Simulation And Test Of Pyrolysis,Gasification And Combustion Of Rural Waste Based On ASPEN Plus

Due to the increasing waste output in villages and the relatively scattered distribution of villages,the cost of collection,transport and centralized treatment is too high.Compared with other methods,fixed-bed pyrolysis gasification technology is more suitable for the treatment of small-scale waste treatment in villages.Based on the characteristics of domestic waste in villages of China,this paper establishes a model of pyrolysis,gasification and combustion system for rural waste in order to provide reference for the application and operation of the actual process system.The research content mainly includes:(1)Conducted field sampling investigation and analysis on the composition and physical and chemical characteristics of domestic waste in villages,and summarized the composition,moisture content and calorific value of domestic waste in villages.The characteristics of different regions of China are compared.And the ASPEN Plus software used in the simulation of this article,the modules in the software and the basic calculation methods and principles are introduced.(2)According to the actual data of waste from villages,a fixed bed pyrolysis and gasification model of village waste was established on the ASPEN Plus platform.The actual process was divided into three stages: drying,pyrolysis,and gasification.Simulation of the pyrolysis stage uses a RYield reaction module and a RGibbs reaction module.A RGibbs reaction module is used as the gasification stage.The effect of gasification temperature(500～1000℃),air ratio(0.1～1),water vapor ratio(0.1～1)and different gasification agents(steam,carbon dioxide,mixture of steam and flue gas)on the pyrolysis and gasification characteristics of rural garbage.The results show that mixing flue gas produced by coke combustion with steam as a gasification agent is an economical and efficient method.At the same time,a self-designed two-stage gasifier is used to verify the accuracy of the model.The mixture of microcrystalline cellulose and PE in different proportions(2:1 and 4:1)is used as raw materials.Different water vapor ratios(0.8 and 1.6)are set as the working conditions.The results show that the model has certain accuracy.(3)Based on the fixed-bed pyrolysis gasification model,a flue gas circulation system for coke combustion was established.The composition,LHV,and carbon conversion rate of the syngas that participated in the flue gas circulation process under different working conditions(S/C=0.3,AR=0.1,AR=0.25)are studied.The feasibility of the flue gas circulation system is proved.On the basis of the flue gas circulation system,the syngas combustion module is added,and energy self-sufficiency of the pyrolysis,gasification and combustion system is studied.Waste with different calorific values are used as raw materials.The feasibility of energy self-sufficiency in the integrated system is initially studied.