title: Continuous dry fermentation of swine manure for biogas production.
abstract: A down plug-flow anaerobic reactor (DPAR) was designed for the feasibility study on continuous dry fermentation of swine manure without any additional stirring. Using fresh swine manure as the feedstock with TS concentration (w/w) of 20%, 25%, 30%, and 35%, stable volumetric biogas production rates of 2.40, 1.92, 0.911, and 0.644L · (Ld)(-1) and biogas yields of 0.665, 0.532, 0.252, and 0.178 L g(-)(1)VS were obtained respectively, and the TS degradation rates were 46.5%, 45.4%, 53.2%, and 55.6%, respectively. With the increase of feedstock TS concentration, the concentration of ammonia nitrogen grew up to the maximum value of 3500 mg L(-1). Biogas production was obviously inhibited when the concentration of ammonia nitrogen was above 3000 mg L(-1). The maximal volumetric biogas production rate of 2.34 L ·(Ld)(-1) and biogas yield of 0.649 L g(-1)VS were obtained with TS concentration of 25% at 25°C without inhibition. Liquidity experiments showed that TS concentration of digestate could be less than 15.8%, and the flow rate of digestate more than 0.98 m s(-1) when the feedstock TS concentration was less than 35%, which indicated the digestate could be easily discharged from a DPAR. Therefore, it is feasible to conduct a continuous dry fermentation in a DPAR using fresh swine manure as the feedstock with TS concentration less than 35%, whereas the feedstock TS concentration should not exceed 30% to achieve the maximal biogas production rate and biogas yield.
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China.
authors.forename: Chuang
authors.initials: C
authors.lastname: Chen
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zheng
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China; Bioprocess Control AB, Scheelevägen 22, 223 63 Lund, Sweden.
authors.forename: Gang-Jin
authors.initials: GJ
authors.lastname: Liu
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China; Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture, Chengdu 610041, PR China; Southwest Collaborative Innovation Center of Swine for Quality & Safety, Chengdu 611130, PR China. Electronic address: dengliangwei@caas.cn.
authors.forename: Liang-Wei
authors.initials: LW
authors.lastname: Deng
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Long
authors.affiliation: Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China.
authors.forename: Zhan-Hui
authors.initials: ZH
authors.lastname: Fan
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000693:Anaerobiosis; D000818:Animals; D056804:Biofuels / Q000032:analysis*; D019149:Bioreactors; D005285:Fermentation; D008372:Manure / Q000032:analysis*; D034421:Sus scrofa; D018505:Waste Management / Q000379:methods*
chemical_list: D056804:Biofuels; D008372:Manure; D000641:Ammonia
keywords: Ammonia inhibition; Biogas; Down plug-flow anaerobic reactor (DPAR); Dry fermentation; Swine manure