Biological conversion of synthesis gas into fuels

Liquid and gaseous fuels may be produced from coal biologically by the indirect conversion of coal synthesis gas. Methane has been produced from synthesis gas using acetate and CO 2/H 2 as intermediates, utilising a number of CO-utilising and methanogenic bacteria. Also, a bacteria has been isolated from natural inocula that is capable of producing ethanol from synthesis gas through indirect liquefaction. This presentation summarises the research to optimise the performance of these cultures. These conversions, involving H 2 and CO which are only slightly soluble, are severely 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.