title: Optimization of membrane stack configuration for efficient hydrogen production in microbial reverse-electrodialysis electrolysis cells coupled with thermolytic solutions.
abstract: Waste heat can be captured as electrical energy to drive hydrogen evolution in microbial reverse-electrodialysis electrolysis cells (MRECs) by using thermolytic solutions such as ammonium bicarbonate. To determine the optimal membrane stack configuration for efficient hydrogen production in MRECs using ammonium bicarbonate solutions, different numbers of cell pairs and stack arrangements were tested. The optimum number of cell pairs was determined to be five based on MREC performance and a desire to minimize capital costs. The stack arrangement was altered by placing an extra low concentration chamber adjacent to anode chamber to reduce ammonia crossover. This additional chamber decreased ammonia nitrogen losses into anolyte by 60%, increased the coulombic efficiency to 83%, and improved the hydrogen yield to a maximum of 3.5 mol H2/mol acetate, with an overall energy efficiency of 27%. These results improve the MREC process, making it a more efficient method for renewable hydrogen gas production.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: Xi
authors.initials: X
authors.lastname: Luo
authors.forename: Joo-Youn
authors.initials: JY
authors.lastname: Nam
authors.forename: Fang
authors.initials: F
authors.lastname: Zhang
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Liang
authors.forename: Xia
authors.initials: X
authors.lastname: Huang
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
mesh_terms: D000641:Ammonia / Q000032:analysis; D001674:Bioelectric Energy Sources; D057919:Biological Oxygen Demand Analysis; D004560:Electricity; D004566:Electrodes; D004572:Electrolysis; D006859:Hydrogen / Q000378:metabolism*; D008567:Membranes, Artificial; D009584:Nitrogen / Q000032:analysis; D010084:Oxidation-Reduction; D012996:Solutions; D013696:Temperature
chemical_list: D008567:Membranes, Artificial; D012996:Solutions; D000641:Ammonia; D006859:Hydrogen; D009584:Nitrogen