Fabrication, permeation, and corrosion stability measurements of silica membranes for HI decomposition in the thermochemical iodine-sulfur process

Myagmarjav, O.; Shibata, Ai*; Tanaka, Nobuyuki; Noguchi, Hiroki; Kubo, Shinji; Nomura, Mikihiro*; Takegami, Hiroaki

International Journal of Hydrogen Energy, 46(56), p.28435 - 28449, 2021/08

https://doi.org/10.1016/j.ijhydene.2021.06.079

Improvement of HI concentration performance for hydrogen production iodine-sulfur process using crosslinked cation-exchange membrane

Tanaka, Nobuyuki; Sawada, Shinichi*; Yamaki, Tetsuya*; Kodaira, Takahide*; Kimura, Takehiro*; Nomura, Mikihiro*

Chemical Engineering Science, 237, p.116575_1 - 116575_11, 2021/06

https://doi.org/10.1016/j.ces.2021.116575

We have been developing the ion exchange membranes by a radiation grafted polymerization method to improve HI concentration performance for Electro-electrodialysis (EED) in the thermochemical water-splitting hydrogen production iodine-sulfur process. In this work, the crosslinking structures were introduced to the ion exchange membranes. The proton conductivity (), transport number (t), and water permeation factor () of these crosslinked ion exchange membranes were measured and the effect of crosslinks to these performance indexes were investigated. The introduction of crosslinks was found to improve the selectivity of H and water transport (increase of t and decrease of ), although the somewhat decreased. The EED model that we established to discuss the permeation mechanism of EED system was used to theoretically analyze the effect of crosslink on the performance indexes. Based on this analysis of measurement results, the introduction of the crosslink was found to little affect the absorbed amount of HIx solution and H diffusion coefficient in the tested membranes, whereas it could lead to decrease I diffusion coefficient. The results of and t could reflect these effects. In addition, we found the fact that crosslink can inhibit the swelling due to the absorption of the HIx solution. As a result, the value decreased owing to the introduction of crosslink.

Comparison of experimental and simulation results on catalytic HI decomposition in a silica-based ceramic membrane reactor

Myagmarjav, O.; Tanaka, Nobuyuki; Nomura, Mikihiro*; Kubo, Shinji

International Journal of Hydrogen Energy, 44(59), p.30832 - 30839, 2019/11

https://doi.org/10.1016/j.ijhydene.2019.09.132

Research and development on membrane IS process for hydrogen production using solar heat

Myagmarjav, O.; Iwatsuki, Jin; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Ioka, Ikuo; Kubo, Shinji; Nomura, Mikihiro*; Yamaki, Tetsuya*; Sawada, Shinichi*; et al.

International Journal of Hydrogen Energy, 44(35), p.19141 - 19152, 2019/07

https://doi.org/10.1016/j.ijhydene.2018.03.132

Development of ion-exchange membranes for the membrane Bunsen reaction in thermochemical hydrogen production by iodine-sulfur process

Nomura, Mikihiro*; Kodaira, Takahide*; Ikeda, Ayumi*; Naka, Yasuhito*; Nishijima, Haruyuki*; Imabayashi, Shinichiro*; Sawada, Shinichi*; Yamaki, Tetsuya*; Tanaka, Nobuyuki; Kubo, Shinji

Journal of Chemical Engineering of Japan, 51(9), p.726 - 731, 2018/09

https://doi.org/10.1252/jcej.17we183

Thermochemical hydrogen production by the iodine-sulfur process decomposes water into hydrogen and oxygen by combining the chemical reactions of iodine and sulfur. Two types of acids are produced through the Bunsen reaction. To improve the performance of this reaction, ion-exchange membranes for the membrane Bunsen reaction should be developed. In the present study, a cation-exchange membrane was prepared by using a radiation-graft polymerization method. It was found that a divinylbenzene crosslinking procedure was very effective in reducing water permeation through the membrane, and the membrane Bunsen reaction was successfully carried out by using the developed crosslinked membrane. Therefore, the developed crosslinked membrane is a potential candidate for cation-exchange membranes for the membrane Bunsen reaction.

Preparation of an H-permselective silica membrane for the separation of H from the hydrogen iodide decomposition reaction in the iodine-sulfur process

Myagmarjav, O.; Ikeda, Ayumi*; Tanaka, Nobuyuki; Kubo, Shinji; Nomura, Mikihiro*

International Journal of Hydrogen Energy, 42(9), p.6012 - 6023, 2017/03

https://doi.org/10.1016/j.ijhydene.2017.01.074

Static analysis of the thermochemical hydrogen production IS process for assessment of the operation parameters and the chemical properties

Kasahara, Seiji; Onuki, Kaoru; Nomura, Mikihiro*; Nakao, Shinichi*

Journal of Chemical Engineering of Japan, 39(5), p.559 - 568, 2006/05

https://doi.org/10.1252/jcej.39.559

Sensitivity analysis of the operation parameters and the chemical properties in the thermochemical hydrogen production IS process (iodine-sulfur process) was carried out for a static flow sheet. These parameters were evaluated by hydrogen production thermal efficiency, mass flow rate or heat exchange based on heat/mass balance. The most important parameters were concentration of HI after the electro-electrodialysis (EED) cell and apparent transport number of proton of the cation exchange membrane in the EED cell. HI concentration operation should be operated carefully because the parameters for optimum thermal efficiency and for optimum flow rate and heat exchange were different. For the chemical properties, composition at the inlet of the HI decomposition procedure and HIx pseudo-azeotropic composition had great effects. HI concentration after the EED cell should be optimized for each composition. Order of priority for assessment of the operation parameters and chemical properties was determined by the evaluation.

Flowsheet study of the thermochemical water-splitting IS process for effective hydrogen production

Kasahara, Seiji; Kubo, Shinji; Hino, Ryutaro; Onuki, Kaoru; Nomura, Mikihiro*; Nakao, Shinichi*

Proceedings of AIChE 2005 Spring National Meeting (CD-ROM), 8 Pages, 2005/04

Japan Atomic Energy Research Institute (JAERI) has been conducting the research and development on the thermochemical water-splitting IS process for effective hydrogen production using nuclear heat of close to 1000 C that can be supplied from High Temperature Gas-cooled Reactor (HTGR). The activity covers the studies on the process control for the continuous hydrogen production, the process improvements in the HI decomposition procedure and the preliminary screening of corrosion resistant materials of construction. Present status of the study is presented, especially, focusing on the process flowsheeting study concerning the application of membrane process for the HI processing.

Evaluation of thermal efficiency to produce hydrogen through the IS process by thermodynamics

Nomura, Mikihiro; Kasahara, Seiji; Onuki, Kaoru

JAERI-Research 2002-039, 24 Pages, 2003/01

JAERI-Research-2002-039.pdf:1.01MB

Thermal efficiency to produce hydrogen from water through the IS process was evaluated by a viewpoint of thermodynamics. Thermal efficiency is decided by a temperature from a heat source and limited by the works calculated by the Carnot efficiency for any hydrogen production methods. The maximum thermal efficiency is 81.3% for a thermal cycle between 1123K and 733K. The thermal efficiency of the IS process was evaluated by G-T diagrams of each reactions and separation processes. The maximum value is 78.2% without considering the works for separations of acids from water. However, the effects of the works for separations on thermal efficiency are essential for the IS process, because Gibbs energies of separations of acids from water are always positive. The thermal efficiency could be changed from 53.5% to 76.6% by the calculation with or without the separation processes.

Development of ion exchange membranes for water splitting thermochemical IS process

Kodaira, Takahide; Ikeda, Ayumi*; Matsuyama, Emi*; Kono, Nobuho*; Sawada, Shinichi; Yamaki, Tetsuya; Nomura, Mikihiro*

no journal, , 

In the thermochemical water splitting IS process, the Bunsen reaction (SO + I + 2HO = HSO + 2HI) needs to be achieved in an electrochemical cell with an ion exchange membrane, which renders separation procedures unnecessary. As part of a JST-ALCA project, therefore, we have been developing ion exchange membranes for this application by using methods of radiation crosslinking and/or radiation graft polymerization. Our preliminary experiments made it possible to confirm controllability of the degree of grafting, , ion exchange capacity by varying the conditions of the grafting. Importantly, controlling the fixed-charge density of the membrane should both lower permeability of SO and enhance the transport number of H.