R&D Activities ● Chemical Research GroupRITE Today 2021

Chemical Research Group
Members (as of Dec. 2020)
Shin-Ichi Nakao, Group Leader, Chief Researcher
Toshiyuki Hasegawa, Deputy Group Leader, Chief Researcher
Katsunori Yogo, Associate Chief Researcher
Koji Baba, Associate Chief Researcher
Kazuya Goto, Senior Researcher
Teruhiko Kai, Senior Researcher
Hidetaka Yamada, Senior Researcher
Firoz Alam Chowdhury, Senior Researcher
Makoto Ryoji, Senior Researcher
Shuhong Duan, Researcher
Fujinori Ito, Researcher
Tomohiro Kinoshita, Researcher
Takayasu Kiyokawa, Researcher
VU Thi Quyen, Researcher
Nobuhiko Fuchigami, ResearcherHanako Araki, Research AssistantKeiko Komono, Research Assistant
Ryuichi Shirai, Research AssistantKozue Kataoka, Research Assistant
Rie Sugimoto, Research AssistantJunko Yonezawa, Research AssistantMisato Mori, Research AssistantNaomi Yoshino, Research Assistant
Noriko Onishi, Research Assistant
Mai Kashima, Research AssistantKeiko Mori, Research AssistantYoichi Fujiwara, Research AssistantTakashi Teshima, Research AssistantHidenori Ogata, Research Assistant
Kumiko Ogura, Research Assistant

Challenges Associated with the Advanced Industrialization of CO2Capture Technologies
1. Technologies for CO2 capture

separation and capture technologies for various CO 2

In December 2015, the Paris Agreement was adoptedemission sources. Recently, in a policy statement

at COP21.* To meet the conditions of the agreement, it

speech of the 203rd extraordinary session of the Diet inis essential to promote innovative ways to dramatically

October 2020, Prime Minister Suga said, "Eliminate

reduce emissions on a worldwide basis. In June 2019,greenhouse gas emissions to zero by 2050. In otherJapan released a long-term strategy as the growth strat-words, we aim to realize a carbon neutral, decarbonized

egy based on the Paris Agreement and the Integrated

society by 2050." Negative emission technology is re-Innovation Strategy 2019, where it has been shown thatquired to achieve carbon neutral, and direct air capture

the carbon capture, utilization and storage and carbon(DAC) of CO2 from the atmosphere, which has been at-recycling (CCUS/carbon recycling) process is an im-

tracting attention recently, is particularly important.

portant innovative technology that enables carbon neu-

Against this background, it is necessary to promotetrality in the world. In CCUS/carbon recycling, the com-the practical application of CCUS by proposing optimal

bination of the reuse of separated and recovered CO2

separation and capture technologies for the various CO2from fossil fuels and materials by treating CO 2 as a car-emission sources. In particular, in order to introduce

bon resource (CCU) and the storage of separated andand put into practical use CCS, which is expected to re-recovered CO2 underground (CCS) is expected to haveduce CO2 on a large scale as a measure to addressa significant CO2 reduction effect. Furthermore, it has

global warming, it is estimated that it will account forbeen shown that CO2 separation and capture technolo-

about 60% of the cost. CO2 separation and recovery

gies are the basis for CCUS, and the targets for the tech-from emission sources as a means of cost reduction are

nologies are to reduce the cost of CO2 separation andimportant.

capture to 1,000 yen/t-CO2 by 2050 and to establish CO2

The Chemical Research Group studied the different

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R&D Activities ● Chemical Research GroupRITE Today 2021

CO2 capture technologies with a special focus on chem-

RITE joined the International Test Center Networkical absorption, adsorption, and membrane separation(ITCN) and now actively uses overseas networks to-methods. This work involved the development of newwards the commercialization of CO2 separation and re-materials and processing methods, as well as investiga-

covery technology.

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

*COP21: 2015 United Nations Climate Change Confer-

far generated significant outcomes and assisted in theence

progress of research in this particular field.
Specifically, we developed high performance chemi-

2. Chemical absorption method for CO2 capture

cal absorbents, and chemical absorbents with particular

In the absorption method, CO2 is separated by usingpromise was selected for application in a commercial

the selective dissolution of CO2 from a mixed gas into a

CO2 capture plant owned by a private Japanese com-solvent. In particular, the chemical absorption method

pany.

based on the chemical reaction between amine and CO2

With regard to solid sorbent technology, we havein a solvent can be applied to gases with a relatively low

also been developing sorbents for CO2 capture to effi-

CO2 concentration, such as combustion exhaust gas,

ciently reduce energy consumption. Currently, the low-

and the method is one of the most mature CO2 capture

temperature regenerable solid sorbent that we devel-technologies.

oped is being evaluated for practical use. Research on

Energy consumption in the process of solvent regen-practical application is now underway in collaboration

eration and the degradation of amines are factors in thewith a private company. In the near future, we will install

cost increase of the chemical absorption method. Fo-a test facility at a coal power plant for practical applica-cusing on the fact that the structure of amine molecules

tion.

is closely related to these factors, RITE started a newMembrane separation is expected to be an effective

amine solvent: since the COCS project (METI's Subsidy

means of separating CO2 from high-pressure gas mix-Project) started in 2004, RITE has been working on thetures at low cost and with low energy requirements. As

development of a high-performance amine solvent thata member of the Molecular Gate Membrane module

reduces the cost of CO2 capture.

Technology Research Association, RITE has been devel-

In the COURSE50 project (NEDO’s consignment pro-oping membranes to selectively capture CO2 from pres-ject) since 2008 with the goal of reducing CO2 emissions

surized gas mixtures containing H2, such as those gen-by 30% in the steelmaking process, RITE is working witherated in the integrated coal gasification combined cy-

Nippon Steel Corporation to upgrade the chemical ab-cle (IGCC) at low cost and with low energy use. We aresorption method. The chemical absorbent and process

also developing membranes with large areas using thedeveloped by the COURSE50 project was adopted bycontinuous membrane-forming method and develop-

the energy-saving CO2 capture facility ESCAP® of Nip-ing membrane elements for the mass production ofpon Steel Engineering Co., Ltd., which was commercial-membranes and membrane elements in the future. Inized in 2014.

addition, we evaluated the separation performance andESCAP® Unit 1 was constructed on the premises ofprocess compatibility of our membrane elements using

Muroran Works for general industrial use including bev-

coal gasification real gas and are proceeding with de-erages (120t-CO2/day). This is the world's first commer-velopment aimed at commercialization.

cial facility using the chemical absorption method for44

R&D Activities ● Chemical Research GroupRITE Today 2021

the combustion exhaust gas from a hot blast furnace ata steelworks as a CO2 source. In 2018, ESCAP® Unit 2
started operation at the Niihama Nishi Thermal Power
Station (143t-CO2/day). This is the first commercial facility in Japan to capture CO2 by the chemical absorption method from the combustion exhaust gas of coalfired power generation as the CO2 source. The recovered CO2 is used as a raw material in a nearby chemicalfactory.

Fig. 2 Liquid absorbent and solid sorbent

In 2010, RITE started the development of solidsorbent materials mainly for CO2 capture from the combustion exhaust gas of coal-fired power plants (METIconsignment project). In the fundamental researchphase (FY 2010–2014), we succeeded in developing a
new amine suitable for solid sorbents and achieved acapture energy of 1.5 GJ/t-CO2 or less in a laboratory
scale test. This solid sorbent is an innovative material
that enables not only low energy capture but also a low
Fig. 1 Equipment of energy-saving CO2 absorption process ESCAP® at Niihama Nishi power station, Sumitomo Joint Electric Power Co., Ltd.

temperature process at 60℃.
In

thepracticalapplication

researchphase(METI/NEDO consignment project) from FY 2015 to2019 with Kawasaki Heavy Industries, Ltd., as a partner,

3. Solid sorbent method for CO2 capture

scale-up synthesis of solid absorbent (>10 m3), bench

Unlike a chemical absorbent in which amine is dis-scale test (>5 t-CO2/day), and real-gas exposure tests atsolved in a solvent, such as water, a solid sorbent is onea coal-fired power plant were conducted, which

in which amine is supported on a porous material, suchachieved a CO2 capture cost of less than 3,000 yen/t-as silica or activated carbon. In the process using a solid

CO2. Compared to other projects that used amine solid

sorbent, the heat of vaporization and sensible heatsorbents, the capture scale, energy, and cost of this pro-caused by the solvent can be suppressed, so reduction

ject were all at the top level globally.

of CO2 capture energy can be expected.

In 2020, RITE was adopted by the NEDO commissioned project with Kawasaki Heavy Industries, Ltd. In
this project, with the cooperation of Kansai ElectricPower 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
from the coal-fired power plant will start in 2022. Currently, RITE is proceeding with rationalization and the45

R&D Activities ● Chemical Research GroupRITE Today 2021

cost reduction of solid sorbent material manufacturing

We found that novel polymeric membranes com-technology, elucidation of a material degradation

posed of dendrimer/polymer hybrid materials (termedmechanism, development of degradation prevention

molecular gate membranes) exhibited excellent CO2/H2

technology, and the upgrading of process simulation

separation performance. Fig. 5 presents a schematic

technology toward pilot scale tests.

that summarizes the working principles of a moleculargate membrane. Under humidified conditions, CO2 reacts with the amino groups in the membrane to form
either carbamate or bicarbonate, which then blocks thepassage of H2. Consequently, the amount of H2 diffusing to the other side of the membrane is greatly reduced, and high concentrations of CO2 can be obtained.
A poly(vinyl alcohol) (PVA) polymer matrix is used forpressure durability and to immobilize the dendrimers.

Fig. 3 Development roadmap of solid sorbent method forCO2 capture

4. Membrane separation
CO2 separation by membranes involves the selective
permeation of CO2 from the pressure difference between the feed side and the permeate side of the membrane. So, CO2 capture at low cost and energy is expected by applying the membrane processes to precombustion (Fig. 4). For this reason, we are currently developing novel CO2 selective membrane modules that
effectively separate CO2 during the IGCC process.

Fig. 5 Schematic illustration of the working principles ofthe molecular gate membrane

We developed new types of dendrimer/polymer hybrid membranes that provide superior separation of
CO2/H2 gas mixtures. Based on this work, the MolecularGate Membrane module Technology Research Association (MGMTRA consists of the Research Institute of Innovative Technology for the Earth [RITE] and a private
Fig. 4 Schematic of the IGCC process with CO2 capture by
CO2 selective membrane modulescompany) is researching new membranes, membraneelements (Fig. 6), and membrane separation systems.

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R&D Activities ● Chemical Research GroupRITE Today 2021

Fig. 7 Separation performances of four-inch membrane
module using real gas and using simulated gas before
Fig. 6 CO2 selective membrane, membrane element, andmembrane module.
Membrane element: The structure with a large membrane

and after the real gas test.
Temperature: 85C, Total pressure 0.8 MPaA
Simulated gas: CO2/He/N2.

area composed of the membrane, support, and spacer.
Membrane module: The structure in which the membraneelement is placed.

In the future, we plan to develop commercial-scale
membrane modules and the membrane systems, basedon the results of the projects.

Based on the achievements of the project by theMinistry of Economy, Trade and Industry (METI), Japan,

5. New challenges

the CO2 Separation Membrane Module Research andAs mentioned above, the Chemical Research Group

Development Project (FY 2011–2014) and CO2 Separa-

has been focusing on the development and practicaltion Membrane Module Practical Research and Devel-

application of CO2 capture technologies for large-scale

opment Project (FY 2015–2018) in the current NEDO

CO2 emission sources, such as steel industries andproject, CO2 Separation Membrane Module Practicalpower plants. Finally, we will introduce two examples of

Research and Development (FY 2018–2021), we are de-new challenges. One is the capture of CO 2 from the at-veloping membranes with large areas using a continu-mosphere, or direct air capture (DAC), and the other isous membrane-forming method while developing

the development of technology to immobilize CO2 asmembrane elements. As a result, two-inch and four-carbonate.

inch membrane elements with enough pressure dura-In order to achieve carbon neutrality, a technology

bility were successfully prepared.

that can remove CO2 emitted into the atmosphere, thatIn addition, we conducted pre-combustion CO2 capture

is, a negative emission technology, is indispensable. In

tests of the membrane elements using coal gasification

recent years, DAC has been attracting attention as one

gas at the Wakamatsu Research Institute, Electric Powerof the representative negative emission technologies,

Development Co. Ltd. in Japan in order to identify andand is being studied overseas. It is hoped that the re-then solve the technical problems of the membrane el-covered energy and costs will be significantly reducedements (Fig. 7). As a result, it was confirmed that thefor future implementation. In Japan, challenging re-membrane elements were durable against the real gas

search and development is being carried out in NEDO's(containing impurities, such as H2S).

"Moonshot R & D Project" that started in 2020. RITE has
started studying the optimum materials and systems for47

R&D Activities ● Chemical Research GroupRITE Today 2021

DAC in cooperation with Kanazawa University and pri-

which is a stable compound, by reacting with CO2 (Fig.

vate companies in this project: the following three items

9). By combining the unique processes developed bywill be developed to establish carbon recycling technol-

RITE and R&D skills with the technological capabilities

ogies that capture CO2 from the atmosphere and con-and broad insights of the two leading steel and cement

vert the recovered CO2 into valuable resources.

industries, synergistic effects are expected for techno-

R&D items 1: Development of a new solid sorbent

logical development.

material for low-concentration CO2 capture and a system to recover low-concentration CO2 with high efficiency.
R&D items 2: Development of CO2 conversion technology (Fischer–Tropsch synthesis) using an inorganic
separation membrane for synthesizing liquid hydrocarbon fuel from CO2 with high efficiency and low energy
consumption.
R&D items 3: Life cycle assessment (LCA) evaluation

Fig. 9 CO2 fixation as carbonatesand economic evaluation regarding the conversion process to liquid hydrocarbon fuel using CO 2 recoveredfrom the atmosphere.

6. Conclusion
As stated above, the Chemical Research Group hasenergetically promoted the development of CO2 separation and recovery technology mainly for the chemical
absorption method, the solid sorbent method, andmembrane

separation.

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 solidFig. 8 Development of highly efficient direct air capture(DAC) and carbon recycling technologies

sorbent method, we have begun studying combustion
exhaust gas from coal-fired power plants for a 40 tCO2/day scale pilot test from FY 2020. In membrane

In the technology of CO2 fixation as a carbonate, RITE

separation, we confirmed the separation ability of CO2

developed a unique process over many years. Fromand H2 in an actual gas test using a membrane element

2020, JFE Steel Co., Ltd., Taiheiyo Cement Co., Ltd., andfrom coal gasification gas. In addition, we have just be-RITE set up a study group to target steel slag and waste

gun to develop DAC technology newly adopted in NE-concrete and then use alkaline earth metals extracted

DO's Moonshot R&D Project and CO2 fixation technol-from these for utilization with the CO2 emitted from fac-ogy using steel slag and waste concrete.

tories and other facilities. We are cooperating in the de-

The Chemistry Research Group will work vigorously

velopment of technology for recovering as carbonates,on individual research topics with these themes. Among48

R&D Activities ● Chemical Research GroupRITE Today 2021

them, for the themes close to the practical stage, we will
carry out scale-up studies and actual gas tests with theaim of establishing the technology at an early stage. At
the same time, we would like to develop innovativetechnologies and propose CO2 separation and recovery
technologies that can save more energy and reduce
costs.

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