Study On Separation Of Mixed 1,2,4,5-tetramethylbenzene —the By-production Of Coal From Gasoline

The 1,2,4,5-tetramethylbenzene and 1,2,4-trimethylbenzene are the fundamental organic chemical materials, and extensive used for industrial applications .In general ,they are from the separation of aromatics reformer C9,C10 fraction. Recent years, because of oil crisis, the property of reforming catalyst is gradually improving, resulting the over point of C9,C10 aromatics fraction higher and higher and the content of 1,2,4,5-tetramethylbenzene and 1,2,4-trimethylbenzene are in aromatics fraction lower and lower , and the spreading production scale of final product .so ,the price of them keep high. The by-product of gasoline from coal in a company of Shanxi province is comprised of 1,2,4,5-tetramethylbenzene ,1,2,4-trimethylbenzeneare and petroleum solvent ,which are high value-added product. For the optimization of product mix and increasing the income on investment, it is necessary to separate and purify the material.The experimental material is the by-product of gasoline from coal. According to the related documents and the property of un-separating material, it should be necessary to adopt distillation and crystallization. In the course of experiments , mainly studied the separation sequence of distillation and crystallization and the purity of goal product ;at the same time ,drawing on the experience of experimental results from a company in Hebei province and linking the property of raw materials ,determined reasonable separating process and respectively got the purity 97% and 95% of 1,2,4,5-tetramethylbenzene and 1,2,4-trimethylbenzene,meeting for the final customer.Based on the experiment study, in reference of petrochemical industry 1,2,4,5-tetramethylbenzene and 1,2,4-trimethylbenzene process ,combined with the continuous industry characteristics, initially decided on the raw materials separating process and draw the process. For the distillation feasibility, applied the simulation software Aspen plus carrying on the distillation process simulation, which provided theory basis for the engineering design and application.