Life Cycle Assessment-Directed Optimization of Hydrogen Sulfide Removal During Biomass-Derived Hydrogen Production
Biomass-derived hydrogen (Bio-H2), which is produced through a gasification process, can be used as the fuel in fuel cells. However, impurities such as H2S and HCl produced as by-products during the gasification process can reduce the voltage output and shorten the lifespan of Bio-H2-based fuel cells. Therefore, efficient means of removing H2S produced during the production of Bio-H2 are needed. Generally, the removal of unwanted by-products requires large amounts of metal oxide as an adsorbent, which has a large environmental impact. Here, we examined how to reduce the amount of adsorbent needed for the removal of H2S during the production of Bio-H2. A life cycle assessment approach was then used to assess the environmental impact of removing H2S. For the production of Bio-H2 at low temperatures, adsorption of H2S with Fe2O3 and ZnO was found to be promising. We also found that the Bio-H2 could be further purified by replacing the conventional pressure swing adsorption process with a two-step process. In our novel Bio-H2 production process, the H2S removal performance of the entire process was comparable with that of a conventional process. Moreover, our novel process had 91% less impact on the life cycle assessment index abiotic depletion.
KeywordsH2S removal Fe2O3 ZnO HAS-Clay Zeolite A-5 Bio-H2 PSA LCA
- 1.Ministry of Agriculture, Forestry and Fisheries of Japan. The basic biomass utilization promotion plans; 2010.Google Scholar
- 4.Dowaki K, Ohkubo R, Koido K, Ikeda H, Kameyama M. The actual status and the prospect of Blue Tower Gasification Technology. J Jpn Inst Energy. 2012;91(10):1035–46. in Japanese.Google Scholar
- 5.ISO 14687-2:2012. Hydrogen fuel product specification part 2: proton exchange membranes (PEM) fuel cell applications for road vehicles. 2012.Google Scholar
- 19.Watanabe Y, Sato Y, Kawano D, Koido K, Dowaki K. A life cycle assessment of the biomass-to-liquid considering the fuel consumption of a truck. J LCA Jpn. 2013;9(1):20–36. in Japanese.Google Scholar