Research On Optimization In Anaerobic Fermentation Of Mixed Cattle Manure And Corn Straw

With the development of science and technology,the demand for energy is becoming more and more intense.The problem of over exploitation and utilization of fossil energy is becoming more and more serious.China produces a large number of straw and other crop waste every year,if not properly and timely and effective treatment and take place in the incineration,is not only a waste of resources,but also will cause serious pollution to the environment.In addition,with the continuous development of animal husbandry,livestock and poultry manure production in China is also rising,how to deal with such waste is also a safe problem.The mixed anaerobic fermentation technology can reduce the environmental impact of agriculture and animal husbandry at the same time.There are many factors that influence the complex biochemical process of mixed anaerobic fermentation.Therefore,how to control and coordinate the relationship between the various factors is the key to ensure the effect of mixed anaerobic fermentation.In this study,the optimal pretreatment method was determined by comparing the contents of the components of the raw material after different pretreatment.Mixed anaerobic fermentation of corn straw and cow dung,the single factor experiment to select the optimal Pretreatment Based on the study of total different solid content?TS%?and cow dung?Cattle Manure,CM?and corn straw?Corn Straw,CS?mixing ratio?TS?and the effects of the addition of trace elements of Fe²⁺ ion on anaerobic fermentation system;And the combination design of Box-Behnken center,the influence factors of the model regression analysis,optimization of anaerobic fermentation process conditions,effects of different temperatures on the properties of the dynamic fermentation device of anaerobic fermentation system.Conclusions are as follows:?1?In different corn straw pretreated as substrate for anaerobic fermentation experiment,analysis before and after the treatment of maize straw were found after treatment,after alkaline hydrolysis,the total solid content of corn straw removal rate reached 63.25%,cellulose,hemicellulose and lignin removal of 15.69%,39.62% and 29.88% rates were reduced sugar content in enzymatic hydrolysis test was 47.26%,significantly higher than the mechanical crushing and acid hydrolysis.In this experiment,the cumulative gas production rate of alkali hydrolysis test group was the highest,reaching 935 mL.?2?The anaerobic fermentation of various factors in single factor experiment.The results showed that: in the total solid content?TS%?8%?Cattle,Manure,CM?of cow dung and corn straw?Corn Straw,CS?mixing ratio?TS?for 2:1,adding amount of trace elements of Fe²⁺ ions was 1.0 mg·L^-1,Nissan biogas production,cumulative gas production,gas production of methane content were highest in test group.?3?Based on the response surface method,experimental design of Box-Behnken center combination,using Design-Express 8.0.6 software to establish two models,the regression analysis and the results show that factors of amount of TS% and CM/CS and trace elements Fe²⁺ ion three influence on the effect of anaerobic fermentation of cumulative gas production quantity is very significant,the optimal process parameters.TS% 8.52%,CM/CS 1.63:1,trace elements Fe²⁺ dosage was 1.225 mg·L^-1,the theory of cumulative gas production is 7732.4 mL,through the actual verification obtained the total gas production of 7694 m L,shows that the model can optimize the parameter of anaerobic fermentation.?4?Based on the optimal process parameters,a dynamic test device was used to carry out the experiment of medium and low temperature dynamic anaerobic fermentation.Through the comparative study on the characteristics of anaerobic fermentation,it is indicated that temperature is one of the main factors affecting the anaerobic fermentation system.