The SeparationTechnology Research And Exploitation Of1-Chloro-2-ethylhexane+2-Ethyl-1-hexanol System

2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507, PC-88A) is a kindof organop hosphorus extractant, which is widely used to extract and separatenon-ferrous and rare earth metals. Tributyl phosphate (TOP) is a kind of flameretardant and cold-resistant plasticizer. During the synthesis process of P507or TOP,byprod ucts such as1-chloro-2-ethylhexane and2-ethyl-1-he xanol are produced.1-Chloro-2-ethylhexane and2-ethyl-1-hexa nol are both important chemicals, and theyalso act as reactant during the synthesis of P507. So it has economic values to separateand recycle the two chemicals.To our knowledge, no experimental VLE data have been found in the openliterature for the system of1-chloro-2-ethylhexane and2-ethyl-1-hexanol, also thedifference of boiling po ints at normal pressure between the two chemicals is no morethan11.25℃. So it remains uncertain whether the binary system has an azeotrope.This creates further problems for the design of distillation separation.In this paper, isobaric vapor-liquid equilibria data of binary systems comprising1-chloro-2-ethylhexane and2-ethyl-1-hexanol were measured at various pressures,and the experimental data were checked with the Herington consistency test method,which showed thermod ynamic cons istency. All the experimental data were correlatedwith the Wilson, nonrando m two-liquid (NRTL), and universal quasi-chemical(UNIQUAC) activity coefficient mode ls to obtain the binary interaction parametersusing Aspen Plus software. Matlab software programming was used for distillationsimulations on the basis of experimental VLE data. The results show that, when theoperation pressure is10kPa, the number of theoretical plate is40, and the reflux raitoequals to7.2, the distillate contains97%molar fraction of1-chloro-2-ethylhexane.When the operation pressure is2.65kPa, the number of theoretical plate is40, a nd thereflux raito equals to7.4, the distillate contains98%molar fraction of1-chloro-2-ethylhexane. Chemical purification method was used to further purify thedistillate produced from batch distillation, and the final purity of the samples is up to99.2%by gas chromatography analysis.The RadFrac module was used to simulate the rigorous distillation for theseparation of1-chloro-2-ethylhexane and2-ethyl-1-hexanol at3kPa, on the ba sis of regression parameters, and the realeted design parameters were determined. As aresult, the distillate contains98.4%mass fraction of1-chloro-2-ethylhexane.Extractive distillation for the separation of1-chloro-2-ethylhexane and2-ethyl-1-hexanol was studied. Screening possible extraction solve nt was carried outwith experience method. Binary and ternary related VLE data were studied at10kPa.The conclusions are as follows. Diethylene glycol has noticeable effect as anextractant for the separation, and the volatility of1-chloro-2-ethylhexane in contrastwith2-ethyl-1-hexanol is sharply increased at high concentration ranges of1-chloro-2-ethylhexane, and the azeotropy is disappeared. What’s more, compositeextractant comprising diethylene glycol monobutyl ether and1,4-butanediol has abetter effect. Finally, the RadFrac module was used to simulate the rigorous extractivedistillation of1-chloro-2-ethylhexane and2-ethyl-1-hexanol on the basis of regressionparameters at10kPa, and the realeted design parameters were determined.This study will provide valuable data and theory foundation for industrial designand utility.