Study On Vapor-liquid Equilibrium For Binary System Of Sulfur-containing Compounds

In the field of coal chemical industry,coking crude benzene is an important way to produce benzene,toluene and xylene in China.However,the removal of sulfur-containing compounds from coking crude benzene is a significant technical problem,especially thiophene and methylthiophene.In the field of petrochemical,the catalytic cracking technology has been one of the most important method to produce gasoline in China,and the sulfur content is much higher than other developed countries.As the sulfur-containing compound standards has been continuously improved,sulfur of chemical products must be removed.The vapor-liquid equilibrium data is one of the key indexes in designing separation equipments and separation processes.In this study,2-methylthiophene and 2,5-dimethylthiophene were selected as the research object due to lack of vapor-liquid equilibrium data on the thiophenes system in published literature.In this study,the VLE data for twenty-three binary systems containing thiophenes(2-methylthiophene and 2,5-dimethylthiophene)with alkane(2,2,4-trimethylpentane,n-heptane,n-nonane,n-decan),alkene(2,3-dimethyl-1-butene,2,3-dimethyl-2-butene,1-octene,cyclohexene),cycloalkane(methylcyclopentane,cyclohexane,methylcyclohexane,dimethylcyclohexane)were measured at 90.00 KPa by using Rose still,and all the binary system were passed the thermodynamic consistency tests.These experimental data were correlated by Wilson model,NRTL model and UNIQUAC model,and the interactional parameters for the binary systems were obtained.In order to estimate the unpublished system by using the experimental result,all components were split by UNIFAC-Dortmund and UNIFAC-Original group contribution methods.Moreover,the interaction parameters between groups were established in this work.The experimental data was correlated by using the two models,and the correlation data and experimental data were analyzed.The finding by analysis is that system of 2,2,4-trimethylpentane + 2-methylthiophene and ethylcyclohexane + 2,5-dimethylthiophene exist cancelling azeotropism,Where the latter is a positive deviation solution and exist a lowest constant boiling point.