In-Situ Continuous Production of Hydrogen Gas from Molasses Using Mutated Enterobacter aerogenes ADH43 for Fuel Cell Application

Abstract

The performance of the continuous stirred tank reactor (CSTR) for the in-situ production of hydrogen gas (H2) integrated with a polymer electrolyte membrane fuel cell (PEMFC) was investigated. Facultative anaerobe fermentation of Enterobacter aerogenes ADH-43 was conducted into CSTR 50 rpm of agitation speed , 37 0C of temperature, 6.3 of pH, and 0.15, 0.3, 0.45, 0.60 h-1 of dilution rate. Bio-H2 produced was assesed after inserting it into a fuel cell to generate electricity and measuring voltages. The system was integrated with a ceramic membrane having 0.2 µm pore size for recycling the retentate cell into reactor and separating the permeate supernatant during the fermentation. The obtained H2 was purified from CO2 by absorption in Ca(OH)2 solution prior to feed to PEMFC. The CSTR was initially operated on batch basis to increase the bacterial cell density to ensure the production of sufficient H2 and develop a feeding culture strategy for the continues operation mode. The result showed that the highest H2 production was achieved at continuous system resulted in 0.30 h-1 of optimum dilution rate. The maximum H2 volume of 9.76 l H2/l sugar , the yield of 1.84 mol H2/mol sugar, and the flow rate of 115 ml H2/min were obtained. Furthermore, colony count of 9.81 log cfu/ml, pH of 5.73, maximum electrical current of 0.38 Ampere, electrical power of 2.20 Watt, and electrical voltage of 5.75 volt after given resistance using LED of 25 ohm was also reached.

Keywords

• H production
• E. aerogenes
• Molasses CSTR
• Ceramic membrane
• PEMFC