—W H I T E PA P E R

Energy efficiency
in iron and steel making

2

ENERGY EFFICIENCY—Reducing energy consumption,
costs and emissions in the ironand steel industry
The iron and steel industry emits 2.3 Gt of CO2 per year, which amounts to
7% of total global carbon emissions.1 To meet global climate and energy
goals, the IEA estimates that these emissions must be cut by 50% by 2050.1
This will require both decarbonization of the steel process – meaning
removing coal/fossil fuels from the energy supply – and improving energy
efficiency.

IN IRON AND STEEL MAKING

3—
Decarbonizing
the iron and steel industry
The largest industrial consumer of coal
On average, producing 1 ton of steel using traditional technology releases
1.85 tons of CO2 emissions. 2 The majority of these emissions come from thetwo main steps in the process. First, the conversion of iron ore into iron using
blast furnaces and second, turning iron into steel using basic oxygen furnaces.
Even today, coal is used in iron and steel making to generate heat and to makecoke. As a result, the steel industry uses coal to meet 75% of its energy needs
making it the largest industrial consumer of coal. 3—
70% of the steel produced in
the world uses coal.4—
Energy and coal use in iron and steel making processes.

Coke making

Iron making

Steel making

Steel finishing

Coal
Basic oxygen furnance
Coke oven
Blast furnanceCasting

Electric arc furniture

Coke, Pellet, Iron ore,
Sintered ore andLimestone

Rolling
Steel recycling

4

ENERGY EFFICIENCY—
New processes are being
developed which could
completely decarbonize
iron making.

In the steel making process, electric arc furnaces are a
viable alternative to basic oxygen furnaces. Because
these are electrically powered, they offer the potential toeliminate the use of fossil fuels and transition to renewablesources of electricity. Furthermore, new processes arebeing developed that use hydrogen to replace carbon
and coke as reducing agents in production, which could
completely decarbonize the iron making process.
However, it must be realized that both electric arc furnaces
and producing hydrogen also require a significant amountof energy. For example, in 2019, 157 million tonnes of steel
was produced in the EU. 60% of this – 94 million tonnes –could be produced using hydrogen methods. 5 Since it takes
about 50 to 55 kilowatt hours (kWh) to produce 1 kg ofhydrogen, it has been calculated that making 94 million
tonnes of steel using H2 would require 296 TWh ofelectricity. This would account for 10% of the EU’s total
electricity consumption. 5,6 Therefore, it’s important thatlosses are minimized and efficiency is maximized at allstages of the iron and steel production process.

Technological steps towards
decarbonization7
Improving the efficiency of blast furnaces and basic
oxygen furnaces• Optimizing the blast furnace mix• Fuel injection technologies• Using coke oven gas
Using biomass• Sustainable biomass from sugar or eucalyptus• To replace fossil-based fuels and reductants
Electric arc furnaces• Using renewable electricity• Using recycled scrap steel or direct reduced ironHydrogen• To replace fossil fuels• To power electric arc furnaces• To act as fuel and reductant in direct reduced ironprocesses

IN IRON AND STEEL MAKING

5—
Energy use
in iron and steel making
A significant industry challenge
Iron and steel production is very energy intensive, withenergy and raw materials accounting for 60-80% of thecosts.8 Globally, the industry accounts for 8% of global final
energy use and it is estimated that steel production has
doubled in the past two decades, which has caused a
subsequent doubling of the industry’s greenhouse gas
emissions.9 Furthermore, it is predicted that by 2050, thedemand for steel could increase by another 40%. 10
Due to the need to reduce energy consumption andemissions, and energy costs, there is a big push in theindustry to find ways to improve energy efficiency.
These include improving the energy efficiency of current
processes, improving material efficiency and developing
new steel making technologies. Hydrogen and renewableenergy are also likely to play a big role in fossil-freetechnology.

—
Producing steel fromrecycled scrap requires
1/8th of the energy
needed to produce steel
from iron ore.12

Recycling to reduce energy use
The steel industry uses a high percentage of recycled raw
material and most steel production uses recycled scrap
steel. All the scrap steel that is collected globally is recycled,with a recycling rate of approximately 85%. In plants thatuse electric arc furnaces, up to 100% of the raw materials
can be from recycled sources, while blast furnaces typicallyuse up to 30%. 11
Compared to producing steel from iron ore, producing itfrom recycled steel saves significant amounts of energy
because all the steps used to convert ore to iron, such as theblast furnace process, are avoided. As a result, producing
steel from recycled material also generates significantly
fewer CO2 emissions than producing it from iron ore. It’s
estimated that every tonne of recycled steel scrap that isused to product steel prevents 1.5 tonnes of CO2 being
emitted. 11 However, since the industry already has arelatively high recycling rate, further reductions in energy
use and emissions will be hard to achieve via recycling alone.

6

ENERGY EFFICIENCY—Iron and steel
production processes
Energy intensive processes with significant losses
Fired heaters like blast furnaces and other furnaces use themajority of the energy involved in the iron and steel making
process, consuming about 81% of the final energy. Therecan also be significant energy losses in an iron or steel
plant, with up to 23% of the energy that enters the plant
being lost to inefficiencies in equipment and distribution. 13
While, motor systems account for a relatively small
proportion of energy use, at around 7%, it has been
estimated that up to 70% of the energy consumed by these
motors is lost due to system inefficiencies. 1 This meansthat there are actually very good opportunities to reduceenergy use in motor systems throughout the industry.
These kinds of improvements are straightforward andquick to implement, and they typically have attractive payback periods.
Motor applications in iron and steel making
Motor systems are used throughout the whole process inapplications including hot and cold rolling mills, blowers,
fans, pumps, compressors, roller tables, conveyors andother materials handling systems such as overhead cranes.
Within these applications, the losses can often use moreenergy than the actual work done by the motor. For
example, a U.S. Department of Energy report found that in
the iron and steel industry up to 70% of the energy input tomotor systems can be lost due to system inefficiencies. 14—
Energy end-use in the steel industry13

Facilities
3%
Steam
7%

Other
2%

Motor
systems7%

Firedheaters81%

IN IRON AND STEEL MAKING

7—
Improving energy efficiency
in iron and steel applications
Energy efficient motors
Motors are always required for applications like pumps, fansand compressors, and improving the energy efficiency ofthe motor system can have a big impact on the efficiencyof the application overall. When looking for ways to improvethe energy efficiency of a motor system, it is worth
considering the efficiency of the system overall, life cycle
costs, as well as the age and efficiency class of the motor.

—
Overall motor system efficiency –a comparison of reduction in energy
consumption in a motor system

Energy is by far the biggest cost associated with a running
an electric motor system, and it accounts for over 90% of
the costs over a motor’s lifetime, while the purchase priceonly accounts for about 5% or less. 15 Many facilities also
operate motors well beyond their expected lifetime and insome markets up to 60% of industrial motors are over
10 years old. 16 These older motors typically have greater
losses and hence lower efficiency than newer motors,
with an energy efficiency class of IE3 or even IE2.
As a result, investing in more modern, more energy efficient
motors, is likely to be an effective way to reduce losses,
energy consumption and cost over the course of a motor’slife time. The potential energy savings of upgrading to a
motor with a higher IE efficiency class are quite easy toestimate: five international classes are specified by the IEC,
ranging from IE1 to IE5, with IE1 being the least efficient and
IE5 the most efficient. Each class of efficiency equates to
20% lower motor losses. For example, IE4 motors have 20%
lower losses that IE3 motors, and 40% lower losses than an
IE2 motor. 17
Overall motor system efficiency
While reducing motor losses is worthwhile, and reduces the
motor’s operating costs throughout its life, the energy thissaves throughout the whole motor system is only one partof the picture.
We should consider that while VSDs help increase theefficiency of motors of any age, many of the systems inwhich they are employed are old and lag behind current IE
standards. In these cases, particularly noticeable savings
may be realised through upgrading the motor to a higher
class.

It is important to note that any upgrades must also take theefficiency of the motor system as a whole into account –efficiency gains in the motor may be squandered if the restof the system is inefficient. Motor systems can be or canbecome inefficient for many reasons. For example, poorly
maintained equipment is often responsible for significant
drops in efficiency. For pumps, it has been estimated that
regular maintenance can reduce energy consumption by
between 2% and 7%. As another example, over-dimensioned
equipment, such as motors, fans or pumps will also reduceenergy efficiency. Correcting oversized pumps could
reduce electricity consumption by 15% to 25%, estimatessuggest. 18

8

ENERGY EFFICIENCY

Variable speed drives
Using variable speed drives (VSDs) to control motors cansignificantly improve the energy efficiency of motor
systems and the applications they run. In the iron and steel
industry, the majority of fan and pump applications operate
at partial load and use mechanical control methods likevalves, brakes and throttles to regulate flow. With thesemethods, motors run at a higher speed than necessary andwaste energy, losing it as friction and heat. Variable speed
drives (VSDs) can be used to overcome this type of
inefficiency. VSDs control the speed and torque of anelectric motor directly, enabling direct regulation of theflow. This means that the work the motor does matches theactual demands of the application and no more. This resultsin higher efficiency at a range of different flow rates and it
eliminates the need for mechanical flow control and theassociated losses.
Because VSDs enable motors to run at lower speeds,
they can generate significant savings. This is because inapplications with a centrifugal pump or a fan, the power
consumption of the motor is proportional to the cube of its
speed, and there is also a quadratic relationship between
the speed and torque. Therefore, using lower motor speeds
and lower motor torque will result in a measurable reduction
in energy consumption and cost. On average, adding avariable speed drive to a fan, pump or compressor can
reduce energy use by about 25%, and in some cases
companies have seen savings of up to 50%. 19,1 With thesekinds of savings, the investment can payback in as little
as a year.

Pumps
Pumping systems are used throughout iron and steel
production to pump a range of gasses and liquids including
by-product gasses, process air and cooling water. Thesepumping systems lose efficiency over time if they are notmaintained properly and older systems will also be lessefficient than more modern ones. It has been estimatedthat the energy efficiency of these pumping systems could
be improved by 5-10% by using improved equipment and by
reducing friction through better maintenance. In addition,
optimizing pump systems, for example, by using more
efficient pumps, improving pump controls, proper pumpand pipe sizing, and using VSDs could improve energy
efficiency by a further 10-20%. 18

Fans
Fan systems are used in a variety of applications in steel
production, including ventilation, extraction systems andmaterial handling. The efficiency of fan systems can be
improved in several ways, including choosing the mostefficient fan type for the application, proper fan sizing,
better airflow design, and using VSDs. For example, it has
been estimated that the energy saving potential in fan
systems in the steel industry in the US is about 6%. 20
In practice, the energy savings will depend on theapplication, however the savings can be significant. For
example, in a basic oxygen furnace where large fans areused to control air quality and to control gasses in batchtype processes, where flow demand varies greatly, adding
VSDs has been shown to reduce power demand by 20%.
And, when VSDs are added to an improved fan system,
energy savings of 50% have been obtained. 21

Compressors
Different types of compressor systems are used throughout
iron and steel making, from the overall process pneumatics
air supply, up to and including applications like air
separation processes, which use very large compressor
motors. According to some estimates, more than 85% of
the electrical energy input into a compressor is lost as
waste heat. However, there are good opportunities in most
systems to improve energy efficiency. These include better
maintenance to ensure optimum performance, minimizing
leaks in pipes and equipment, using filters and cleaningsystems to ensure good compressed air quality, right sizing
compressors and pipes, better compressor control andusing VSDs. Typically, adding a VSD to a rotary compressor
system can reduce energy consumption by up to 15%.
In addition, heat recovery units may be able to recover
50 to 90% of the available thermal energy from compressor
systems for useful work. 22 Since air separation, in particular,
is a very energy intensive process, high efficiency motors
and compressor systems should be used to minimize
electricity consumption and costs.

IN IRON AND STEEL MAKING

Water treatment
The steel industry uses large quantities of water forprocesses like cooling, descaling and dust scrubbing. For
example, an integrated steel plant has an average water
intake of about 28.6 m3 per tonne of steel produced.
However, after use around 90% of this water is cleaned,cooled and returned to the source. At each stage of thecycle, from extraction to use to cleaning and return, pumps
are used to transport the water, and this pumping consumes
a lot of energy. Therefore, an effective way to reduce energy
use is to prevent unnecessary pumping. One way to do thisis to reuse water this reduces the energy needed to extract
and transport water. Another way is to ensure that thecorrect amount of water is provided. For example, in a hot
strip mill, automatic flow control systems with integrated
VSDs can be used to the regulate water levels in the header
tanks to prevent the cooling water from overflowing. 23
Rolling mill processes
In steel rolling mill processes, motor systems drive
applications like the actual rolling mills, as well as cooling,
lubrication and descaling pumps, furnace combustion
and fume extraction fans, run out tables and othermaterial handling equipment. Due to the high loads andtemperatures that these applications handle, they are very
energy intensive. As a result, motor systems account for
about 40-45% of the total primary energy consumptionof a steel rolling mill. Since rolling mill applications involve
quickly changing loads, wide torque ranges and highaccuracy, modernizing the motor systems with VSDs andmore efficient motors can reduce energy consumption andmaintenance, as well as improving production quality. 24
Air separation with ABB products
Air separation is the dividing of atmospheric air into its
constituent gases, typically nitrogen and oxygen. The
process is required in steelmaking during the oxygen
converter process. Oxygen is blown through molten pig ironto create low-carbon steel. In order to obtain the oxygen
needed for this process, large synchronous motors drive air
separation compressors. High-purity gases can be obtained,
but the method is highly energy-intensive, requiring large
motors. ABB has produced and delivered a 44 megawatt
6-pole synchronous motor that has achieved a world recordin energy efficiency. The motor has an efficiency 0.25%
greater than contractually required by the customer, an air
separation plant. This type of motor typically has an average
efficiency of between 98.2 and 98.8%. The energy efficiency
improvement realised by ABB could result in saving 100 MWhof energy a year – equivalent to the annual energy
consumption of 240 European households. 25

CUSTOMER CASE

Futureproofing rolling millefficiency
Kanthal® – a world-leading brand in sustainable
heating technology and resistance materials – chose
ABB solutions for their new drive system at theirHallstahammar blooming mill. The decades-old DC
motor and drive system was removed and replacedwith a modern AC design. The system provides
numerous benefits including enhanced reliability,
improved performance, and an increase in total
efficiency of around 3.5%.

CUSTOMER CASE

Optimizing processes in
the long term
When steel producer SSAB needed to upgrade their
hot strip mill in Borlänge, they formed a long-term
partnership with ABB. A three-phase installation andcommissioning program between 2021 and 2023 –tied to planned maintenance shutdowns – will
modernize the old roller table motors and drives
with new, optimized multidrives and AC motors,
integrated into a distribution control system. These
motors and drives will result in improved continuous
operation with reduced energy consumption,
maintenance, and spare part requirements.

9

10

ENERGY EFFICIENCY—
Conclusion
While iron and steel making will continue to requiresignificant amounts of energy, as discussed, there are clear
opportunities in the industry to improve energy efficiency
and reduce the use of fossil fuels. Production processes
can be decarbonized using electric arc furnaces and withhydrogen-based technology. And, by modernizing
applications which rely on motor systems to reduce
inefficiencies, measurable savings in energy use andenergy costs can be achieved. Thanks to savings like these,
investments in technologies like VSD-motor systems canquickly pay back, while also helping companies to meetglobal climate and energy goals.

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The potential of hydrogen for decarbonising steel production | Think Tank | European Parliament (europa.eu)
EA, Iron and steel technology roadmap, Towards more sustainable steelmaking, October 2020, page 11;https://www.iea.org/reports/iron-and-steel-technology-roadmap
https://www.worldcoal.org/coal-facts/coal-steel/#steel-production
Meinke-Hubeny_Vito_Carbon-free steel production_20210224.pdf, page 7;
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The potential of hydrogen for decarbonising steel production | Think Tank | European Parliament (europa.eu)
McKinsey & Company, Decarbonization challenge for steel, Hydrogen as a solution in Europe, April 2020, page 4-5;
https://www.mckinsey.com/~/media/McKinsey/Industries/Metals and Mining/Our Insights/Decarbonization challenge for steel/Decarbonization-			
challenge-for-steel.pdf
IEA, Iron and steel technology roadmap, Towards more sustainable steelmaking, October 2020, page 16;
https://www.iea.org/reports/iron-and-steel-technology-roadmap
IEA, Iron and steel technology roadmap, Towards more sustainable steelmaking, October 2020, pages 32, 35 and 38;
https://www.iea.org/reports/iron-and-steel-technology-roadmap
IEA, Iron and steel technology roadmap, Towards more sustainable steelmaking, October 2020, page 57;
https://www.iea.org/reports/iron-and-steel-technology-roadmap
World Steel Association, Public Policy Paper, Climate change and the production of iron and steel, 2021, page 4;
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IEA, Iron and steel technology roadmap, Towards more sustainable steelmaking, October 2020, page 12;https://www.iea.org/reports/iron-and-steel-technology-roadmap
ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY, Energy Efficiency Improvement and Cost Saving Opportunities
for the U.S. Iron and Steel Industry, An ENERGY STAR(R) Guide for Energy and Plant Managers, October 2010, Chapter 4 Energy use, page 15; (PDF) 			
Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R)
Guide for Energy and Plant Managers (researchgate.net)
U.S. DOE (2004) Energy Use, Loss and Opportunities Analysis: U.S. Manufacturing & Mining. U.S. Department of Energy,
Office of Energy Efficiency and Renewable Energy, Industrial Technologies Program. December 2004, page 45;
https://energy.gov/sites/prod/files/2013/11/f4/energy_use_loss_opportunities_analysis.pdf
ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY, Energy Efficiency Improvement and Cost Saving Opportunities
for the U.S. Iron and Steel Industry, An ENERGY STAR(R) Guide for Energy and Plant Managers, October 2010, Chapter 11, Motor Systems, page 53; 			
(PDF) Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and 			Plant Managers (researchgate.net)
Lawrence Berkeley National Laboratory, U.S. industrial and commercial motor system market assessment report,
Volume 1: characteristics of the installed base, January 2021, Page 67, permalink: https://escholarship.org/uc/item/42f631k3 )ABB White Paper, Designing for optimum energy management, page 4, July 2021;
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Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and Plant Managers (researchgate.net)
For an example of the calculations involved, see “Program Insights: Variable frequency drives,” Consortium for Energy Efficiency, 2019;https://www.cee1.org/content/variable-frequency-drives)
ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY, Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel 		Industry, An ENERGY STAR(R) Guide for Energy and Plant Managers, October 2010, Chapter 13, Fan Systems, Page 65; (PDF) Energy Efficiency Improvement and Cost 		
Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and Plant Managers (researchgate.net)
ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY, Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel 		Industry, An ENERGY STAR(R) Guide for Energy and Plant Managers, October 2010, Chapter 18, Steel Making BOF, Page 86; (PDF) Energy Efficiency Improvement and 		
Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and Plant Managers (researchgate.net)
ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY, Energy Efficiency Improvement and Cost Saving Opportunities for the U.S. Iron and Steel 		Industry, An ENERGY STAR(R) Guide for Energy and Plant Managers, October 2010, Chapter 14, Compressed Air Systems, Page 68; (PDF) Energy Efficiency 			Improvement and Cost Saving Opportunities for the U.S. Iron and Steel Industry An ENERGY STAR(R) Guide for Energy and Plant Managers (researchgate.net)
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in Steel Rolling Industries (Indonesia), 2014, Chapter 4.2 Rolling Mill, page 46; http://sameeeksha.org/books/Manual-on-Energy-Efficiency.pdf
https://new.abb.com/news/detail/1789/ABB-motor-sets-world-record-in-energy-efficiency-saves-half-a-million-dollars

IN IRON AND STEEL MAKING

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