Biological production of liquid and gaseous fuels from synthesis gas

Abstract

Liquid and gaseous fuels may be produced biologically from coal by the indirect conversion of coal synthesis gas. Methane has been produced from synthesis gas using acetate and CO2/H2 as intermediates, utilizing a number of CO-utilizing and methanogenic bacteria. Also, a bacterium that is capable of producing ethanol from synthesis gas through indirect liquefaction has been isolated fron natural inocula. This paper summarizes research to optimize the performance of some of these cultures. These conversions, involving H2 and CO, which are only slightly soluble in the liquid media, may be mass transfer limited, and methods to enhance mass transport are examined. Experimental results and models for several reactor designs, including CSTR and packed columns, are presented and discussed.