纤维乙醇废水生产沼气的工艺设计

发布时间：2018-04-23 13:48

本文选题：纤维乙醇废水 + 正交实验　；参考：《南阳师范学院》2017年硕士论文

【摘要】：能源问题是可持续发展中的一个重要主题。随着经济的不断发展,能源短缺和环境污染问题日益突出。纤维乙醇的研发已成为当前各国新资源战略的重点,我国也在大力发展非粮乙醇。河南天冠企业集团有限公司目前已完成了万吨秸秆乙醇科技攻关,并已运行3万吨秸秆乙醇项目。但在生产中实现原料多级利用,提高经济效率,需要对后期的纤维乙醇废水做深度开发利用。河南天冠集团对传统乙醇生产废物利用技术已成熟,但在工业化进程中还需技术不断创新。通过对纤维乙醇废水沼气利用中发酵液回流循环技术、纤维乙醇废水固态发酵产沼气工艺等关键技术的研究,实现秸秆原料生物乙醇-沼气二级能源梯度生产,提高原料能源转化率,为发展绿色循环经济提供技术支撑。通过单因素梯度预实验优化了纤维乙醇废水沼气发酵的条件为菌液含量20%,TS 12%,氮源含量(氮源总固体占发酵体系总固体的百分数)12%牛粪或10%猪粪。正交实验在预实验的基础上进行设计对预实验的结果进行验证改进,以废水固液分离的废液为原料的正交实验结果为菌液含量20%,装罐率90%,总固体12%,氮源为10%牛粪；在此发酵条件下,产气量15.37 L,容积产气率6.83 L/L,物料利用率44.1%。以废水固液分离的固废为原料的正交实验结果显示,菌液含量30%,装罐率90%,总固体12%,氮源10%牛粪；在此发酵条件下,产气量,产气量15.085 L,容积产气率为6.7 L/L,物料利用率为45.9%。以废水为原料的正交实验结果显示菌液20%,装罐率90%,总固体12%,氮源4%牛粪。在此发酵条件下产气量,产气量31.577 L,容积产气率14.03 L/L,物料利用率49.5%。中试发酵是对工业生产的模拟,是将实验室成果转化为工业生产的中间环节。在正交实验中通过对三组实验结果的计算分析得出最佳产气条件为pH 7.5,20%菌液含量,90%装罐率,12% TS,4%氮源。在优化的发酵参数条件下,自制厌氧发酵装置,进行了机械+回流混合搅拌(MRMS)与机械搅拌(MS)进行发酵工艺比较。采用机械+回流混合搅拌工艺产气率高,容积产气率比机械搅拌工艺增加41.2%,物料利用率提高13%,COD去除率降低10.3%,TN去除率提高9.1%。
[Abstract]:Energy is an important theme in sustainable development. With the development of economy, energy shortage and environmental pollution are becoming more and more serious. The research and development of cellulosic ethanol has become the focus of the new resource strategy in various countries, and China is also vigorously developing non-grain ethanol. Henan Tianguan Enterprise Group Co., Ltd. has completed the scientific and technological research of ten thousand tons of straw ethanol, and has run 30,000 tons of straw ethanol project. But in order to realize multilevel utilization of raw materials and improve economic efficiency, it is necessary to develop and utilize the fiber ethanol wastewater in the later stage. The waste utilization technology of traditional ethanol production in Henan Tianguan Group is mature, but the technology innovation is needed in the process of industrialization. Through the research on the key technologies, such as fermentation broth recirculation technology in the utilization of fiber ethanol wastewater and solid-state fermentation of fiber ethanol wastewater to produce biogas, the two-stage energy gradient production of straw raw material bio-ethanol and biogas was realized. To improve the conversion rate of raw material energy to provide technical support for the development of green recycling economy. The biogas fermentation conditions of cellulosic ethanol wastewater were optimized by single factor gradient pre-experiment. The results showed that the fermentation conditions were as follows: microbial liquid content 20% TS 12% nitrogen source content (total solid of nitrogen source:% of total solid in fermentation system) 12% cow dung or 10% pig dung. On the basis of the pre-experiment, the orthogonal experiment was designed to verify and improve the results of the pre-experiment. The orthogonal experiment using the waste liquid separated from waste water as the raw material was as follows: the content of bacteria liquid 20%, the tank filling rate 90%, the total solid 12%, the nitrogen source 10% cow dung; Under these fermentation conditions, the gas yield was 15.37 L, the volumetric gas yield was 6.83 L / L, and the material utilization ratio was 44.1%. The orthogonal experiment using solid waste separated from waste water as raw material showed that the content of bacterial liquid was 30, the filling rate was 90, the total solid was 12, and the nitrogen source was 10% cow dung, under this fermentation condition, the gas production, gas production, volumetric gas production were 15.085 L, volumetric gas production rate was 6.7 L / L, and the material utilization ratio was 45.9%. The results of orthogonal experiment using wastewater as raw material showed that 20% of bacteria liquid, 90% of tank filling rate, 12% of total solid, 4% of cow dung from nitrogen source. Under this fermentation condition, gas production, gas production, volume gas yield and material utilization ratio were 31.577 L / L, 14.03 L / L and 49.5 L, respectively. Pilot-scale fermentation is the simulation of industrial production and the intermediate link of converting laboratory results into industrial production. Through the calculation and analysis of the results of three groups of experiments in the orthogonal experiment, the optimum conditions for gas production were found to be pH 7.5% 20% bacterial liquid content 90% tank filling rate and 12% TSN 4% nitrogen source. Under the optimized fermentation parameters, the fermentation process was compared between the mechanical reflux mixing agitation (MRMS) and the mechanical stirring (MSM) in a self-made anaerobic fermentation device. By using mechanical reflux mixing mixing process, the gas production rate is high, the volume gas production rate is 41.2% higher than that of the mechanical mixing process, the material utilization ratio is increased by 13% COD removal rate and the removal rate of TN is decreased by 10.3% and the TN removal rate is increased by 9.1%.
【学位授予单位】：南阳师范学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S216.4

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