Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment

PeerJ

article

Tran T. Giang¹  Siriporn Lunprom¹  Qiang Liao³  Alissara Reungsang¹  Apilak Salakkam¹ 

[1] Department of Biotechnology, Faculty of Technology, Khon Kaen University;Research Group for Development of Microbial Hydrogen Production Process from Biomass, Khon Kaen University;Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education;Institute of Engineering Thermophysics, Chongqing University

关键词: Physico-chemical pretreatment;    Microalgal biomass;    Renewable energy;    Anaerobic digestion;    Dark fermentation;    Third generation biofuel;   

DOI  :  10.7717/peerj.6637

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundOwing to the high growth rate, high protein and carbohydrate contents, and an ability to grow autotrophically, microalgal biomass is regarded as a promising feedstock for fermentative hydrogen production. However, the rigid cell wall of microalgae impedes efficient hydrolysis of the biomass, resulting in low availability of assimilable nutrients and, consequently, low hydrogen production. Therefore, pretreatment of the biomass is necessary in order to achieve higher hydrogen yield (HY). In the present study, acid-thermal pretreatment of Chlorella sp. biomass was investigated. Conditions for the pretreatment, as well as those for hydrogen production from the pretreated biomass, were optimized. Acid pretreatment was also conducted for comparison.ResultsUnder optimum conditions (0.75% (v/v) H2SO4, 160 °C, 30 min, and 40 g-biomass/L), acid-thermal pretreatment yielded 151.8 mg-reducing-sugar/g-biomass. This was around 15 times that obtained from the acid pretreatment under optimum conditions (4% (v/v) H2SO4, 150 min, and 40 g-biomass/L). Fermentation of the acid-thermal pretreated biomass gave 1,079 mL-H2/L, with a HY of 54.0 mL-H2/g-volatile-solids (VS), while only 394 mL/L and 26.3 mL-H2/g-VS were obtained from the acid-pretreated biomass.ConclusionsAcid-thermal pretreatment was effective in solubilizing the biomass of Chlorella sp. Heat exerted synergistic effect with acid to release nutrients from the biomass. Satisfactory HY obtained with the acid-thermal pretreated biomass demonstrates that this pretreatment method was effective, and that it should be implemented to achieve high HY.

【 授权许可】

CC BY