Sequential generation of hydrogen and methane from glutamic acid through combined photo-fermentation and methanogenesis.
Glutamic acid can hardly produce hydrogen via dark- or photo-fermentation without pretreatment. In this study, a novel process of acidogenic pretreatment with bacteria and zeolite treatment for NH4(+) removal was proposed to use glutamic acid as feedstock in photo-fermentation for efficient hydrogen production. Glutamic acid pretreated with acidogenic bacteria produces soluble metabolite products. After zeolite treatment, the acidulated solution, which mainly contains acetate, butyrate, and NH4(+), shows a decrease in NH4(+) concentration from 36.7mM to 3.2mM (NH4(+) removal efficiency of 91.1%). After NH4(+) removal, the treated solution is incubated with photosynthetic bacteria, exhibiting a maximum hydrogen yield of 292.9mL/g(-glutamic acid) during photo-fermentation. The residual solution from photo-fermentation is reused by methanogenic bacteria to produce a maximum methane yield of 102.7mL/g. The heating value conversion efficiency from glutamic acid to gas fuel significantly increases from 18.9% during photo-fermentation to 40.9% in the combined photo-fermentation and methanogenesis process.
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
Ao
A
Xia
Jun
J
Cheng
Richen
R
Lin
Jianzhong
J
Liu
Junhu
J
Zhou
Kefa
K
Cen
D000641:Ammonia / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D005285:Fermentation; D018698:Glutamic Acid / Q000378:metabolism*; D006859:Hydrogen / Q000302:isolation & purification / Q000378:metabolism*; D008697:Methane / Q000302:isolation & purification / Q000378:metabolism*; D058433:Photobioreactors / Q000382:microbiology*; D012037:Refuse Disposal / Q000379:methods; D012722:Sewage / Q000382:microbiology*
D012722:Sewage; D018698:Glutamic Acid; D000641:Ammonia; D006859:Hydrogen; D008697:Methane