The Study Of Hydrogen Production Through Anaerobic Fermentation By Immobilized Bacteria

As a clean, high energy value and renewable energy carrier, hydrogen is considered as one of the most promising energy alternatives in the current era of climate and energy crisis. Hydrogen production by biological methods is attractive because it is a process operated under mild conditions and many of the solid waste or waste water can be used as substrate for simultaneous energy recovery and environment treatment. But the traditional suspension fermentation system is easy to be washed out, and have a low efficiency of hydrogen production.To solve these problems, hydrogen produced by immobilized mixed culture of strain A1 and B1 was studied.This study compared three different carriers for mixed culture immobilization. The results show that crops straw was the optimal adsorption carrier. The average cumulative production for hydrogen was 1845 mL for 10 batches fermentation, and the average hydrogen yield was 1.50mol H2/mol glucose, which is 62.5% higher than that of suspended fermentation. Furthermore, the activity of amylase was 2-3 times higher than that of suspended fermentation. At the same time the activity of hexokinase was improved greatly by immobilization.Xylose was used as substrate for hydrogen production by immobilized mixed bacteria. The results showed that the immobilized nixed bacteria can quickly use of xylose, the maximum rate of hydrogen production was 4.5 times faster than that of suspended fermentation. The average cumulative production of hydrogen was 1972 mL for 10 batches. The average utilization rate of substrate was 96%, and the average hydrogen yield was 1.47 mol H2/mol xylose.In this paper, the ability of producing hydrogen was improved by immobilized technology, and the speed of producing hydrogen has been speeded up remarkably. And it verified that immobilized cells can be repeated use, which laid a foundation for continuous fermentation to produce hydrogen by immobilized cells.