Comparison of fermentative hydrogen production from glycerol using immobilized and suspended mixed cultures

This study explored the fermentative hydrogen production by immobilized microorganisms from glycerol, which is the byproduct of biodiesel production, and compared it with suspended fermentation. The effect of immobilization on hydrogen production process was examined. Results showed that both cumulative hydrogen production (CHP) and hydrogen yield (HY) were enhanced by microbial immobilization. The highest CHP and HY of 64 mL/100 mL and 0.52 mol H-2/mol glycerol were obtained by immobilized microorganisms, compared to 9 mL/100 mL and 0.29 mol H-2/mol glycerol in suspended microorganisms. Immobilization enhanced CHP and HY by 611.1% and 79.3%. In addition, immobilized microorganisms showed stronger tolerance to high substrate concentration and higher capability in glycerol utilization, which is of great significance for hydrogen production from glycerol. The enhanced hydrogen production may be due to the favorable micro-environment for different microorganisms in immobilized beads. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrated that using immobilized microorganisms for hydrogen production from glycerol can enhance both cumulative hydrogen production and hydrogen yield, with improved tolerance to high substrate concentration and higher capability in glycerol utilization. The enhanced hydrogen production may be attributed to the favorable micro-environment created for different microorganisms in immobilized beads.