酒精-沼气双发酵耦联工艺中酒精发酵生酸原因解析与控制  

Analysis and control of acidity production in ethanol fermentation during integrated ethanol and methane fermentation process

作　　者：王柯[1,2] 杨圣乾 张建华[1,2] 毛忠贵[1,2] 

机构地区：[1]江南大学,工业生物技术教育部重点实验室,江苏无锡214122 [2]江南大学生物工程学院,江苏无锡214122

出　　处：《食品与发酵工业》2016年第12期7-12,共6页Food and Fermentation Industries

基　　金：工业生物技术教育部重点实验室“现代工业生物技术高效开发与应用”专项科研项目子项目(JUSRP51504);生物燃料技术国家重点实验室开放课题(KFKT2014001)

摘　　要：在酒精-沼气双发酵耦联工艺中,将沼液和酒糟的混合水回用于酒精发酵过程,可有效解决传统酒精生产工艺存在的能耗大、废水处理成本高的问题。但是产业化应用中,该工艺会引起酒精发酵生酸较高。本文对造成这一问题的原因进行了研究,并探索了相应的解决方案。结果表明,沼液和酒糟混合、储存过程中,沼液中的产酸菌能够吸收利用酒糟中的营养物质快速生长并生成大量挥发性有机酸。产酸菌会对酿酒酵母产生竞争性抑制作用,而挥发性有机酸则会对酿酒酵母产生毒害作用。通过向沼液中加入适量的克菌灵可有效杀灭产酸菌,延缓混合水的酸化,从而消除对酒精发酵的影响。In the integrated ethanol and methane fermentation process, the mixture of digestate and stillage was reused as process water for the ethanol fermentation, thereby the problems of massive energy consumption and high cost for wastewater treatment faced by ethanol production process was resolved. However, in the industrial applica- tion, this integrated process caused high level of acidity production in the ethanol fermentation. In this study, reasons for this problem were explored and corresponding strategies were chosen. Results showed that in the mixing and sto- ring process of digestate and stillage, the acidogenic bacteria in digestate could utilize the nutrient substances con- tained in stillage to grow and produce a mountain of volatile fatty acids （VFAs）. These acidogenic bacteria could out -compete Saccharomyces cerevisiae for substrates, and the VFA could cause toxicity to S. cerevisiae as well. Adding moderate amount of Kejunling to digestate could kill acidogenic bacteria and delay acidification of the mixture of diges- tare and stillage, thereby eliminating their effect on the ethanol fermentation.

关 键 词：酒精发酵 酿酒酵母 厌氧消化 挥发性有机酸 克菌灵 

分 类 号：TQ223.122[化学工程—有机化工] TQ920.6[轻工技术与工程—发酵工程]