Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment
Background Owing 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 bioma...
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PeerJ Inc.
2019-03-01
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| author | Tran T. Giang Siriporn Lunprom Qiang Liao Alissara Reungsang Apilak Salakkam |
| author_facet | Tran T. Giang Siriporn Lunprom Qiang Liao Alissara Reungsang Apilak Salakkam |
| author_sort | Tran T. Giang |
| collection | DOAJ |
| description | Background Owing 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. Results Under 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. Conclusions Acid-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. |
| first_indexed | 2024-03-09T06:26:21Z |
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| language | English |
| last_indexed | 2024-03-09T06:26:21Z |
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| spelling | doaj.art-dc2168136f514ed48df5a5ae01651bb02023-12-03T11:19:50ZengPeerJ Inc.PeerJ2167-83592019-03-017e663710.7717/peerj.6637Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatmentTran T. Giang0Siriporn Lunprom1Qiang Liao2Alissara Reungsang3Apilak Salakkam4Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, ThailandDepartment of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, ThailandKey Laboratory of Low-grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education, Chongqing, ChinaDepartment of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, ThailandDepartment of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, ThailandBackground Owing 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. Results Under 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. Conclusions Acid-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.https://peerj.com/articles/6637.pdfPhysico-chemical pretreatmentMicroalgal biomassRenewable energyAnaerobic digestionDark fermentationThird generation biofuel |
| spellingShingle | Tran T. Giang Siriporn Lunprom Qiang Liao Alissara Reungsang Apilak Salakkam Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment PeerJ Physico-chemical pretreatment Microalgal biomass Renewable energy Anaerobic digestion Dark fermentation Third generation biofuel |
| title | Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment |
| title_full | Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment |
| title_fullStr | Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment |
| title_full_unstemmed | Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment |
| title_short | Improvement of hydrogen production from Chlorella sp. biomass by acid-thermal pretreatment |
| title_sort | improvement of hydrogen production from chlorella sp biomass by acid thermal pretreatment |
| topic | Physico-chemical pretreatment Microalgal biomass Renewable energy Anaerobic digestion Dark fermentation Third generation biofuel |
| url | https://peerj.com/articles/6637.pdf |
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