摘要
为揭示牛粪在中温干发酵过程中流变特性和产气特性随厌氧消化进行的变化机理,同时对流变特性和产气特性之间的影响机理进行了分析,为实际沼气工程提高产气量及合理选择运行策略提供参考。通过自制的恒温厌氧发酵装置对初始总固体质量分数分别为8%、15%、20%和22%的牛粪进行了中温(37℃±1℃)厌氧发酵,并使用在线振动式粘度计研究了其表观粘度变化情况。结果表明:在厌氧发酵过程中,牛粪的总固体质量越大,表观粘度越大,表观粘度随着厌氧消化时间的增加而减小,8%、15%、20%和22%的牛粪表观粘度的最大值分别是1.16 mPa·s、10.07 mPa·s、70.93 mPa·s和95.78 mPa·s;累计产气量和累计产甲烷量与初始固体质量成正比;溶解性化学需氧量(SCOD)和挥发性脂肪酸(VFAs)含量随着厌氧消化时间的增加先增大后减小;氨氮含量随初始总固体质量增加而增大,且随着厌氧消化时间的增加而增大后趋于稳定。研究结果可用于指导禽畜粪便中温沼气工程提高发酵效率。
In order to reveal the change mechanism of rheological characteristics and gas production characteristics of cow dung in the process of medium temperature dry fermentation, and to analyze the influence mechanism between rheological characteristics and gas production characteristics, this study provides a reference for the actual biogas project to improve gas production and reasonably select operation strategy. In this paper, cow dung with initial total solid mass fraction of 8%, 15%, 20% and 22% was fermented at medium temperature(37℃±1℃) by self-made constant temperature anaerobic fermentation device, and the changes of apparent viscosity were studied by on-line vibrating viscometer. The results showed that in the process of anaerobic fermentation, the greater the total solid mass of cow dung, the greater the apparent viscosity, and the apparent viscosity decreased with the progress of anaerobic digestion. The maximum values of the apparent viscosity of 8%, 15%, 20% and 22% of cow dung were 1.16 mPa·s, 10.07 mPa·s, 70.93 mPa·s and 95.78 mPa·s respectively. The cumulative gas production and cumulative methane production are directly proportional to the initial solid mass. The contents of soluble chemical oxygen demand(SCOD) and volatile fatty acids(VFAs) first increased and then decreased with the progress of anaerobic digestion. The content of ammonia nitrogen increases with the increase of initial total solid mass, and tends to be stable with the progress of anaerobic digestion. The results can be used to guide the medium temperature biogas project of livestock manure and improve the fermentation efficiency.
作者
李金平
石慧博
万丹丹
黄娟娟
Vojislav Novakovic
LI Jinping;SHI Huibo;WAN Dandan;HUANG Juanjuan;Vojislav Novakovic(Gansu Key Laboratory of Complementary Energy System of Biomass and Solar Energy,Lanzhou 730050,China;Collaborative Innovation Center for Supporting Technology of Northwest Low-Carbon Towns,Lanzhou 730050,China;School of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Department of Energy and Process Engineering,Norwegian University of Science and Technology,Trondheim,Norway,NO-7491)
出处
《中国沼气》
2022年第6期20-28,共9页
China Biogas
基金
国家重点研发计划项目(2019YFE0104900)
国家自然科学基金项目(51676094)
甘肃省高等学校产业支撑项目(2021CYZC-33)
兰州市人才创新创业项目(2017-RC-34,2020-RC-126)。
关键词
中温发酵
流变特性
干发酵
在线粘度计
产气特性
medium temperature fermentation
rheological properties
dry fermentation
online viscometer
gas production characteristics
