The Process Research Of Separation Of Mixed Cresol

Cresol usually refers to a mixture of o-cresol,m-cresol and p-cresol,these three ingredients can be used to produce synthetic fragrance products,is also an important fine chemical intermediates,and have a very wide range of applications in pesticides,dyes,medicine,antioxidants and other fields.Cresol mainly derived from chemical synthesis or coking,oil,tarsands,oil shale dry distillation and urban gas by-product,and also be obtained by chemical methods which will produce moer by-products and need to be separated,because of the relatively small difference in the boiling point of m-cresol and p-cresol,it is difficult to separate it with the traditional separation methods.The industrialization of cresol separation has not been achieved in China,so it has a very important significance to study the separation process of cresol.In this paper,several water-stable acid-ionic liquid catalysts with-SO₃ H functional groups were prepared.The prepared ionic liquids were characterized by IR,TG and HMNR.And the synthesis conditions of ionic liquids were optimized.The optimum reaction temperature was60?,the reaction time was 4h,and the stirring rate was 1500r/min.Then the effects of ionic liquid type and its composition on the alkylation of cresol were investigated.The results showed that,when the [HO₃SC₃NEt₃]Cl-ZnCl₂ was used as the ionic liquid catalyst,the conversion rate of isobutylene was the highest,and the catalytic effect was best,when the mole fraction of ZnCl₂ in the ionic liquid [HO₃SC₃NEt₃]Cl-ZnCl₂ was 84%,the catalyst works best.The mixture of m-cresol and p-cresol was separated from the condition of the presence of catalyst,the effects of catalyst type,reaction temperature,reaction time and space velocity of isobutylene on the conversion and selectivity of cresylation were investigated.And then the orthogonal reaction was used to obtain the optimum conditions for the separation of m-cresol from petroleum.In the final,the decarburization distillation products were used as raw materials to study the dehydrochlorination reaction,including the type of catalyst and the amount of catalyst used to obtain the higher purity m-cresol.