Research On Recovery Of Industrial Waste Gas Of Methyl Acetate And N-butyl Acetate

Methyl acetate and n-butyl acetate are recovery value of volatile organic compounds.As methyl acetate and n-butyl acetate have a low flash point and volatile characteristics,so it will produce a low concentration of industrial gas with methyl acetate and n-butyl acetate during producing and using process.The industrial gas with methyl acetate and n-butyl acetate is harmful to environment and physical health.However,little research has been done on purification and recovery of methyl acetate and n-butyl acetate at present.In this paper,established the process which not only the exhaust were under the standards but aslo achieved the goal of methyl acetate and n-butyl acetate recovery and absorbent recycling.Firstly,this paper used the mathematical model of absorber and desorption column,and select NRTL property method for the process.Then based on the property of methyl acetate and n-butyl acetate,part of the absorbers were filtered out.And through the model of calculation of gas solubility in the Flash module of Aspen Plus,compared with other absorbents,ethylene glycol was chosed as the absorbent.Simulate the process of absorption and desorption,and various factors affecting the absorption process was investigated,such as plate number,the temperature of the feed liquid and the liquid flow rate.At the same time,discussed the optimum operating conditions of desorption column of T2 and T3.Via simulation,some of the data has been obtained to meet the emissions standards and consume less absorbent.The number of theoretical plates was 15,the temperature of the feed liquid was 30?and the liquid flow rate is 82 kmol/h.Based on this,the number of the T2 desorption column theoretical plate was designed as 5,the feed entered into the plate from the third plate and reflux ratio was2.8,we can get better separation and consume less energy.And for the T3 desorption column,theoretical plate designed as 11,the feed entered into the plate from the fourth plate and reflux ratio as 3 was the optimum operating conditions.Ethylene glycol for absorbing methyl acetate from waste gas were studied in a packing tower.Factors such as inlet gas flow rate,inlet liquid temperature and inlet liquid flow rate were taken into consideration for the recovery of methyl acetate,the gas absorption coefficient K_Ya and the height of transfer unit H_OG.Results showed that when inlet waste gas flow rate was 18L/min,inlet liquid temperature was 30?and inlet liquid flow rate was60mL/min,the recovery of methyl acetate could reach 91.42%.K_ya was 174.62 kmol·m^-3h^-1and H_OG was 0.36 m.Finally,on the basis of steady-state model,we completed absorption-desorption process dynamic simulation.From the feed flow rate and composition change response,It can be concluded that CS2 control scheme system is better when the feed flow rate change±10%and composition change±0.3%.