R&D Activities ● Chemical Research GroupRITE Today 2022

Chemical Research Group
Members (as of Dec. 2021)
Shin-Ichi Nakao, Group Leader, Chief Researcher
Toshiyuki Hasegawa, Deputy Group Leader, Chief Researcher
Katsunori Yogo, Chief Researcher
Koji Baba, Associate Chief Researcher
Teruhiko Kai, Senior Researcher
Kazuya Goto, Senior Researcher
Firoz Alam Chowdhury, Senior Researcher
Toshinori Muraoka, Senior Researcher
Kenichiro Yasuhara, Senior Researcher
Makoto Ryoji, Senior Researcher
Fuminori Ito, Researcher
Tomohiro Kinoshita, Researcher
Takayasu Kiyokawa, Researcher
Quyen Thi Vu, Researcher
Shuhong Duan, Researcher
Nobuhiko Fuchigami, Researcher
Lie Meng, Researcher

Hanako Araki, Research Assistant
Noriko Onishi, Research AssistantHidenori Ogata, Research Assistant
Kumiko Ogura, Research Assistant
Mai Kashima, Research AssistantKozue Kataoka, Research AssistantKeiko Komono, Research Assistant
Ryuichi Shirai, Research Assistant
Rie Sugimoto, Research AssistantTakashi Teshima, Research AssistantYozo Narutaki, Research AssistantYoichi Fujiwara, Research AssistantKeiko Mori, Research AssistantMisato Mori, Research Assistant
Miku Yamada, Research AssistantNaomi Yoshino, Research AssistantJunko Yonezawa, Research Assistant

Challenges Associated with the Advanced Industrialization of CO2
Capture Technologies
1. Technologies for CO2 capture

Strategy for 2050 Carbon Neutral formulated in Decem-

The Paris Agreement was adopted at COP 21 in De-

ber 2021 (detailed in June 2021), various types are avail-cember 2015, and in order to minimize the adverse ef-

able. Efforts to prevent global warming are being pro-fects of climate change, such as abnormal weather, themoted from various areas. CCUS (Carbon dioxide Cap-rise in global average temperature before the Industrial

ture, Utilization, and Storage) / Carbon Recycling is an

Revolution was kept well below 2°C. Pursuing efforts toimportant innovative technology that enables carbon

keep the temperature down to 1.5°C was the goal. After

neutrality. In CCUS/carbon recycling, the combination

that, in response to the heightened sense of crisis, suchof the reuse of separated and recovered CO2 from fuels

as further temperature rises and the enormous naturaland materials by treating CO2 as a carbon resource

disasters occurring on a global scale, the Glasgow Cli-

(CCU), and the storage of separated and recovered CO2mate Agreement at COP 26 in November 2021 demon-

underground (CCS) is expected to have a significant CO2

strated the determination to pursue efforts to limit the

reduction effect. Furthermore, it has been shown thattemperature rise to 1.5°C with the world's first numeri-

CO2 separation and capture technologies are the basis

cal target of 1.5°C. According to the IPCC, the 1.5°C tar-for CCUS, and the targets for the technologies are to

get requires a 45% reduction in CO2 by 2030 compared

reduce the cost of CO2 separation and capture to 1,000

to 2010 and net zero by 2050.

yen/t-CO2 by 2050 and to establish CO2 separation and

In Japan as well, in response to the 2050 Carbon Neu-

capture technologies for various CO2 emission sources.

tral Declaration in October 2020 and the Green Growth

Negative emission technology is required to achievecarbon neutrality, and direct air capture (DAC) of CO2

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R&D Activities ● Chemical Research GroupRITE Today 2022

from the atmosphere, which has been attracting atten-

means of separating CO2 from high-pressure gas mix-tion recently, is particularly important. In the Carbon Re-

tures at low cost and with low energy requirements. As

cycling Technology Roadmap (Ministry of Economy,a member of the Molecular Gate Membrane module

Trade and Industry) revised in July 2021, DAC was added

Technology Research Association, RITE has been devel-

as a new technology field with progress.

oping membranes to selectively capture CO2 from pres-Against this background, it is necessary to promotesurized gas mixtures containing H2, such as those gen-the practical application of CCUS by proposing optimalerated in the integrated coal gasification combined cy-

separation and capture technologies for the various CO2cle (IGCC) at low cost and with low energy use. We are

emission sources. In particular, in order to introduce

also developing membranes with large areas using theand put into practical use CCS, which is expected to re-continuous membrane-forming method and develop-

duce CO2 on a large scale as a measure to address

ing membrane elements for the mass production of

global warming, it is important to reduce the cost ofmembranes and membrane elements in the future. In

separating and recovering CO2 emitted from large-scale

addition, we evaluated the separation performance andsources.

process compatibility of our membrane elements using

The Chemical Research Group studied the different
CO2 capture technologies with a special focus on chem-

coal gasification real gas and are proceeding with development aimed at commercialization.

ical absorption, adsorption, and membrane separation

In addition, as part of the NEDO moonshot R&D pro-methods. This work involved the development of new

ject, we have begun studying technologies for captur-

materials and processing methods, as well as investiga-

ing CO2 from the atmosphere by direct air capture

tions of capture systems. The Group’s studies have thus

(DAC) and using it as fuel or raw materials. While pro-

far generated significant outcomes and assisted in the

moting the development of amine compounds suitable

progress of research in this particular field.

for the separation and recovery of low concentration

Specifically, we developed high performance chemi-

CO2, we are working on the development of a DAC sys-

cal absorbents, and chemical absorbents with particular

tem that can separate and recover CO2 from the atmos-

promise were selected for application in a commercial

phere with high efficiency in cooperation with Kana-

CO2 capture plant owned by a private Japanese com-zawa University and private companies.

pany.

As described above, RITE is working on the develop-

With regard to solid sorbent technology, we havement of innovative technologies that will be the foun-been engaged in research and development of solid ab-

dation for a wide range of next generation, leading-sorbent materials with high CO2 efficiency recovery andedge research and development for CO2 reduction andlow energy consumption and have found solid absor-

aiming to establish technologies that can be imple-

bent materials and systems with good CO2 desorption

mented in society. In addition, we joined the Interna-

performance at low temperatures. Currently, in thetional Test Center Network (ITCN) and now actively use

NEDO consignment project, we are preparing for aoverseas networks towards the commercialization ofscale-up test using actual combustion exhaust gas fromCO2 separation and recovery technology.

a coal-fired power plant in collaboration with a private*COP 21: 2015 United Nations Climate Change Confer-company.

ence

Membrane separation is expected to be an effective

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R&D Activities ● Chemical Research Group

2. Chemical absorption method for CO2 capture

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nearby chemical factory.

In the absorption method, CO2 is separated by using

In addition, the latest research found the possibility

the selective dissolution of CO2 from a mixed gas into aof further reducing energy consumption by using thesolvent. In particular, the chemical absorption method

absorption solvent with an organic compound instead

based on the chemical reaction between amine and CO2

of water and continues to explore new ones. The solvent

in a solvent can be applied to gases with a relatively low

can control the reaction mechanism of CO2 absorption

CO2 concentration, such as combustion exhaust gas,

and the effect of polarization.

and the method is one of the most mature CO2 capture
technologies.
Energy consumption in the process of solvent regeneration and the degradation of amines are factors in thecost increases of the chemical absorption method. Focusing on the fact that the structure of amine molecules
is closely related to these factors, RITE started a newamine solvent: since the COCS project (METI's Subsidy
Project) started in 2004, RITE has been working on thedevelopment of a high-performance amine solvent that
reduces the cost of CO2 capture.
In the COURSE50 project (NEDO consignment project) since 2008 with the goal of reducing CO2 emissions

Fig. 1 Equipment of energy-saving CO2 absorption process ESCAP® at Niihama Nishi power station, Sumitomo Joint Electric Power Co., Ltd.

by 30% in the steelmaking process, RITE is working with
Nippon Steel Corporation to upgrade the chemical ab-

3. Solid sorbent method for CO2 capture

sorption method. The chemical absorbent and process

Unlike a chemical absorbent in which amines are dis-developed by the COURSE50 project was adopted bysolved in a solvent, such as water, a solid sorbent is one

the energy-saving CO2 capture facility ESCAP® of Nip-in which amines are supported on a porous material,

pon Steel Engineering Co., Ltd., which was commercial-

such as silica or activated carbon. In the process using aized in 2014.

solid sorbent, the heat of vaporization and sensible heat

ESCAP® Unit 1 was constructed on the premises of
Muroran Works for general industrial use, including

caused by the solvent can be suppressed, so reductionof CO2 capture energy can be expected.

beverages. This is the world's first commercial facility
using the chemical absorption method for the combustion exhaust gas from a hot blast furnace at a steelworks
as a CO2 source. In 2018, ESCAP® Unit 2 started operation at the Niihama Nishi Thermal Power Station. This is
the first commercial facility in Japan to capture CO2 by
the chemical absorption method from the combustion
exhaust gas of coal-fired power generation as the CO2
source. The recovered CO2 is used as a raw material in a

Fig. 2 Liquid absorbent and solid sorbent

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R&D Activities ● Chemical Research GroupRITE Today 2022

In 2010, RITE started the development of solid

Currently, RITE is proceeding with the production ofsorbent materials for CO2 capture from the combustionsolid absorbents on a 100 m3 scale optimized on theexhaust gas of coal-fired power plants (METI consign-basis of the results of the scale-up synthesis of solid ab-

ment project). In the fundamental research phase (FYsorbents and bench scale tests for pilot scale tests. We

2010–2014), we succeeded in developing a new amine

are also elucidating the material deterioration mecha-

suitable for solid sorbents, and in a laboratory scale test,

nism, developing deterioration prevention technology,

we obtained the prospect of capture energy of 1.5 GJ/t-

and studying efficient operating conditions using pro-

CO2 or less. This solid sorbent system is an innovativecess simulation technology.

material that enables not only low energy capture but
also a low temperature process at 60°C. Compared to

4. Membrane separation

other businesses that use amine-based solid absor-

CO2 separation by membranes involves the selective

bents, this business is at the top level globally in terms

permeation of CO2 from the pressure difference be-of low-temperature regeneration.

tween the feed side and the permeate side of the mem-

In

the

practical

application

researchphase

brane. So, CO2 capture at low cost and with low energy(METI/NEDO consignment project) from FY 2015 tois expected by applying the membrane processes to2019 with Kawasaki Heavy Industries, Ltd., as a partner,

pre-combustion (Fig. 4). For this reason, we are cur-scale-up synthesis of solid absorbent (>10 m ), benchrently developing novel CO2 selective membrane mod-scale test (>5 t-CO2/day), and real-gas exposure tests atules that effectively separate CO2 during the IGCC pro-a coal-fired power plant were conducted.

cess.

3

Fig. 3 Development roadmap of solid sorbent method forCO2 capture

In 2020, RITE was adopted by the NEDO commissioned
project with Kawasaki Heavy Industries, Ltd. In this project, with the cooperation of Kansai Electric Power Co.,
Ltd., a pilot scale test facility (– 40 t-CO2/day) will be
constructed at the Maizuru power plant, and CO2 capture tests from the combustion exhaust gas emitted

Fig. 4 Schematic of the IGCC process with CO2 capture by
CO2 selective membrane modules

We found that novel polymeric membranes composed of dendrimer/polymer hybrid materials (termedmolecular gate membranes) exhibited excellent CO2/H2
separation performance. Fig. 5 presents a schematicthat summarizes the working principles of a moleculargate membrane.

from the coal-fired power plant will start in 2022.

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R&D Activities ● Chemical Research Group

Fig. 5 Schematic illustration of the working principles of

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Fig. 6 CO2 selective membrane, membrane element, andmembrane module.

the molecular gate membrane

Membrane element: The structure with a large mem-

Under humidified conditions, CO2 reacts with theamino groups in the membrane to form either carbamate or bicarbonate, which then blocks the passage of
H2. Consequently, the amount of H2 diffusing to thebrane area composed of the membrane, support, andspacer.
Membrane module: The structure in which the membrane element is placed.

other side of the membrane is greatly reduced, and highconcentrations of CO2 can be obtained. A poly (vinyl alcohol) (PVA) polymer matrix is used for pressure durability and to immobilize the dendrimers.
We developed new types of dendrimer/polymer hybrid membranes that provide superior separation of
CO2/H2 gas mixtures. Based on this work, the Molecular
Gate Membrane module Technology Research Association (MGMTRA consists of the Research Institute of Innovative Technology for the Earth [RITE] and a privatecompany) is researching new membranes, membraneelements (Fig. 6), and membrane separation systems.
Based on the achievements of the project by the
Ministry of Economy, Trade and Industry (METI), Japan,
the CO2 Separation Membrane Module Research andDevelopment Project (FY 2011–2014) and CO2 Separation Membrane Module Practical Research and Development Project (FY 2015–2018), we developed themembranes with large areas using a continuous mem-brane-forming method while developing membrane elements in the NEDO project, CO2 Separation Membrane
Module Practical Research and Development (FY 2018–2021). As a result, two-inch and four-inch membraneelements with enough pressure durability (2.4 MPa)
were successfully prepared. In addition, we conductedpre-combustion CO2 capture tests of the four-inch
membrane elements using coal gasification gas, and it
was confirmed that the membrane elements were durable against the real gas (containing impurities, such as
H2S).
In the new NEDO project, CO2 Separation Membrane
System Practical Research and Development/Development of CO2-H2 membrane separation systems using
high-performance CO2 separation membrane modules,
we plan to conduct the practical research and development to improve the separation performance and durability of the membrane elements, to scale up the membrane modules and to design the membrane systems

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R&D Activities ● Chemical Research Group

suitable for the CO2 utilization process based on the re-

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in the atmosphere (Fig. 8).

sults of the previous projects.

5. CO2 capture technology from the atmosphere
RITE has been conducting a national project in the
NEDO Moonshot R&D Project with the development of
a highly effective direct CO2 capture method from airand carbon recycling technologies in collaboration with
Kanazawa University and private companies. This project is a part of the Environment Innovation Strategy
launched by the Japanese government in 2020 that

Fig. 8 New designed lab test equipment for DAC

aims to establish technologies that enable Beyond Zeroby 2050.

In order to realize an economically acceptable DAC,

A method of capturing CO2 directly from the atmos-

not only material development but also process devel-

phere called Direct Air Capture (DAC) is one of the neg-

opment is important. We introduce a simulation tech-

ative emission technologies. Seven research themes on

nology to reveal the most suitable process without

DAC have been adopted in the Moonshot R & D Project.

chemical/time

Fig. 7 shows our R & D items and a carbon cycle society

friendly development technique will be also used in theas our goal.

Moonshot R&D Project.

consuming.

This

environmentally

6. CO2 fixation
CO2 fixation (CO2 mineralization) has the same basic
concept as enhanced weathering, which is one of negative emission technologies. It is a technology that reacts CO2 with alkaline earth metals and immobilizes it
as a chemically stable carbonate, which is attracting attention as a CO2 fixation technology that does not affectFig. 7 Development of highly efficient DAC and carbon
recycling technologies

RITE is trying to synthesize new amines suitable for
DAC and transform solid sorbents into low-pressure
drop structured materials. Developed materials aretested in the actual air around RITE. Because of the dayto-day variations in the local atmosphere’s conditions,
we designed new equipment to control and test the effects of temperature, humidity, and CO2 concentration

the ecosystem. Especially in recent years, early implementation of the CO2 fixation by using by-products andwastes containing alkaline earth metals is expected tobuild a sustainable society.
RITE developed a unique process over many years.
From 2020, two Japanese private companies and RITE
set up a study group to target steel slag and waste concrete and then use alkaline earth metals extracted fromthese for use with the CO2 emitted from factories andother facilities. We are cooperating in the developmentof technology for recovering as carbonates, which is a48

R&D Activities ● Chemical Research Groupstable compound, by reacting with CO2 (Fig. 9).

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and propose CO2 separation and recovery technologies
that can save more energy and reduce costs.
In particular, in sustainable development scenarios
for decarbonization in the future, it is said that the contribution of CO2 capture from natural gas and biomass
combustion will increase, and negative emission technologies, such as DACCS, are also required. Therefore,
in the future, it is necessary to proceed with technological development so that it can handle these lower-con-Fig. 9 CO2 fixation as carbonates

centration CO2 emission sources. As the CO2 concentration decreases, the amount of gas to be treated in-

7. Conclusioncreases and the high oxygen concentration also in-

As stated above, the Chemical Research Group has

creases. Therefore, it will be important to develop ma-

energetically promoted the development of CO2 sepa-

terials with lower cost and higher deterioration re-ration and recovery technology mainly as the chemical

sistance and system development corresponding toabsorption method, the solid sorbent method, andthem.

membraneseparation.

Thechemicalabsorption

method has been deployed from the demonstration
stage to commercial machines for blast furnace exhaustgas and combustion exhaust gas from coal-fired power
plants and has already been put to practical use as a
CO2 separation and recovery technology. In the solid
sorbent method, we have begun studying combustion
exhaust gas from coal-fired power plants for a 40 tCO2/day scale pilot test, which is planned for FY 20232024. In membrane separation, we confirmed the separation ability of CO2 and H2 in an actual gas test using amembrane element from coal gasification gas. In addition, we are working on the development DAC technology newly adopted in NEDO's Moonshot R&D Project
and CO2 fixation technology using steel slag and waste
concrete.
The Chemistry Research Group will work vigorously
on individual research topics with these themes. For thethemes close to the practical stage, we will carry out
scale-up studies and actual gas tests with the aim of establishing the technology at an early stage. At the sametime, we would like to develop innovative technologies

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