Development of an electrochemical cell for efficient hydrogen production through the IS process

Mikihiro Nomura, Shin Ichi Nakao, Hiroyuki Okuda, Seiji Fujiwara, Seiji Kasahara, Kazuhiko Ikenoya, Shinji Kubo, Kaoru Onuki

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45 Citations (Scopus)

Abstract

The Bunsen reaction (SO2 + I2 + 2H2O = H2SO4 + 2HI) was examined by an electrochemical cell featuring a cation-exchange membrane as the separator, using sulfuric acid dissolving sulfur dioxide as the anolyte and hydriodic acid dissolving iodine as the catholyte. In galvanostatic electrolysis, the molality of H 2SO4 in the anolyte and that of HI in the catholyte were increased up to 17.8 and 14.9 mol kgH2O-1, respectively. These concentrations were far higher than those that were obtained by the Bunsen reaction carried out in the presence of a large amount of iodine (such as I2/HI = 4). I2 concentration after the concentration procedure was at I2/HI = 0.95, which is lower than the reported value. I2 is one of the recycling agents in the IS process. HI and H2SO4 were successfully concentrated under low I 2 concentration. The concentration of HI agreed with the calculated value, based on the amount of electricity consumed, indicating high current efficiency. Heat/mass balance using this type of electrochemical cell through the IS process is discussed for evaluation of the reactor. The thermal efficiency to produce hydrogen was calculated at 42.1%, without heat recovery for electricity, by optimizing HI and H2SO4 concentrations after application of the electrochemical cell.

Original languageEnglish
Pages (from-to)1991-1998
Number of pages8
JournalAIChE Journal
Volume50
Issue number8
DOIs
Publication statusPublished - 2004 Aug 1

Keywords

  • Bunsen reaction
  • Cation-exchange membrane
  • Electrochemical cell
  • Hydrogen production
  • IS process

ASJC Scopus subject areas

  • Biotechnology
  • Environmental Engineering
  • Chemical Engineering(all)

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  • Cite this

    Nomura, M., Nakao, S. I., Okuda, H., Fujiwara, S., Kasahara, S., Ikenoya, K., Kubo, S., & Onuki, K. (2004). Development of an electrochemical cell for efficient hydrogen production through the IS process. AIChE Journal, 50(8), 1991-1998. https://doi.org/10.1002/aic.10162