化工进展2017，Vol.36Issue(5)：1605-1611,7.DOI:10.16085/j.issn.1000-6613.2017.05.007
熔融结晶法分离提纯对二甲苯
Purification ofp-xylene by melt crystallization
摘要
Abstract
Adsorption separation of mixed xylene can obtainp-xylene,but it still contains a small amount of toluene. A new separation process ofp-xylene and toluene by melt crystallization was proposed. The solid-liquid equilibrium phase diagram ofp-xylene and toluene was measured by differential scanning calorimetry(DSC). The experimental data showed that the binary system presented a eutectic point. On the basis of the solid–liquid equilibrium,liquid film crystallization experiments were carried out. It can obtain p-xylene products with the purity over 99.5%. The results indicated that it was feasible to separatep-xylene and toluene by melt crystallization. According to the experimental process,the dynamic mathematical model of liquid film crystallization was established. The model values agreed well with the experimental data,which verified the accuracy of the model. With the modeloptimization of operating conditions,the appropriate spray density and cooling rate can weaken the problem of uneven crystal layer growth. Cost accounting about melt crystallization and distillation separation processes was carried out respectively. The results showed that the fixed investment of crystallization was much lower than the distillation and operation conditions were stable. Crystallization was easy to get high purity products,but its energy consumption was slightly higher than distillation. Thus,the crystallization was suitable for small batch production,and the distillation was appropriate for high-volume production.关键词
熔融结晶/对二甲苯/固液平衡/建模/成本核算Key words
melt crystallization/p-xylene/solid-liquid equilibrium/modeling/cost accounting分类
化学化工引用本文复制引用
沈澍,李士雨..熔融结晶法分离提纯对二甲苯[J].化工进展,2017,36(5):1605-1611,7.基金项目
国家自然科学基金委与中国石油联合基金重点项目(U1462206). （U1462206）
