title: Improvement of the energy conversion efficiency of Chlorella pyrenoidosa biomass by a three-stage process comprising dark fermentation, photofermentation, and methanogenesis.
abstract: The effects of pre-treatment methods on saccharification and hydrogen fermentation of Chlorella pyrenoidosa biomass were investigated. When raw biomass and biomass pre-treated by steam heating, by microwave heating, and by ultrasonication were used as feedstock, the hydrogen yields were only 8.8-12.7 ml/g total volatile solids (TVS) during dark fermentation. When biomass was pre-treated by steam heating with diluted acid and by microwave heating with diluted acid, the dark hydrogen yields significantly increased to 75.6 ml/g TVS and 83.3 ml/g TVS, respectively. Steam heating with diluted acid is the preferred pre-treatment method of C. pyrenoidosa biomass to improve hydrogen yield during dark fermentation and photofermentation, which is followed by methanogenesis to increase energy conversion efficiency (ECE). A total hydrogen yield of 198.3 ml/g TVS and a methane yield of 186.2 ml/g TVS corresponding to an overall ECE of 34.0% were obtained through the three-stage process (dark fermentation, photofermentation, and methanogenesis).
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Ao
authors: A
authors: Xia
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: juncheng@zju.edu.cn.
authors: Jun
authors: J
authors: Cheng
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Lingkan
authors: L
authors: Ding
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Richen
authors: R
authors: Lin
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Rui
authors: R
authors: Huang
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Junhu
authors: J
authors: Zhou
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Kefa
authors: K
authors: Cen
mesh_terms: D000143:Acids / Q000737:chemistry; D056804:Biofuels; D018533:Biomass; D002241:Carbohydrates / Q000737:chemistry; D002708:Chlorella / Q000378:metabolism*; D003624:Darkness; D005285:Fermentation; D006859:Hydrogen / Q000737:chemistry; D008027:Light; D008697:Methane / Q000737:chemistry*; D008872:Microwaves; D058433:Photobioreactors; D013227:Steam; D013997:Time Factors
chemical_list: D000143:Acids; D056804:Biofuels; D002241:Carbohydrates; D013227:Steam; D006859:Hydrogen; D008697:Methane
keywords: Chlorella pyrenoidosa; Energy conversion efficiency; Fermentation; Hydrogen; Methanogenesis