The study on co-fermentation of hydrogen and methane produc-tion by <italic>Eupatorium adenophorum</italic> spreng

Abstract

The experiment demonstrates the co-fermentation of hydrogen and methane production by pretreated Eupatorium adenophorum Spreng through pH value determination of the fermentative system. The pH range of 4.7?5.5 favor hydrogen production before methane production, while the pH range of 6.5?7.5 favor methane production before hydrogen production. The experiment shows that the TS and VS utilization ratio of first hydrogen production then methane production is higher than that of first methane production then hydrogen production. The use ratio of cellulose, hemicellulose and lingin of hydrogen production followed by methane production is 32.60%, 45.80% and 50.26% higher than that of methane production followed by hydrogen production, respectively. One method of assessing the termination of hydrogen production from fermentation is observing the time when testing group hydrogen production equals control group hydrogen production. The rate of methane generation of hydrogen production followed by methane production is 18.85% higher than that of methane production followed by hydrogen production, which can shorten the overall fermentation time. The energy utilization efficiency of hydrogen production followed by methane production is 68.54%, while the efficiency of methane production followed by hydrogen production is 15.35%. This experiment suggests that hydrogen production followed by methane production of co-fermentation by pretreated Eupatorium adenophorum Spreng is a preferable approach compared with methane production followed by hydrogen production, only methane production, or only hydrogen production.