Study On Anaerobic Fermentation Of Kitchen Waste For Biogas Production And Decarbonization

Biogas is widely used in biomass energy.Anaerobic fermentation process is used to treat organic waste and obtain high purity biogas,which can be used for lighting,heating,power generation,vehicle fuel,etc.However,the efficiency of the whole process needs to be further improved.In this context,the restaurant waste treatment plant of Guangxi Lande renewable energy Co.,Ltd.was investigated on the spot,and a method suitable for the optimization of anaerobic fermentation process parameters of restaurant waste was proposed;at the same time,the hydrate separation technology was applied to the biogas decarbonization process.The main research work of this project is as follows:?1?The dual problems of current energy structure and environmental degradation are analyzed,and the characteristics and main technical means of food waste treatment are introduced.At the same time,the research progress of methanogenesis technology of kitchen waste at home and abroad is described from the aspects of pretreatment,fermentation and purification.Combined with the current energy development mode and environmental protection requirements,this paper expounds the significance of three processing treatment of kitchen waste.?2?Based on the anaerobic fermentation technology,a multi-objective optimization method is proposed to establish the anaerobic fermentation evaluation system.Six influencing factors,including reaction temperature,total solid concentration?TS?,pH value,salt content,organic load and C/N ratio,are selected as the evaluation indexes,and the weight value of the indexes is determined by the combination weighting method of layer analysis and entropy weight method.Nine fermentation process schemes were designed and optimized by ELECTRE-?method.The 9#is the best process improvement scheme,which is more conducive to the production of biogas from kitchen waste.?3?According to the field investigation,the proportion of carbon dioxide in biogas is 35%-45%,which is the main gas impurity in biogas.Thus,based on the Chen-Guo hydrate phase equilibrium theory,the phase equilibrium model of Methane Separation by hydrate is established from three aspects:hydration phase?Chen-Guo model?,gas phase?PR equation?and liquid phase?activity model?,and the phase equilibrium pressure of CO₂ hydrate generation is calculated.The results show that the phase equilibrium pressure increases with the increase of temperature when the mixture composition is constant,the higher the CH₄ content is,the higher the phase equilibrium pressure is,and the number of iterations increases with the increase of pressure.Finally,the relationship between temperature and pressure during hydrate formation is fitted.