The Optimization Of The Parameter For Main Chemical Engineering Units In The Polygeneration System Starting With Dual-gas Sources

Polygeneration energy system would be an effective solution to the energy shortage and environmental problem in China,with high energy conversion efficiency,good economic benefits etc.Dual gases polygeneration system starts with the coking-oven gas and the gasified gas.It made good use of coking-oven gas in our country,colligated coking-oven gas and gasified gas in chemical composing and chemical converting.From the utilization of element and energy, we want to actualize it to be maximum.In this paper,we made use of chemical flow simulation software—Aspen Plus to establish and validate coal gasification, CH₄/CO₂ reforming and single dimethyl ether synthesis modules.Based on these modules,it is considered by revising chemistry and energy conversion to find out the choke point unit in energy using quotiety.The trend of energy using quotiety and apparent energy of every unit by its' parameters have been analyzed and the whole chemical process to optimize the parameters of every unit.Results in this paper are based on Jincheng coal,we have gotten the conclusions as followings:1,Through the analysis of gasification,we have gotten the scope of the energy using quotiety of gasification is 20%～46%.When the T=1000K,P=0.5MPa, ratio of steam to coal S/C=1.7,ratio of oxygen to coal O/C=0.5,the energy using quotiety of gasification is the highest.2,Through the study of CH₄/CO₂ reforming,the change range of energy using quotiety of reforming is 45%～88%.From the utilization of energy,it is prosperous to get higher energy using quotiety of reforming at T=750℃, P=0.3MPa,space velocity 6000L·h^-1·Kg^-1,COG/GG=0.5～1 of material.3,Through the analysis of single dimethyl ether synthesis,the range of energy using quotiety with synthesis unit is 1.4%～70%,fixuped the quantity of material, the energy using quotiety of synthesis unit is highest at T=260℃,P=15MPa, space velocity 3000L·h^-1·Kg^-1.4,After the comparison of utilizable energy quotiety with gasification,CH₄/CO₂reforming,single dimethyl ether synthesis units,the utilizable energy quotiety of gasification is lower.The gasification unit is the choke point unit with utilizable energy quotiety in the main chemical units of dual-gas polygeneration system.The variety range of reforming and dimethyl ether synthesis is bigger,so the effect of parameters to utilizable energy quotiety of the two units is obvious.5,When the energy using quotiety of whole chemical process was taken as a goal to optimize the parameters of gasification and CH₄/CO₂ reforming unit,the effect of temperature of gasification is the biggest,then is the ratio of oxygen to coal and steam to coal,the pressure is the smallest.When the utilizable energy quotiety of the whole chemical process is higher,the best condition of gasification is T=1000K,P=1.5MPa,S/C=1.4～1.7,O/C=0.1.The effect of COG/GG of reformer is biggest,and then is pressure,temperature and space velocity is about the same.After the reforming unit was analyzed,we have gotten the parameters of this unit:T=950℃,P=1atm,COG/GG=5,space velocity is 2000～3000L·h^-1·Kg^-1.6,The utilizable energy quotiety of every unit and the whole chemical process is not high at the same time.When the utilizable energy quotiety in the whole chemical process is highest,the gasification unit is T=1000K,P=1.5MPa, S/C=1.4～1.7,0/C=0.1;the CH4/CO₂ reforming unit is T=950℃,P=1atm, OG/GG=5,space velocity 2000～3000L·h^-1·Kg^-1;and the dimethyl ether synthesis unit is T=260℃,P=15MPa,space velocity 3000L·h^-1·Kg^-1.