Conversion of carbon dioxide in biogas into acetic acid by Clostridium thailandense immobilized on porous support materials
Srisuda Chaikitkaew,
Nantharat Wongfaed,
Chonticha Mamimin,
Sompong O-Thong,
Alissara Reungsang
Affiliations
Srisuda Chaikitkaew
Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand; Research Group for Development of Microbial Hydrogen Production Process from Biomass, Khon Kaen University, Khon Kaen, 40002, Thailand
Nantharat Wongfaed
Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand; Research Group for Development of Microbial Hydrogen Production Process from Biomass, Khon Kaen University, Khon Kaen, 40002, Thailand
Chonticha Mamimin
Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand; Research Group for Development of Microbial Hydrogen Production Process from Biomass, Khon Kaen University, Khon Kaen, 40002, Thailand
Sompong O-Thong
Biofuel and Biocatalysis Innovation Research Unit, Nakhonsawan Campus, Mahidol University, Nakhonsawan, 60130, Thailand
Alissara Reungsang
Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand; Research Group for Development of Microbial Hydrogen Production Process from Biomass, Khon Kaen University, Khon Kaen, 40002, Thailand; Academy of Science, Royal Society of Thailand, Bangkok, 10300, Thailand; Corresponding author. Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand.
This study aimed to convert CO2 in biogas into acetic acid using immobilized Clostridium thailandense cells on various support materials, including activated carbon, expanded clay, and coir. Immobilized cells and free cells were evaluated for their CO2 conversion ability into acetic acid using H2 as an electron donor at an H2 to CO2 in biogas ratio of 2:1 (v/v), 30 °C, 150 rpm. Results showed that immobilized cells on activated carbon increased CH4 content to 96.9% (v/v), and acetic acid production to 15.65 mmol/L within 96 h. These values outperformed free cells. The activated carbon-immobilized cells could be reused two times without losing efficacy in the purification of biogas and acetic acid production. This work indicates that using the immobilized cells offers a sustainable approach to biogas upgrading, reducing the environmental footprint of biogas production by increasing its energy content and purity.
