Feature

RITE Today 2021

Beyond Zero Expo
Takashi Honjyo, Senior Managing Director
Isamu Yagyu, Group Leader, Chief Researcher, Research & Coordination Group
Yoshifumi Kawaguchi, Deputy Group Leader, Research & Coordination Group
Yasuaki Minoura, Manager, Research & Coordination Group
Haruo Kanaboshi, Planning Manager, Research & Coordination Group
Michiyo Kubo, Research & Coordination Group
Nami Tatsumi, Research & Coordination Group
Keigo Akimoto, Group Leader, Chief Researcher, Systems Analysis Group
Toshiyuki Hasegawa, Deputy Group Leader, Chief Researcher, Chemical Research Group
Katsunori Yogo, Associate Chief Researcher, Chemical Research Group
Hidetaka Yamada, Senior Researcher, Chemical Research Group
Kenji Uchida, Deputy Group Leader, Chief Researcher, CO2 Storage Research Group
Saeko Mito, Senior Researcher, CO2 Storage Research Group
Kenichiro Yasuhara, Senior Researcher, Inorganic Membranes Research Center

1. Introduction
As indicated in Prime Minister Suga's policy speechon 26th October, 2020, it is required that our society has
net-zero CO2 emissions by 2050. In order to achieve this,it will be important to reduce energy requirements
through higher efficiency, and to maximize the use ofenergy that does not emit CO2, such as solar and wind
power. In addition, it will also be important to establish

Fig.1 Conceptual image of the Osaka, Kansai Expo venue

systems that realize carbon neutrality by capturing the(Courtesy of the Japan Association for the 2025 World Ex-

CO2 that is unavoidably emitted and using undergroundposition)storage or fixation and utilization. Through the spreadand development of this underground storage technol-

To construct this system, it will be necessary to limit

ogy and fixation and utilization technology, andthe power supplied to the venue during the period tothrough the further reduction of CO2 emissions, it isenergy that does not emit CO2. Also, for city gas, thethought that we will be able to approach the realization

CO2 emissions from production and consumption willof a Beyond Zero state which exceeds neutral (in otherbe offset with credits. The hydrogen used will also bewords, zero), as described in the Environment Innova-

either green or blue hydrogen and be carbon neutral. Intion Strategy. At the Osaka, Kansai Expo in 2025 (Fig.1),

addition, electric or hydrogen vehicles will be used in-rather than a simple exhibition of Beyond Zero, we willside the venue and the CO2 generated by any gasoline

propose the Beyond Zero Expo as a pioneering systemvehicles will be offset with credits in the same way as forfor achievement within the venue during the exhibitioncity gas. We will achieve carbon neutrality as a starting

period.

point through these efforts.
As the next step, in this proposal, we will capture CO2from the atmosphere in the venue and either store it
underground or fix and utilize it, in order to realize a

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RITE Today 2021

state Beyond Zero and to promote environmental tech-displays at the Expo venue. We want to create a Beyond

nology.

Zero Pavilion of the equipment together with an exhibi-

The concentration of CO2 in the atmosphere is abouttion of carbon neutral, DAC, underground storage, and

400 ppm, which is only a few hundredths of the concen-

other CO2 fixation and carbon recycling technologies, totration of CO2 in the current practical applications ofpromote Japan's environmental technologies to thecapture technology. It is not really possible to say thatmany visitors.

the technology to capture this efficiently has alreadybeen established. However, if we make full use of

CCS

Injection wells

Japan's cutting-edge technology, then we believe that
it will be possible to produce a DAC (Direct Air Capture)

Lignite gasification+
CCS

Atmosphere

Liquefaction

Carbon neutral hydrogen

CO2 capture device(DAC device)
Methanation

device that efficiently captures CO2 in units of tons (perof a process called CO2 Capture and Storage, or CCS)

only be a few hundred tons, which is actually quite small

Acrylic

FC busNuclear

Solar

Tableware,
lighting andsouvenirs
Carbon neutral electricity
Vegetables

Carbon neutral city gas
Guest house kitchenwithin the venue in order to process the captured CO2
permanently. The amount stored during the period will

Methanol synthesis

City gasday) by 2025, and to install and operate it at the venue.
Next, we will also perform underground storage (partPlantfactory

CO2

Emissions trading
Hydro

Wind

J-Credit participants, etc.
(Parties introducing energy-savingor renewable energy, etc.)

Fig.2 Conceptual image of the Beyond Zero Expo proposal(as there are proven results of 300,000 tons over three
years at Tomakomai). However, the fact that the storage

This special issue gives a detailed introduction towill be in Osaka, which is a large city, will make it a rev-

each technology for the realization of the Beyond Zeroolutionary attempt unprecedented in the world, so it

Expo. First, Chapter 2 discusses the need to achieve car-will have great significance.

bon neutrality and the prospect of achieving Beyond

In addition, carbon recycling technology will also be

Zero. Chapter 3 then introduces DAC, undergroundrealized within the venue as an environmental technol-

storage, and other technologies. As a summary, Chapter

ogy. Specifically, a methanation device for producing

4 discusses the relationship between this proposal andmethane from CO2 from the DAC device mentioned

the basic policy of the Osaka, Kansai Expo.

above and carbon-free hydrogen will be installed within
the venue. The methane produced will then be supplied

2. For the achievement of carbon neutrality

to the guest house kitchen and elsewhere as city gas.

As described in the previous chapter, on 26th Octo-

Similarly, CO2 will be supplied to the plant factory in-ber, 2020, Prime Minister Suga declared the intention tostalled in the venue and the vegetables cultivated will

"Aim for carbon neutrality and decarbonization by

be provided to the guest house kitchen on a daily basis.

2050". Here we discuss what measures are required to

In addition, acrylic resin made using methanol pro-achieve carbon neutrality.

duced from CO2 fixation as a raw material will be used

2.1. Multiple possibilities for carbon neutrality achieve-

to manufacture fixtures and fittings for the venue andmentsouvenirs.

The Special Report on Global Warming of 1.5°C

Fig.2 shows a summary of these proposals. Further-(SR15) by the Intergovernmental Panel on Climate

more, we want to position the equipment as exhibition

Change (IPCC) noted that to limit the increase to 1.5°C,

6Feature

RITE Today 2021

it will be necessary to achieve a net near-zero level ofthrough the reduction of materials and energy services

global CO2 emissions in around 20501). Carbon neutral

through digitization. For the reduction of CO2 emissions

in 2050 is in line with this.

per unit of power, it tends to be easier to reduce these

In SR15, four typical pathways are presented. Of thesefor electricity than for non-electric power, so the IPCC

four, the two extreme pathways are as follows. The firstalso emphasizes the importance of promoting electrifi-

is a scenario of exhaustive energy conservation, known

cation whilst simultaneously promoting the decarboni-as the Low Energy Demand (LED) scenario. On the en-zation of power sources2). On the other hand, for bothergy demand side, the amount of energy currently be-energy conservation and the reduction of CO2 emis-

ing used greatly exceeds the level that is originally nec-

sions per unit of power, when the effort for a large re-essary. There is a possibility that the use can be greatly

duction is increased, in other words, when the effort to

reduced by changes such as advances in digitization

bring the figures to close to zero is increased, the costs

technology. The scenario shows that if social changes

increase rapidly. Furthermore, there are some sectors

also occur, then a society with low energy demand andwhere the reductions are more difficult than those for

low CO2 emissions can be realized. (The RITE Systems

CO2, such as methane from livestock production. One

Analysis Group launched the research project, EDITS

major direction for achieving carbon neutrality will be(Energy Demand changes Induced by Technological andto cancel out those remaining emissions by using neg-

Social innovations) research project in FY2020 andative emission technologies (NETs). However, as men-

started detailed international studies on low-energy de-tioned in the previous section, there are several differ-mand scenarios.) The LED scenario described in SR15

ent prospects for the level of contribution of each. We

does not assume the use of CDR (Carbon Dioxide Re-should aim for carbon neutrality with a wide range of

moval) technology. Another model scenario is theoptions.

achievement of carbon neutrality during the time whenwhilst also using a large amount of CDR technology. In
addition to CCUS, the CDR also includes biomass withCCS (BECCS), which produces negative emissions, andthe direct capture and storage of atmospheric CO2(DACCS). It will be desirable to have multiple scenarios
as we go on to enhance the feasibility of carbon neu-

CO2 emissions
CO2 intensity of electricity or non-electric energy(Illustrative)

fossil fuels continue to be cheap, by using fossil fuelsElectric powerwith net-zero emissions

Electric power

energyImprovementofelectrification
rate

Electricity
saving or
Reduction in
embodied
electricity ofgoods /
services

Decarbonizationof power source(renewables,
nuclear, CCUS
etc.)

from load balancing thermal
Energy consumption Emissions
power or uncaptured CO from CCS etc.
2trality so that it can be achieved at an early stage.

Non-electric energy
with net-zero emissions Non-electric

Conversion tonatural gas ,Bioenergy,
Hydrogen,
CCUS,
Methanation
etc.

Non-CO2 GHGs

Energy saving
or Reductionin embodied
energy ofgoods /
services

Fossil fuel emissions in case thatelectrification is technically andeconomically difficult

To be offset by NETs
e.g., forestation,
BECCS, DACS

Fig.3 Conceptual image of measures for net zero emissions

2.2. Image of carbon neutrality achievementin terms of greenhouse gas emissions

Fig.3 shows a conceptual image of measures for net
zero emissions (= carbon neutral) in terms of green-

In the same way, Fig.4 shows an image of measures

house gas emissions. Broadly speaking, there is energy

for net-zero from the viewpoint of primary energy sup-conservation and there is the reduction of CO2 emis-

ply in Japan. In principle, it is necessary that primary en-

sions per unit of power. Firstly, what is fundamentally

ergy only consists of renewable energy, nuclear energy,

important is the conservation of energy, including

and fossil fuels with CCS. However, it is also important7

Feature

RITE Today 2021

to consider the utilization of overseas resources for re-reach net zero in around 2060 and 2050 respectively,

newable energy and CCS, and in doing so, conversion

and then become negative (Beyond Zero). For green-

to hydrogen is important. Hydrogen is also called green

house gas emissions, the scenarios have net zerohydrogen when it originates from renewable energy

reached in around 2100 and 2065, respectively, andand blue hydrogen when it originates from fossil fuel +then a negative figure after that. For the 1.5°C scenario,

CCS. To improve convenience, it may also become im-in the assumptions for this model, there were no feasi-

portant to convert hydrogen to ammonia or synthetic

ble solutions without the assumption of DAC (Table 1).

fuel for transportation and utilization. However, there isa high possibility that fossil fuel use without CCS will

Table 1 DAC-related model analysis scenarios

also remain. It will be necessary to cancel this out withmeasures such as afforestation, BECCS, and CO2 miner-

Emission

DAC

scenarios

costs

2℃(No DAC)No DAC

2℃(DAC，High

alization (CO2 fixation in concrete sector, etc.). However,High cost)

due to volume constraints, the use of DACCS is also

Low cost)

2℃(DAC，<２℃(>66%)

cost
Low
cost

considered important. There is a limit to the storage ca-

1.5℃(No DAC)

<1.5℃ in

No DAC

1.5℃(DAC，

2100

High

pacity of CCS, which includes BECCS and DACCS, so it isHigh cost)(>66%),cost

1.5℃(DAC，

Overshoot ofLow

Low cost)

temperaturecost

important to secure CO2 storage sites and also it is very
important to consider the utilization of CO2 storagesites overseas.

Feasibility
〇
〇
〇
×
〇
〇

Note) The assumptions for DAC are based on Ref. 4). The
required energies in 2050 are 5.5-7.2 GJ/tCO2 and 4.7
GJ/tCO2 for the high and low cost scenarios, respectively.

【Domestic primary energy supply】
Energy saving or
Reduction in embodied
energy of goods/services(incl. Society 5.0)

Fig.5 shows the balance between global CO2 captureand storage/use in the results from this model analysis.

【Use of overseas resources】
Nuclear(For details of the analysis, see reference 3.) Even under

Nuclear
Domestic renewables

DecarbonizedenergyRenewable energy

the scenario where the cost of DAC is assumed to be

Measures of grid to expand
renewables (incl. storage battery)Use of renewables surplus
for hydrogen

Use of overseas renewables(green hydrogen) (import ofhydrogen, syn. fuels (CCU))

high (a maintenance of the current technology level),Sys. fuels prone to be generated fromfossil fuels if the constraint on CO2 isloose in the producing country, while from
BECCS or DAC (with increased cost) if theconstraint is strict.

the cost of the energy inputs will be reduced by utilizing

Use of overseas CO2 reservoir (pre-combustion CO2
capture) (import of blue hydrogen)

Fossil fuels + CCS

Remainingfossil fuels

Fossil fuels w/CCS
Fossil fuels
w/o CCS

Domestic CO2 storage

BECCS, DACS

Use of overseas CO2
reservoir (postcombustion)

Forestation, mineralization (concrete CCU)

Negative emission technologies (NETs)【Use of overseas
resources】

Fig.4 Conceptual image of measures for net zero emissionsin terms of primary energy supply in Japansurplus renewable energy, so when aiming for carbon
neutrality, it is evaluated as a cost-efficient option inaround 2050. In the scenario where it is low cost, thereis even more extensive use. As the use of DACCS makes
negative emissions possible, it will still be possible to2.3. Example of comprehensive analysis using the global
energy and climate change mitigation assessment
model: The role of DACCS
Next is an example analysis of the total global
measures for carbon neutrality by using the global en-

use fossil fuels without CCS at an appropriate level.
There is still a long way to go in DAC technology development, but it will contribute to the achievement of
cost-effective carbon neutrality as a whole, and also
bring achieving Beyond Zero into view.

ergy and climate change mitigation assessment model,
DNE21+. In the emissions scenarios, in the scenarios forless than 2°C and for less than 1.5°C, the CO 2 emissions

8

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RITE Today 2021

80

60

Capture

60

20

0

-20

-40

-60

40
40

20
20

0
0
-20
-20

-40
-40

Syn. methanol (CCU for chemicals)

-60

-80

Storage,utilization

-80
-80

2050

2050

2℃(DAC,
DAC)
2℃(No
DAC)
2℃(No
High cost)
2℃(DAC,
2℃(DAC,
2℃(DAC,cost)
HighHighcost)
Low cost)
2℃(DAC,
2℃(DAC,
1.5℃(DAC,
cost)
LowLow
cost)
High cost)
1.5℃(DAC,
1.5℃(DAC,
cost)
HighHighcost)
1.5℃(DAC,
Low cost)
1.5℃(DAC,
1.5℃(DAC,
cost)
LowLow
cost)

2℃(DAC,High cost)
DAC)
2℃(No
DAC)
2℃(No
2℃(DAC,Low cost)
2℃(DAC,
2℃(DAC,cost)
HighHighcost)
1.5℃(DAC,
2℃(DAC,
2℃(DAC,High cost)
cost)
LowLowcost)
1.5℃(DAC,
1.5℃(DAC,
1.5℃(DAC,
Low cost)
cost)
HighHighcost)
1.5℃(DAC,
1.5℃(DAC,
2℃(No DAC)
cost)
LowLow
cost)-60

2℃(No DAC)

CaptureCO2 cap: DAC (HT, elec.)
CO2 cap:
cap: DACDAC (HT,(LT) elec.)
CO2
CO2 cap:
cap: DAC
crinker
prod.
CO2
(LT)
CO2 cap:
cap: crinker
steel prod.
CO2
prod.
CO2 cap:
cap: steelhydrogenCO2
prod.prod.
CO2 cap:
cap: hydrogenbiomass power
CO2
prod.
CO2 cap:
cap: biomass
gas power
CO2
power
CO2 cap:
cap: gasoil power
CO2
power
CO2 cap:
cap: oil
coal
power
CO2
power
CO2
cap: coal
EOR
CO2
cap:
power
Storageandutilization
CO2 cap:
cap: EORECBM
CO2CO2 cap:
cap: ECBM
depr. gas well
CO2
CO2 cap:
cap: depr.
deep gassalineaquifer
CO2
well
Syn. cap:
methaneCO2
deep(methanation)saline aquifer
Syn. methane
liquids (methanation)
Syn.
CCUliquids
in concrete sector
Syn.
Syn. inmethanolfor chemicals)
CCU
concrete(CCU
sector60

40
CO2回収と貯留・利用量[GtCO2/yr]
CO2回収と貯留・利用量[GtCO2/yr]

CO2 capture, storage, and utilization [GtCO2/yr]

8080Table 2 Status of DAC technology development overseas 5）
Company name

Materials

Energy /Cost of CO2
separation and capture

Remarks

Climeworks(Swiss)Amine modified
filter (Solidsorbent material
and resin filter)

9.0 GJ/t-CO2，
600 $/t-CO2(Target costaround 2025: 100 $/t-CO2)

Launched the world's first commercial
plant(900t-CO2/y), which has alreadybeen installed in eight locations. Energy
and costs are high.

Carbon Engineering(Canada)Aqueous solution
containing
KOH/Ca(OH)2

5.3 GJ/t-CO2，
94-232 $/t-CO2

Plan to put two 500,000 t-CO2/y DAC
plants into operation in 2022 with
Occidental Petroleum. The only company
using alkaline aqueous solution.

Global Thermostat(USA)

Amine-containing
ceramics(Solidsorbent material)

4.4 GJ/t-CO2，
150 $/t-CO2(Target cost: 50$/t-CO2)

Working in cooperation with Georgia
Institute of Technology. Has alreadyinstalled six units and constructed 4,000
t-CO2/y pilot plant.

Center for Negative
Carbon Emissions(USA)

Ion-exchange
resin

220 $/t-CO2(Target cost: 30 $/t-CO2）

Adsorption/desorption using
dehumidification/humidification swing.
Proposing installation of AT alongexpressways.

The VTT TechnicalResearch Center(Finland)Ion-exchange
resin

8.9GJ/t-CO2

1～2kg-CO2/d on Day/night capture cycle

2100

2100

2050
2100
Fig.5 Balance between
global CO
2 capture and storage/use

The target CO2 concentration of DAC is only 400 ppm.
This is two to three orders of magnitude lower than that

3. Technology introductionof exhaust gas from coal- and natural gas-fired power

3.1. DAC

plants. This is a main reason that the DAC cost will be

Since the concept to capture CO2 from the atmos-

high. The amount of air that contains one ton of CO2 isphere was proposed as a feasible option for climate

approximately 1.27 million m3. What this means is thatmitigation technology, development of direct air cap-even if the capture rate is 100%, it would take the air ofture (DAC) technologies have attracted much attention.

one Tokyo Dome to capture 1 ton of CO2 from the air.

According to the Energy Technology Perspectives 2020,

In order to make DAC realistic, it will be necessary to

for the achievement of sustainable development sce-develop CO2 separation materials with unprecedented

narios, BECCS (Bio-energy with CCS) and DACCS (Direct

high performance, and to construct a process that

Air CO2 Capture and Storage) are expected to achieve

makes it possible to absorb and desorb large amounts

negative emissions of 3 Gt-CO2/y by 2070. The utiliza-of air efficiently. Now, RITE is working on the develop-

tion of captured CO2 by DAC is also be considered, how-ment of new materials based on our experience in theever, the effect of removing the CO2 from the atmos-

development of solid sorbents and amine compounds

phere by CCU is small. DAC can be used as a negative

and a highly efficient DAC system with the cooperation

emission technology by combining it with storage asof private companies and universities (Fig.6).

DACCS.
DAC is considered to be energy intensive and costly,

Development ofmaterials and systems

Air (CO2 400 ppm)

but it does use less land area and water than BECCS,
afforestation, or reforestation, so it is possible to sup-・Development of new sorbent
for DAC・Reduction of pressure loss
(blowing power)
・Downsizing of equipment
・High-efficiency process development

CO2 captured airpress the problem of competition with land use for foodproduction, and the adverse impacts on biodiversity.

Large-scaledemonstrations

As shown in Table 2, some researches are being car-・Direct capture of several tons/day of
CO2 from the atmosphere
CO2
CO
2
CO2

ried out in the United States and Northern Europe.
However, the capture cost is currently high. Therefore,

Fig.6 Development of technology to capture CO2 from thebased on a detailed cost estimation, the reduction of

atmosphereboth costs (CAPEX) and thermal and electric energy(OPEX) are required.

9

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RITE Today 2021

In this proposal, we want to make full use of Japan's

1mm Seal layer(E.g., Mudstone)

cutting-edge technology to produce a DAC device that
efficiently captures CO2 in units of tons (per day), and to
install and operate it at the venue.

Reservoir（E.g., Sandstone）

3.2. Underground storage of CO2
Methods for CO2 injection and storage in the groundinclude EOR (Enhanced Oil Recovery), where CO2 is injected into oil fields to perform enhanced oil recovery,
ECBM (Enhanced Coal Bed Methane), where CO2 is injected into coal seams to recover methane, and CO2 geological storage in deep saline aquifers.

Grain

Fig.7 Schematic diagram of underground CO2 storage

The geological structures necessary for the storage of
CO2 underground include a "reservoir" and a "seal layer".

Fig.8 shows a general outline of a CO2 storage site.

Sedimentary layers such as porous sandstone are suita-

The CO2 is captured from the source generating it andble for the "reservoir", and saline aquifers with large

then either stored directly below ground from facilities

permeability correspond to this.

on the surface, below the seabed from ground facilities,

Saline aquifer storage is a method of storage that tar-or below the seabed from offshore facilities.

gets sandstone layers at depths of 800 m or more below
ground. The sandstone layers are geological strata
formed by the accumulation of sand grains. Salt water
which is not used for groundwater utilization fills thegaps between the sand grains. Fig.7 shows a conceptual

OnshoreStorage site
Injection
well

Separation &CaptureOffshore
Storage site

Transport via
pipeline

CO2
CO2

image of saline aquifer storage. CO2 is injected into thesandstone layer via a well that is drilled from the groundsurface. CO2 pushes away the part of salt water and ac-

Fig.8 General outline of an underground CO2 storage site

cumulates in the gaps, and also some of it is dissolvedin the salt water. It is possible to store the CO2 stably

As discussed in the previous chapter, the under-

over a long period of time if there is a seal layer such as

ground storage of CO2 is one of the important options

mudstone above the sandstone layer. Mudstone hasfor sequestering the CO2 that is captured.

strong sealing properties and allows hardly any gas or
liquid to pass through.

A large number of CO2 injection wells would be required for CCS at a level that would suppress global
warming. However, the number is only a small fractionof the number of oil production wells that have been
drilled to date around the world. It is expected that theunderground storage of CO2 will be utilized in earnest
and become one of the measures against global warming. An introduction to this kind of underground CO 2

10

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RITE Today 2021

storage at the Osaka, Kansai Expo will be very meaning-

There are also expectations for methanation as a tech-

ful for spreading knowledge of CCS to a wide audience.

nology for that storage and for the stabilization of the

In this proposal, underground storage will be carried

power system.

out within the venue. The amount stored during the pe-

The reason for converting hydrogen to methane isriod of the event will only be a few hundred tons, whichthat the storage, transportation, and use of hydrogenis actually quite small (as there are proven results ofwould require new capital investment and the develop-

300,000 tons over three years at Tomakomai). However,ment of new equipment technology. However, methane

the fact that the storage will be in Osaka, which is a large

has almost the same composition as natural gas, so if itcity, will make it a revolutionary attempt unprecedented

is connected to a gas pipeline, then it can be used with-in the world, so it will have great significance.

out building new equipment. In addition, the possibilities for methane as an energy carrier are attracting at-

3.3. Other

tention from the viewpoint of low carbonization for the

3.3.1. Methanation

utilization of heat from primary energy.

Methanation is a technology to synthesize methane

In Europe, where decarbonization is in progress, Audi

from CO2 and hydrogen. The synthesis requires energy,

is operating a demonstration plant with a methanation

but unlike hydrogen, it has the major advantage that it

capacity of 315 Nm3/h, which makes it the largest

is possible to utilize the existing city gas infrastructure,demonstration plant in the world. It performs the

so it is attracting much attention.

methanation using electricity derived from renewable

The technology itself is an existing technology thatenergy and CO2 separated from biogas, with the as-

was discovered in 1911 by the French chemist Sabatier.

sumption that the price for renewable energy will fall

In Japan, as part of a NEDO project to develop effective

when a large amount of it is placed on the market. Also,

CO2 utilization technologies, INPEX and Hitachi Zosen

in China, which aims to achieve net zero CO2 emissions

constructed a test facility with a methane synthesis ca-

by 2060, Hitachi Zosen announced in December 2020

pacity of 8 Nm3/h in 2019 and have conducted demon-that it would conduct a feasibility study for methanation

stration testing such as continuous operation. On thetechnology, and plans to evaluate the supply chain andother hand, there have not yet been any examples ofbusiness profitability for social implementation.

utilization as city gas. The issues for this are scaling up

In this proposal, we are considering the installation ofand the improvement of the conversion efficiency anda methanation device within the venue. The device will

economic efficiency. The synthesis requires four times

use CO2 from the DAC device mentioned above andas much hydrogen as CO2, but if the hydrogen is pro-supply the methane to the guest house kitchen andduced using the surplus electricity from renewable en-elsewhere as city gas.

ergy sources, then the use of synthetic methane can reduce the amount of natural gas used as a fossil fuel and3.3.2. Methanol synthesis

contribute to decarbonization. In addition, if a large

Methanol is used widely as a raw material to produce

amount of renewable energy power is introduced as alower olefins such as ethylene and propylene. It is alsomeasure to achieve net-zero carbon, then one issue willa basic raw material for chemicals such as synthetic res-be the storage of the large amount of surplus electricity.

ins, adhesives, chemicals, and paints. The annual de-11

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RITE Today 2021

mand for it globally is about 80 million tons. It is pro-

Methanol synthesis

duced under high temperatures and high pressures

Using Methanol derived from CO2 that captured from the atmosphere in the Expovenue to manufacture acrylic resin for use in tableware and souvenirs

through multiple manufacturing processes, and themain raw materials currently used are fossil resources
such as natural gas, liquefied petroleum gas, and coal.
Instead of using fossil resources as the raw materials
to obtain methanol, it can be synthesized by using hy-【Reaction formula】

CO2 + 3H2

Methanol

CH3OH + H2O

CO2 captured fromexhaust gas andthe atmosphere

Acrylic resin(PMMA)

H2 from zero emissions

Acrylictableware

Methacrylic acid
MAA

MMA
MonomerLighting using acrylic

drogen derived from renewable energy and CO2 obtained by capturing it from the atmosphere or from theIndirect lighting using PMMA sheets

combustion exhaust gas from facilities such as coal
combustion power plants and blast furnaces. Doing thisPMMA sheets and Japanese paper
A reflective agent is applied
are laminated and bonded, andby printing and emits light
lit from the bottom

Fig.9 Methanol utilization at the Expomakes it possible to simultaneously reduce greenhousegas emissions while producing the useful industrial
product methanol.

3.3.3. Plant factory
Plant factories are a facility that could utilize CO2 on

The methanol that is obtained from these raw mate-a global scale in the future. Plant factories can be either

rials of CO2 obtained from capture and hydrogen de-

the artificial light type or the solar light type. Of these,

rived from renewable energy can then be reacted withan artificial light type plant factory (Fig.10) uses artificial

methacrylic acid to synthesize an acrylic resin (PMMA).

light as the light source and has air conditioning andAcrylic resins have high transparency and impact re-liquid nutrient cultivation to control the environmental

sistance and are easy to process and color, so they are

elements necessary for plant growth (light, temperature,used in various applications such as window materials

humidity, CO2 gas concentration, and airflow). Thesefor buildings and vehicles, covers for lighting fixtures,

can stably cultivate high-quality plants throughout theand signboards.

year6).

In this proposal, we would like to show examples ofFor example, for leaf lettuces, for which the technol-

the realization of a carbon recycling society by using

ogy has already been applied, it is necessary to add 22

this acrylic resin at the venue. This includes use in ex-

kg of CO2 in order to produce 3,000 leaf lettuces (of 100

hibits and souvenirs, and in transparent boards sur-g each), and this greatly contributes to productivity6). In

rounding the DAC (Direct Air Capture) equipment dis-

addition, further development and advances can be ex-

played at the Expo venue as equipment to capture CO2

pected, such as through the research and developmentfrom the atmosphere (Fig.9).

currently being carried out for strawberry production.
In this proposal, carbon recycling and the latest technology for plant factories will be promoted by setting
up a small factory to produce the latest vegetables forwhich the technology has been applied. The factory will
use CO2 captured by the DAC within the venue and will
supply the vegetables to the guest house kitchen.

12

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RITE Today 2021

4)

M. Fasihi et al., J. Cleaner Prod. (2019)

5)

ICEF[Direct Air Capture of Carbon Dioxide]etc., Prepared based on data published by each company

6)Japan Plant Factory Industries Association Website

Fig.10 Example of an artificial light type plant factory（Source: Techno FarmTM Website）

4. Conclusion
At the 2025 Osaka, Kansai Expo, rather than just exhibiting about Beyond Zero, we are proposing a pioneering system that uses technologies such as thosedescribed above to achieve Beyond Zero within thevenue during the period of the Expo.
The outline of this proposal was already presented on
September 24, 2020 at a symposium hosted by RITE,
and it was also reported on October 14 as an article in
the Chemical Daily.
Also, in the basic policy for the Osaka, Kansai Expothat was decided by the Cabinet on December 21, 2020,
the third of the twelve basic concepts is active efforts
for radical innovation toward carbon neutrality. We will
make further efforts to refine and actualize our proposal
for the realization of this basic policy.

References
1)

IPCC Special Report “Global warming of 1.5℃” (2018)2)

5th Assessment Repot of IPCC WG3 (2014)

3)

F. Sano et al., The 36th Conference on Energy, Economy, and Environment (2021)13