Bioreactor Scale-up for Water-Gas Shift Reaction

A scale-up study has been performed with three different size reactors to establish the optimum operating conditions for the hydrogen production from synthesis gas by biological water-gas shift reaction using the photosynthetic bacterium Rhodosprilliunt rubrum. Optimum medium composition and operating conditions previously determined in a bench scale ۱.۲۵ L continuous stirred tank reactor (CSTR) were used for this study with geometrically similar ۲.۵, ۵.۰ and ۱۴.۰ L CSTR. The hydrogen production rate, cell concentration and carbon monoxide (CO) conversion were monitored in this scale-up study. The light energy supply was linearly increased with the working volume of the reactors. The agitation rates were determined by the equal power/volume rule. There were good agreement between the calculated agitation rates and the experimentally observed values for all the three different reactors, A ۷۰% carbon monoxide conversion was obtained with ۳۰, ۶۰ and ۱۵۰ sccm gas flow rate for the ۲.۵, ۵.۰ and ۱۴.۰ L fermentors respectively. At ۷۰% CO conversion the ۲.۵ and ۵.۰ L reactors showed ۲۵% improvement ir~ performance and the ۱۴.۰ L reactor showed ۱۱% improvement. The estimated mass transfer coefficients for all four reactors showed very similar values under the optimum operating condition (average KLa= ۱۱۷ h-۱). A ۶۶۴ h long performance of the process show very stable behavior.

کلیدواژه ها:

Bioreactor Scale ، up ، Water ، gas Shift ، Hydrogen production ، Rhodospirilliun Rubrum. Photosynthetic Bacterium