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Efficient CO2 capture is indispensable for achieving a carbon-neutral society while maintaining a high quality of life. Since the discovery that ionic liquids (ILs) can absorb CO2, various solvents composed of molecular ions have been developed and their CO2 solubility has been studied. However, it is challenging to optimize these materials to realize targeted properties as the number of candidate ion combinations for designing novel ILs is of the order of 1018. In this study, electronic- structure informatics was applied as an interdisciplinary approach to quantum chemistry calculations, and combined with machine learning to search 402,114 IL candidates to identify those with better CO2 solubility than known materials. Guided by the machine-learning results, trihexyl(tetradecyl)phosphonium perfluorooctanesulfonate was synthesized and it was experimentally confirmed that this IL has higher CO2 solubility than trihexyl(tetradecyl)phosphonium bis(trifluoromethanesulfonyl)amide, which is the previous best IL for CO2 absorption. The method developed in this study could be transferable to gas-absorbing liquids in general, such as deep eutectic solvents (hydrogen-bonded mixed organic solvents in a broad sense), which also have numerous practical applications. Therefore, we believe that our method for developing functional liquids will significantly contribute to the development of a carbon-neutral society.

Theoretical and experimental investigations have been performed to obtain carbonic anhydrase (CA) mimic catalysts that are effective for CO2 absorbents containing highly concentrated amines. One of...

Tetraethylenepentamine (TEPA) and its derivatives were used to functionalize mesocellular silica foam (MSU-F) supports by wet impregnation for utilization as solid sorbents for CO2 capture. TEPA de...

Ab initio quantum chemical calculations, combined with the SMD solvation model, have been conducted to reveal CO2 absorption mechanisms and the origin of the reduced stability of carbamate in aqueous solution of 2-amino-2-methyl-1-propanol (AMP). The calculated Gibbs free energy change for all the elementary steps in the conversion of carbamate to bicarbonate reveals that the reduced thermodynamic stability of AMP carbamate is largely ascribable to the shift of the equilibrium from the carbamate to the zwitterion intermediate, from which CO2 can be released and successively converted to bicarbonate. This feature of AMP is an attribute of the electronic effects of the substitution by methyl groups specifically at the α-carbon. Furthermore, the steric effects of the methyl groups are investigated from a dynamical point of view that suggests a new scenario in which the methyl groups promote the release of CO2 from the zwitterion intermediate.

This work low viscous new amine based non-aqueous solvent (NAS) was developed for recovery of carbon dioxide (CO2) from post-combustion flue gases. The NAS system was made by mixing alkyl-functionalized single amine/polyamine as absorbent and alcohol/non-alcohol as solvent. The developed NAS does not form any precipitate/solid upon exposure to CO2 and showed low viscosity (cP < 20) homogeneous mixture (single phase) at the whole range of CO2 loading with the advantages of higher absorption and regeneration rates, higher cyclic capacities, and higher CO2 recoveries compared to bench mark MEA-based aqueous absorbents.

Amine functionalized materials have been widely investigated as promising candidates for CO2 capture. Tetraethylenepentamine (TEPA) is the commercial amine that has been commonly impregnated into porous supports for post-combustion CO2 capture. Commercial technical-grade TEPA is a mixture of four main ethyleneamine compounds with close boiling points including linear, branched, and two cyclic TEPA products. This study investigated the stability of the four main components of TEPA under accelerated oxidizing conditions. The CO2 adsorption performances of the sorbents containing TEPA components decreased after the exposure to O2. Among the isolated components in commercial TEPA, 1,4,7,10,13-pentaazatridecane displayed the most sensitivity to O2, which were supported by infrared spectroscopic, gas chromatography, and NMR analysis.

Chemical modification of the amino functional groups of amine-impregnated solid sorbents is an effective strategy for drastically improving the regeneration performance for CO2 capture. In this study, isopropyl groups were introduced into tetraethylenepentamine (TEPA) to obtain N-(isopropyl)-TEPA (IP-TEPA), which was impregnated in mesocellular silica foam (MSU-F). The obtained solid sorbent enabled low-temperature regeneration with a low regeneration energy. To clarify the role of the IP groups, experimental and computational methods were used to compare the IP-TEPA/MSU-F sorbent with TEPA/MSU-F in terms of CO2 working capacity, reaction product stability, self-diffusion coefficient, 13C spin–lattice relaxation time, and CO2 capture performance in steam-aided vacuum swing adsorption.

In the present paper, we investigated CO 2 capture with six amine based absorbents, including three formulated solvents. Aqueous solutions of the amines (mass fraction; 30% for single amine and >30% for blended solvents) were used to evaluate the performance for CO 2 capture. Gas scrubbing, vapor-liquid equilibrium (VLE), and reaction calorimetry experiments were conducted in the laboratory to obtain the absorption rate, the amount of CO 2 absorbed, cyclic CO 2 capacity, and heat of reaction for each absorbent. The results of these absorbents were compared with the conventional amine absorbents (MEA, AMP, DEA, and MDEA). Three high performing formulated absorbents (RN-1, RN-2, and RN-3) were developed, and these had lower heats of reaction, higher cyclic capacities, and comparable absorption rates compared with MEA. Some blended solvents were already demonstrated with real blast furnace gas at pilot test plants with capacities of 1 ton-CO 2 /day and 30 ton-CO 2 /day and showed promising results in terms of reducing absorbent regeneration energy.

Tetraethylenepentamine (TEPA) components are separated by fractional distillation, and the structure of each fraction is established using spectroscopic methods. Then, solid sorbents incorporating these components are prepared, and the capacities and rates of CO2 absorption of the sorbents are evaluated to elucidate how the molecular structure affects the absorption performance.

A novel amine-based solid sorbent was prepared for CO 2 capture, and the CO 2 adsorption characteristics were evaluated for simulated flue gas. Furthermore, CO 2 capture tests using a lab-scale three-column fixed-bed system were performed. A novel amine compound was synthesized by attaching hindered functional groups to the terminal primary amino groups of a polyamine, followed by impregnation into pelletized mesoporous MSU-F silica. This novel amine-impregnated solid sorbent overcame the problem of limited CO 2 diffusion and exhibited extremely high regenerability even at low temperatures. Lab-scale CO 2 capture tests suggested that operation conditions such as temperature, cycle time, rinsing time, flow rate, and regeneration method directly affected CO 2 capture performance. In particular, direct low-temperature steam stripping desorption drastically enhanced CO 2 capture performance. Steam-aided vacuum swing adsorption (SA-VSA) process was feasible for our amine-based solid sorbent and enabled the recovery of CO 2 with high purity (>98%) and recovery rate (>93%). The regeneration heat calculated from the amount of recovered CO 2 and the amount of supplied steam was considerably lower (1.47 GJ/t-CO 2 ) than that of liquid amine solvents and other amine-based solid sorbents.

The iron and steel industry accounts for a considerable percentage of CO2 emissions from industrial sector and is a main application target for promoting the implementation of CCS (Carbon dioxide capture and storage) as a global warming countermeasure technology. RITE has conducted research and development (R&D) on chemical absorption that separates and recovers CO2 from blast furnace gas for more than 10 years, and has been successful in developing new absorbents with low energy consumption. This report presents the results obtained from RITE’s R&D activities.

COURSE50 (ultimate reduction of CO2 in the steelmaking process through innovative technology for Cool Earth 50) aims to capture, separate, and recover CO2 from blast furnace gas. From a practical realization viewpoint, three points are important. The first is energy consumption to regenerate the absorbent, second is the energy cost of the heat for regeneration, and third is the facility cost. The advantage afforded by the COURSE50 approach in relation to the CO2 capture process is the utilization of unused waste heat from the steel mills. Energy consumption to regenerate the absorbent is determined mainly by three factors: the regeneration reaction determined primarily by the structure of the chemical absorbent, the energy required to heat that volume of absorption liquid, which is affected by the absorption rate of the agent, and the heat loss from the processes. The most influential factor is the energy required for the regeneration reaction. We discovered high-performance absorbents with the advantages of high absorption rates, high cyclic capacities, and low heats of reaction, and we then compared these with monoethanolamine (MEA) and N-methyldiethanolamine (MDEA). The newly discovered absorbents performed well in terms of absorption rates and cyclic capacities. Among these absorbents, some showed lower heats of reaction than MDEA. These results provide a basic guideline for the discovery of potential amine-based absorbents that may lead to the development of new absorbent systems for CO2 capture.

The present study was aimed at developing a non-aqueous absorbent system that does not form any precipitate/solid upon exposure to CO2. More specifically, the non-aqueous absorbent system must be a homogeneous mixture (single phase) within the whole range of CO2 loading. At the same time, sufficient amine regeneration must occur at a low temperature of 80–90 °C compared to reference non-aqueous monoethanolamine (MEA)-based absorbents. To achieve this target, 18 alcohols were investigated as solvents and 4 alkyl-linked alkanolamines were evaluated as absorbents. Several experiments mixing alkanolamines with alcohols were performed to evaluate their CO2 capture performance. High-performance non-aqueous liquid absorbents (without solid/precipitate formation) with the advantages of higher absorption rates, higher cyclic capacities, higher regeneration efficiencies, lower specific heats, and lower heats of reaction compared to reference MEA-based non-aqueous absorbents were successfully developed herein. The favorable features of these absorbents will provide the basis for the discovery of potential non-aqueous amine-based absorbents.

In the present paper, we investigated five synthetic amine based absorbents, including three formulated solvents. Aqueous solutions of the amines (mass fraction; 30% for single amine and >30% for blended solvents) were used to evaluate the performance for CO 2 capture. Gas scrubbing, vapor-liquid equilibrium (VLE), and reaction calorimetry experiments were conducted in the laboratory to obtain the absorption rate, the amount of CO 2 absorbed, cyclic CO 2 capacity, and heat of reaction for each absorbent. The results of these absorbents were compared with the conventional absorbent monoethanolamine (MEA). Three high performing synthetic absorbents (IPAE, IPAP and IBAE) were found, and these had lower heats of reaction, higher cyclic capacities, and comparable absorption rates compared with MEA. All formulated absorbents showed excellent cyclic CO 2 capacity and keeping moderately good absorption rate and lower heats of absorption. Some blended solvents were already demonstrated with real blast furnace gas at pilot test plants with capacities of 1 ton-CO 2 /day and 30 ton-CO 2 /day and showed promising results in terms of reducing absorbent regeneration energy.

The solubility of CO 2 was measured in aqueous solutions of 2-(isopropylamino)ethanol (IPAE) and 2-(propylamino)ethanol (PAE) at 313 K, 373 K and 393 K and CO 2 partial pressures ranging from 5 kPa to 0.2 MPa. With different CO 2 loadings, speciation analyses were conducted by accurate quantitative 13 C nuclear magnetic resonance spectroscopy using inverse-gated decoupling. IPAE had a larger capacity for CO 2 than PAE because of the dominant formation of bicarbonate rather than carbamate. However, a significant amount of carbamate was also observed with low CO 2 loadings in the IPAE solutions. The results for these secondary amine solutions were compared with those of the primary amines monoethanolamine and 5-aminopentanol.

In the present paper, we investigated CO2 capture with 24 tertiary amine absorbents, including three synthetic amines, with systematic modification of their chemical structures. Aqueous solutions of the amines (mass fraction 30%) were used to evaluate the performance for CO2 capture. Gas scrubbing, vapor–liquid equilibrium (VLE), and reaction calorimetry experiments were conducted in the laboratory to obtain the absorption rate, the amount of CO2 absorbed, cyclic CO2 capacity, and heat of reaction for each absorbent. The results for these absorbents were compared with the conventional tertiary absorbent N-methyldiethanolamine (MDEA). Seven of the investigated absorbents performed well with high absorption rates and cyclic capacities. Among these absorbents, some showed lower heats of reaction than MDEA. These results provide basic guidelines for discovery of potential tertiary amine-based absorbents that may lead to development of new absorbent systems in the CO2 capture area.

In the present paper we investigated seven synthetic and eleven commercial amine based absorbents with systematic modification of their chemical structures. A 30 wt% of these aqueous amine solutions were used for performance evaluation. Three laboratory experiments, which were gas scrubbing test, reaction calorimetry and vapor-liquid equilibrium measurement, were conducted in order to obtain fundamental information on their absorption rate, saturated CO 2 loading, absorption capacity, heat of reaction and cyclic capacity. The results of these absorbents were then compared with conventional absorbents MEA and MDEA which were chosen as the base case for all comparisons. We found four high performance absorbents with advantages of high absorption rate, high cyclic capacity and low heats of reaction compared with MEA and MDEA. It is expected that the use of lower reaction enthalpy and higher absorption rate can reduce absorbent regeneration energy costs significantly. The results presented in this paper can provide basic guidelines for finding potential secondary and tertiary amine based absorbents that may lead to a better approach for the development of new absorbent systems in the CO 2 capture area.

Ab initio calculations combined with the continuum solvation model have been conducted to obtain complete reaction pathways involved in the CO2 capture into monoethanol (MEA) aqueous solution. We have investigated the reaction pathways for the decomposition of MEA carbamate into bicarbonate. Although the already known pathways invoke a generation of free CO2(aq), we are concerned with another mechanism which does not involve such an intermediate. The neutral hydrolysis of the MEA carbamate was found to be a slow reaction that has an essentially two-step nature. We propose an alternative pathway that involves the carbamic acid as an intermediate that undergoes an alkaline hydrolysis leading to the formation of bicarbonate. Taking account of the novel reaction pathways elucidated here as well as the established routes for the formation of carbamate and bicarbonate may lead to a comprehensive understanding and a better prediction of the chemical CO2 capture process under specific conditions including pH (concentration of amine) and partial pressure of CO2.

Various N-tert-butoxycarbonyl (N-Boc) amino acids, such as glycine, valine, and serine, were combined to 4-chloromethylstyrene. The resulted monomers were readily polymerized to give polystyrenes tethering an amino acid by a conventional free radical polymerization technique. After deprotection of the N-Boc group with trifluoroacetic acid, the obtained polystyrene derivatives were soluble in ethanol and spin-coated on a commercial poly(ether sulfone) porous membrane to fabricate a composite membrane for CO2 separation over H2. The CO2 selective layer of synthesized PSt was ca. 200 nm thick, and the composite membranes showed preferential CO2 separation over H2, while parent polystyrene passed through H2 rather than CO2. Especially, the separation factor \( \alpha_{{{\text{CO}}_{ 2} /{\text{H}}_{ 2} }} \) was raised after alkaline treatment to form free primary amine on the terminus of graft chain. Serine tethered polystyrene showed the highest \( \alpha_{{{\text{CO}}_{ 2} /{\text{H}}_{ 2} }} \) (16) among them, which suggested the hydroxyl group would enhance the CO2 affinity of primary amine.

In order to establish energy-saving technology for CO 2 capture from blast furnace gas, novel absorbents were developed in the laboratory and evaluated at a 1 t CO2 /d test plant. At first, CO 2 absorption and desorption behaviors of single-component amine solvents for simulated blast furnace gas (CO 2 /N 2 = 20%/80%) were investigated through a screening test using a small scrubbing bottle. These amine solvents were additionally analyzed using nuclear magnetic resonance ( 13 C NMR) spectroscopy and reaction calorimetry. The results of the laboratory experiments showed that there was a trade-off between absorption rate and enthalpy of absorption but some absorbents had unique features. For example, 2-isopropylaminoethanol (IPAE) had high absorption rate and small enthalpy of absorption. Then, new IPAE-based amine solvents (RITE solvents: RITE-A and RITE-B) were formulated and evaluated at the 1 t CO2 /d test plant. CO 2 regeneration energies of the RITE solvents were 3.3 and 3.1 GJ/t CO2 , respectively. With certain process conditions and plant specifications optimized, RITE-B was estimated to have the potential to achieve 2.5 GJ/t CO2 .

This work focuses on synthesizing and selecting hindered new amine absorbents to reduce the regeneration energy cost for CO2 capture. To achieve this target we synthesized seven secondary and two tertiary amine based CO2 absorbents with systematic modification of their chemical structures by an appropriate placement of substituent functional groups especially the alkyl functions (e.g. methyl, isopropyl, isobutyl, secondary butyl etc.), relative to the position of the amino group. Performances evaluations of these new absorbents in aqueous solutions were carried out based on their CO2 absorption rate, absorption capacity and heat of reaction measurements. Particular attention was paid to absorbents with a potential for high absorption rate and low heats of reaction. The results for the synthesized amino alcohols were then compared with conventional absorbents AMP and MDEA which were chosen as the base case for all comparisons. We found three high performance absorbents with advantages of high absorption rate and low heats of reaction compared with AMP and MDEA. Absorbents higher CO2 absorption rate and lower heat energy consumption characteristics will reduce the regeneration energy cost of CO2 during stripping.

A conductor-like screening model for real solvents (COSMO-RS) was applied to the study of the amine−H2O−CO2 system. pKa values for 25 amines including a variety of alkanolamines and some cyclic or aromatic amines were calculated by the COSMO-RS method coupled with the density functional theory (DFT). The predictions of pKa values were compared using different DFT levels for geometry optimization and also with those based on another solvation model (SM5.4/A). The DFT-COSMO calculation at the BP/TZVP level has shown a relatively good correlation with experimental values for the 25 amines (R2 ≅ 0.8) at a low computational cost. With this method, we have developed a calculation model to predict the equilibrium ratio between carbamate and bicarbonate anions in a CO2-loaded aqueous amine solution and have confirmed the validity of the prediction model by 13C NMR spectroscopy.

To improve the CO 2 separation performance of a poly(amidoamine) (PAMAM) dendrimer composite membrane, the addition of hyaluronic acid (HA) in a chitosan (CTS) gutter layer and the application of a novel hydroxyl PAMAM dendrimer for CO 2 selective material are proposed. The addition of HA in the coating solution for CTS gutter layer formation increased the swelling degree of the corresponding CTS–HA film and led to an increased CO 2 permeance of the resulting composite membrane, and a decrease in the CO 2 /N 2 separation factor. A PAMAM dendrimer composite membrane with CTS–HA(20) gutter layer, which was prepared with a coating solution of 20 wt.% HA solid content, showed a high permeance of 10.0 × 10 −10 m 3 (STP) m −2 s −1 Pa −1 while maintaining a high CO 2 separation factor of 130. The HA addition increased the PAMAM dendrimer content in the gutter layer. A composite membrane prepared with a novel hydroxyl PAMAM dendrimer in the CTS–HA(20) gutter layer exhibited an excellent CO 2 /N 2 selectivity of 1100 and CO 2 permeance of 8.8 × 10 −10 m 3 (STP) m −2 s −1 Pa −1 .

The reaction of N,N′-oligomethylenebis(3-oxobutanamide)s with 1,1-diarylethenes in the presence of manganese(III) acetate in acetic acid at 100° produced N N′-oligomethylenebis(2-methyl-5,5-diaryl-4,5-dihydrofuran-3-carboxamide)s. Similarly, the reaction of 3-oxobutanamidoethyl 3-oxobutanoate or N,N′-(3,6-dioxaoctamethylene)bis(3-oxobutanamide) with 1,1-diphenylethene gave (2-methyl-5,5-diphenyl-4,5-dihydrofuran-3-amido)ethyl 2-methyl-5,5-diphenyl-4,5-dihydrofuran-3-carboxylate or N,N′-(3,6-dioxa-octamethylene)bis(2-methyl-5,5-diphenyl-4,5-dihydrofuran-3-carboxamide) in moderate yields.

The palladium-catalyzed reduction of 1-hydroxy-8-aza-2,3-dioxabicyclo[4.3.0]nonanes, which were readily obtained by the manganese(III)-mediated oxidative formal [2+2+2] cycloaddition of pyrrolidinedione derivatives with alkenes and molecular oxygen, led to formal extrusion of one of the peroxide oxygens and produced 1-hydroxy-7-aza-2-oxabicyclo[3.3.0]octanes in quantitative chemical yields.

A simple azabicyclic peroxide synthesis was achieved by the manganese(III)-mediated oxidative formal [2+2+2] cycloaddition. A mixture of tetramic acid derivatives and alkenes was oxidized with manganese(III) acetate under a dry air stream to give 1-hydroxy-8-aza-2,3-dioxabicyclo[4.3.0]nonan-7-ones in good to quantitative chemical yields.

The free sugars and fatty acids (both free and bound) of different parts of jackfruit (Artocarpus heterophyllus) were isolated. The sugars and fatty acids were identified and quantified by gas-liquid chromatography as their trimethylsilyl derivatives and methyl esters, respectively. Fructose, glucose and sucrose were found to be the major sugars in all parts of jackfruit, except in the bark, which is devoid of glucose. Capric, myristic, lauric, palmitic, oleic, stearic, linoleic and arachidic acids were found as major fatty acids with varying proportions in different parts of jackfruit.

Ab initio molecular orbital calculations combined with the polarizable continuum model (PCM) formalism have been carried out for a comprehensive understanding of the mechanism of carbon dioxide (CO2) absorption by aqueous amine solutions. CO2 is captured by amines to generate carbamates and bicarbonate. We have examined the direct interconversion pathways of these two species (collectively represented by a reversible hydrolysis of carbamate) with the prototypical amine, monoethanolamine (MEA). We evaluate both a concerted and a stepwise mechanism for the neutral hydrolysis of MEA carbamate. Large activation energies (ca. 36 kcal/mol) and lack of increase in catalytic efficiency with the inclusion of additional water molecules are predicted in both the mechanisms. We also examined the mechanism of alkaline hydrolysis of MEA carbamate at high concentrations of amine (high pH). The addition of OH(-) ion to carbamate anion was theoretically not allowed due to the reduction in the nucleophilicity of the former as a result of microsolvation. We propose an alternative pathway for hydrolysis: a proton transfer from protonated MEA to carbamate to generate the carbamic acid that initially undergoes a nucleophilic addition of OH(-) and subsequent low-barrier reactions leading to the formation of bicarbonate and free MEA. On the basis of the calculated activation energies, this pathway would be the most efficient route for the direct interconversion of carbamate and bicarbonate without the intermediacy of the free CO2, while the actual contributions will be dependent on the concentrations of protonated MEA and OH(-) ions.

We investigated the solubility of CO2 in aqueous solutions of alkanolamines at 40C and 120C over CO2 partial pressures ranging from a few kPa to 100 kPa to evaluate the potential for CO2 capture from flue gas. CO2 capacities were compared between monoethanolamine, N-ethyl ethanolamine and N-isopropyl ethanolamine. Speciation analyses were conducted in the alkanolamine solutions at different CO2 loadings by accurate quantitative 13 C nuclear magnetic resonance spectroscopy. N-isopropyl ethanolamine showed a large capacity for CO2 because of the formation of bicarbonate. However, we also found that at a lower CO2 loading a significant amount of carbamate was present in the aqueous N-isopropyl ethanolamine solutions.

A simple azabicyclic peroxide synthesis was achieved by the manganese(III)-mediated oxidative formal [2+2+2] cycloaddition. A mixture of tetramic acid derivatives and alkenes was oxidized with manganese(III) acetate under a dry air stream to give 1-hydroxy-8-aza-2,3-dioxabicyclo[4.3.0]nonan-7-ones in good to quantitative chemical yields.

The palladium-catalyzed reduction of 1-hydroxy-8-aza-2,3-dioxabicyclo[4.3.0]nonanes, which were readily obtained by the manganese(III)-mediated oxidative formal [2+2+2] cycloaddition of pyrrolidinedione derivatives with alkenes and molecular oxygen, led to formal extrusion of one of the peroxide oxygens and produced 1-hydroxy-7-aza-2-oxabicyclo[3.3.0]octanes in quantitative chemical yields.

Japanese government declared a goal to reduce CO 2 emissions to half of those in 2005 as the objective “Cool Earth 50”. One promising means of reducing CO 2 emission is the development of integrated coal gasification combined cycle with CO 2 capture & storage (IGCC-CCS). In the IGCC-CCS process, CO 2 separation membranes will play an important role for reducing CO 2 capture costs. Estimates indicated that the CO 2 capture cost from a pressurized gas stream using a membrane would be 1,500 JPY/ton- CO 2 or less. We are currently developing CO 2 molecular gate membrane, with the goal of producing a new, high-performance separation membrane modules. In the concept of the molecular gate membrane, the pathway for gas molecules is occupied solely by CO 2 , which acts as a gate to block the passage of other gases. Consequently, the amount of H 2 permeating to the permeate side of the membrane is greatly limited and high concentrations of CO 2 can be obtained. Poly(amidoamine)(PAMAM) dendrimers, candidate materials for molecular gate membranes, shows high separation performance in separation of CO 2 /N 2 and CO 2 /H 2 . In RITE, PAMAM dendrimer/polymer hybrid membranes were developed for CO 2 separation from flue gas (CO 2 /N 2 ) and from IGCC process (CO 2 /H 2 ). Although dendrimer itself is viscous liquid, the dendrimer/polymer hybrid membranes are stable under pressure difference conditions, and thus suitable for practical use. The CO 2 /H 2 selectivity of the membrane showed more than 30, which is required to apply membrane modules for IGCC process. From these results, a PAMAM dendrimer/polymer hybrid membrane is a promising candidate for IGCC process with CO 2 capture. Based on these materials, modification of membrane materials is ongoing to improve CO 2 separation performance further. In the development of commercial membrane modules using the PAMAM dendrimer/polymer hybrid materials, RITE, Kuraray Co., Ltd., Nitto Denko Corporation and Nippon Steel Engineering Co., Ltd. established Molecular Gate Membrane module Technology Research Association, and membrane materials, membrane modules and separation systems are being developed with collaboration in the research association.