Bioconversion of Waste gases into Biofuel via Fermentation in a Continuous Stirred Tank Bioreactor

Abstract

Biological hydrogen production was carried out in a continuous stirred tank bioreactor. A photsynthetic bacterium, Rhodospirillum rubrum, was used as biocatalyst to oxidize carbon monoxides in the waste gas generated from biomass in a gasification process. The fresh liquid media was supplied for microbial growth which contained sodium acetate as carbon source at initial concentration of 4gL(-1). The optimum media space velocity or the suitable ratio of liquid flow rate to the reactor volume (F/VL) was 0.02 h(-19. At the steady state conditions, the concentration of acetate was independent of the dilution rate and it was approximately 1.5gL(-1). The average cell dry weight in the fermentation broth was at satisfactory concentration, approximately 3.4gL(-1) with dilution rate at 0.55 mL min (-1). the maximum value of KLa and CO covnersion were about 58 h(-1) and 80%, respectively, with agitation speed at 500 rpm and gas flow rate at 14 mL min (-1). At this condition, the maximum yield of hyddrogen production was 0.82 mmol H2 mmol (-1) CO.