Effect of carbon dioxide on the kinetics of the Fischer-Tropsch synthesis on iron catalysts

A recently proposed kinetic expression applicable to feed ratios H/sub 2//CO of 0.8 or less correlates the synthesis rate by an equation containing an inhibition term for CO/sub 2/ and assumes that water vapor concentrations are too low to offer significant inhibition. Experimental studies here with synthesis gas of H/sub 2//CO ratios of 0.67-0.72 to which CO/sub 2/ was added show, in contrast, that CO/sub 2/ is relatively inert. The data are well correlated by an equation developed by Huff that contains an inhibition term for H/sub 2/O but not for CO/sub 2/. The authors suggest that the inhibition attributed to CO/sub 2/ was instead actually caused by H/sub 2/O formed by the reverse water gas shift reaction.