2012.

15

ISO, Carbon dioxide capture, transporta on andgeological storage -- Geological storage, Interna onal
Standards Organiza on, 2017.

24

16

S. Bachu, Progress in Energy and Combus on Science,
2008, 34, 254–273.

17

S. M. Benson, K. Bennaceur, P. Cook, J. Davison, H. deConinck, K. Farhat, A. Ramirez, D. Simbeck, T. Surles,
P. Verma and I. Wright, in Global Energy Assessment- Toward a Sustainable Future, Cambridge University
Press, Cambridge, UK and New York, NY, USA and theInterna onal Ins tute for Applied Systems Analysis,
Laxenburg, Austria, 2012, pp. 993–1068.

18

T. Dixon, S. T. McCoy and I. Havercro , Interna onal
Journal of Greenhouse Gas Control, 2015, 40, 431–448.

19

GCCSI, Understanding industrial CCS hubs and clusters,
Global CCS Ins tute, Melbourne, 2016.

December 2019

CHAPTER 3
CASE STUDIESCEMENT
Industry Overview
Cement is the founda on for the built environment.
When combined with aggregates and water, cement
makes the concrete used in roads, runways, buildings,
bridges, dams and other structures on which socie esaround the world depend.
In recent years, over 4 Gt of cement have been produced
annually.1,2 Global demand for cement has been growing
rapidly, expanding by nearly a factor of four between
1990 and 2014, when it reached around 600 kg/capita.1
The vast majority of growth in produc on since 1990 has
occurred in China, making China’s per capita produc on
today triple the global average. Global demand for
cement is expected to con nue growing, with somerebalancing of supply and demand at the regional level(including reduced produc on in China and increased
produc on in India and other Asia-Paciﬁc countries).3

In 2014, produc on of cement contributed over 2 GtCO
to global greenhouse gas (GHG) emissions (about 6%of the global total).4,5 Of this amount, around 40% was
emi ed from the use of fossil fuels to provide process
heat in clinker produc on, while the remaining 60% was
emi ed directly from the chemical decomposi on oflimestone (see Box 3-1). These ﬁgures do not include
indirect emissions from genera on of electricity used in
cement manufacturing (e.g., crushing and conveying ofmaterials) or mining of limestone and other minerals.

Decarbonization pathways
Many strategies for decarbonizing cement produc on
have been proposed. Some have been implemented.
There are many technical op ons for reducing the COfootprint of cement produc on directly,3,6,7,8 as well asa growing literature that considers the problem more
holis cally.1,9 Approaches proposed to date include:■ Switching to less carbon-intensive fuels, such assustainable biomass and wastes that would otherwise
be incinerated or improperly landﬁlled—a prac cethat is becoming more common today.3,7,10■ Improving the eﬃciency of exis ng cement plants
through retroﬁts that reduce both thermal energy
demand in clinker produc on and overall electricity
demand.3,7,10

BOX 3 1 Cement and Concrete
Concrete that is used in the construc on industry is a mixture of cement (some mes referred to as binder), waterand solid aggregates such as sand, gravel and crushed stone (some mes referred to as ﬁller). A typical mixture
by volume is 10-15% cement, 15-20% water and 60-75% aggregate. Manufacturing tradi onal Portland cement
involves hea ng limestone (calcium carbonate) and other minerals (primarily aluminosilicates) in a kiln to forma material known as clinker, which is mixed with other cons tuents (e.g., gypsum, ﬂy ash, steel slag) and groundinto a ﬁne powder. When this is mixed with water and aggregates, a series of chemical processes (“curing”)
converts the cement powder into interlocking crystals, which grow stronger over me.
ot
These crystals give concrete very good compression strength—so it can support a lotof weight—but poor tension strength, meaning that it cannot resist being pulled
apart unless other materials are added, such as steel (“rebar”). The length ofme it takes concrete to reach its required strength is referred to as “design age”
and is impacted by the amount and formula on of the cement, as well as curingcondi ons. The hydrated calcium oxide found in cement is very reac ve with CO
and, in fact, the cement naturally absorbs CO out of the atmosphere over its life—
although this is only a small frac on of that released during clinker produc on.

25

December 2019

■ Waste heat recovery for electricity produc on that

reduces demand for higher carbon intensity oﬀsite
power genera on.3,10■ Applica on of carbon capture and storage (CCS) to
reduce the emissions from both fuel combus on
and decomposi on of limestone (calcina on) to lime
during clinker produc on.3,7,10–13■ Reducing the clinker content of cement through theaddi on of supplementary carbonaceous materials(SCMs)—e.g., ﬂy ash, steelmaking slag, limestone andcalcined clay—and op mizing the choice of SCMs forthe applica on.1,3,7,10,14,15■ Op mizing design of concrete structures and choiceof concrete formula ons to use concrete more
eﬃciently,1 and increasing the design age of concrete
structures—i.e., allowing a longer me for the cement
to reach the design strength—in order to reduce theamount of cement required.14■ Development and applica on of alterna ve binders
for cement,1,10 such as beliteye’elimite-ferrite (BYF)
clinkers,16 carbonate calcium silicate clinkers (CCSC),16
or alkali-ac vated materials (AAM).17■ Industrializa on of cement produc on in emerging
economies to increase eﬃciency of produc onprocesses, improve quality control and reduce overall
waste genera on.1,9■ Be er managing concrete waste from demoli on inorder to accelerate natural uptake of CO2 throughcarbona on of the ac ve phases in cement, which
could theore cally result in full uptake of the originalemission from calcina on, albeit in the distantfuture.18,19
Some op ons in this menu (e.g., use of biomass fuels,
eﬃciency improvements and waste heat recovery)
are rela vely straigh orward, with li le impact on the
cement making process or resul ng product. Other
op ons (e.g., CCS) would require more substan al
and capital-intensive modiﬁca ons. Some op ons
would require changes in the way cement is used (e.g.,
op miza on of design, increased design age) or evenreplacement of conven onal cements to some extent(e.g., alterna ve binders). Of these op ons, the only
two that would directly result in reduc ons in process
heat emissions from ordinary Portland cement (OPC)
manufacturing are subs tu on of sustainable biomass
for fossil fuels and CCS. Li le has been wri en about
the use of hydrogen and electricity for provision of the26heat needed in cement making. This case study reviews
the way heat is provided in manufacturing of OPC andthen examines the poten al beneﬁts and costs of fuelsubs tu on, CCS, hydrogen and electricity.

The cement manufacturing process
OPC is composed of calcium carbonate, clay and lesser
amounts of other minerals (e.g., sand, bauxite andalumina). These materials are crushed, mixed togetherin speciﬁc propor ons and ground into a raw mealthat is heated to produce Portland cement clinker. The
clinker is then mixed with rela vely small amounts ofgypsum (calcium sulphate)—added to slow se ng of
the cement—and ground into the ﬁne powder that is
OPC. It is in these later steps that SCMs and ﬁllers (e.g.,
limestone) can be added to create specialized cements.
This process is illustrated inOPC is composed of calcium
carbonate, clay and lesser amounts of other minerals(e.g., sand, bauxite and alumina). These materials
are crushed, mixed together in speciﬁc propor ons
and ground into a raw meal that is heated to produce
Portland cement clinker. The clinker is then mixed withrela vely small amounts of gypsum (calcium sulphate)—
added to slow se ng of the cement—and ground into
the ﬁne powder that is OPC. It is in these later steps that
SCMs and ﬁllers (e.g., limestone) can be added to create
specialized cements. This process is illustrated inOPC is
composed of calcium carbonate, clay and lesser amountsof other minerals (e.g., sand, bauxite and alumina).
These materials are crushed, mixed together in speciﬁc
propor ons and ground into a raw meal that is heated
to produce Portland cement clinker. The clinker is thenmixed with rela vely small amounts of gypsum (calcium
sulphate)—added to slow se ng of the cement—andground into the ﬁne powder that is OPC. It is in theselater steps that SCMs and ﬁllers (e.g., limestone) canbe added to create specialized cements. This process is
illustrated in Figure 3A-1, which represents today’s stateof-the-art cement-making process., which represents
today’s state-of-the-art cement-making process., which
represents today’s state-of-the-art cement-making
process.
In the state-of-the-art “dry-kiln” process (OPC is
composed of calcium carbonate, clay and lesser amountsof other minerals (e.g., sand, bauxite and alumina).
These materials are crushed, mixed together in speciﬁc
propor ons and ground into a raw meal that is heated
to produce Portland cement clinker. The clinker is thenDecember 2019

Figure 3A-1. Current state-of-the-art dry-kiln Portland cement manufacturing process.

mixed with rela vely small amounts of gypsum (calcium
sulphate)—added to slow se ng of the cement—andground into the ﬁne powder that is OPC. It is in theselater steps that SCMs and ﬁllers (e.g., limestone) canbe added to create specialized cements. This process
is illustrated inOPC is composed of calcium carbonate,clay and lesser amounts of other minerals (e.g., sand,bauxite and alumina). These materials are crushed,
mixed together in speciﬁc propor ons and ground intoa raw meal that is heated to produce Portland cementclinker. The clinker is then mixed with rela vely small
amounts of gypsum (calcium sulphate)—added to slow
se ng of the cement—and ground into the ﬁne powderthat is OPC. It is in these later steps that SCMs and ﬁllers(e.g., limestone) can be added to create specialized
cements. This process is illustrated in Figure 3A-1, which
represents today’s state-of-the-art cement-making
process., which represents today’s state-of-the-art
cement-making process.), raw meal is conveyed tothe top of a tower that holds a series of 3-6 cyclone
separators arranged one above another. As the mealdescends through this series of cyclones, it is gradually
heated by contac ng hot exhaust gases, which are, inturn, gradually cooled. These hot exhaust gases comefrom burning fuel in the calciner and rotary kiln. Meal
is directly heated to around 900 °C by burning fuel inthe calciner, which is located near the end of the seriesof cyclones. Meal passes from there into the rotarykiln, where the meal is ﬁnally converted into nodulesof clinker at temperatures of around 1,450 °C (and gas
temperatures of nearly 2,000 °C). Of the total heat input
to the plant, 60-70% occurs in the pre-calciner and the27

remainder occurs in the rotary kiln.10,13 The hot clinker
exi ng the rotary kiln is then cooled, prehea ng the airthat is used in the kiln and pre-calciner.
As this descrip on implies, diﬀerent temperatures are
required in the cement making process and the process
is highly heat integrated. This means that the op malmeans of providing heat to the pre-calciner may not
be the same as in the kiln. In addi on, changes thatmight impact the ﬂow rates of gas in the system must
be carefully evaluated, as they may impact the clinker
capacity of the plant. Moreover, because combus ongases are in direct contact with the cement, the impact
of changes to the fuel composi on must be carefully
considered to avoid nega vely impac ng product quality.

Substituting biofuels for fossil fuels
In 2014, coal provided 70% of the direct thermal energy
input to cement manufacturing globally, followed byoil and gas at 24% and “alterna ve” fuels at 6%.3 Thealterna ve fuel category includes both waste (e.g.,municipal solid waste, sewage sludge and hazardous
wastes) and bioenergy crops, although waste dominatesin energy termsa. Where coal is used as the fuel input tothe state-of-the-art described earlier, direct emissions
from coal combus on contribute around 300 kgCO2-e ofthe total 900 kgCO2-e of direct and indirect (electrical)
emissions for each metric ton of clinker; where gas isused, emissions from fuel combus on fall to 180 kgCO2a

High temperatures and long residence mes in the cement making
process make it eﬀec ve for incinera on of waste (and hazardous waste in
par cular).

December 2019

Figure 3A-2. The greenhouse gas footprint of clinker produced using alterna ve fuels, coal with CCS op ons, hydrogen andelectricity. These results include combus on emissions from process heat and calcina on in the cement plant, genera on ofelectricity, and produc on of hydrogen (but not upstream emissions from fossil fuels produc on). The coal baseline and CCS
op ons are based on data presented in the CEMCAP project.22

e/t clinker as shown in Figure 3A-2b. Switching fromfossil fuels to waste materials can result in emissions
reduc ons that vary as a func on of the source fromwhich the waste material is derived and how it would
have otherwise been disposed. For example, using
biomass-based wastes (e.g., wood or agriculturalprocessing wastes) would generally result in the directemissions from combus on being reduced to zero as,
by conven on, the CO2 emi ed during combus on was
drawn from the atmosphere during growth (as assumed
in Figure 3A-2). As a result, in the 2017 IEA 2DS scenario,
the share of waste (and biomass fuels) used directly incement manufacturing grows strongly by 2050.5

equals the amount of CO sequestered in biomass. This
conven on, widely adopted in life cycle assessment (LCA
Further, upstream emissions associated with agriculture(e.g., fer lizers, harves ng and transport) and land-use
change are non-zero and should be a ributed to thefuel.24 Waste biomass would, by conven on, not carrythese emissions burdens. Thus, on a lifecycle basis,use of bioenergy crops for process heat would result inlesser emissions reduc ons than biomass-based wastes.
There is a limited sustainable biomass (both waste andcrop-based) available for use in materials or as fuels
globally, so there will likely be strong compe on forbiomass that will limit its cost-eﬀec veness in prac ce.3

Emissions reduc ons that might emerge from useof bioenergy crops (e.g., switchgrass, poplar) aresomewhat more complicated to evaluate. (See Chapter
2B.) While the direct emissions would also be zeroby conven on, in reality there is a ming diﬀerence
between CO2 emissions and uptake by biomass that canhave signiﬁcant impact for long rota on crops.23i.e. theCO released from biofuel combus on approximately

Because biomass-based fuels tend to have a lower
energy content (per unit mass) than fossil fuels—or, as
will be discussed, hydrogen—they are not suitable forproviding the high temperatures required in the kiln
directly but can be used in the calciner to provide lower
temperature heat. For example, bioenergy crops such as
miscanthus, switchgrass, poplar and pine all have a lower
hea ng value of 17-19 GJ/t25, whereas most kilns requirea fuel with a hea ng value of 20-22 GJ/t at a minimum.10
Burning alterna ve fuels in the calciner requires useof mul -channel burners in the calciner and carefulmonitoring of the levels of impuri es, such as chloride,in the clinker.10 However, these issues are handled inprac ce today at facili es that burn alterna ve fuels andb

Assuming an electric grid intensity of 519 gCO /kWh,5 IPCC emissions
factors20 and other energy requirements, as detailed in the CEMCAP
base case.13 These ﬁgures do not include the upstream emissions fromproduc on and distribu on of fossil fuel or mining of raw materials. In
the case of natural gas, for example, inclusion of these emissions would
increase emissions by around 20% per ton of OPC based on recent
es mates of average US natural gas upstream emissions.21
28

December 2019

do not appear to be a major barrier. A higher degree ofsubs tu on of biomass and waste for other alterna ve
fuels could be achieved by gasiﬁca on of the feedstocks
and subsequent use of the syngas (i.e., a mixture ofcarbon monoxide and hydrogen) as fuel, but this is at the
research stage in the cement sector.11

Application of CCS to cement making
The poten al importance of CCS to reduce emissions
from cement manufacturing was recognized by the late1990s26 and has been emphasized through successive
analyses and road-mapping ac vi es.3,7,10,11,27 The valueof CCS to the cement industry is that it could reduce
direct emissions from cement manufacturing—bothfrom process heat and calcina on—by 95%13 the chilledammonia process, membrane-assisted CO liquefac on,
and the calcium looping process with tail-end andintegrated conﬁgura ons. For comparison, absorp onwith monoethanolamine (MEA and, when coupledwith alterna ve fuels, result in zero (or even nega ve)emissions. Thus, CCS has an important role to playamongst the mul ple emissions mi ga on op ons forthe cement industry.
While all three classes of CO2 capture technology(see Chapter 2D) could be applicable to cement
manufacturing, post-combus on and oxy-combus ontechnologies are seen as the leading candidates.10
Solvent-based, post-combus on capture technologies(e.g., amine-based solvents, chilled ammonia) canbe added to a cement plant without making major
modiﬁca ons to the cement-making process or
impac ng cement produc on. However, both require
substan al amounts of addi onal steam that would
need to be generated on site (from addi onal fuel)or imported from neighboring facili es.13the chilledammonia process, membrane-assisted CO liquefac on,
and the calcium looping process with tail-end andintegrated conﬁgura ons. For comparison, absorp onwith monoethanolamine (MEA Amine-based capturesystems have been the focus of many engineeringstudies, and one was successfully pilot-tested by Norcem
between 2013 and 2017 at a plant in Norway.10,13
In addi on to the conven onal solvent-based op ons,
calcium looping (CaL) technology has also been
inves gated for applica on to cement plants for postcombus on capture. CaL shares many similari es withcement making, as it is a cyclic process in which CO2
is captured from ﬂue gas using CaO, which results in
29

CaCO3—the same material found in raw meal for OPC—
and the CO2 is then driven oﬀ by the same calcina on
process. The CaL process can be added to the cement
plant in either the “tail-end” conﬁgura on, which
requires no major modiﬁca ons to the cement making
process, or in the “integrated” conﬁgura on by using ashared calciner, which entails major modiﬁca ons to thecement plant. The tail-end conﬁgura on has no impact
on cement produc on, while the integrated process
could impact cement quality. In both cases, fuel andlimestone consump on increases and, depending on
the conﬁgura on and design choices, the plant could
become a net generator of electricity.13the chilledammonia process, membrane-assisted CO2 liquefac on,
and the calcium looping process with tail-end andintegrated conﬁgura ons. For comparison, absorp onwith monoethanolamine (MEA The CaL process has
been demonstrated at MW-equivalent scale for postcombus on capture in power genera on,28,29 is being
pilot-tested by Taiwan Cement Corpora on10 and will befurther tested in the EU-funded Cleanker Project in Italy.c
Oxyfuel technology could also be applied to cement
plants by conver ng the precalciner and, op onally, thekiln to use pure oxygen (rather than air) for combus onof the fuel and by recycling some of the CO2-rich ﬂue gas
to control temperature in combus on. 11,30 This would
necessitate changes to the burners in the precalcinerand kiln, modiﬁca ons to reduce air leakage into thesystem and changes to the clinker cooler, but it requires
less signiﬁcant modiﬁca ons than the integrated CaL
conﬁgura on.13,30 It would require addi onal electricity(for air separa on), but no addi onal fuel input. The
increased concentra on of CO2 in the kiln, precalcinerand preheater would impact heat transfer and thedegree of calcina on of the product (at a constanttemperature), which could impact product quality if not
appropriately managed.30 Oxyfuel technology has been
pilot-tested at a Lafarge cement plant in 2011 and 2012
in Denmark and has been widely studied.11,30
Applying CCS to cement produc on would reduce the
combined direct process heat and calcina on emissions
from cement making by upwards of 95%. However,
the overall reduc on depends on the type of capturesystem applied and the carbon intensity of energy
inputs (e.g., supplemental fuel, electricity).13the chilledammonia process, membrane-assisted CO2 liquefac on,
cSee h p://www.cleanker.eu/home-page-it.html

December 2019and the calcium looping process with tail-end andintegrated conﬁgura ons. For comparison, absorp onwith monoethanolamine (MEA For example, in the caseof a cement plant that uses coal as the primary fueland natural gas to provide steam for an amine-based
capture system (without capture) and draws electricity
at the global average emissions intensity, the overall
emissions reduc on would be closer to 60% (i.e., from
900 to 370 kgCO2-e/t clinker) as shown in Figure 3A-2.
On the other hand, the integrated CaL process would
reduce emissions by upwards of 80% from a coal-fueledbaseline to around 140 kgCO2-e/t clinker. Unfortunately,
these substan al emission reduc ons would also resultin an increase of 50% (MEA) to 80% (integrated CaL) inthe cost of clinker produc on, rela ve to a state-of-theart baseline. This corresponds to mi ga on costs of$100 and $70/tCO2 avoided, respec vely.12
None of these CO2 capture technologies have yet been
demonstrated at full-scale on a cement plant. However,this may soon change, as the Norwegian government isinves ng in development of an integrated CCS projectthat would capture CO2 from the Norcem cement plant
at Brevik, Norwayd. If funded, this demonstra on project
would not only provide valuable informa on about CO2
capture in the cement industry, but would also develop
the CO2 transport and storage infrastructure that iscurrently missing in Europe. The absence of transportand storage infrastructure poses a barrier to deploymentof CCS across industries globally and will need to beaddressed if this emissions reduc on op on is to betaken up for cement or any other sector.
Given that the most promising technologies available
for capture from cement produc on are diﬀerent
from those in power genera on (e.g., CaL) and, formaximum emissions reduc on beneﬁt, should be
integrated into the process, con nued focused researchand pilot tes ng would be beneﬁcial. For example, theLEILAC project (an EU-funded research project) aims
to demonstrate Direct Separa on calcining technology
for cement manufacture at pilot-scale, in which raw
meal is heated indirectly, separa ng fuel combus on
from the calcina on process.31 Other emerging
capture technologies, such as molten carbonate
fuel cells,32necessary for sustaining the endothermic
calcina on process and the forma on of clinker.

dConven onal approaches to CO2 emission reduc on in
cement plants are based on post-combus on capture
with chemical solvents, requiring a substan al energy
consump on for regenera on, or oxycombus on in
the cement kiln, involving a deep redesign of the plant.
The aim of this work is inves ga ng the applica on of
Molten Carbonate Fuel Cells in cement plants for CO2
capture from the plant exhaust gases, using the fuelcells as ac ve CO2 concentrators of combus on ﬂue
gases and eventually obtaining a puriﬁed CO stream
through a cryogenic process. A novel conﬁgura on with
MCFCs added along the exhaust line has been assessedby means of process simula ons. The results show aremarkable poten al in terms of equivalent avoided CO2
emissions (exceeding 1000g/kWh may also prove to be
an a rac ve op on when integrated into the cement
making process.

Use of hydrogen as an alternative fuelHydrogen is not currently used as an alterna vefuel in cement making, nor has use of hydrogen as
an alterna ve fuel in cement making been widely
inves gated. While the combus on temperature ofhydrogen in air is more than suﬃcient to provide
the temperatures required in the cement kiln, thecombus on proper es of hydrogen mean that it
would need to be burnt in specially designed burners
or mixed with solid par cles (e.g., clinker dust) to beeﬀec ve.33 How use of hydrogen impacts clinker quality
also appears to be an open ques on. Given the state ofresearch on hydrogen for cement making, there may beother unknown issues as well.33
Technical challenges of hydrogen combus on
notwithstanding, use of green hydrogen generated
from electrolysis with fully renewable electricity would
eliminate process heat emissions as shown in Figure
3A-2—an overall reduc on of around 30% rela ve toa coal-fueled plant. Of course, the intermi ent natureof renewables would necessitate energy (or hydrogenstorage) to support con nuous opera on of a cement
plant, so alterna ves would be to use grid electricity
for electrolysis or grey hydrogen from steam-methane
reforming (SMR). At the current global average grid
intensity, however, the emissions from a plant that useshydrogen generated using grid electricity would be 1.4
mes that of a coal-based plant (Figure 3A-2). The gridemissions factor would need to be around 250 kgCO2/

See h ps://www.norcem.no/en/carbon_capture30

December 2019

kWh to achieve the same overall emissions intensity asa coal-ﬁred cement plant and around 180 kgCO2/kWh tomeet that of an SMR plant (without CCS). Extending theanalysis illustrated in Figure 3A-2 to include upstream
emissions associated with natural gas supply (andrenewable genera on) would likely favor blue hydrogen(i.e., from SMR with CCS) over electrical routes. Thishighlights the interlinked nature of hydrogen withdecarboniza on of the electricity sector.
As in the case of biofuel subs tu on, use of hydrogenfor process heat has no impact on the emissions from
calcina on or other indirect emissions from electricity
genera on. Thus, subs tu on of hydrogen would be
limited to a 30% reduc on rela ve to a coal-ﬁred case,all else being equal. This would increase the overall costof clinker produc on by at least a factor of three (forgreen hydrogen) on the basis of fuel alone, making theoverall cost of emissions mi ga on much higher thanfor direct applica on of CCS. Should Direct Separa on
calcina on technology be shown to be viable,31 it
could make hydrogen subs tu on a more a rac ve
op on. Such a combina on would allow capture of thecalcina on emissions, somewhat reducing the mi ga on
cost. Nonetheless, given the rela vely low poten al
and high cost of emissions reduc ons through use ofhydrogen fuel, it may not be a valuable approach topursue in a deep decarboniza on scenario.

Direct electrical heating
Li le has been wri en about direct electrical hea ng
for cement manufacturing. It should be technicallypossible to heat raw meal to a suﬃcient temperature todecompose CaCO3 and form the ac ve phases of cement
using electrical-resistance hea ng (or other methods
discussed in Sec on 2C). As in the hydrogen case, if
Direct Separa on calcining technology is successful, it
would not only allow CO2 resul ng from calcina on of
the raw meal to be captured in a concentrated form andgeologically stored but would also enable eﬃcient use ofother heat sources such as electrical-resistance hea ng.
However, Direct Separa on calcining (using electricity,or otherwise) would only allow for a par al replacementof process heat with electricity, as it does not replace
the rotary kiln. Indirectly heated rotary calciners—i.e.,a rotary kiln to which heat is provided by natural gas orelectric resistance elements—are manufactured today
for speciﬁc applica ons where the atmosphere in the
calciner must be controlled, such as pyrolysis. However,31

the capacity of commercially available rotary calciners
are many mes smaller than those used in state-ofthe-art cement plants and maximum temperatures are
somewhat lower (as discussed in Sec on 2C), sugges ng
further development is requirede.
For the same energy input, the cost of using electricity
directly to generate heat (at nearly 100% eﬃciency)
would be lower than using hydrogen produced via
electrolysis (as today, electrolysis at large scales isaround 70% eﬃcient).34 At the same me, in a systemthat combined Direct Separa on calcining technology
with an electrically heated rotary calciner, all of thecalcina on emissions could be captured. This could
result in lower overall avoidance cost than the hydrogen
routes and could poten ally be compe ve with current
approaches to CCS. However, considerable further
research is needed to assess these technologies before
any strong conclusions can be drawn.

Conclusion
Manufacturing of cement is a substan al contributor
to global GHG emissions. As the demand for cement is
projected to grow in the decades ahead, the sector willneed to aggressively reduce its emissions to reach levels
consistent with a 2 °C or 1.5 °C target.
A wide range of op ons for emissions reduc ons havebeen evaluated, ranging from eﬃciency improvements
to subs tu on of SCMs for emissions-intensive clinker
to changes in the way cement is used in construc on.
Around 40% of the direct CO2 emissions from cement
manufacturing are associated with process heat forclinker produc on, while the remainder are generated
from decomposi on of calcium carbonate in the process.
Given that the vast majority of cement is produced
using coal for heat today, subs tu on of lower-carbon
intensity fuels is already having a substan al impact.
Biomass-based wastes and sustainable biofuels havean important role to play, but they can only subs tutefor a frac on of the heat input in cement making (dueto their low hea ng value) and, given their limited
supply, may not be cost eﬀec ve in large quan es.
Reducing emissions from hea ng via CCS is an important
op on that has been researched for many years andis now being demonstrated. While rela vely costly
in comparison to use of alterna ve fuels (and othere

For example, indirectly heated kilns are available from IBU-tec, FEECO,
and Kurimoto Ltd.

December 2019

mi ga on op ons), it has the dis nct beneﬁt of being
able to reduce the total emissions—both process heatand calcina on—by upwards of 90%. Use of hydrogen,green or otherwise, as an alterna ve fuel appears
to have less poten al, as it is more costly than direct
applica on of CCS in the cement plant and would reduce
only the emissions from process heat. Direct Separa on
technology, however, could enable more cost-eﬀec ve
emissions reduc ons from hydrogen subs tu on, directelectrical hea ng and carbon capture. There may also
be op ons that have not yet been iden ﬁed in literature
to combine fuel subs tu on with CCS to achieve zero oreven nega ve emission cement.
This case study highlights the challenges of trying toseparately address process heat emissions from thoseresul ng from carbon in the feedstock and highlights
the need to examine emission-reduc on op ons inindustrial processes in an integrated fashion. Con nued
research, development and demonstra on in the areaof emissions reduc ons in cement-making is needed toachieve zero emissions processes.
1

K. L. Scrivener, V. M. John and E. M. Gartner, Ecoeﬃcient cements: Poten al, economically viablesolu ons for a low-CO , cement based materials
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2

R. M. Andrew, Earth Syst. Sci. Data, 2018, 10, 195–217.

3

IEA, Technology Roadmap: Low-Carbon Transi on in the
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France, 2018.

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C. Le Quéré, R. M. Andrew, P. Friedlingstein, S. Sitch,
J. Hauck, J. Pongratz, P. A. Pickers, J. I. Korsbakken,
G. P. Peters, J. G. Canadell, A. Arneth, V. K. Arora, L.
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Ciais, S. C. Doney, T. Gkritzalis, D. S. Goll, I. Harris, V.
Haverd, F. M. Hoﬀman, M. Hoppema, R. A. Houghton,
G. Hur , T. Ilyina, A. K. Jain, T. Johannessen, C. D. Jones,
E. Kato, R. F. Keeling, K. K. Goldewijk, P. Landschützer,
N. Lefèvre, S. Lienert, Z. Liu, D. Lombardozzi, N. Metzl,
D. R. Munro, J. E. M. S. Nabel, S. Nakaoka, C. Neill, A.
Olsen, T. Ono, P. Patra, A. Peregon, W. Peters, P. Peylin,
B. Pfeil, D. Pierrot, B. Poulter, G. Rehder, L. Resplandy,
E. Robertson, M. Rocher, C. Rödenbeck, U. Schuster,J. Schwinger, R. Séférian, I. Skjelvan, T. Steinhoﬀ, A.
Su on, P. P. Tans, H. Tian, B. Tilbrook, F. N. Tubiello,
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IEA, Energy Technology Perspec ves 2017: Catalysing
Energy Technology Transforma ons, Interna onal
Energy Agency, Paris, France, 2017.

6

D. Sandalow, R. Aines, J. S. Friedman, C. McCormickand S. T. McCoy, Carbon Dioxide U liza on (CO U): ICEF
Roadmap 2.0, Innova on for Cool Earth Forum, Tokyo,
Japan, 2017.

7

IEA, Cement Technology Roadmap 2009: Carbon
emissions reduc ons up to 2050, Interna onal Energy
Agency, Paris, France, 2009.

8

E. Benhelal, G. Zahedi, E. Shamsaei and A. Bahadori,
Journal of Cleaner Produc on, 2013, 51, 142–161.

9

S. A. Miller, V. M. John, S. A. Pacca and A. Horvath,
Cement and Concrete Research, 2018, 114, 115–124.

10

ECRA and CSI, Development of State of the ArtTechniques in Cement Manufacturing: Trying to Look
Ahead, Revision 2017, European Cement Research
Academy, Duesseldorf, Germany, 2017.

11

IEAGHG, Deployment of CCS in the Cement Industry,IEA Greenhouse Gas R&D Programme, Cheltenham,
United Kingdom, 2013.

12

S. O. Gardarsdo r, E. De Lena, M. Romano, S.
Roussanaly, M. Voldsund, J.-F. Pérez-Calvo, D. Berstad,C. Fu, R. Anantharaman, D. Su er, M. Gazzani, M.
Mazzo and G. Cin , Energies, 2019, 12, 542.

13

M. Voldsund, S. O. Gardarsdo r, E. De Lena, J.-F.
Pérez-Calvo, A. Jamali, D. Berstad, C. Fu, M. Romano, S.
Roussanaly, R. Anantharaman, H. Hoppe, D. Su er, M.
Mazzo , M. Gazzani, G. Cin and K. Jordal, Energies,
2019, 12, 559.

14

S. A. Miller, A. Horvath and P. J. M. Monteiro, Environ.
Res. Le ., 2016, 11, 074029.

15

K. Scrivener, F. Mar rena, S. Bishnoi and S. Maity,
Cement and Concrete Research, 2018, 114, 49–56.

16

E. Gartner and T. Sui, Cement and Concrete Research,
2018, 114, 27–39.

17

J. L. Provis, Cement and Concrete Research, 2018, 114,
40–48.

18

F. Xi, S. J. Davis, P. Ciais, D. Crawford-Brown, D. Guan, C.
Pade, T. Shi, M. Syddall, J. Lv, L. Ji, L. Bing, J. Wang, W.
Wei, K.-H. Yang, B. Lagerblad, I. Galan, C. Andrade, Y.
Zhang and Z. Liu, Nature Geosci, 2016, 9, 880–883.

19

C. Pade and M. Guimaraes, Cement and Concrete
Research, 2007, 37, 1348–1356.

20

H. S. Eggleston, L. Buendia, K. Miwa, T. Ngara andK. Tanabe, Eds., 2006 IPCC Guidelines for Na onal
Greenhouse Gas Inventories, Ins tute for Global
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Environmental Strategies, Japan, 2006, vol. Volume 2:
Energy.
21

J. A. Li leﬁeld, J. Marrio , G. A. Schivley and T. J. Skone,
Journal of Cleaner Produc on, 2017, 148, 118–126.

22

M. Voldsund, R. Anantharaman, D. Berstad, E. De Lena,
C. Fu, S. O. Gardarsdo r, A. Jamali, J.-F. Pérez-Calvo, M.
Romano, S. Roussanaly, J. Ruppert, O. Stallmann and D.
Su er, CEMCAP compara ve techno-economic analysis
of CO capture in cement plants (D4.6), 2019.

28

B. Arias, M. E. Diego, J. C. Abanades, M. Lorenzo, L.
Diaz, D. Mar nez, J. Alvarez and A. Sánchez-Biezma,Interna onal Journal of Greenhouse Gas Control, 2013,18, 237–245.

29

J. Hilz, M. Helbig, M. Haaf, A. Daikeler, J. Ströhle and B.
Epple, Fuel, 2017, 210, 892–899.

30

F. Carrasco-Maldonado, R. Spörl, K. Fleiger, V. Hoenig,
J. Maier and G. Sche necht, Interna onal Journal ofGreenhouse Gas Control, 2016, 45, 189–199.

23

F. Cherubini, G. P. Peters, T. Berntsen, A. H. Strømman
and E. Hertwich, GCB Bioenergy, 2011, 3, 413–426.

31

T. P. Hills, M. Sceats, D. Rennie and P. Fennell, Energy
Procedia, 2017, 114, 6166–6170.

24

R. J. Plevin, J. Beckman, A. A. Golub, J. Witcover and M.
O’Hare, Environ. Sci. Technol., 2015, 49, 2656–2664.

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ECN.TNO, Phyllis2 - Database for biomass and waste,h ps://phyllis.nl/, (accessed August 16, 2019).

M. Spinelli, M. C. Romano, S. Consonni, S. Campanari,
M. Marchi and G. Cin , Energy Procedia, 2014, 63,
6517–6526.

33

V. Hoenig, H. Hoppe and B. Emberger, Carbon CaptureTechnology - Op ons and Poten als for the Cement
Industry, European Cement Research Academy,
Duesseldorf, Germany, 2007.

34

IEA, Technology Roadmap: Hydrogen and Fuel Cells,Interna onal Energy Agency, Paris, France, 2015.

26

IEAGHG, The reduc on of greenhouse gas emissions
from the cement industry, IEA Greenhouse Gas R&D
Programme, Cheltenham, UK, 1999.

27

IEAGHG, CO Capture in the Cement Industry, IEA
Greenhouse Gas R&D Programme, Cheltenham, UK,
2008.

33

December 2019

IRON AND STEEL
Industry overview
The global iron and steel industry is one of the largest in
the world, with sales of $2.5 trillion in 2017.1 The 2018
produc on of crude steel was 1,808 million tons, up 7%
from 2017 and a 10-fold increase since 1950.2,3 Steelis one of the largest products by weight produced byhumanity—one of very few commodi es manufactured
at the gigaton scale—and it is used in a vast range ofindustries including construc on, automo ve, shipping,aerospace and energy equipment. Because of thisenormous scale and the fact that conven onal iron andsteel produc on is energy- and emissions-intensive,
the sector is responsible for approximately 7% of
global CO2 emissions.4 Finding prac cal approaches todecarbonizing iron and steel produc on is therefore ofvital importance to achieving climate goals.
Any successful approach to decarbonizing iron and steel
must take into account the fact that the industry is ina state of ﬂux. A decade of rapid expansion and recent
demand satura on has led to severe overcapacity, withaverage plant use at approximately 75%. If all planned
steel produc on projects are realized, global capacity
could increase by 4-5% between 2019 and 2021, pu ng
further pressure on use.5,6 Steel produc on has also
been increasingly concentrated, with 51% of 2018
produc on in China (up from 38% in 2008), while India,
Japan, the US, Korea and Russia collec vely accountfor an addi onal 25%. Meanwhile, steel consump on

averages 200 kg per capita globally but varies from a lowof 30 kg per capita in Africa to a high of 283 kg per capita
in NAFTA countries. Since trade is global, with exports
equal to 27% of produc on in 2018, prices are strongly
aﬀected by global compe on.2

Decarbonization pathways
The two main processes used to produce steel are theolder blast furnace/basic oxygen furnace route (BOF)
and the newer electric arc furnace route (EAF) (seeFigure 3B-1). The BOF route begins with raw iron ore
and includes many processing steps. For this reason, it
is usually performed at rela vely large integrated steel
mills that also incorporate facili es for sintering iron ore
and producing coke from coal. The EAF route primarily
uses recycled steel scrap as its feedstock and includes
fewer processing steps. It is therefore usually performed
at smaller, “mini-mill” facili es where steel scrap iswidely available.
The dominant energy requirement in producing virginsteel is extrac ng metallic iron from raw iron ore(smel ng). In the BOF route, this is performed at blast
furnaces, which consequently have very high emissions.
Steel that has already been produced and recycled as
scrap can be reprocessed via the EAF route without thisstep, leading to very large energy and emissions savings(as much as 90% reduc on8). Addi onally, since EAF isalmost en rely electriﬁed, powering it with low-carbon
electricity can almost en rely eliminate its emissions.

Figure 3B-1. Primary iron and steelmaking routes (adapted from Carpenter et al7). While both BOF and EAF routes can use
hot metal, scrap and DRI as feedstocks, BOF primarily uses hot metal while EAF primarily uses scrap.
34

December 2019

As a result, the transi on from BOF to EAF resultsin signiﬁcantly reduced emissions. Globally, BOF
accounts for approximately three-quarters of steel
produc on and EAF for one quarter, down from its
peak of 33% in 2000. The balance between BOF andEAF varies drama cally within diﬀerent countries,
mostly as a result of the availability of scrap steel andreliable, low-cost electricity (see Figure 3B-2). For
example, due to the long history of steelmaking in the
US and Mexico and the large amount that is recycled,
two-thirds of steel produc on is via EAF. The average
emissions intensity of steel produc on is therefore
rela vely low at 1,736 kg CO2/ton (US) and 1,080 kg
CO2/ton (Mexico).3,9 (The local electric grid emissions
intensity also impacts these values.) In China over
90% of steel produc on is via BOF, and the average
emissions intensity is correspondingly higher at 2,148
kg CO2/ton crude steel.9,10
In considering the possible future adop on of EAF
Figure 3B-2. Share of steel produc on via EAF in diﬀerent region/(displacing BOF), it is instruc ve to note that thecountries; data from worldsteel.14,15
stock of steel per capita has historically saturated at
11-15 tons in countries that have fully industrialized.11
However, understanding the stock of steel and theiron suitable for the EAF route, but it avoids the use ofamount available for recycling is complex and wouldcoke, signiﬁcantly reducing its emissions. Expanding
beneﬁt from addi onal research.12 A scenario analysis of
the use of DRI for EAF steel produc on is therefore asteel produc on based on mass ﬂow analysis suggests
poten al route to low-carbon virgin steel produc on.
that the last required blast furnace for primary steel(See below for further discussion of DRI.)
produc on could be built as early as 2020.13
While the EAF route primarily uses recycled steel scrap,
it is able to produce virgin steel using direct reduced iron
(DRI) as a feedstock. DRI processes iron ore to a metallic

Process heat in iron and steel making
It is important to note that while both BOF and EAF
require large amounts of process heat, the two routes

BOX 3 2 BOF vs EAF in China
Because EAF steel produc on is so much less emissions-intensive, transi oning from BOF to EAF can lead to verynts
large emissions reduc ons. However, doing so requires signiﬁcant capital investmentse.
and conﬁdence that there will be a suﬃcient supply of recycled scrap steel available.
This is of par cular interest in China, where steelmaking is dominated by BOF (seeFigure 3B-2) but where there are signs of a growing availability of scrap steel inthe medium-term. This issue has been underscored by a recent surge in available
scrap steel due to the shu ering of ineﬃcient induc on furnaces. However, many
Chinese BOF facili es (par cularly blast furnaces) are rela vely new and eﬃcient,making their replacement less economically a rac ve. The evolu on of BOF vsEAF steelmaking in China will be an important driver of global industrial emissions
over the next several decades.5,16

35

December 2019

Figure 3B-3. Blast furnace for ironmaking. Iron ore, coke and limestone are added in layers at the top, sinking slowly to thebo om. Hot air is blasted into the furnace, igni ng the coke in the combus on zone and producing CO gas and heat. Coke
also physically supports the descending layers of iron ore and provides porosity for movement of CO gas and liquid iron.

generate it in very diﬀerent ways. In BOF steelmaking,process heat is provided through the combus on ofcoke. Coke also serves three other func ons: chemical
reduc on of iron ore, physical support of the burdenin blast furnaces, and porosity for hot gas and molten
metal movement (see below). This mul -purpose roleof coke means that simply replacing coke combus onwith other sources of process heat is imprac cal. In
EAF steelmaking, process heat is provided electrically,
which also makes direct replacement unappealing as anemissions-reduc on strategy and also unnecessary to
the extent that the electricity comes from low-carbon
sources. The complexi es of process heat in iron andsteelmaking therefore generally require signiﬁcant
process change to decarbonize.
While EAF oﬀers many advantages, BOF steelmaking will
con nue to be a large share of global produc on. Thereis also a large installed base of blast furnaces and related
equipment that represents a large investment of capital.
Finding technical methods to reduce emissions intensityof the BOF route without major process changes istherefore of great interest and will form the bulk of the
discussion to follow.
36

Process description: BOF
BOF steelmaking is used to produce new steel fromraw iron ore and other ingredients. The ﬁrst step in theprocess is to combine iron ore—primarily magne te(Fe3O4) and hema te (Fe2O3)—with limestone and ﬁne
par cles of coke (coke breeze) in a process known as
sintering. The coke is ignited and burns at 1,300-1,480°C, partly mel ng the materials and producing a coarse
agglomerate called sinter that is appropriate for bulk
handling. The heated sinter is usually cooled in open air
or with water sprays; waste heat recovery is technicallyfeasible but rare.17,18
In parallel to sinter produc on, metallurgical-grade
coal is heated in the absence of air at 900-1,100 °C
to produce coke. The hea ng drives oﬀ vola les andleaves a nearly pure carbon mass that is both porousand structurally strong. Heat is provided by combus ng
a por on of the coke oven gas (COG), the remainder ofwhich is usually used in other combus on units at an
integrated steel plant. At an integrated steel mill, bothsintering and coking facili es are usually co-located withthe rest of the iron and steel making facili es because of
December 2019

their importance to the iron and steel making.9,19
The sinter, coke, addi onal pellet or lump ore, andlimestone are then fed to a large blast furnace for theiron smel ng process (see Figure 3B-3). The furnace
is charged with materials from the top, which form
alterna ng layers and sink slowly towards the bo om.
Water-cooled nozzles (tuyeres) inject air heated to900-1,300 °C near the bo om. This blast air is heated in
hot blast stoves, which primarily burn top gas recycledfrom the blast furnace, possibly with the addi onof some coke oven gas.20 This hot blast air burns thecoke, forming carbon monoxide (CO) and hea ng thiscombus on zone to 1,500 °C or higher. Fuel combusted
for hea ng the hot blast stoves results in the majority of
CO2 emi ed from a blast furnace.7
The hot CO rises through the furnace and reacts withthe sinking iron ore, chemically reducing it to iron andCO2. The heat also decomposes the limestone into lime
(CaO) and CO2; the lime in turn reacts with trace silicon
impuri es to form calcium silicate (CaSiO3) slag. The
molten iron and slag sink to the bo om of the furnace
where they are tapped, while the CO2 and other hotgases (known collec vely as “blast furnace gas”) rise to
the top where they are used for a variety of purposes,
including pre-hea ng the tuyere blast air and genera ng
electricity.
A key feature of the blast furnace is the alterna ng
addi on of charge materials to the top, which form
layers that slowly sink. They are partly
supported on the coke, which is structurally
strong and slows their descent, while also being
porous enough to allow molten metal to ﬂow
downwards and hot gases to ﬂow upwards. This
allows for a long-dura on interac on within the
furnace (counter-current ﬂow), op mizing thechemical reac ons.

providing heat and reducing the total carbon content.
The resul ng molten steel and slag are then tapped atperiodic intervals. In contrast to the blast furnace, thesteelmaking furnace requires no addi onal heat input
because all of the necessary heat is provided by theoxygen-carbon reac ons.

Emissions reduction in the BOF route
The CO2 emissions from BOF come from a wide variety
of sources (see Figure 3B-4). The largest share (39%) isfrom ﬂue gas emi ed from power genera on. However,this genera on is based on combus ng blast furnacegas (BFG) and coke oven gas (COG), complica ng thea ribu on of these emissions (some natural gas may be
combusted as a supplementary fuel). The next largest
share is from the stoves that heat air for injec on via
the tuyeres in the blast furnace (18%), with important
contribu ons from the sinter plant and coke plant (both16%).7 However, the hot air stoves, coke ovens and sinterplant also combust large por ons of BFG and/or COG,
illustra ng the close process integra on of the overall
BOF process.
While these are all process heat contribu ons toemissions, replacing any one of them with an alterna ve
process hea ng method, such as combus ng hydrogenor providing electric heat, would disrupt this integra on.
This would lead to a need to handle excess BFG and
COG that is no longer being combusted, or (in the case

The iron that is tapped from the bo om of theblast furnace is called pig iron or hot metal.
It is mostly pure iron, with a rela vely highcarbon content (approximately 4%) comparedto ﬁnished steel. At integrated steel mills, it istransferred directly into a steel-making furnace,along with up to approximately 30% scrap steel.
Within the steelmaking furnace, a watercooled lance injects pure oxygen, which reacts
Figure 3B-4. CO2 emissions from diﬀerent processes within BOF
with the remaining carbon in the hot metal,
steelmaking. Adapted from Carpenter, 2012.7

37

December 2019

of coke oven modiﬁca ons) reduce the amount of COG
available for use by various processes. This integra on
makes piecemeal process heat modiﬁca on una rac ve
for BOF technology and leads instead to an examina onof carbon capture (see below) or op ons that favormaterial subs tu on in the process, which include:■ Reduction or elimination of sinter in favor ofpelletized ore for charging blast furnaces: Because
sinter produc on has a rela vely high emissions
intensity, reducing or elimina ng it in favor ofpelle zed ore signiﬁcantly reduces emissions.21 Thisrequires no capital investment or process changes forblast furnace opera on and can improve overall blast
furnace performance.22■ Substituting biomass-derived charcoal for cokein blast furnace charge, sintering and/or tuyere
injection: Charcoal derived from processes suchas autothermal pyrolysis of biomass can poten ally
replace or substan ally subs tute for the use of coalderived coke in blast furnaces, providing a source ofcarbon for combus on, structural strength to support
charged materials and suﬃcient porosity. Treatedbiomass could also be used as a coke subs tute inother steps of the BOF route. This would require
investment in pyrolysis equipment and establishmentof a reliable biomass supply, but minimal or nochanges to blast furnaces.23 Biomass subs tu on forcoke has an es mated emissions reduc on poten alof 32-58% for the BOF route.24 Based on a variety offactors including the availability of sustainable sourcesof biomass, the most suitable countries for biomass
subs tu on in iron and steelmaking are Canada,
Sweden, China, the US and France.25■ Modiﬁcation of the coking process: There are avariety of approaches to reducing emissions fromcoking ovens, including single-chamber-system (SCS)
coking—which uses single, large-volume ovens toachieve high thermal eﬃciencies—and coke ovenunder-ﬁring with advanced diagnos cs to improve
hea ng eﬃciency.9■ Reducing coke use through pulverized coal andhot oxygen injection to the blast furnace: This
technique subs tutes a frac on of blast furnace coke
consump on with direct coal injec on (bypassing
the coke-making process) and can achieve good
combus on with addi onal oxygen injec on.9
■ Reducing coke and coal use through co-injectionof hydrogen: The CO2 Ul mate Reduc on in
38

Steelmaking Process by Innova ve Technology for
Cool Earth 50 (COURSE50) program in Japan has
experimented with the use of hydrogen reduc onin blast furnaces to reduce coke consump on andemissions. Using coke oven gas, either directly or
reformed to increase the hydrogen content, theprogram demonstrated hydrogen reduc on at a test
blast furnace in Luleå, Sweden.26 Germany-based
steelmaker thyssenkrupp has recently announced testsof hydrogen injec on in a blast furnace to subs tutefor coal dust as a reductant.27■ Improving hot blast stove operation: A number oftechniques can be used to improve stove eﬃciency,
including air pre- or super-hea ng (see below), useof ceramic burners, and staggered airﬂow throughmul ple stoves.7■ Optimizing blast furnace operation using
modeling and simulation with high-performancecomputing: Observing condi ons within the blast
furnace during opera on is diﬃcult, so precise control
over the process, including op mized injec on ofcoal and charge, is not usually achieved. Simula ons
using computa onal ﬂuid dynamics can improve theunderstanding of blast furnace processes and lead toprocess op miza ons.28■ Plasma torch super-heating of hot blast air:Plasma torches use an electric arc to convert aworking gas to a plasma, achieving temperatures ofapproximately 5,000 °C. Introducing a plasma torchusing BFG and low-carbon electricity to superheat hot
blast air could reduce the total coke use of the BOF
route.29

Process description: EAF and DRIIn EAF steelmaking, a refractory-lined vessel is ﬁrst
charged with a mixture of steel scrap and DRI. Graphite
electrodes within the vessel are powered with either AC
or DC electric current, and an electric arc forms between
the electrodes and the charge material. The material isheated both through resis ve hea ng from the passing
electric current and radiant hea ng from the arc,
which can reach temperatures of 3,000 °C. EAF vessels
range from a few tons to hundreds of tons per charge,
using transformers that range from 10 to 300 MVA
and currents of up to 100 kA or higher. Depending on
furnace design and the charge proper es, approximately
1.6 GJ of electrical energy is consumed per ton of melted
steel.7,9
December 2019

EAFs are usually charged with scrap but can also accept
DRI or even pig iron as part of the charge (see Figure3B-1). DRI is produced by reducing iron in solid form
(without mel ng), most commonly using a hydrogencarbon monoxide mixture (syngas) produced byreforming natural gas as a reducing agent; no coke isrequired. Mul ple processes exist, but approximately
two-thirds of global DRI produc on (100.5 Mt in2018) uses the MIDREX process, with HYL/Energiron
represen ng 15.5%.30 The emissions beneﬁts come fromtwo dis nct proper es of natural gas in ironmaking:the emissions intensity per unit of thermal energy fromcombus on is nearly half that of coal, and methane asa reducing agent is twice as eﬀec ve as carbon on anemissions basis.31
India manufactures the largest amount of DRI globally,and primarily uses a process based on combus ng andgasifying low-grade coal to produce CO as a reducing
agent. The coal-based DRI process is suitable for smaller
produc on units but has higher energy intensity.
Mul ple types of reactors are used, including sha
furnaces, rotary kilns and ﬂuidized bed reactors.7

Medium- to long-term decarbonization
options involving significant process change
A number of alterna ve iron-making processes
have been developed and/or are in the process ofdevelopment. These involve substan al process changes
and generally seek to reduce or eliminate the useof coke and blast furnace technology broadly. These
approaches include the following:■ Expanded use of smelting reduction for hot

metal production: Smel ng reduc on processes
iron ore to hot metal in two stages. Ore is charged toa reduc on sha reactor where process gases thatare produced from the melter-gasiﬁer reactor mostly
reduce the ore to DRI. The DRI is then moved to themelter-gasiﬁer with discharge screws, and the ﬁnal
reduc on and mel ng processes take place there. The
two most commonly used processes are COREX andFINEX, the la er of which is able to charge ore without
agglomera on. No coke is required in the process,yielding important emissions savings.9■ Upgraded smelting process: The HIsarna process
has been developed within the Ultra-Low Carbon
Dioxide Steelmaking (ULCOS) framework as anintegrated hot metal produc on method. This process
combines mul ple processes in a single cyclone oven,39

avoiding the use of coke or the need to sinter ore. Oreand lower-grade steam coal are fed to the reactor,
which is also able to accept a signiﬁcant frac on of
scrap and biomass. Tata Steel has demonstrated theprocess at a pilot plant in the Netherlands.32■ Biomass-nugget smelting: US-based Carbontec
Energy Corpora on is developing an alterna vesmel ng technology that packages ore, biomass andlimestone in compact “nuggets” (brique es) that arethen heated. This pyrolizes the biomass and leads
to reduc on of the ore, without the use of coke orsintering.33■ Expanded use of hydrogen reduction of iron ore:
Several processes, including HYBRIT and H2FUTURE,
are being developed to use hydrogen as a reducing
agent for iron ore. The product would be DRI and,
when this is combined with EAF steelmaking using
low-carbon electricity for hydrogen produc on fromelectrolysis, the resul ng process can have very low
emissions intensity. When charging the EAF with 25%
scrap, emissions from this route would be lower thanthe BOF route for grid emissions intensi es below 661
kgCO2/MWh.34 Hydrogen reduc on has the advantage
of signiﬁcant opera onal ﬂexibility, since electrolyzers
can be ramped up and down to follow variable
renewable genera on.35■ Electrolytic steel production: Many metals,
including aluminum, zinc and nickel, are produced
at scale using electrolysis. Steel produc on has been
demonstrated using this technique, with molten oxide
as the electrolyte (which is able to withstand theopera onal temperature of 1,600 °C) and carbon-free
anodes. The emissions savings from this techniquefundamentally come from elimina ng a carbonbased reductant (such as CO) and using electricity
directly instead. Technology developed at MIT andcommercialized by Boston Metal, as well as the
ULCOWIN process, present pathways to electroly csteel produc on.9,36

Integrating CCS into iron and steel making
Carbon capture from ﬂue gas at a BOF integrated
steel mill has substan al technical poten al for
reducing overall emissions. Santos et al. examined
three such scenarios: two based on post-combus on
capture technology using a conven onal solvent(monoethanolamine, MEA), applied to the ﬂue gas fromthe hot stoves and steam genera on plant (resul ng
in 50.1% overall reduc on in CO2 emissions), with theDecember 2019

CO2 reduc on

Break-even cost($/t HRC)

Cost of CO2
avoided ($/t)

None

0%

$575

N/A

Post-combus on A

Hot stoves, steam plant

50%

$652

$74

Post-combus on B

Hot stoves, steam plant, cokeoven, lime kiln

60%

$678

$81

OBF

Blast furnace gas

47%

$630

$57

Case

Gas streams treated

Reference

Table 3B-1. CO2 emissions reduc on, break-even costs and cost of CO2 avoided for a BOF reference scenario and threecarbon capture scenarios.37

higher-capture scenario also trea ng ﬂue gas from thecoke ovens and lime kilns (resul ng in 60.3% overall
reduc on in CO2 emissions); and a ﬁnal scenario basedon an oxygen-blown blast furnace (OBF) in which
capture using a solvent blend (methyldiethanolamine,
MDEA, with piperazine, PZ) is deployed on the BFG(resul ng in 46.5% overall reduc on in CO2 emissions)(see Table 3B-1).37 The use of carbon capture increases
the break-even price of steel produc on (without
subsidies) from $575/t hot rolled coil (HRC) to $652/t
HRC and $678/t HRC, respec vely, in the ﬁrst two cases(post-combus on), and to $630/t HRC in the third case(OBF). These costs correspond to CO2 avoidance costsof $74/tCO2, $81/tCO2 and $57/tCO2, respec vely.
The rela vely low value of the OBF case is primarily
due to a signiﬁcant reduc on in coke consump on
and corresponding emissions reduc on from the cokeovens. In all three cases, cost increases were driven
by increased consump on of natural gas (due toincreased plant energy consump on, although energy
consump on increase was almost negligible
in the OBF scenario) and investment costfor capture equipment.

The ULCOS consor um has pursued the developmentof carbon capture from BFG through the concept of
Top Gas Recycle-Blast Furnace (TGR-BF). This techniquereplaces hot blast air with pure oxygen and recycles
BFG a er capturing CO2 for re-injec on into the blast
furnace; it has demonstrated savings of 20% or greaterin CO2 emissions.39 RIST and POSCO in South Korea havedemonstrated the use of aqueous ammonia solvents andlow-grade waste heat to capture CO2 from BFG.40
The dominant DRI process, MIDREX, could poten ally
accommodate CO2 capture from the slip stream ofrecycled top gas using pressure swing adsorp on(PSA). However, this would require addi onal processchanges and has not been demonstrated. By contrast,
CO2 capture is an integral part of the exis ng HYL/
Energiron process and is in commercial opera on at
the Al Reyadah facility in the UAE, where captured
CO2 is used for oﬀshore EOR. However, in general thisprocess only reduces overall emissions per ton of steel

Several research projects are underway todemonstrate CCS for BOF ironmaking. The
COURSE50 program in Japan has focusedon developing chemical and physicaladsorp on technologies for capturing CO2
from BFG, and is targe ng a cumula ve CO2
emissions reduc on of 30% when combinedwith co-injec on of hydrogen (see above,
and Figure 3B-5).38 By developing new
sorbent materials, the project has reduced
the energy requirements for regenera on
and has enabled the use of facility waste
Figure 3B-5. The COURSE50 program in Japan has focused on developing
heat (e.g., from slag, hot stove gas, etc.).
chemical and physical adsorp on technologies for capturing CO2 fromblast furnace gas. Credit: NEDO.
40

December 2019

by 25-35%, assuming average grid emissions intensity
for the associated EAF.37,41 The FINEX smel ng reduc onprocess produces low-nitrogen tail gas that is compa blewith CO2 capture with no substan al process changes,
although the overall emissions reduc ons per ton ofsteel are likely to be less than 50%.37,42

Conclusions: Addressing process heat in ironand steel making■ Both the BOF and EAF routes require substan alamounts of process heat, but that heat is generated invery diﬀerent ways.
■ EAF emissions are almost en rely due to electricity
genera on (because the process is essen ally fully
electriﬁed), so the produc on of low-carbon process
heat is directly linked to the supply of low-carbon
electric power.
■ The BOF route generates heat by combus ng coke
derived from metallurgical coal. The process is highly
integrated, with the use of oﬀ-gases such as blast
furnace gas (BFG) and coke oven gas (COG) for various
hea ng opera ons, including hot blast stove hea ng
and power genera on. It is therefore not prac cal toreplace any individual hea ng unit opera on without alarger process redesign.
■ There are a range of op ons to reduce emissions in
the BOF route, including the use of biomass, plasma
superhea ng of blast air, reducing sinter and hydrogen
injec on.
■ Emerging iron-making processes such as smel ng
reduc on and direct-reduced iron (DRI) oﬀer more
ﬂexibility in op ons to provide low-carbon heat.
However, they are incompa ble with conven onal
blast furnace technology and represent a substan alprocess change.
■ CCS oﬀers a route to substan al emissions reduc on
from conven onal (BOF) steelmaking. Capture can beapplied to various ﬂue gas streams at an integrated
steel mill or BFG. Some smel ng reduc on and DRI
processes are highly amenable to carbon capture,
while others will require more research.
1

The role of steel manufacturing in the global economy,
Oxford Economics (2019).

2

World Steel in Figures 2019, worldsteel (2019).

3

Mineral Commodity Summaries 2019, Iron and Steel,
US Geological Survey (2019).

41

4

Global steel industry: Outlook, challenges andopportuni es, worldsteel (2017).

5

Chalabyan, A. The current capacity shake-up in steel
and how the industry is adap ng, McKinsey & Company(2018).

6

Mabashi, D. Latest developments in steelmaking
capacity, OECD (2019).

7

Carpenter, A. CO abatement in the iron and steel
industry, IEA Clean Coal Center (2012).

8

Li, Y. et al. CO emissions from BF-BOF and EAF
steelmaking based on material ﬂow analysis, Advanced
Materials Research (2012).

9

Hasanbeigi, A. et al. Emerging energy-eﬃciency andcarbon-dioxide-emissions-reduc on technologies forthe iron and steel industry, LBNL (2013).

10

Tolomeo, N. et al. US steel sector thrives as mills move
up quality ladder, S&P Global Pla s (2019).

11

Pauliuk, S. Steel all over the world: Es ma ng
in-use stocks of iron for 200 countries, Resources,
Conserva on and Recycling (2013).

12

Gauﬃn, A. et al. The global societal steel scrap reserves
and amounts of losses. Resources (2016).

13

Milford, R. et al. The roles of energy and material
eﬃciency in mee ng steel industry CO targets,
Environmental Science & Technology (2013).

14

Steel Sta s cal Yearbook 2018, World Steel.

15

Steel Sta s cal Yearbook 2010, World Steel.

16

Zhong, F. Is it me for China to switch to electric arc
furnace steelmaking? World Steel (2018).

17

Demonstra on of a Waste Heat Recovery System at a
Steel Plant in India, NEDO (2014).

18

Fernandez-Gonzalez, D. et al. Iron ore sintering:
Process. Min. Proc. Ext. Met. (2017).

19

AP42, Fi h Edi on, Chapter 12: Metallurgical Industry.
US Environmental Protec on Agency.

20

Sarna, S. Genera on of hot air blast and hot blast
stoves. Ispat Guru website (2015).

21

Ly on, W. Barriers to industrial decarboniza on.
Sandbag.org (2018).

22

Agrawal, A. Blast furnace performance under varying
pellet propor on. Trans. Ind. Inst. Met. (2019).

23

Jahanshahi, S. et al. Recent progress in R&D on
assessment of biomass/designer chars for steel
produc on, Innova on of Ironmaking Technologies andFuture Interna onal Collabora on Conference (2014).
December 2019

24

Mathieson, J. et al. Poten al for the use of biomass in
the iron and steel industry, Chemeca 2011 (2011).

25

Mandova, H. et al. Global assessment of biomass
suitability for ironmaking – Opportuni es forco-loca on of sustainable biomass, iron and steel
produc on and suppor ve policies, Sustainable Energy(2018).

26

27

28

29

Nishioka, K. et al. Sustainable aspects of CO ul mate
reduc on in the steelmaking process (COURSE50
project), Part 1: Hydrogen reduc on in the blast
furnace. J. Sust. Met. (2016).
Thyssenkrupp, “World ﬁrst in Duisburg as NRW
economics minister Pinkwart launches tests at
thyssenkrupp into blast furnace use of hydrogen”, Press
Release, 11/11/2019; h ps://www.thyssenkrupp-steel.
com/en/newsroom/press-releases/world-ﬁrst-induisburg.html.
Fisher, A. et al. Improving steel produc on with a virtual
blast furnace, Lawrence Livermore Na onal Laboratory(2016).
Patel, N. et al. The use of plasma torches in blast
furnace iron making, 46th Ironmaking Seminar (2016).

30

2018 World Direct Reduc on Sta s cs, MIDREX (2019).

31

Tanaka, H. Poten al for CO emissions reduc on in
MIDREX direct reduc on process, Kobe Steel (2013).

32

Fleschen, D. A possible future of steelmaking: HIsarna.
Market Steel (2018).

42

33

Fisher A. et al. U liza on simula on to guide furnace
designs for the E-Iron nugget process. Lawrence
Livermore Na onal Laboratory (2017).

34

Vogl, V. Assessment of hydrogen direct reduc on forfossil-free steelmaking, J. Cleaner Prod. (2018).

35

Ahman, M. et al. Hydrogen steelmaking for a lowcarbon economy. Stockholm Environment Ins tute andLund University (2018).

36

Allanore, A. Features and challenges of molten oxide
electrolytes for metal extrac on, J. Elec. Soc. (2015).

37

Santos, S. et al. Iron and steel CCS study (Technoeconomics integrated steel mill), IEAGHG, 2013/04, July
2013.

38

Tonomura, S. et al. Concept and current state of
CO Ul mate Reduc on in the Steelmaking Process(COURSE50) aimed at sustainability in the Japanese
steel industry, J. Sust. Met. (2016).

39

Van der Stel, J. et al. ULCOS top gas recycling blast
furnace process (ULCOS TGRBF): Final report, European
Commission (2014).

40

POSCO, Posco Report 2017.

41

Sakaria, D. Case Study: Al Reyadah CCUS Project.
Carbon Sequestra on Leadership Forum (2017).

42

POSCO, The FINEX Process: Economical andenvironmentally safe ironmaking (2015).

December 2019

CHEMICALS
Industry overview
The global chemical sector (including petrochemicals
and reﬁning) is enormous and varied. Total sales in2017 were $4 trillion.1 The chemical sector has grown
rapidly over the past decade and is projected to con nue
growth for many years.2 In 2017, the chemical sector
vented ~1.6 Gt CO2, roughly 3% of global CO2 emissions.
Energy demand was greater for chemicals than for either
cement or steel, reﬂec ng enormous heat consump on(Figure 3C-1).3
The chemical sector represents the largest frac on of US
industrial produc on and GHG emissions. Chemical andreﬁning industries respec vely emit 177 and 184 million
tons CO2e annually—roughly 25% of total US industrial
CO2 emissions—with 28% concentrated in Texas andLouisianaa. To achieve key climate goals, prac cal
approaches to decarbonizing chemical produc on is ofvital importance.
Unlike cement or steel produc on, which produce asmall number of commercial products, the chemical
sector produces an enormous variety of diﬀerent
products using diﬀerent processes. These include
drop-in fuels (e.g., gasoline, diesel, jet fuel, bunkerfuel), rela vely simple feedstocks and compounds(e.g., ethylene, methanol) and complex products (e.g.,
lubricants, carbon ﬁber). The variety of produc on
methods and products complicates strategies for
decarboniza on.
Similarly, most chemical facili es have a wide set offeedstocks and fuels. Reﬁneries consume naturalgas, natural gas liquids and heavy hydrocarbons (e.g.,
bitumen, asphalt) which serve as feedstocks as well as
fuels. Hydrogen is also an important feedstock. In the US
and EU, hydrogen produc on and dedicated pipelines
e directly to reﬁning and chemical facili es. In OECD
countries, natural gas is the predominant heat fuel andfeedstock, while in China, India and Southeast Asia, coalprovides a large frac on of both heat and hydrogen.

Complexities of Operation
The complexity of the chemical sector is matched by thecomplexi es of facility opera on. The range of chemicala

See h ps://www.epa.gov/ghgrepor ng/ghg-repor ng-program-data-sets

43

Figure 3C-1. Global energy demand and direct (process)CO2 emissions by sector, 2017. Source: IEA.3

produc on processes is extremely varied, including
the Haber-Bosch process (ammonia), methana on(methanol produc on), ethylene cracking (ethylene)
and pyrolysis of heavy crude (carbon black produc on).
Many of these reac ons require ﬁt-for-purpose reactorsthat cannot be readily replaced.
In general, many chemical applica ons require heat thatis rela vely low in temperature (300-600 °C) comparedto other industries. This could open more poten alsources of low-carbon heat to applica on, including
advanced nuclear systems or advanced electrical hea ng(e.g., induc on or radia ve hea ng approaches). Thisis par cularly true for systems that require steam as a
primary feedstock (e.g., ethylene cracking), since boilers
and steam generators today operate on a wide rangeof heat fuels and inputs. While the temperature range
for chemical applica ons is lower than for cement, steel
and glass, the temperatures are generally too high forconven onal low-carbon heat systems (i.e. heat pumps).
A concern speciﬁc to the chemical industry is the broad
distribu on of heat sources. Unlike in cement and steel,
where most of the emissions ﬂow from one or two large
reactors (e.g., a kiln or blast furnace), it is unusual toﬁnd a single large source in most chemical plants—there
are excep ons, e.g. cataly c crackers for fuel reﬁning
and synthesis. Large chemical plants have dozens oreven hundreds of small emissions sources ed to heatproduc on, including burners, furnaces and boilers.
Decarbonizing these small, distributed sources would
likely add complexity and cost to plans for heat supply
subs tu on. As such, poten al subs tutes for lowDecember 2019carbon heat may be limited by the breadth and diversityof heat consump on in a plant. Moreover, some large
process units (e.g., cataly c crackers, carbon blacksynthesis units) generate heat by par al oxida on andcombus on of feedstocks and fuels in the key reac ons.
This limits the kind of subs tu ons that are possible,
since the core process reac ons require carbonaceous
fuels and feedstocks.
To limit our inves ga ons and focus on representa ve
sectors, we selected two pathways for discussion:ammonia, which chemically contains no carbon, andmethanol, which does. Both are large sub-sectors of thechemical industry. Both are globally-traded commodi es
with mature supply chains and technologies. In this way,
both pathways are representa ve of the chemical sector
as a whole, and speciﬁc issues and processes withineach provide some insight into both the challenges andpoten al solu ons to decarbonizing heat and produc on
across other chemical supply chains.

Ammonia
Ammonia is a huge global industry. It underlies almost
all fer lizer produc on (450 million tons, $156 billion
market) and is the largest single commodity within thatmarket, roughly 170 Mt worth $50 billion in 2017.6
Global CO2 emissions from ammonia are roughly
1.5% of global emissions (~490 MT in 2012).7 In theUS, 12.5 million tons of ammonia worth $13.2 billion
came from 34 facili es in 2018, mostly concentrated
in Texas, Oklahoma and Louisiana (in large part due to
low-cost natural gas and associated low-cost hydrogenproduc on), resul ng in 11.8 million tons CO2 annual
emissions.6,8 Annual market growth in the US is about
2.5%, and global annual growth closer to 4%. Some
recent analysis has proposed ammonia as either ahydrogen storage and transporta on medium or as apoten ally carbon-free fuel op on.9 If either op on
entered the market at scale, there would be drama cincrease in ammonia produc on.
Almost all ammonia produc on worldwide uses theHaber-Bosch process, invented and developed largely
from 1900 to 1910.10 The core process involves breaking
the triple bond of nitrogen gas (N2) and reducing it byadding hydrogen to form ammonia (NH3). The triple
bond is very strong, so much energy is required toundertake ammonia synthesis. The process operates
at very high pressure (2200-3600 psi/15-25 MPa),
which requires a lot of compression and mechanicalwork, expensive capital equipment, and a fairly hightemperature (400-500 °C), which requires substan al
heatb.
b
To learn more about the Haber-Bosch Process, see: h ps://www.
sciencedirect.com/topics/engineering/haber-bosch-process (Science
Direct, 2019, The Haber-Bosch Process)BOX 3 3 Synthe c fuels and chemicals
produc on in China and India
A very large share of today’s chemical market is in China, India and Southeast Asia.2 In these regions, access tonatural gas as a feedstock is o en limited, especially in China, India, Vietnam and Indonesia. In contrast, coal andpetcoke are o en abundant and very cheap. This has led many chemical facili es in these countries to use solidcarbon fuels for heat and also for hydrogen produc on. Many of these individual facili es are very large andrge
clustered in key regions (e.g., Ningxia and Ahmedabad)4,5 and would require very large
supplies of low-carbon heat and feedstocks to decarbonize.
One feature of these facili es is that hydrogen produc on commonly occurs throughghcoal or petcoke gasiﬁca on combined with water-gas shi . This produces a verylarge byproduct (process) stream of concentrated CO2, which could be captured
and stored for rela vely low cost. Unfortunately, none of the countries in ques on
have announced or executed serious plans to capture and store CO2. Also, in manyof these regions, water is scarce and agriculture is limited. As such, solid biomass
or biomethane subs tu on for heat is not a likely op on today.

44

December 2019

Figure 3C-3. Simpliﬁed cartoon of Haber-Bosch process.

The power and heat requirements have driven eﬃciency
improvements industry wide, and the industry has
reduced energy requirements 75% since 1930 androughly 40% since 1970.11 Global average footprint ofammonia produc on is es mated to be 1.9 tons CO2/ton
ammonia, with ammonia made from natural gas having
a footprint of 1.1 tons CO2/ton ammonia.12 Over 50% is
associated with hydrogen produc on and roughly 3040% from process heat. Hydrogen is a cri cal feedstock
to ammonia synthesis, and roughly 50% of globalhydrogen produc on goes into ammonia produc on.
Hydrogen is commonly made from natural gas or
longer hydrocarbons at high temperature, which itself
consumes much heat during produc on. (See Chapter
2A). The hydrogen and nitrogen gases run over mul ple
beds with iron-based catalysts followed by cooling(and hea ng) in between. Each catalyst executes one
component of the chemical reac on, and the mul ple
beds are used to increase selec vity and yield.
The major consumers of heat are hydrogen synthesis(steam-methane reforming [SMRs]) and the ammonia
synthesis reactor. Because heat is a major cost toammonia produc on due to mul ple hea ng andcooling steps, most facili es a empt to capture waste
heat through a set of heat exchangers (Figure 3C-3). The

mul ple steps for ammonia synthesis require addi onal
heat to provide energy to upgrade/reduce nitrogen
during each run across cataly c beds (Figure 3C-4).

MethanolLike ammonia, methanol is a huge global industry andinterna onally traded commodity. It is used both as afuel and as a feedstock, usually for plas cs, fuels or more
complex chemicals (e.g., formaldehyde, gasoline anddimethyl ether). The global methanol market produced
110 million tons worth $24.7 billion14 at over 90 plants
worldwidec. Global CO2 emissions from methanol are~100 Mt in 2016.15 About 12 million tons16 of methanol
worth ~$3.6 billion17 came from US facili es, mostly in
Texas and Louisiana. Global annual growth is closer to
7.7% and is projected to grow at an 11% rate, reaching$48 billion in 2024. This demand will be met in part fromnew produc on and export facili es in the US.17
Originally, methanol was derived from wood and was
known as wood alcohol. Today, methanol is typicallymade by feeding syngas into a methanol synthesis
unit followed by dis lla on (Figure 3C-5). Both CO
and CO2 can be converted to methanol, although CO2c45

See h ps://www.methanol.org/the-methanol-industry/

December 2019

Figure 3C-4. Schema c Gibbs free-energy chart showing all process steps in ammonia synthesis. Although the reac on is
exothermic and theore cally yields energy, thermodynamic losses require addi onal energy input. Source:13

conversion requires more hydrogen than CO. Commonly,
the reac on produces addi onal hydrogen, which canbe sold or used inside the facility for heat or power.
Methanol synthesis is insensi ve to the source ofthe primary chemicals, which could be derived from
captured CO2, biofuels, green hydrogen or others.
There are many alterna ve produc on methods formethanol synthesis,18 including biomass-derived
syngas and heat,19 direct electroly c produc on,
waste conversion20 and synthesis from recycled CO2,
and green hydrogen.21 The George Olah plant in
Icelandd uses this last methodology. In some cases, noprocess heat is required; although, for the electricalpathways, substan al amounts of addi onal energy are
required.22,23 Also, unlike ammonia, which burns without
returning carbon to the atmosphere, methanol use
ul mately returns the chemical-embodied carbon to
the air and oceans. If recycled CO2 is notprovided by low-carbon biomass or CO2
captured from the air, it will add CO2 tothe air and oceans.

be replaced with hydrogen burners, electrical hea ng
or steam produced by any carbon-free heat, including
conven onal nuclear reactors. Because of the wide
range of poten al pathways to generate heat, methanol
facili es could serve as a poten ally important tes ng
ground for alterna ve heat supply subs tu on.

Decarbonization pathways for chemicals andrelated heat
Several poten al pathways exist that could meaningfully
contribute to deep reduc on in chemical CO2
emissions. These include demand destruc on, materialsubs tu on, electriﬁca on, carbon capture and storage(CCS) and fuel switching. Es mates for poten al sizeand pace of contribu on to decarboniza on arehighly controversial and some mes involve full facility

In contrast to many of the other sectors
and approaches discussed in this report,
methanol synthesis and dis lla on
operate at fairly low temperatures (~300°C). Small burners and furnaces commonly
provide heat, which hypothe cally coulddSee h ps://www.carbonrecycling.is/george-olah

46

Figure 3C-5. Schema c cartoon of a methanol synthesis plant.
December 2019

replacement or changes in commercial
prac ces and consumer preferences.
As before, this discussion focuses on
low-carbon fuel subs tu on for heat andretroﬁts to exis ng facili es.

Short-term decarbonization
options involve gaseous
substitutes
The most common heat source forchemicals is natural gas. Most facili es
are situated near major natural gas hubs
(current or historical), and supply chainsprovide natural gas both as a feedstockand for heat. This means that the simplest
pathways to subs tute low-carbon heat
systems are with low-carbon gas supplies.

Figure 3C-6. Scenario-based direct CO2 emissions reduc ons in bothprocess- and energy-related emissions for the chemical sector. Source: IEA.11

For these reasons, biomethane is thesimplest op on, as it can immediately subs tute into
exis ng plants with near-zero modiﬁca on of the system(e.g., 24,25). For this to yield low-carbon heat, the lifecycle footprint of the biomethane must be low, whether
supplied by gasiﬁca on, landﬁll or digester. It is not clear
if this is likely to prove compe ve in chemicals—the
IEA Clean Transi on scenario for chemicals found limited
uptake of biofuels and biomass substa on.12
Hydrogen, blue or green, is also a viable op on and is
the most straigh orward to assess in terms of life-cycle
analysis (LCA). The temperature of hydrogen burned in
air is more than suﬃcient for all chemical and reﬁning
processes. Most systems can accommodate 7-20%hydrogen blends based on the speciﬁcs of facility
engineering, and indeed some chemical plants alreadyuse byproduct hydrogen (e.g., from ethylene synthesis)
to produce heat. All of the challenges discussed in
the hydrogen sec on (e.g., embri lement, corrosion,
speciﬁc sensors and controls) would apply to such asystem.

Medium- to long-term decarbonization options
involving significant process change
Unlike blue hydrogen or biomethane, other pathways todecarbonizing reﬁning and chemical produc on are notyet commercial and in many cases are not yet piloted.
However, combina ons of eﬃciency, heat subs tu on
and CCS can provide substan al reduc ons in energyrelated emissions—roughly 50% (Figure 3C-6). While
this set of scenarios ﬁnds li le decarboniza on through47

commercial applica on of electrical or biofuel-provided
heat, other outcomes are possible given diﬀerent
assump ons.
NOTE: Because many chemical products have embedded
carbon (e.g., methanol) which re-enters the air andoceans a er use, truly deep decarboniza on may
ul mately require radically diﬀerent prac ce than isused in today’s industry. Either all embedded carbon
must come from recycled CO2 (e.g., DAC-supplied or
low-carbon-biomass-supplied CO2; biopolymers) oralterna ve processes that do not emit their carbon
content a er use will be required.26
A number of alterna ve processes for ammonia,
methanol and other chemicals have been developedor are under development. These involve substan alprocess changes and generally seek to reduce or
eliminate the use of fossil-fuel feedstocks.
One approach is electrosynthesis of feedstocks, includinghydrogen and syngas, which can be burned for heat andfuel. Both ammonia and methanol can be converted toelectricity through a fuel cell to generate electricity andbyproduct N2 or CO2. Using a reverse fuel cell, methanol
can be generated by adding CO2 and electricity to afuel cell in an aqueous environment or the presenceof hydrogen. Haldor-Topsoe27 has designed and piloted
this approach, which generates a syngas of hydrogenand nitrogen which enters a conven onal Haber-Boschreactor. This approach is similar to the JGP processpiloted at Fukishima28 and does not require heat for
SMR produc on or energy for the air separa on unit.
December 2019

The process would s ll require heat for the ammonia
synthesis reac ons, which could be supplied throughhydrogen or ammonia combus on.

Electrification of heat
Prior sec ons discussed the poten al for electricalmethods (e.g., resistance or dielectric hea ng) toprovide thermal energy to industrial processes. In thecase of chemicals, some electriﬁca on will likely provestraigh orward and simple. For example, processsteam used for chemical synthesis could be supplied byelectrical water heaters with limited capital expenditure.
The same is true for some small electrical furnaces.
Such systems exist today at 0.5-4 MW ra ngs and could
supply distributed steam and heat. However, there
have been no published examples of facili es that haveins tuted such electriﬁca on nor has there been an
industry census regarding the extent to which these
replacements could occur in a straigh orward manner.
For more complex chemical reactors (e.g., ammonia or
ethylene synthesis), commercial electrical reactors are
not commercially available. Given the dimensions andopera onal requirements of commercial facili es, it does
not appear possible to retroﬁt exis ng reactors withelectrical hea ng methods today. In addi on, extremely
low ﬁrm power costs are required to displace otherlow-carbon heat op ons like biomass or CCS (see below:
costs), and displacement costs may vary as a func on offacility age, design and the replacement costs compared
to retroﬁt costs.

Integrating CCS into chemical processes
For many chemical manufacturing processes, CCS cansigniﬁcantly and cost-eﬀec vely reduce CO2 emissions.
According to IEA analysis,3 CCS is the chief op onof many expected to contribute to least-cost GHG
reduc on in the chemical sector, followed by eﬃciency
and the switching of coal to gas. This result is bothrobust and unsurprising. Many produc on pathways(ethanol, methanol, ammonia) have large byproduct CO2
streams. Successful introduc on and deployment of CCS
in chemicals will require investment and engineeringthat integrate CO2 capture into conven onal opera onsof chemical facili es. As elsewhere in this report, we
focus on applica on to exis ng facili es, as opposed to
new processes or integrated designs for new facili es.
Carbon capture, use and storage (CCUS) applied topure streams of CO2 already operate today. Four largehydrogen plants, one small ammonia plant, one reﬁnery
and one ethanol plant operate today with CCS.29 Allof these plants capture process emissions from purebyproduct streams. However, CCS can also contribute
substan ally to reducing heat-related emissions. In
ammonia produc on, for example, the primary process
emissions come from SMR hydrogen produc on. If a
dedicated hydrogen SMR plant was suﬃciently large
to produce hydrogen for both ammonia synthesis andreactor heat, it could achieve 85-90% CO2 emissions
reduc on by turning the plant “blue”—adding CCS to the
SMR facility and using the addi onal hydrogen for heat.
In essence, this could decarbonize both process andFigure 3C-8. Cost es mates for diﬀerent heat decarboniza on pathways for ammonia and methanol.

48

December 2019heat emissions through pre-combus on
separa on of CO2 from fuels.
Post-combus on CO2 separa on may
be another method capable of reducing
emissions at reﬁning and chemicalplants. This may prove most a rac ve
for facili es that have large point
sources (e.g., cataly c crackers, steam
boilers, central furnaces) within theirfence lines. In general, post-combus on
capture will be more complicated,
chieﬂy due to the range and distribu onof CO2 sources associated with bothprocess emissions and heat. While it
may be theore cally possible to retroﬁt
dozens of small sources for capture, it islikely to prove challenging and possibly
infeasible.
In either pre- or post-combus on
applica ons, CCS systems will
Figure 3C-9. Es mated abatement costs for greenﬁeld ammonia produc onrequire transporta on and storageas a func on of electricity cost compared to biomethane and blue hydrogen(CCS on natural-gas SMR). Source: McKinsey (2018)31
infrastructure. Many poten al
facili es for CCS retroﬁt (pre- or
post-combus on) lack pipeline capacity to transportindustrial sectors, including for ammonia and methanol
CO2 and lack ready and available storage sites. Thoseas proxies for the chemical sector (Figure 3C-8). For
opera ng today are largely bespoke contracts for EOR.
ammonia, they es mate a 5-40% increase in ammonia
Although projects have been proposed for CCS clusters
producon costs for most low-carbon heat pathways,
30
and hubs in Europe (e.g., PORTHOS and Teeside),
with
green
hydrogen subs tu on delivering substan ally
the infrastructure has not yet materialized for lackhigher unit produc on costs (60-120% increase). For
of investment. For CCS to contribute substan ally tomethanol, they es mate 5-80% increase (with green
decarboniza on of the chemicals industry, investment inhydrogen increasing costs 125-190%). In the case of
key infrastructure will prove essen al.
methanol, CCS to heat or to the whole facility appeared
to be the lowest cost op ons.
Cost estimates
Es ma ng costs of decarbonizing heat supplies in thechemicals sector remains diﬃcult. In part, this is due tothe range of op ons and the diﬃcul es in es ma ng
the true carbon footprints of viable op ons. It is also
partly is due to factors that are simply diﬃcult to assess
or forecast in the present or future. The es mates
discussed here have large ranges and substan al
uncertain es. In all cases, however, alterna ve
approaches to decarbonizing heat add substan al cost tounit produc on.
Using speciﬁc assump ons for power price andavailability, natural gas price, and other factors,
Friedmann et al. (2019) produced es mates for many
49

These es mates are in line with other publishedes mates. For example, McKinsey (2018)31 es matedthat carbon-free ammonia would increase unit price~5 to 35 percent depending on the future price of
renewable electricity and that power costs would
need to range from $25-45/MWh to be compe vewith other low-carbon synthesis pathways (Figure3C-9). They considered this economic hurdle to be
substan al enough that “decarboniza on would require
technological breakthroughs, a further lowering of zerocarbon energy prices, changing customer preferences(willingness to pay) and/or a regulatory push.” This issimilar to the conclusion of Abanades et al.22 or IEA’s

December 2019

(2013) es mates32 of addi onal energy
requirements for renewable chemical
synthesis (Figure 3C-10).eFinally, the Mission Possible report33
explained the addi onal required energy
to supply only methanol or ammonia as ashipping fuel through electrical synthesis:“Total electricity genera on, whether
for direct use, or for the produc onof hydrogen, ammonia or synthe cfuels, will need to grow from around
20,000 TWh today to 85-115,000
TWh by mid-century. This hugely
increased electricity supply will haveto be produced at 85-90% from directzero-carbon electricity genera on (i.e.
renewables or nuclear) with only 1015% coming from biomass or abatedfossil fuel inputs.”

Figure 3C-10. Addi onal energy requirements for subs tu on of renewable
power for hydrogen-based chemical synthesis. Percentages represent
frac ons of total global market. Source: IEA (2013)32

This framework requires system costs forﬁrm zero-carbon power to be between$5-25/MWhr—an extremely low power price—for such
fuels to be cost compe ve absent policy support.
Alterna vely, it will be essen al to ﬁnd new andinnova ve pathways that require much less addi onal
energy or electricity to produce commodity chemicals.

Conclusions: Addressing process heat inchemical manufacturinglower costs or more advanced technology to becompe ve and scalable.
■ Carbon capture and storage (CCS) will likely prove
important to decarbonizing chemical produc on,either in the manufacture and use of “blue hydrogen”
or to decarbonize ﬂue gas post-combus on.
1

M. Garside, “Total revenue of the global chemicalindustry from 2002-2017,” Sta sta (2019), h ps://www.sta sta.com/sta s cs/302081/revenue-of-globalchemical-industry/2

Oxford Economics, 2019, The Global Chemical Industry:
Catalyzing Growth and Addressing Sustainability
Challenges, 28 p. h ps://www.icca-chem.org/
wp-content/uploads/2019/03/ICCA_EconomicAnalysis_
Report_030819.pdf

3Interna onal Energy Agency (IEA)/Organiza on for
Economic Co-opera on and Development (OECD), “The
Future of Petrochemicals: Towards a more sustainable
plas cs and fer lisers—Execu ve Summary,” IEA
Publica ons (2018), h ps://webstore.iea.org/
download/summary/2310?ﬁleName=English-FuturePetrochemicals-ES.pdf

4

Xing Zhang, “Visi ng the World’s Biggest Single
Coal-to-Liquid Project in Yinchuan, China,” IEA Clean
Coal Centre (2017), h ps://www.iea-coal.org/
visi ng-the-worlds-biggest-single-coal-to-liquid-projectin-yinchuan-china/■ Chemical produc on, including reﬁning, emits

substan al CO2 from heat—roughly 50% of theemissions from chemical produc on result fromproduc on of heat.
■ Almost all heat used in chemical produc on isprovided by natural gas. This suggests that the easiest(near-term) subs tu on op ons come from lowcarbon gas fuels, including decarbonized hydrogen andbiogas.
■ Medium- and long-term approaches require muche

From Katelhon et al.’s analysis of full subs tu on of electrochemicalroutes: “If all addi onal electricity were provided by renewableenergy, the amount of renewable energy required for the full-scale
introduc on of CCU would correspond to 126% and 222% of current
targets [sustainable development scenario of IEA (31)] for the global
renewable electricity produc on in 2030 for the low-TRL and the high-TRL
scenario, respec vely… the need for a further expansion of renewableelectricity produc on capaci es is likely to be a limi ng factor for CCU
in the chemical industry.” (h ps://www.pnas.org/cgi/doi/10.1073/
pnas.1821029116)23
50

December 2019

5

“India’s RIL coke gasiﬁers aid petrochemical strategy,”
Argus Media Group (2019) h ps://www.argusmedia.
com/en/news/1958372-indias-ril-coke-gasiﬁers-aidpetrochemical-strategy

15

Zachary J. Schiﬀer and Karthish Manthiram,“Electriﬁca on and Decarboniza on of the Chemical
Industry,” Joule, (2017), h ps://www.sciencedirect.
com/science/ar cle/pii/S2542435117300156.

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USGS, 2019, 2016 Minerals Yearbook: Nitrogen,h ps://prd-wret.s3-us-west-2.amazonaws.com/assets/palladium/produc on/atoms/ﬁles/myb1-2016-nitro.pdf

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Ammonia Industry, 2016, Ammonia produc on causes
1% of total global emissions, h ps://ammoniaindustry.
com/ammonia-produc on-causes-1-percent-of-totalglobal-ghg-emissions/

ADI Analy cs, LLC, “Economic and Employment
Impacts of U.S. Methanol Industry,” Methanol Ins tute(2017), h p://www.methanol.org/wp-content/
uploads/2017/06/Uday-Turaga-Domes c-MethanolIndustry-Resurgence-1.pdf

17

Marc Alvarado, “Methanol,” Methanol Ins tute(2016), h p://www.methanol.org/wp-content/
uploads/2016/07/Marc-Alvarado-Global-MethanolFebruary-2016-IMPCA-for-upload-to-website.pdf

18“Methanol Produc on,” Methanol Ins tute(2016), h p://www.methanol.org/wp-content/
uploads/2016/06/MI-Combined-Slide-Deck-MDCslides-Revised.pdf

19

BioMCN, “Sales Speciﬁca on Bio-Methanol,” (2014)20

Arlene Karidis, “Enerkem to Make Methanol ThroughGasiﬁca on in Netherlands,” Waste360 (2018), h ps://www.waste360.com/waste-energy/enerkem-makemethanol-through-gasiﬁca on-netherlands

21

Khalid Mubarak and Rashid Al-Hitmi, “QAFAC: Carbon
dioxide recovery plant,” QScience (2012), h ps://
www.qscience.com/docserver/fulltext/stsp/2012/2/
stsp.2012.ccs.22.pdf

22

J. Carlos Abanades, et al., “On the climate change
mi ga on poten al of CO conversion to fuels,” Energy& Environmental Science (2017), v.10, 2491, DOI:
10.1039/C7EE02819A

23

Kätelhön, et al., “Climate Change Mi ga on Poten alof Carbon Capture and U liza on in the Chemical
Industry.” Proceedings of the Na onal Academyof Sciences (2019). h ps://doi.org/10.1073/
pnas.1821029116.

24

Energy Futures Inita ve, 2019, Op onality, Flexibility& Innova on: Pathway for Deep Decarboniza on in
California (May 2019), h ps://sta c1.squarespace.
com/sta c/58ec123cb3db2bd94e057628/t/5ced
6fc515fcc0b190b60cd2/1559064542876/EFI_CA_
Decarboniza on_Full.pdf

25

Materials Economics, 2019, Industrial Transforma on
2050: Pathways to net-zero emissions from EU heavy
industry, 208p. h ps://materialeconomics.com/
publica ons/industrial-transforma on-2050

26

Sandalow, David, Roger Aines, Julio S. Friedman, Colin
McCormick, and Sean T. McCoy, “Carbon Dioxide
U liza on (CO U): ICEF Roadmap 2.0.” Tokyo, Japan:
Innova on for Cool Earth Forum (2017), h p://www.

8

9

10

11

US EPA, 2009, Technical Support Document for
the Ammonia Produc on Sector: Proposed Rulefor Mandatory Repor ng of Greenhouse Gases,
Oﬃce of Air and Radia on, h ps://www.epa.gov/
sites/produc on/ﬁles/2015-02/documents/ _gtsd_ammonia_epa_1-22-09.pdf
Cédric Philibert, “Renewable Energy for Industry:
From green energy to green materials and fuels,” In
Insight Series 2017 – Renewable Energy for Industry,(2017), h ps://webstore.iea.org/insights-series-2017renewable-energy-for-industry
Smil, Vaclav. “Enriching the Earth: Fritz Haber,Carl Bosch, and the TransformaƟon of World Food
ProducƟon.” MIT Press (2001). p. 358. ISBN 978-0-26269313-4.
The European Chemical Industry Council (CEFIC),“European chemistry for growth: Unlocking acompe ve, low carbon and energy eﬃcient future,”
CEFIC (2013), h ps://ceﬁc.org/app/uploads/2019/01/
Energy-Roadmap-The-Report-European-chemistry-forgrowth_BROCHURE-Energy.pdf

12Interna onal Energy Agency (IEA), “The Future of
Petrochemicals: Towards more sustainable plas cs andfer lizers (Full Report)” IEA (2018), h ps://www.iea.
org/petrochemicals/

13

G. Ertl , Surface Science and Catalysis: ”Studies on the
Mechanism of Ammonia Synthesis: The P. H. Emme
Award Address. (1980) In: Catalysis Reviews. 21,
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14“Methanol Market: Global Industry Trends, Share, Size,
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source=GN&utm_medium=PressRelease&utm_
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icef-forum.org/pla orm/upload/CO U_Roadmap_
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30European Commission (EC), “The poten al for CCS and
CCU in Europe. Report to the thirty second mee ngof the European Gas Regulatory Forum 5-6 June2019”, European Gas Regulatory Forum, Madrid, Spain
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to All Electric Ammonia Plants,” NH3 Fuel Associa on,
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energy-transi ons.org/mission-possible

29

52

December 2019

CHAPTER 4INNOVATIONPATHWAYS
Innova on in industrial heat is one of the more diﬃcult
topics in climate change mi ga on, in part due to thelarge number of processes that must be improved.
Industrial heat is deeply embedded in our economy
and implemented in diverse processes. It is much lesssuscep ble than electricity or transporta on to majorchanges in the way energy is delivered, rather than how
it is used. The use of hybrid approaches, such as carbon
capture and storage (CCS) with par al biomass use toimprove the overall carbon footprint, may be vital tosuccessful decarboniza on of industrial heat.
In addi on to the speciﬁc op ons outlined in theprevious chapters, four very diﬀerent innova on
pathways appear likely to be broadly useful for a variety
of industries:
1. Revising the fuel mix to provide low-carbon- or zerocarbon-footprint fuels without major changes in theindustrial process.
2. Improving the way heat is applied in processes,
including heat storage.
3. Hybrid approaches, including CCS with process
improvements and nega ve emissions technologies
that remove the CO2 at sites remote from theindustrial facility.
4. Cross-cu ng systema c changes in hydrogen andbiomass supply that address mul ple industry
sectors.

Delivering zero-carbon fuels via existing
infrastructure
Gas
Today’s natural gas system powers much of the mosteﬃcient industries in the developed world. Most
discussions of a completely decarbonized world
assume that we stop using natural gas and accordingly
abandon that infrastructure. However, in many areas
the gas distribu on grid is a massive distribu on systemalready in place—for instance, in the Los Angeles area

53

there are 100,000 miles of pipeline feeding residen al,commercial and industrial clients.
Currently a small amount of renewable natural gas is
being put into the gas systems in Europe and the US.
Created mainly from anaerobic diges on of waste, likesewage and agricultural waste, using this gas creates anearly carbon-free combus on opportunity. Denmark’s
gas grid has about 50% biomethane content and is
projected to be 100% renewable by 2035. This is a very
high percentage, reﬂec ng an availability of manureand bioenergy crops that is unlikely to be met in othercountries. Recent es mates of the renewable natural gas
capacity of California, for instance, place the total at no
more than 20% of today’s total while using only waste
resources (there is no current energy crop contribu on
to renewable natural gas in California).
As electriﬁca on proceeds in homes and commercial
facili es, the total amount of natural gas used will drop,
making it possible for a higher percentage of the total
to be renewable. By adding power-to-gas systems thatconvert electricity into either hydrogen or methane,na ons may be able to provide a large propor on of theindustrial need for gas via renewable sources. Current
es mates of the allowable percentage of hydrogen ina natural gas system vary widely, depending on issuesof corrosion. In 2018, the GRHYD project in France(Ges on des Réseaux par l’injec on d’Hydrogène pourDécarboner les énergies [grid management throughthe injec on of hydrogen for energy decarboniza on])began blending 6% hydrogen into the natural gas grid
and will test up to 20%.1 Also, whether hydrogen can be
stored in geologic natural gas sites is not known. An R&D
eﬀort to determine these limits is needed. A signiﬁcantlimita on on this op on is the maintenance cost of thegas grid, which presumably must be shared among fewer
users while not changing the more expensive aspects ofthe system. A transi on plan for such a future must be
developed.
If hydrogen at high levels is not permissible in exis ng
gas systems, it could be converted into methane byreac on with CO2. The Saba er process is in use in ademonstra on facility that Audi operates in Germany
to make renewable natural gas.2 An issue with thisapproach is that it creates heat from the exothermic
reac on that must be used if the overall energy balanceof the system is to be reduced. Several research groups
are also pursuing biological systems to directly convert
December 2019electricity into methane via microbial popula ons, led
by Germany’s Electrochea.3 They are conduc ng a smallscale demonstra on at the Na onal Renewable Energy
Laboratory in the US, with promise for direct conversionof renewable energy into methane. This technology useshydrogen and CO2 as the feed for microbes that convert
the gases into methane. When using electrochemical
genera on of hydrogen, the process is about 50%
energy eﬃcient at conver ng electricity into methane.
Obviously, this s ll requires an eﬃcient carbon-freehydrogen source.
Like the Saba er process, near-term methods of u lizing
the exis ng gas grid involve hydrogen, either directly or
as fuel to make other energy carriers, such as methane
and ammonia. New means of crea ng hydrogen are also
in development beyond the green and blue hydrogenmen oned earlier. Methane pyrolysis, where hydrogenis stripped from methane at temperatures of 800-1100°C, is a promising technique that leaves solid carbon asa byproduct or waste to be landﬁlled.4 Two methods
are currently in considera on. In the older method,
methane is bubbled through molten metal, withhydrogen gas and par culate carbon emi ed from thetop. A newer development by BASF uses a proprietarycatalyst in a ﬂow-through system in which hydrogenexits the top and carbon falls out of the bo om of thereactor.5 Rela vely high carbon eﬃciencies are reported
for both systems (above 90%), but the energy demandis substan al, with an es mated eﬃciency of 55% by
Wegen et al.4 However, as compared to systema cchanges in industrial processes, this energy cost could
make sense at industrial scale. Detailed system analysis
is required.
Hydrogen proponents point out that one of thesigniﬁcant drawbacks to natural gas usage—leakage
from pipelines—could be signiﬁcantly limited bytransforming the natural gas to hydrogen near its
source and transmi ng hydrogen in the pipelines witha much smaller impact on climate if leakage occurs.
Combina ons with solar thermal—both as a hightemperature-process heat source for the methane
pyrolysis and as a heat storage system for combining
other renewable energy—are an a rac ve innova on
pathway.
This innova on pathway envisions a mix of gases,
renewable natural gas and hydrogen, playing the rolethat natural gas does today. Other promising technicalapproaches include low-cost electrolyzers and nuclear
54

H2 produc on (e.g., Sulfur-Iodine cycle discussed
previously). Hydrogen produc on may become global
as well, with both Australia6 and the UAE consideringlarge-scale export of hydrogen by refrigerated tanker.
France announced its Hydrogen Deployment Plan for
Energy Transi on in June 2018, the targets of which
include 20-40% low-carbon hydrogen use in industrial
applica ons of hydrogen and a reduc on in electrolysis
cost €2-3/kg by 2028.1 This innova on pathway will
require considera on of the needs for infrastructure
to accommodate that scale of import, but since many
major industrial facili es are near ports, this could be a
drama c change in world energy markets.
An innova on pathway of major hydrogen produc on,
from zero-carbon natural gas conversion or fromrenewable energy followed by liquiﬁed hydrogentransport over the high seas, could drama cally change
the future of industrial heat sources but will requirea massive new set of infrastructure for hydrogengenera on and transport, while allowing exis ng
industry to keep very similar processes and procedures.
In a ﬁrst-of-its-kind design, Kawasaki Heavy Industries(KHI) in collabora on with Shell, is developing a purposebuilt liqueﬁed hydrogen tanker capable of shipping
1250 m3 (88,500kg) liquid hydrogen (LH2) from Victoria
to Japan in 16 days. According to the New Energy
and Industrial Technology Development Organiza on(NEDO), the carrier is forecast to be ready to make its
ﬁrst shipment in 2020/2021. These sorts of op ons
will signiﬁcantly increase the costs of gas but may s ll
be drama cally less costly than wholesale revision ofindustrial processes. An important innova on pathway is
to make a detailed comparison of the transi on costs todetermine if large-scale eﬀorts at rethinking the use ofgas for industrial purposes is warranted in a low-carbon
future.
Hydrogen requires another set of safety and use
approaches if it is to be used in gas pipelines, including
material compa bility, ﬂame awareness (hydrogenis invisible when burning) and odoriza on. Gasket
materials need to be evaluated, and geologic storage ofhydrogen gas needs to be experimentally demonstrated.

Other biofuels
Biomass provides a commonly used approach to replacefossil fuels. Solid forms like torreﬁed biomass can beused directly in place of coal. Bio-char, while commonly
considered as a soil amendment, could be used instead
December 2019

as a fuel. These op ons are par cularly interes ng forthe calciner in cement plants, which are renowned fortheir ability to burn almost any fuel. Bio-oil is created by
fast pyrolysis of biomass and can also be used as a liquid
fuel in many systems that use hea ng oil today, althoughsome hydrogena on is required to stabilize the bio-oil.
These op ons suﬀer from the same availability issues as
renewable natural gas. In most integrated assessment
model evalua ons, there is insuﬃcient biomass tomeet all the compe ng needs in a decarbonized world.
A major innova on pathway issue is evalua ng thecompara ve costs of transi on for using this resource
in industry. Because these fuels can be used with only
minor process changes, they are a rac ve for someindustrial sectors as a means to decarbonize. The
scale is realis c. It takes about 200 kg of coal to create
one ton of cement. Replacing that coal with torreﬁed
biomass—notwithstanding constraints on fuel hea ng
value in the kiln—would require about 2-3 mes asmuch original dry biomass. In California, that would
require about 4-5 million tons of biomass to fuel thestate’s cement produc on. Recent es mates indicatethat about 70 million tons of dried biomass could
be obtained from waste sources in California.7 Using
torreﬁed biomass to eliminate the energy emissions (butnot the calcining emissions) would reduce CO2 emissions
from cement produc on by about 50%. Thus, biomass
for replacement of coal industrial heat, par cularly incement produc on, which is rela vely tolerant of fuelquality, is an innova on pathway that can be consideredalong with the use of biomass to produce liquid fuels.
The major innova on needs in this area are to develop
eﬃcient means of conver ng biomass to transportable
forms without more carbon emissions—for instance,
torrefac on is o en done today with external natural
gas hea ng. Autopyrolysis systems that use the biomass
itself to provide heat would avoid those emissions.
A major innova on issue is the extent to which na ons
may choose to become biomass exporters to provide
industrial heat sources. The opera ons at the Drax
power sta on in England have demonstrated that alarge-scale, long-distance biomass supply chain can becreated and sustained—although the carbon emissions
from this supply chain may be substan al. As withhydrogen, new infrastructure pathways could makedelivery of biomass as an industrial heat source a global
commodity.

55

Of great interest in this area is the possibility of
combining biomass heat sources with CCS, yielding a
por on of nega ve emissions. In this scheme a cementkiln could rela vely easily operate the calciner onbiomass fuel, while capturing and sequestering somefrac on of its total CO2 emissions and thereby oﬀse ng
all of its emissions. For many industrial processes, par alcapture on exis ng equipment is much more prac calthan 100% capture.

Innovation Agenda for Zero-Carbon Fuels
Innova on pathways for zero-carbon fuels focus
on produc on of the fuels, systema c transportand distribu on issues associated with large scale
replacement of natural gas by renewable gases, andmore focused replacement of coal by biomass.
■ Evalua on of the cost beneﬁts and life cycle of thereplacement strategies■ Evalua on of transporta on and distribu on methods
and costs■ Development of safety and use schemes■ Improved produc on schemes and assured zerocarbon technologies■ Evalua on of materials for transport and storage ofhydrogen, including odorants and ﬂame visualiza on.
■ Evalua on of the ming and staging of adding
frac onal amounts of zero-carbon fuels to industrial
systems.

Improved heat application
Electrification
Use of electricity to provide heat in industrial processes
requires massive changes in industrial equipment as
discussed in Chapter 2C. Three major issues arise:
1. There has been li le R&D on massive electriﬁca on
op ons.
2. Transfer of heat in systems such as blast furnaces is afunc on of the physical dimension of the coke, which
supplies support as well as heat.
3. Electriﬁca on can rarely be done in the context ofexis ng equipment.
Dealing with the second issue is par cularly diﬃcult. The
highly tuned nature of the chemical reac ons and heattransfer in a system like a blast furnace makes it unlikely
to be decarbonized by either electricity or biomass;
the most likely approach is CCS (below) or change to
December 2019

completely diﬀerent processes where the chemicalreducing poten al of either hydrogen or biomass can beu lized.
The third issue in the list above is more amenable to an
innova on pathway, as discussed in the electriﬁca on
chapter. The applica on method for electricity toindustrial processes can be changed drama cally byusing direct microwave or induc ve hea ng to deposit
energy. Each industrial process requires R&D toiden fy the most eﬃcient electrical energy deposi on
method, and there is rela vely li le room for genericdevelopment. Each industry must be considered and the
choice of new electrical hea ng method evaluated. Thisrequires very diﬀerent approaches than for revisions to
the gas grid, since every industrial process will requireslightly diﬀerent innova on pathways.
Improved electriﬁca on pathways have had extremelyli le research a en on. Basic understanding of howheat is deposited in material, skin depths for dielectrichea ng, changes in resistance with chemical changes,
and safety issues have been evaluated at small scale but
rarely at the size of industrial processes. Na onal-level
programs addressing key industries are required to ﬁll
this gap.

Solar and stored heat
Many research teams are focused on solar thermal
applica ons to industrial processes. With focusing
mirror systems that can readily exceed 1,000 °C, thisis academically a rac ve but requires appropriate
heat transfer mechanisms to move the heat fromthe mirror system to the industrial process. Typically,
industrial processes at this temperature use direct
combus on hea ng, so there is no exis ng art aroundthe movement of heat at these temperatures. However,the demonstrated ability to store heat in solar-thermal
electricity genera on makes that op on interes ng toindustry.

Reducing or eliminating heat in processing
An obvious eﬃciency pathway is to develop catalysts
that replace heat as a means of speeding chemical
processes. Par cularly in the chemical industry, heathas been the method of choice for speed. Innova onin catalysis will be valuable there. A major innova on
would be the replacement of thermochemical
produc on systems with electrochemical methods,
par cularly those that begin with CO2. A growing
56

literature (e.g.,8,9) indicates that this is possible, butcurrently will use an enormous amount of electricity.
Innova on around more eﬃcient electrochemical
processes, par cularly reduc on in overvoltage andresistance losses, is needed.

Innovation agenda for improved heatapplication
Innova on pathways for electriﬁca on focus on thedetermina on of the most cost-eﬀec ve approaches.
■ Evalua on of the most appropriate electric energy

deposi on methods by industry.
■ Improving combus on systems, burners andcombustors.
■ Evalua on of the compara ve capital costs ofreconﬁguring each industrial process, which will bevery substan al and must be weighed against CCS orzero-carbon fuel op ons. Among the key industrial
processes which will have signiﬁcantly specialized
electriﬁca on methods are:
4. Calcining
5. Reﬁning
6. Dis lla on
7. Glass produc on
8. Removing impuri es from metals
9. Ceramics produc on
10. Drying■ Development of more eﬃcient high-temperature heatstorage.
■ Development of new electrochemical methods that

require much less electricity than today’s incipient
methods.
■ The innova on need for solar and stored heat isaround be er heat transfer systems and ﬂuids formoving heat at those high temperatures.
■ The innova on agenda for reduced heat focuses on
new electrochemical methods that require much lesselectricity than today’s incipient methods.

Carbon capture and storage (CCS) and hybrid
approaches
Carbon capture and storage
CCS has not been extensively applied to industry. In
Chapter 2D we outlined the major opportuni es, which
are focused on R&D to demonstrated speciﬁc CCS
methods for industry. The major challenges are mul ple
December 2019

small emi ers in single facili es like reﬁneries and theneed for speciﬁc process designs for each industry
type. A substan al demonstra on program is required
to reduce the technology risk for each industry’s CCS
approach.
Applica on of CCS to industry will also require thecollec on and geologic storage systems that electric
power systems need. This is an opportunity for na onal
carbon management programs to consider infrastructureneeds like pipelines, but these needs are not speciﬁc toindustrial applica on of CCS.
Oxygen-ﬁred systems are a likely component ofdecarbonized industrial heat. The produc on andtransporta on of oxygen for these systems is asigniﬁcant challenge, also not unique to this report, butof a similar scale to the produc on of hydrogen in termsof impact and complexity.

Hybrid approaches
Throughout this report we have highlighted the
diﬃculty of decarbonizing industrial heat due to thegreat variety of systems that must be decarbonized
and the limited number of op ons for performingthat task. Our discussion has focused on individual
solu ons—hydrogen, electriﬁca on, biofuels, etc.—but
hybrid approaches may also be very useful. These
include par al fuel decarboniza on, par al changes
and electriﬁca on of the produc on environment, andpar al addi on of CCS to par cularly suscep ble parts ofthe produc on scheme that con nue to use fossil fuels
because of their par cular suitability. These solu ons
may start as par al decarboniza on that is highly costeﬀec ve and evolve into full decarboniza on as mul ple
approaches are applied. For instance, improved burner
technology may be incorporated as par al hydrogenor renewable gas become available, or electriﬁca onof small-scale heat sources may occur inside reﬁneries
while larger units like steam methane reformers depend
upon CCS.
Hybrid approaches may be par cularly useful in
combining CCS on exis ng equipment, with par al
biofuel subs tu on on that exis ng equipment. Becauseof the carbon neutral nature of the biofuel, doing
par al carbon capture can oﬀset the emi ed fossil-fuelcomponent, resul ng in net zero emissions. Such
schemes with a biomass component have many ﬂavors,
including gasiﬁca on of biomass to hydrogen, capturing
57

and storing CO2 before it reaches the industrial facility.
Bioenergy with CCS (BECCS) is a likely component ofhybrid systems.
Timing issues will be important for hybrid systems. For
instance, 10% subs tu on of hydrogen is straigh orward
in most burner systems, but higher amounts eventuallyrequire new burners and new delivery materials.
Similarly, the other uses of a gas grid need to beconsidered—will industry share transi on costs withhome and business gas use, or will those be electriﬁed
independently?
The ﬁnal novel hybrid pathway is to use nega veemissions—primarily direct air capture—to oﬀset
industrial emissions. At some level it is extremely likelythat this will be needed, as it is clear that complete
decarboniza on of industrial heat is diﬃcult. Today
costs for direct air capture systems are approximately$600/ton CO2. It is widely expected10 that these costs
can be reduced to the vicinity of $200/ton, and thedevelopers believe that $100 can be obtained. For anindustrial facility opera ng on exis ng equipment with90% capture, it may be cost-eﬀec ve to capture theremaining 10% of the emissions at a large air-capture
facility shared with other facili es.

Innovation agenda for CCS and hybrid
approaches
CCS needs speciﬁc design studies for applica on
to industrial streams. The opportunity for hybrid
approaches in this area is large, requiring thedevelopment of robust cost and life-cycle models to
es mate the costs of combined approaches, including
those that use shared facili es. Another innova on
pathway is to consider if there are op ons to combine
direct air capture, which is very dependent on heat,with industrial waste heat sources.11 While the ﬁrst
priority should always be to reduce waste heat to thegreatest extent possible, where this waste heat is of alow quality and not economically feasible to recover, it
could be used for solid-sorbent-based processes (e.g., in
combina on with heat pumps). This could be par cularly
useful to deal with emissions from the “use phase” ofproducts that are not amenable to CCS. The innova on
agenda is to consider the capital and opera ng costcross-over point where direct air capture becomes themore eﬀec ve way to achieve addi onal decarboniza on
and whether large-scale systems could be u lized topolish the emissions of en re industrial sectors.
December 2019

Near term
Evaluate cost

Zero Carbon beneﬁts andtransport
Fuels
costs

Mid term

Long term

Research
power-to-gas(H2 and CH4)
technologies

Develop safety
methods for H2

Improve
renewable
Determine pipeline
natural gas &H2 limits
H2 produc on
methods

Improve exis ng
combus on
systems

Develop more
eﬃcient heatstorage andtransport

Improved
Heat
Applica on

Evaluateelectricity
deposi on
methods

Evaluate costsof reconﬁguring
processes

HybridDesign CCS
for speciﬁc
industries

Evaluate cost
Evaluate costs of Test hybrid
and lifecycle for oﬀ-site carbon
biomass/capture
hybrid processes management
systems

CrossCu ng

Evaluate costs
and impactsof large-scalehydrogentransport

Evaluate costs
and impactsof large-scalebiomasstransport

Determine
where tocommit exis ng
biomassresources

Develop biomass
Demonstrate large- systems that are
scale hydrogencarbon-nega veshipping
across the lifecycle

Improve H2materials fortransport
and safety

Developlarge-scalehydrogenproduc onandtransport

Table 4-1. Major Innova on Pathways

Cross-cutting issues: system innovation andtransportation pathways for biomass andhydrogen
As we move toward a decarbonized industrial system,
society will have to make choices in two major areas:
how to use available biomass, and whether to use
renewable power to create gas that can be distributed inexis ng networks.
As we saw in the biomass chapter, it is possible toimagine powering a substan al por on of tomorrow’s
industry with biomass, but that use would be incompe on with liquid fuels, pure nega ve emissions
and, of course, the uses for biomass today, including
cooking and hea ng. Most authors today prefer toconsider only the amount of biomass that would beavailable from waste and supplies of biomass that do notplace pressures on the availability of food or ecosystemservices. That amount of biomass is therefore limited
but extremely valuable from a climate perspec ve.
Today there is no clear metric to decide where tocommit our biomass resources—crea ng such a metricis a major innova on pathway. Interna onal agreement
will be important, since the Drax experiment in the UK
has demonstrated that large-scale biomass shippingis feasible, even if it does not achieve the desired
economic and climate impact.
58

Power-to-gas is a second pathway that requires crosscu ng development and agreement. Will we a empt
to repower industry with a zero-carbon gas system?
What methods would be used to create the hydrogen or
renewable natural gas? Today there is no clear economic
pathway to evaluate this op on, mainly because
a en on has been focused on the electric power sector.
As renewables become cheaper, use of hydrogen andrenewable natural gas is less a rac ve for electricity
genera on but may s ll be of primary importance forindustry. However, a reduced gas grid for industry use
s ll needs to be maintained at a considerable cost. A
clear understanding of what it would take to create azero-carbon gas system is necessary to make it possible
to consider this op on.
And just as ocean-shipping of liquid natural gas (LNG)
rapidly changed the energy world, worldwide shippingof biomass and hydrogen could have a similar eﬀect forindustry. Na ons and regions could choose to commit
resources to large-scale produc on of these heatsources and send them by ship to industrialized regions.
The oﬀse ng eﬀects of inves ng in new infrastructure
to ship these products and of maintaining expensive
industrial facili es with minimal changes could makethat an economic- and climate-appropriate solu on formany forms of industrial heat. The me to evaluate theDecember 2019

possible impacts of such choices is now, before massive
investments are made.
These innova on pathways are combina ons of appliedand basic research, reﬂec ng the deep need for new
processes and approaches in industry. Past roadmaps
have called out separate innova on agendas for these
topics, but the need for broad changes suggests a great
number of basic and applied topics. We must movefurther down the innova on pathways before there areclearly deﬁned needs in speciﬁc areas.
Analysis and modeling are key elements of all these
innova on pathways and are more important in the
hybrid and new-fuel scenarios such as shipping large
amounts of biofuel long distances. Indices of successare needed, and tools to compare op ons across broad
swaths of industry must be developed. This need forcompara ve and planning tools is the founda onal
element of all the innova on pathways described here,
as is the need for broadly applicable data about heat use
in industry. Without these, innova on cannot proceed in
the most eﬃcient and diverse ways.
1

IEA (2019) Hydrogen, tracking clean energy progress.
h ps://www.iea.org/tcep/energyintegra on/hydrogen/2

Bullis, Kevin (2013) Audi to Make Fuel Using Solar
Power MIT Technology Review, h ps://www.
technologyreview.com/s/510066/audi-to-make-fuelusing-solar-power/

3

Hafenbradl ,Doris and Mich Hein (2015) Power-to-Gas– A solu on for energy storage. Gas for Energy, Issue 4
2015. h ps://www.gas-for-energy.com/ﬁleadmin/G4E/
pdf_Datein/g4e_4_15/gfe4_15_ _Hafenbradl.pdf

59

4

Wegen, L. et al. (2017) Methane cracking as a bridge
technology to the hydrogen economy. Energy Volume
42, Issue 1, 5 January 2017, Pages 720-731 h ps://doi.
org/10.1016/j.ijhydene.2016.11.029

5

Houlton, Sarah (2019) Curbing industry carbon
emissions. BASF methane pyrolysis h ps://www.
chemistryworld.com/news/curbing-industrys-carbonemissions/3010737.ar cle ChemistryWorld July 16,
2019.

6

CSIRO (2019) Australia hydrogen roadmap. h ps://www.csiro.au/en/Do-business/Futures/Reports/
Hydrogen-Roadmap

7

Williams, Robert B, Bryan M. Jenkins Steve Ka a(2015) An Assessment of Biomass Resources in
California, 2013 (DRAFT) Public Interest Energy
Research (PIER) Program INTERIM PROJECT REPORT.
h ps://biomass.ucdavis.edu/wp-content/uploads/
CA_Biomass_Resource_2013Data_CBC_Task3_DRAFT.
pdf

8

P De Luna, C Hahn, D Higgins, SA Jaﬀer, TF Jaramillo,
EH Sargent (2019). What would it take for renewably
powered electrosynthesis to displace petrochemical
processes? Science 364 (6438).

9

A Kätelhön, R Meys, S Deutz, S Suh, A Bardow (2019)
Climate change mi ga on poten al of carbon capture
and u liza on in the chemical industry Proceedingsof the Na onal Academy of Sciences 116 (23), 1118711194

10

Pacala et al. (2018) Na onal Academies of Sciences,
Engineering, and Medicine. Nega ve Emissions
Technologies and Reliable Sequestra on: A Research
Agenda. Washington, DC: The Na onal Academies
Press. doi: h ps://org/10.17226/25259.

11

Jennifer Wilcox Personal Communica on (August
2019)

December 2019

CHAPTER 5
POLICY
Policy tools are essen al for decarbonizing industrial
heat, both in the short- and long-term. This chapter
discusses the ra onale for policy support and range ofpolicy tools available.

Rationale
The concentra on of carbon dioxide (CO2) in theatmosphere is higher than at any me in human history.
Human ac vi es, including fossil fuel combus on anddeforesta on, con nue to increase that concentra on.
The impacts include heat waves, more severe andfrequent storms, sea-level rise, forest loss, and ocean
acidiﬁca on.1
These problems are classic “externali es.” Market
forces alone will not control CO2 emissions adequately,
since emi ers of CO2 do not bear the full costs of theiremissions. Government policies are essen al.2,3
Reﬂec ng this, more than 175 countries have ra ﬁedthe Paris Agreement, which requires each of themto regularly report on their policies for controllingemissions of CO2 and other heat-trapping gases. The
Paris Agreement calls for “holding the increase in the
global average temperature to well below 2 °C (3.6 °F)
above pre-industrial levels,” “pursuing eﬀorts to limit
the temperature increase to 1.5 °C (2.7 °F) above preindustrial levels” and achieving net zero emissions in thesecond half of this century.4

and others, many governments will be reluctant to impose
policies that disadvantage domes c companies in theseindustries in interna onal trade or might lead companies
to shi produc on abroad. This will constrain the set ofpoli cally acceptable policy responses in many cases.
Many policy tools are available to help withdecarbonizing industrial heat. These are discussed
below.

Policy tools
Government support for R&D
Na onal governments spend roughly $15 billion annually
on R&D for clean energy technologies. These programs
have played important roles in the development ofcountless technologies in recent decades.8
Several recent government R&D programs have targeted
innova ons in industrial heat. These include:
1. A US Department of Energy (DOE) ARPA-E program
on novel heat-exchanger technologies.9,10
2. A French Na onal Center for Scien ﬁc Research
program on high-temperature solar-heated reactors
for industrial produc on of reac ve par culates.11
3. A European Commission program on integra onof solar heat in industrial processes of the agrofood industry.12 Increased funding for R&D
on decarbonizing industrial heat could speed
deployment and yield important beneﬁts. This
roadmap iden ﬁes a number of priority areas for
R&D investment. (See Chapter 4 above.)

Decarbonizing industrial heat is an important partof any strategy for mee ng those goals. As noted inprevious chapters, roughly 10% of global CO2 emissions
come from produc on of industrial heat—more thanemissions from cars and planes.5,6,7 Achieving the goals
set forth in the Paris Agreement would be diﬃcult if not
impossible without cu ng emissions from industrial
heat produc on.

In December 2015, heads of state from more than 20
countries announced Mission Innova on, a coali on
dedicated to accelera ng clean energy innova on.
Member governments (including Japan, China, theUnited Kingdom, Germany and Saudi Arabia) pledged
to double R&D on clean energy within ﬁve years.
The increase in R&D budgets from these countries
in the years ahead oﬀers an opportunity to increase
government R&D funding for decarboniza on ofindustrial heat, including in the areas above.

This will present signiﬁcant challenges. Several industries
with high CO2 emissions from heat produc on (including
iron, steel and some chemicals) are strategicallyimportant to host governments and exposed tocompe on from foreign trade. Some of these industries
provide considerable employment. For these reasons

The US helped launch Mission Innova on and remains amember. Although the US is unlikely to fulﬁll its overall
doubling pledge under the Trump administra on, the US
Congress has increased funding for energy eﬃciency andrenewable energy programs at the US DOE in each of thepast several years.13

60

December 2019

Government Procurement
In many countries, government procurement makes
up more than 10% of GDP.14 Government purchases
can play an important role in star ng and building
new product markets. First, government purchase
contracts can provide developers and manufacturersof new products with an assured market, which can beespecially important in securing debt capital. Second,
government purchases can help establish standard
technical speciﬁca ons for new products, which can help
catalyze eﬃcient supply chains.
Governments are major purchasers of steel, cement,chemicals and other products that require heat in
the manufacturing process. Procurement standards
that give preferences to products with the lowest
embedded carbon content could drive signiﬁcantchanges in industrial behavior. Procurement standards
that authorize purchasing oﬃcials to base decisions
on lifecycle carbon emissions of products could do thesame. California’s Buy Clean statute is a leading exampleof legisla on that directs authori es to pay a en on toclimate impacts in the procurement process. Similarly,
procurement regula ons could give preferences to
products manufactured without the use of fossil fuels togenerate heat.

Fiscal subsidies
Decarbonizing industrial heat will impose costs on
aﬀected businesses. Capital expenditures may berequired to retroﬁt facili es or build new facili es. The
cost of physical assets may need to be wri en oﬀ if
those assets are re red before the end of their useful
lives. Opera ng expenses may increase if inputs are
more expensive than current fossil fuel inputs.
Government policies can help to reduce those costs withﬁscal subsidies. These can take several forms. Leading
op ons are discussed below.
A. Tax Incen ves. Tax incen ves can play an importantrole in spurring deployment of clean energy
products. In Norway, for example, generous tax
incen ves helped plug-in electric vehicles capture
50% of new car sales in 2018.15 In the US, federal
tax incen ves have played an important role inpromo ng deployment of solar and wind power.
Such incen ves could play a similar role in promo ng
alterna ves to the use of fossil fuels in industrial
heat produc on. There are many possible structures
61

for such tax incen ves. They include:■ Investment tax credits: Governments could
provide businesses a tax credit for a percentageof the capital costs incurred in transi oning to
low-carbon industrial heat. (This would be similar
to the US federal government’s investment tax
credit for solar power, which has historicallyprovided a tax credit of 30% of the cost of any
solar installa on in the US.)
■ Produc on tax credits: Governments
could provide a tax credit for any products
manufactured using low-carbon industrial heat.
(This would be somewhat similar the US federal
government’s produc on credit for wind power,
which provides a tax credit based on the kWh ofwind power sold at a facility.)■ Waiver of sales, value-added taxes or importtaxes: Governments could waive taxes thatwould otherwise be imposed on any products
manufactured using low-carbon heat. (This would
be similar to Norway’s incen ves for electricvehicles, which include waivers of import andsales taxes that apply to conven onal vehicles.)B. Grants. Grants are among the most direct ways
to provide ﬁnancial support for the low-carbon
transi on. Grant programs are widespread in many
countries, o en to assist in deployment of ﬁrst-ofa-kind or early-stage technologies. Governments
could provide grants to help defray the capital costs
associated with the transi on to decarbonizing
industrial heat processes.
C. Loan guarantees. Cu ng the cost of debt capital canhelp make a project ﬁnancially viable. Government
loan-guarantee programs seek to do that by reducing
risk to lenders, resul ng in lower borrowing costs.
The US DOE’s loan-guarantee programs helped
launch the u lity-scale solar industry in the US,among other successes. Loan guarantees for thecapital expenditures required for decarbonizing
industrial heat could signiﬁcantly speed deployment.
D. Feed-in tariﬀ for renewable natural gas. A
feed-in-tariﬀ provides a guaranteed price for anenergy product for a set number of years. This candrama cally improve bankability of projects and help
to scale up produc on. Feed-in-tariﬀs have beenused to help launch markets for solar power andother renewables around the world. Germany and
the Netherlands have implemented feed-in tariﬀs for
December 2019biogas. This is an important tool for helping promote
produc on and use of renewable natural gas.
E. Contracts for Diﬀerences. Contracts for Diﬀerences
are used in the United Kingdom to support lowcarbon electricity genera on. In a Contract forDiﬀerences, the government guarantees a power
supplier will receive a stated amount, covering thediﬀerence between that amount and the amount thepower supplier actually receives. This policy could be
used to help support deployment of low-carbon heattechnologies as well.16

Low-carbon product standards
A low-carbon product standard sets a limit on
the product’s life cycle emissions. Low-carbon
fuel standards—the leading example of such an
approach—have been adopted in California, Oregon,
Bri sh Columbia and the European Union. California’s
low-carbon fuel standard requires producers of
petroleum-based fuels to reduce the carbon intensity of
their fuels 10% from 2010 levels by 2020. The EU’s Fuel
Quality Direc ve requires reduc ons of 6% in the carbon
intensity of fuels from 2010 levels by 2020.
Such standards could be applied to a range of products
currently manufactured using fossil fuels to generate
heat. The administra ve complexi es associated withsuch a program could be considerable, in part because
many of the most relevant products are inputs into otherproducts. However low-carbon product standards could
provide considerable incen ve for manufacturers to ﬁndalterna ve ways of genera ng such heat.

Infrastructure development
The transi on to low-carbon industrial heat may require
new infrastructure (such as electric transmission lines
or hydrogen pipelines). Governments can play a central
role facilita ng the development of such infrastructure
through permi ng, ﬁnancing and other measures.
Governments can also take a direct role throughdevelopment and ownership of such infrastructure
where it serves a common good—as is o en the case forroad, rail, district hea ng and water infrastructure.

Carbon prices
A price on carbon dioxide emissions, whether throughan emissions trading program or tax mechanism,
provides emi ers with an important incen ve to cut
emissions. Carbon pricing enjoys overwhelming support
62

among academic economists as the most cost-eﬀec ve
approach for addressing climate change.17
Carbon pricing con nues to grow steadily around theworld. Fi y-seven jurisdic ons covering 20% of global
greenhouse gas (GHG) emissions now have carbon
pricing ini a ves that have been implemented or arescheduled for implementa on.18,19
Unfortunately the results of those programs are
not encouraging in several respects. First, very few
carbon-pricing programs have resulted in carbon prices
suﬃcient to signiﬁcantly reduce emissions. Governments
have generally been unwilling to impose such prices,o en due to strong opposi on from the businesses andindividuals most exposed to energy price increases.
Second, programs in several jurisdic ons (including
those in Australia and several US states) have beensuspended or terminated due to changes in poli cal
leadership.
The carbon prices that might be needed to induce atransi on from fossil fuels for industrial heat produc on
are unclear. These levels likely vary considerably fromindustry to industry and even facility to facility. In theabsence of readily available subs tute processes forgenera ng heat, the carbon prices required to induce
a transi on from fossil fuels would likely be quite high.
Few if any countries have demonstrated a willingness to
set carbon prices at these levels.
Nevertheless, a growing number of businesses use“shadow carbon prices” when making long-term capital
investment decisions. (That is, the businesses apply acarbon price in calcula ng returns on capital, even if
no carbon price or a lower carbon price is imposed in
the jurisdic on in which they operate.) These shadow
carbon prices may play an important role in aﬀec ng
capital investment decisions on the margin. The
adop on of mandatory carbon pricing programs injurisdic ons around the world, even with carbon prices
at modest levels, may encourage business use of shadow
carbon prices.

Carbon tariffs
In 2017, 440 million tons of steel was tradedinterna onally. This was more than a quarter of global
produc on.20 Other products that require heat in the
manufacturing process—including some chemicals—aretraded interna onally in high volumes as well. Many
governments may be reluctant to impose costs related
December 2019to decarbonizing industrial heat on the manufacture ofsuch products, due to concerns about disadvantaging
such products in interna onal trade.
Carbon tariﬀs (some mes called “carbon border tax
adjustments”) are a tool for addressing that concern. A
country that requires its manufacturers to transi on to
low-carbon industrial heat could tax imports of relevant
products from countries that fail to do so. This could
level the playing ﬁeld, elimina ng the disadvantage
domes c manufacturers face from higher costs
associated with decarbonizing their hea ng processes.
No carbon tariﬀs have ever been adopted. There at least
three prac cal concerns with carbon tariﬀs:■ Such tariﬀs may not be legal under the rules of theWorld Trade Organiza on (WTO). As a general rule,
the WTO prohibits restric ons on the import of goods
based on anything other than a ributes of goods atthe border. (Countries are not allowed to discriminate
between goods based on characteris cs of upstream
manufacturing processes.) There are excep ons,
including some that might apply to carbon tariﬀs (suchas an excep on related to environmental protec on).
In recent years the permissibility of carbon tariﬀs
under the WTO has been debated extensively byleading trade experts. The issue has not been resolved
by a WTO tribunal.21-24■ Challenging design and administra ve ques ons must
be addressed to implement a carbon tariﬀ program.
Decisions must be made about which products are
subject to the tariﬀs. (For example: Would steel from azero-emissions steel plant located in a country withoutcarbon emissions limits be subject to the tariﬀ?)
Decisions must also be made about how to set carbon
tariﬀ levels. Depending on those decisions, extensive
data collec on and processing could be required toeﬀec vely administer the tariﬀs.
■ Although carbon tariﬀs could in theory level theplaying ﬁeld for manufacturers in their home markets,
they do nothing to help manufacturers selling abroad.
A manufacturer that incurred addi onal costs todecarbonize industrial heat processes would s ll be
at a cost disadvantage in foreign markets. Other tools,
such as cost rebates for exports, would be required toensure level playing ﬁelds abroad.

63

Mandates
Governments mandates can be eﬀec ve in helping build
markets for clean energy products. In the US, many state
governments require u li es to purchase a minimum
percentage of their power from renewable sources. In
India, a similar requirement is imposed by the Ministryof New and Renewable Energy. These requirements havebeen important to the early growth of wind and solar
power in both countries.25
Other experiences suggest cau on, however. The US
federal government mandate has required the use ofcellulosic ethanol in fuel supplies for almost a decade.
Nevertheless, the cellulosic ethanol industry remains
in its infancy and waivers to that requirement havebeen granted on a regular basis. Technology-forcing
requirements—in which governments require private
actors to meet standards that are not yet technicallyachievable—have been successful in some instances but
not in others.26
Government mandates could help spur the transi on to
low-carbon industrial heat. Governments could prohibit
the use of fossil fuels in genera ng heat in certain
industrial sectors a er a certain date, for example.
Or governments could require the use of low-carbon
industrial heat technologies a er a certain date.
Business investment in compliance strategies with suchmandates could help to spur innova on.

Voluntary industry associations
Industry associa ons such as World Steel Associa on,
World Petroleum Council, World Cement Associa on andWorld Business Council on Sustainable Development canhelp develop methods and standards for decarbonizing
industries. They can play an important role in
informa on-sharing on such topics as well. Governments
can encourage such ac vi es by hos ng mee ngs,
providing recogni on and oﬀering ﬁnancial support.

Clean Energy Ministerial
The Clean Energy Ministerial is a global forum where
major economies work together to share best prac cesand promote policies and programs that encourageand facilitate the transi on to a global clean energy
economy. A Clean Energy Ministerial ini a ve on
industrial heat decarboniza on could help to share bestprac ces and accelerate their adop on. Any country that

December 2019

par cipates in the Clean Energy Ministerial could launchsuch an ini a ve.
Decarboniza on of industrial heat is unlikely to happen
at scale as a result of voluntary measures. Policy
supports will be required for this transi on. The diversityof industries in which supports are needed complicatespolicy design and implementa on. More research,
analysis and consulta on with key stakeholders areneeded to shape the best policies to help meet thischallenge.
12

3

IPCC, 2018: Summary for Policymakers. In: Global
Warming of 1.5°C. An IPCC Special Report on theimpacts of global warming of 1.5°C above pre-industrial
levels and related global greenhouse gas emission
pathways, in the context of strengthening the global
response to the threat of climate change, sustainable
development, and eﬀorts to eradicate poverty[Masson-Delmo e, V., P. Zhai, H.-O. Pörtner, D. Roberts,
J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia,
C. Péan, R. Pidcock, S. Connors, J.B.R. Ma hews, Y.
Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M.
Tignor, and T. Waterﬁeld (eds.)]. World MeteorologicalOrganiza on, Geneva, Switzerland, 32 pp., h ps://www.ipcc.ch/sr15/
Sir Nicholas Stern, “Stern Review on the Economics of
Climate Change,” The Na onal Archives: HM Treasury,(2006), h ps://webarchive.na onalarchives.gov.uk/+/h p://www.hm-treasury.gov.uk/sternreview_index.htm
Alison Benjamin, “Stern: Climate change a ‘market
failure,’” Guardian (2007) (quo ng Sir Nicholas Stern–”Climate change is a result of the greatest market
failure the world has seen”), h ps://www.theguardian.
com/environment/2007/nov/29/climatechange.
carbonemissions

4

Paris Agreement Ar cles 2(1)(a) and 4(1)5

IEA, “CO Emissions Sta s cs: An essen al tool for
analysts and policy makers,” Site accessed 11/27/19,
h ps://www.iea.org/sta s cs/co2emissions/.

6

7

Colin McMillan et al., “Genera on and Use of Thermal
Energy in the U.S. Industrial Sector and Opportuni es
to Reduce its Carbon Emissions,” Na onal Renewable
Energy Laboratory (2016) at p. viii (industrial heatproduc on roughly 10% of total US CO emissions),
h ps://www.nrel.gov/docs/fy17os /66763.pdf
Interna onal Organiza on of Motor Vehicle
Manufacturers (OICA), “Climate Change and CO ,” OICA
(2008), h p://oica.net/wp-content/uploads/climatechange-and-co2-brochure.pdf at p.6 (cars, trucks andbuses combined are 16%).
64

8Mission Innova on, “Tacking Progress,” Site accessedon 11/27/19, h p://mission-innova on.net/our-work/
tracking-progress/.

9

ARPA-E, “DOE Announces $36 Million for HighTemperature Materials Projects,” ARPA-E News(2019), h ps://arpa-e.energy.gov/?q=news-item/
doe-announces-36-million-high-temperature-materialsprojects

10

ARPA-E, “ARPA-E Announces Funding Opportunity to
Develop Novel Heat Exchanger Technologies,” ARPA-E
News (2018)h ps://arpa-e.energy.gov/?q=news-item/
arpa-e-announces-funding-opportunity-develop-novelheat-exchanger-technologies

11

NKS Energie, “Funded Projects under Horizon
2020: Secure, clean and eﬃcient energy,”
European Union Open Data Portal (2016)
at p. 13, h ps://www.nks-energie.de/lw_resource/datapool/systemﬁles/elements/
ﬁles/5B5C11BA3DC812B5E0539A695E86ECA3/current/
document/H 020_-_Low_Carbon_Energy_Projects_
funded_2014.pdf

12

Ship2Fair, Site accessed 11/27/19, h p://ship2fair-h2020.eu/.

13

Adrian Cho, “Congress sends Trump energy spending
bill that includes healthy boost for science,” Science,(2018), h ps://www.sciencemag.org/news/2018/09/
congress-sends-trump-energy-spending-bill-includeshealthy-boost-science

14

Esteban Or z-Ospina and Max Roser, “Public Spending,”
Our World in Data (2017), h ps://ourworldindata.org/
public-spending/15

Akshat Rathi, “Half of all cars sold in Norway in 2018
were electric,” Quartz (2019), h ps://qz.com/1514111/
half-of-all-cars-sold-in-norway-in-2018-were-electric/

16

Department for Business, Energy & Industrial Strategy,“Contracts for Diﬀerence: Policy Paper,” Gov.UK(2019), h ps://www.gov.uk/government/publica ons/
contracts-for-diﬀerence/contract-for-diﬀerence17

George Akerlof, et al., “Economists’ Statement on
Carbon Dividends,” Climate Leadership Council (2019),
h ps://www.clcouncil.org/economists-statement/

18

The World Bank, “57 Carbon Pricing Ini a ves
Now in Place Globally, Latest World Bank Report
Finds: Press Release,” The World Bank Group(2019) h ps://www.worldbank.org/en/news/
press-release/2019/06/07/57-carbon-pricing-ini a vesnow-in-place-globally-latest-world-bank-report-ﬁnds.
print

19

Interna onal Carbon Ac on Partnership (ICAP),“Emissions Trading Worldwide: Status Report,” ICAP
December 2019

(2019), Eds. Marissa San karn, et al., Berlin: ICAP,h ps://icapcarbonac on.com/en/?op on=com_
a ach&task=download&id=613
20

US Department of Commerce, Interna onal Trade
Administra on, Steel Import Monitoring and Analysis,“Global Steel Report,” Global Steel Trade Monitor(2018), h ps://www.trade.gov/steel/pdfs/globalmonitor-report-2017.pdf at pp. 3 and 11

21

Carbon Tax Center, “Border Adjustments,” (Date
Accessed: September 30, 2019), h ps://www.
carbontax.org/nuts-and-bolts/border-adjustments/

22

Jennifer Hillman, “Changing Climate for Carbon
Taxes: Who’s Afraid of the WTO?,” German Marshall
Fund of the United States: Climate & Energy Paper
Series 2013 (2013), h ps://www.scribd.com/
document/155956625/Changing-Climate-for-CarbonTaxes-Who-s-Afraid-of-the-WTO

23

Joost Pauwelyn, “Carbon Leakage Measures and Border
Tax Adjustments Under WTO Law,” Social Science

65

Research Network (SSRN) (2012), h ps://papers.ssrn.
com/sol3/papers.cfm?abstract_id=2026879
24

Adele C. Morris, “Policy Brief: Making Border Carbon
Adjustments Work in Law and Prac ce,” Tax Policy
Center: Urban Ins tute & Brookings Ins tu on (2018),
h ps://www.taxpolicycenter.org/sites/default/ﬁles/publica on/155511/policy_brief_making_border_
carbon_adjustments_work_in_law_and_prac ce.pdf

25

Tom Kenning, “Revision to ‘single most important
policy’ to drive solar ready for approval,” PV
Tech (2015), h ps://www.pv-tech.org/news/
intersolar-india-revision-to-single-most-importantpolicy-to-drive-solar-re

26

David Gerard and Lester Lave, “Implemen ng
Technology-Forcing Regula ons,” Technological
Forecas ng and Social Change (2005), h p://faculty.lawrence.edu/gerardd/wp-content/uploads/
sites/9/2014/02/18-TFSC-Gerard-Lave.pdf

December 2019

CHAPTER 6
FINDINGS AND
RECOMMENDATIONS
Decarbonizing industrial heat produc on will requireinnova ng in mul ple sectors. Progress will requirea set of ac ons grounded in improved knowledge,strong analy cal founda ons and support from key
stakeholders. In this chapter, we summarize our key
ﬁndings and recommenda ons.

Findings
Finding 1: Emissions from industrial heat production
limit progress on climate goals. Roughly 22% of

greenhouse gas (GHG) emissions come from industry,and roughly 40% of those emissions are the result ofburning fuel to generate heat. This places heat-relatedindustrial emissions close to 10% of total global GHG
emissions—more than cars and planes combined.
Deep decarboniza on will be diﬃcult or impossible
without progress in decarbonizing industrial heatsources.
Finding 2: The operational requirements andcommercial realities of many industries limit
opportunities for decarbonization. The industrial sector

is actually many diﬀerent sectors with dis nct products,
markets, technologies and opera onal requirements.
Many industrial processes require temperatures above
300 °C and some above 1,000 °C. The narrow marginsof the business and high-capital expense of industrial
facili es frequently require high-capacity factors for
proﬁtability. Many industrial products are globally tradedcommodi es that are extremely sensi ve to price. Manyare strategic industries whose economic viability is of
considerable importance to host na ons.
Finding 3: There are few options today for lowcarbon heat generation for industry. High-temperature

requirements and high-capacity factors limit the op ons
for subs tu on of fossil fuel heat with low-carbon
alterna ves. For new facili es and especially forexis ng facili es, commercially available op ons today
face enormous challenges based on both cost andperformance. Many industrial processes are highly

integrated, making it diﬃcult to pursue simple fuelsubs tu on without a larger system redesign. Biofueland hydrogen combus on may be the most promising
op ons for the highest temperature applica ons.
(Although electrical hea ng pathways can generatehigh temperatures, they would require very large
capital investments in many industries.) CCUS applied tohydrogen produc on or combus on facili es remains an
op on and has the beneﬁt of also managing byproductprocess emissions, but sector-speciﬁc analyses to date
are limited. More broadly, there is a lack of analysis on
the costs, beneﬁts and tradeoﬀs between alterna ve
op ons.
Finding 4: Existing options face challenges basedon price, performance and viability. Fossil fuels

provide the overwhelming majority of industrial heat
today. Preliminary analysis suggests that all possible
alterna ves carry substan ally higher costs, typically
50-500% more, and may have even higher system costs(e.g., due to addi onal infrastructure requirements).
In some cases, the carbon reduc ons associated withan alterna ve are unclear (i.e., grid-based electricity or
biofuels). Ques ons remain about the ability of some
op ons to scale. Many of those op ons do not provide
suﬃciently high temperatures for some applica ons.
In many cases, it is unclear if a par cular approach
represents a viable alterna ve at all, as it is unclear
how it might be used to deposit heat where needed in
speciﬁc applica ons.
Finding 5: There appear to be many pathways
to improving cost, performance and viability of
low-carbon industrial heat options. Despite thechallenges alterna ves face today, most approaches
could be drama cally improved. Although the precise
magnitude of poten al cost, performance and life-cycle
improvements are unclear, substan al improvements
in system engineering, performance, processintensiﬁca on, heat recovery, capital cost and capacity
are possible in most systems. Novel approaches to someindustrial processes appear to be able to provide large
improvements in cost and life-cycle decarboniza on,
although most require further explora on and tes ng
before scale-up
Finding 6: Many potential policy options exist that
could improve the speed and magnitude of industrial
decarbonization and deployment of low-carbon
alternative heat systems. Government procurement

may be an especially potent policy tool. Governments
66

December 2019

are major purchasers of cement, iron and steel, andother industrial products. Procurement rules that givepriority to products produced in low-carbon processes
could spur innova on and deployment. Investments in
R&D through tax incen ves or grants could also havea signiﬁcant payoﬀ. In contrast, economy-wide carbon
taxes may have limited impact on GHG emissions fromindustrial heat produc on. In part, this is due to the
exposure of many industries to compe on from global
trade. All op ons would beneﬁt from addi onal analysis.

Recommendations■ Recommendation 1: Key stakeholders should

priori ze industrial heat produc on as a key elementof any climate mi ga on strategy. Governments,
companies and researchers should priori ze
characteriza on and analysis of their industrial sectors.
Core data and informa on, such as capacity factors,
fuel purchased and facility-based eﬃciency, should begathered and made publicly available.
■ Recommendation 2: Industry-speciﬁc analy cal
frameworks and innova on agendas are essen al.
Governments and companies together should
develop new ini a ves and R&D programs to focus on
industrial-sector decarboniza on with a focus on heat
supplies. Governments, academic researchers andindustrial leaders should cooperate to develop new
publicly available data, analy cal tools and training

programs. These programs should be created withinappropriate ministries and should be commensurate
in scale to R&D programs in electric power andtransporta on decarboniza on. Basic, use-inspired
and applied research should receive support, as shouldpilot tests and commercial demonstra ons (ideally inpartnership with industry and at opera ng facili es).
Industrial heat decarboniza on should be added aspriori es to Mission Innova on and the Clean Energy
Ministerial.
■ Recommendation 3: Governments should iden fy
and implement a set of policy ac ons to accelerate
decarboniza on of industrial heat, star ng with“buy clean” procurement standards. Such standards
are among the most promising and immediately
ac onable policy tools. Because mul ple approaches
will be necessary to successfully deliver deep andrapid decarboniza on of industrial heat produc on,
governments should assess which policy op ons best
suit their economic, poli cal and natural resource
base.

Final thoughts
This Roadmap is an ini al foray into an important andcomplex topic. A core ﬁnding of this Roadmap is that
more work is needed on this topic. The urgency ofclimate change requires rapid ac on. More data, input
and technology op ons for decarbonizing industrial heat
are urgently needed.

DISCLAIMER:
Roger Aines and Joshuah Stolaroﬀ contributed to the technical evalua ons in this document. The policy
recommenda ons were prepared by the other contributors. The technical evalua ons by Dr. Aines and Dr.
Stolaroﬀ were prepared as an account of work sponsored by an agency of the United States government.
Neither the United States government nor Lawrence Livermore Na onal Security, LLC, nor any of theiremployees makes any warranty, expressed or implied, or assumes any legal liability or responsibility forthe accuracy, completeness, or usefulness of any informa on, apparatus, product, or process disclosed, or
represents that its use would not infringe privately owned rights. Reference herein to any speciﬁc commercial
product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily
cons tute or imply its endorsement, recommenda on, or favoring by the United States government or Lawrence
Livermore Na onal Security, LLC. The views and opinions of authors expressed herein do not necessarily stateor reﬂect those of the United States government or Lawrence Livermore Na onal Security, LLC, and shall not be
used for adver sing or product endorsement purposes. Prepared by LLNL under Contract DE-AC52-07NA27344.

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December 2019