Comparison of the use of sucrose and glucose as a substrate for hydrogen production in an upflow anaerobic fixed-bed reactor

This study evaluated the use of two types of substrates, glucose and sucrose, feeding an anaerobic fixed-bed bioreactor. The biogas produced was composed of H2 and CO2, without methane. Maximum hydrogen yields were 3.22 mol H2 mol−1 sucroseconverted and 1.51 mol H2 mol−1 glucoseconverted. The main intermediates were acetic acid, butyric acid, and ethanol. The greatest difference, however, was in the stability of the process. The operation of the reactor with sucrose exhibited a drop in biogas production, whereas operation with glucose was stable after a slight decrease in biogas production. This decrease may have been caused by the differential growth of microbial populations in each reactor, namely, the growth of organisms that use the Wood-Ljungdahl metabolic pathway.