Research On Comprehensive Calculation Model Of Biomass Gasification Based On Aspen Plus

Biomass gasification is a process that uses air,water vapor and other gasifying agents to convert biomass fuel into carbon monoxide,hydrogen and methane under high temperature conditions in the gasifier.It is an efficient and clean biomass energy utilization technology.In the process of biomass gasification,pyrolysis,as a necessary stage of the gasification process,plays a vital role in the gasification results.In this paper,lignocellulosic biomass is divided into three categories: softwood,hardwood and herbaceous plants.By comparing the actual pyrolysis product yield with the product yield obtained by superposing the three components,the temperature variables are introduced and the interaction between the three components of biomass is considered,get the pyrolysis product correction coefficient.Using this correction coefficient to modify the biomass pyrolysis model based on the element equilibrium method,the product yield distribution of the biomass pyrolysis stage was obtained.Aspen Plus software was used to establish a kinetic model of biomass gasification reaction in a fixed suction bed.The product yield distribution in the pyrolysis stage was derived from the pyrolysis model in this paper.The redox stage is represented by a full-mix reactor(RCSTR)with accurate kinetic parameters,then the simulation results are compared with experimental data to verify the accuracy of the model.Furthermore,using the biomass gasification model established in this paper,the effect of different biomass raw materials on the gasification results was studied;Sensitivity analysis of gasification temperature,air flux and air inlet temperature was conducted to study the effects of these three variables on gasification gas production results.The results show that the calculated value of the modified pyrolysis model in this paper is closer to the experimental data than the original model;the simulation value of the gasification model established with Aspen Plus software is compared with the experimental data,and the error is within 5%,indicating that the model established has a certain adaptability.Gasification analysis of three types of biomass: softwood,hardwood,and herbaceous plants.The volume fractions of gasification products of softwood and hardwood biomass are similar,and there are many differences between herbaceous plants.The gasification temperature under a given gasification condition for sensitivity analysis,when the gasification temperature is less than 1100 K,the gasification efficiency increases rapidly with the increase of the gasification temperature.When the gasificationtemperature is greater than 1100 K,the gasification efficiency increases slowly with the increase of the gasification temperature,and the optimal gasification temperature is about1100K;the calorific value of gas production first increases and then decreases with the increase of the equivalent ratio,and the maximum value is obtained at the equivalent ratio of about 0.4,and the optimal equivalent ratio is about 0.4;The heat value of gas production increases slightly with the increase of air inlet temperature.Increasing the air inlet temperature can slightly increase the heat value of gasification.