Developing an online composition prediction for an HI-I-HO system using deep neural network

Tanaka, Nobuyuki; Takegami, Hiroaki; Noguchi, Hiroki; Kamiji, Yu; Myagmarjav, O.; Ono, Masato; Sugimoto, Chihiro

Chemical Engineering Science, 299, p.120479_1 - 120479_11, 2024/11

https://doi.org/10.1016/j.ces.2024.120479

We developed a deep neural network method to predict the composition of the iodine-sulfur process of thermochemical water-splitting hydrogen production using measurable properties. Unlike conventional titration analysis, this approach allows a quick understanding of fluid composition, providing essential information for controlling operating conditions. This study focused on the HI-I-HO three-component system within the IS process. Using Gibbs phase rule, the DNN model was constructed using online measurable parameters, such as temperature, pressure, and density, as input conditions. The model was trained with experimental data, and the structural parameters were tuned. Composition prediction using actual trend data demonstrated good correlation with titration analysis measurements. Furthermore, the local interpretable model-agnostic explanations method was incorporated to gain insights into the significance of input parameters for compositions from the DNN model, providing valuable information on crucial parameters for effective composition control.

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

Hydrogen production using thermochemical water-splitting iodine-sulfur process test facility made of industrial structural materials; Engineering solutions to prevent iodine precipitation

Noguchi, Hiroki; Kamiji, Yu; Tanaka, Nobuyuki; Takegami, Hiroaki; Iwatsuki, Jin; Kasahara, Seiji; Myagmarjav, O.; Imai, Yoshiyuki; Kubo, Shinji

International Journal of Hydrogen Energy, 46(43), p.22328 - 22343, 2021/06

https://doi.org/10.1016/j.ijhydene.2021.02.071

An iodine-sulfur process offers the potential for mass producing hydrogen with high-efficiency, and it uses high-temperature heat sources, including HTGR, solar heat, and waste heat of industries. R&D tasks are essential to confirm the integrity of the components that are made of industrial materials and the stability of hydrogen production in harsh working conditions. A test facility for producing hydrogen was constructed from corrosion-resistant components made of industrial materials. For stable hydrogen production, technical issues for instrumental improvements (i.e., stable pumping of the HIx solution, improving the quality control of glass-lined steel, prevention of I precipitation using a water removal technique in a Bunsen reactor) were solved. The entire process was successfully operated for 150 h at the rate of 30 L/h. The integrity of components and the operational stability of the hydrogen production facility in harsh working conditions were demonstrated.

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

Module design of silica membrane reactor for hydrogen production via thermochemical IS process

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

International Journal of Hydrogen Energy, 44(21), p.10207 - 10217, 2019/04

https://doi.org/10.1016/j.ijhydene.2019.02.192

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

Development of a ceramic membrane reactor for hydrogen production from HI decomposition

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

no journal, , 

Study on a membrane reactor equipped with the one-end-closed silica membrane for hydrogen iodide decomposition

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

no journal, , 

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

Sakaba, Nariaki; Inagaki, Yoshiyuki; Myagmarjav, O.; Noguchi, Hiroki; Iwatsuki, Jin; Tanaka, Nobuyuki; Kamiji, Yu; Ioka, Ikuo; Kubo, Shinji

no journal, , 

The research and development program of the IS process using the membrane technology and solar heat is now on progress aiming at improvement of the hydrogen production efficiency up to 40%. In the HSO decomposition reaction process, oxygen production process, the decomposition rate of sulphur trioxide (SO) is expected more than 80% at the reaction temperature of 800 - 900C. On the other hand, the decomposition rate of SO decreases to around 30% in the reaction temperature of 600C which temperature will be provided by solar heat, ceramic oxygen permselective membrane and catalyst have been developing to promote SO decomposition in the reaction temperature of 600C. In addition, the ceramic hydrogen permselective membrane and catalyst to promote HI decomposition for hydrogen production, the cation-exchange membrane and catalyst to reduce amount of iodine in the HI circulation process. Also, the corrosion-resistance material to use metal components in the HSO decomposition process is underway. This work was supported by Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), energy carrier (Funding agency: JST).

A Highly hydrogen permeable silica membrane supported on a porous alumina for the hydrogen production

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

no journal, , 

The thermal decomposition of hydrogen iodide (HI) to produce hydrogen in a membrane reactor was investigated using the separation characteristics of a silica membrane with the aim of improving the one-pass decomposition rate of HI decomposition reaction in the thermochemical IS process. The silica membranes were prepared by a counter diffusion chemical vapor deposition (CVD) of hexyltrimethoxysilane (HTMOS) using alumina porous support. The membrane reactor phenomenon was evaluated using determined H production rate from HI decomposition at 400C. It was found from experiments that produced H rate was approximately 1.5 mL min in permeated site. Hydrogen was successfully produced and extracted from the HI decomposition membrane reactor with a utilization of the HTMOS silica membrane. The HTMOS silica membrane was effective for the HI decomposition at higher reaction temperature of 400C in the membrane reactor.