R&D Activities ● Inorganic Membranes Research Center

RITE Today 2021

Inorganic Membranes Research Center
Members (As of Dec. 2020)
Shin-ichi Nakao, Director of the Center, Chief Researcher
Yuichiro Yamaguchi, Deputy-Director, Chief Researcher
Hidetoshi Kita, Chief Researcher
Masahiro Seshimo, Senior Researcher
Kenichiro Yasuhara, Senior Researcher
Makoto Ryoji, Senior Researcher
Hye Ryeon Lee, Researcher

Hiromi Urai, Research AssistantYuko Nara, Research AssistantKazuaki Sasa, Research AssistantNobuaki Oono, Research AssistantChiyoko Shindo, Research Assistant
Akiyoshi Fujii, Research AssistantKeiko Komono, Research AssistantResearch and Development of Innovative Environmental and Energy
Technologies that Use Inorganic Membranes and Efforts for Practical
Use and Industrialization
1. Introduction

partment, hydrogen separation, purification, manufac-

Inorganic membranes, such as silica membranes andturing, separation, and recovery are performed using

zeolite membranes, have the features of excellent heatsilica membranes, zeolite membranes, and palladium

resistance and environmental resistance, in addition tomembranes, each of which offers excellent characteris-high separation performance, and are expected to ap-tics. We are conducting research on the ways to more

ply to various applications. Compared to the conven-effectively use the CO2 produced. In the Industrial Col-tional separation and purification methods of distilla-

laboration Department, the Industrialization Strategy

tion and adsorption, inorganic membranes can save en-Council, which consists of 18 companies of inorganic

ergy, and they are also being developed for CO 2 sepa-

separator and support substrate manufacturers andration and purification, as well as for hydrogen separa-user companies, aims to share the vision among manu-tion and purification, which are indispensable for a so-facturers and user companies by planning joint research.

ciety that intends to use hydrogen in practical ways.

Member companies have regular opportunities to share

Therefore, the use of the membranes is attracting aideas and promote activities through study groups.

great deal of attention as an environmental and energy

In 2020, we constructed a membrane reactor (MR) us-technology that contributes to the preservation of theing a silica membrane and a palladium membrane in a

global environment. However, practical application has

project that directly decomposes methane and pro-so far been limited to alcohol dehydration. In the future,duces hydrogen, which was commissioned by the New

innovative environmental and energy technologies us-

Energy and Industrial Technology Development Organ-ing inorganic membranes will be required for earlyization (NEDO), and confirmed the high conversion ratecommercialization and industrialization.

of the membrane reactor with this reaction system. We

The Inorganic Membrane Research Center (IMeRC)
has two departments: the Research Department and theIndustrial Cooperation Department. In the Research De-

reported to the committee of NEDO, and the project
was completed.
As for CO2 separation, capture, and utilization (CCU:Carbon Capture and Utilization), we developed a zeolite57

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membrane with high selectivity for water and applied it

the objective was follows: a) development of a high hy-to a membrane reactor to enhance the conversion rate

drogen permselective membrane with durability underfor methanol. We confirmed a three-fold improvement

high temperature conditions (>500°C), b) developmentin the conversion rate compared to conversion in theof a catalyst that activates at relatively low reaction tem-reactor. In addition, NEDO's Moonshot research andperatures for the membrane reactor, and c) the devel-development program was commissioned jointly withopment of membrane reactors consisting of a hydrogen

Kanazawa University and the Chemical Research Groupseparation membrane and a catalyst with a demonstra-for the development of highly efficient direct air capturetion of their effectiveness. (Fig. 1)(DAC) and carbon recycling technologies, and IMeRC
conducts research to develop a process to produce liquid fuel from the CO2 collected from the atmosphere
At the Industrialization Strategy Council, the second
phase (2019–2020) of the Common Base (ReliabilityEvaluation Method) Research Group and the CO2 Separation Research Group was completed, and seminars
were held on the Web.
This paper introduces the main achievements and future prospects of the research division, such as hydro-Fig. 1 Application of a membrane reactor to the hydrogengen production from methane and CCU technology de-production process from methane decomposition

velopment, and the status of the activities of the Industrialization Strategy Council.

For the development of a hydrogen permselective
membrane in a), silica and palladium membranes are

2. Development of CO2-free hydrogen production tech-candidates. The guidelines for membrane formation

nology from methane decomposition

were narrowed down based on membrane formation

To realize a society that relies on hydrogen, a method

experiments and literature searches. The development

is required to produce hydrogen at low cost and in largeof silica membranes was examined using various silica

quantities. With the focus on methane, which can besources, and the silica source was selected by evaluat-

stably supplied for a long time because of the shale gas

ing permeation separation performance. As a result, werevolution, hydrogen and solid carbon are produced bywere able to achieve the target performance for thispyrolysis, and hydrogen production costs can be re-project with a membrane using dimethoxydime-

duced by selling the carbon. A membrane reactor,thylsilane (DMDMS: a silicon compound in which two

which is applied to that reaction, could produce hydro-

methyl groups and two methoxy groups are bonded togen at low cost and save on energy consumption. In ad-Si as the center) as a silica source. Furthermore, by care-dition, the process has the advantage of not emitting

fully examining the membrane formation conditions forcarbon dioxide and is a technological development thatDMDMS, it was possible to form silica membranes that

contributes to a decarbonized society.

exhibited high heat resistance (Fig. 2).

Adopted as a contract project of NEDO in FY 2019,58

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candidates. Regarding the catalysts, 20 types with different preparation conditions, such as coprecipitation
temperature, dropping method, type of precipitant, andcomposition, were prototyped, and as a result of evaluating the reactivity, a catalyst with relatively high performance was selected for the membrane reactor. (Fig.
3)

Fig. 2 Results of heat durability tests of silica membranes

Fig. 3 Trial production and performance evaluation of cat-with different membrane forming conditions

alysts for methane decomposition

Regarding the development of palladium mem-Regarding the development of the membrane reactor

branes, we examined the membrane formation condi-in c), a membrane reactor was designed and manufac-tions of Pd-Cu alloy membranes, which are expected totured, and a membrane reaction test was conducted us-improve heat resistance while maintaining high hydro-

ing the Ni/Fe/Al2O3 catalyst selected in b) and a palla-

gen permeability, as a pore-filled membrane, which isdium membrane and a silica membrane were chosen

an inorganic membrane developed by the RITE Re-for use as the hydrogen separation membrane. A reac-search Center of Technology. It was confirmed from thetion test was performed. It was confirmed that the con-SEM-EDX of the formed membrane that the membraneversion rate was improved by applying the Pd mem-

could be formed with the desired composition (Pd 60brane and the silica membrane under the conditions ofCu 40 wt%). Furthermore, by scrutinizing the membranea reaction temperature of 600°C and a reaction pressureformation conditions, the hydrogen permeability of theof 0.4 MPa, the effectiveness of the membrane reactor

intrapore-filled Pd membrane at 500°C was improved to

was demonstrated, and it was confirmed that the ob-

1.3 x 10-6 mol m-2 s-1 Pa-1 (previously 8 x 10-7). We devel-tained carbon has a structure in which graphene is lam-

oped a hydrogen permeable membrane with heat re-inated around the catalyst (Fig. 4).

sistance and achieved the target performance.

On the other hand, the hydrogen permeation perfor-Regarding the catalyst development in b), we con-mance of the Pd membrane after the test was reduced

ducted a literature survey targeting hydrogen produc-

to about one-half. From the SEM-EDX results of thetion by direct decomposition of methane in Japan andmembrane after the test, it was confirmed that carbon

other countries, grasped the technological develop-

was dissolved in the Pd layer, suggesting that the de-ment trends, and investigated catalysts that could becrease in hydrogen permeation performance was due

applied to membrane reactors. As a result, Ni/Fe/Al2O3

to the solid solution of carbon. We are working on

catalysts, which have been reported to produce highcountermeasures for the new issue.

yields at relatively low temperatures, were selected as59

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CO2 + 3H2 ⇄ CH3OH (methanol) + H2O

To solve these problems, a membrane reactor can beapplied to the application because generated water canbe removed from the reaction system through themembrane, and the reaction will be promoted to themethanol producing side. However, it is difficult to apply the A-type zeolite (LTA) membrane, which is often
used for water separation, from the viewpoint of hydroFig. 4 Results of membrane reaction test using palladium
membrane and SEM image of obtained carbon

thermal stability.
Herein, we successfully developed a novel zeolite
membrane for water separation, which has higher hy-3. CO2 utilization technologies in RITEdrothermal stability compared to the conventional LTA-

Recently, CO2 utilization technologies have been ac-

type zeolite membrane. The membrane was applied totively researched and developed in countries aroundthe membrane reactor for methanol synthesis via CO2

the world, including the EU, as being effective in reduc-hydrogenation, and the CO2 conversion from the mem-ing CO2 emissions. On the other hand, in the hydro-

brane reactor showed higher rates than those from a

genation of CO2, water is generated by the reaction,

conventional packed-bed reactor (Fig. 5). In the future,

which decreases the reaction rate. In addition, most re-we will proceed with research and development of prac-actions are exothermic, and the removal of the reaction

tical uses for the methanol synthesis membrane reactor.

heat is one of the problems. In order to solve theseproblems, highly efficient, energy-saving CO2 utilization
technology has been developed at the Inorganic Membranes Research Center using a membrane reactor.

3.1. Development of effective methanol synthesis fromCO2 hydrogenation
Methanol is an important intermediate for chemical
products, and demand is expected to grow in the future.
Methanol is mainly synthesized using syn-gas (mixturegases of CO and H2); however, synthesis requires hightemperatures and pressure. Generally, Cu/ZnO-based
catalysts are used with the reaction within the temperature range of 473–573 K. On the other hand, the one-Fig. 5 Membrane reactor for methanol synthesis using apass yield shows low values owing to thermodynamic

zeolite membrane

equilibrium limitations. This is remarkable in the methanol synthesis from CO2 hydrogenation represented by
the following reaction formula.

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3.2. Development of liquid hydrocarbon fuel synthesis

the reaction field via hydrogen permselective mem-technology using CO2 as a raw material captured frombranes, such as a silica and palladium. We succeeded in

the airdeveloping the Si-rich LTA-type zeolite membrane with

The NEDO project Moonshot Research & Develop-

improved hydrothermal stability compared to the con-ment Program was adopted in collaboration with Kan-ventional LTA-type zeolite membrane. We are also in-azawa University since 2020. At the IMeRC, we acceptedvolved in the development of pore-filled Pd membranes

the challenge of developing the technology to convert

and silica membranes with excellent hydrogen perm-

the captured CO2 into liquid hydrocarbon fuel by FT

selectivity. In the future, we will make the best use of(Fischer-Tropsch) synthesis. Similar to methanol synthe-

the knowledge we acquired and strongly promote thesis, the water produced from the reaction causes cata-development of inorganic membranes and membranelyst deactivation and a reaction rate reduction in FT syn-reactors applicable to FT synthesis. We then intend tothesis. Another problem was that reaction control wasunravel the science of inorganic membranes that wedifficult because the product followed the ASF (Ander-have left unattended.

son-Schulz-Flory) distribution.
4. Activities and efforts toward commercialization andindustrialization
The core of the industrial collaboration department ofthe IMeRC is the Industrialization Strategy Council. A total of 18 separation membrane and support manufacturers and user companies (as of January 2021) participate on this council. Our goal is to establish an inorganicFig. 6 Overview of the Moonshot project at RITE

membrane industry that contributes to innovative environmental and energy technologies by promoting aTherefore, in this project, we will develop high effi-common vision for manufacturers and user companies,

ciency, energy-saving CO2 utilization technology fromas well as a joint research plan involving national pro-the CO2 captured from the air as the raw material forjects and other initiatives.

the membrane reactor. Research and development
items are as follows.
a) Development of a membrane applicable to FT synthesisb) Development of a membrane reactor for FT synthesis

We are promoting a variety of activities, which include
the following:a) Sponsoring needs and seeds matching meetings
toward the practical use of innovative environmental and energy technologies that use inorganic
membranes, and the establishment and operationc) Search for the optimal process structureof a research group that will prepare the future

Catalyst deactivation can be suppressed if the gener-roadmap

ated water can be removed from the reaction side byusing a hydrophilic membrane, such as zeolite. Furthermore, the reaction can be controlled by supplying H2 tob) Planning joint implementation projects funded by
the government and NEDOc) Acceptance of researchers from council members

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to the Research Section of the IMeRC and the im-branes, the seminars have been highly rated as mean-plementation of training workshops

ingful places for interaction between member compa-d) Offering technical guidance from the IMeRC Advi-nies and front-line researchers.

sory Board and Research Sectione) Hosting exclusive technology seminars for council
membersf) Offering exclusive supply services (Needs and Seeds
Technology Information) to council members

In 2020, because of the relationship with the COVID19 virus, although there were some changes from theoriginal plan, such as postponing the holding of work-Fig. 7 Lecture at the Seminar (April 2019)

shops, a working group was established that would use
the Web and promote studies as the CO2 Separation

5. In conclusion

Study Group and the Common Infrastructure (reliabilityIn 2020, we constructed a membrane reactor (MR) inevaluation, etc.) Study Group and subordinate organi-a project that directly decomposes methane and pro-zation. The group met a total of four times as the CO2duces hydrogen, which was commissioned by NEDO,Separation Study Group and a total of seven times as

and confirmed the high conversion rate of the mem-the Common Infrastructure (reliability evaluation, etc.)

brane reactor with this reaction system. We reported toStudy Group, and they further deepened the investiga-

the committee of NEDO. Regarding this project, a newtion. The Common Infrastructure Study Group aims toproject is scheduled to start in 2021, and we plan tolaunch a government-sponsored project after 2021 bywork toward more practical use through this project.

conducting a concrete preliminary test for accelerated

Steadily achieved results in research and develop-

deterioration of zeolite membranes and to acquire basic

ment made effective use of CO2; in addition, NEDO's

data for establishing long-term reliability. The CO2 Sep-

Moonshot research and development program wasaration Study Group studied the main theme of the ap-

commissioned for the development of highly efficientplicability of inorganic membranes to natural gas fields

direct air capture and carbon recycling technologies,

containing high concentrations of CO2.

and we conduct the research to develop the process on

In addition, seminars for council members were held

produce the liquid fuel from collected CO2 from the at-on the Web (three times a year in FY 2020). In the future,mosphere. With the acquisition of a long-term funded

we plan to give lectures on the latest R&D trends andproject, it will be possible to organize the IMeRC, and inneeds, seeds, and practical development cases of mem-the future, we would like to work diligently to become

branes from advisory boards, member companies, anda core organization that leads the development andmembrane-related companies, and there will be lively

practical application of inorganic membranes in thequestions, answers, and discussions. It is done. In addi-world.

tion to gaining useful knowledge related to the practicalapplication and industrialization of inorganic mem-62