Exploit Carbon Materials to Accelerate Initiation and Enhance Process Stability of CO Anaerobic Open-Culture Fermentation
journal contributionposted on 16.01.2018, 00:00 by Fan Lü, Ke-jian Guo, Hao-wen Duan, Li-ming Shao, Pin-jing He
The aim of this study was to investigate the possibility of improving anaerobic fermentation of carbon monoxide (CO), a dominant component in syngas, through the assistance of different carbon materials (activated carbon, biochar, graphene, carbon cloth, and carbon fiber). Results showed that only biochar and activated carbon could promote CO utilization when the pCO increased from 0.07 to 0.21 atm and promoted CO methanization but was delayed until the pCO further increased from 0.21 to 0.41 atm. Compared to the control without carbon material addition, the CO conversion rate increased by up to 149% and 193% and the methane (CH4) production rate was up to 238% and 186%, respectively, for the biochar and activated carbon scenarios. Graphene and carbon cloth did not accelerate CO utilization but could stabilize the bioreaction at a high pCO. Natural stable carbon isotope signals revealed that CH4 production from CO was mainly via acetate at low pCO and via hydrogen at high pCO. Results from high-throughput sequencing showed that biochar and activated carbon boosted the growth of Rikenellaceae and Thiobacillus in the solid phase. Synergistaceae which can be in coculture with Methanobacterium was boosted in the liquid phase in biochar group and activated carbon group.