络合法分离富集重石脑油中正构烷烃

SEPARATION OF n-ALKANES FROM HEAVY NAPHTHA BY COMPLEXING METHOD

从石脑油中分离或富集正构烷烃可以降低催化重整和乙烯生产的成本,优化原料组成,提高生产效率。使用尿素和硫脲为络合剂、质量分数95%的乙醇为活化剂,将正辛烷、异辛烷、甲基环己烷、甲苯按不同比例混合作为模拟石脑油进行络合富集,考察络合相产品中各组分含量及正辛烷收率。结果表明:使用尿素硫脲络合富集重石脑油中的正构烷烃是可行的,络合试验最佳反应条件为:质量分数为95%的乙醇活化剂用量80 mL,模拟石脑油用量60 mL,尿素硫脲质量比5021,络合温度-10℃,时间1 h;少量芳烃会对正辛烷分离效果产生一定的负面影响,工业上可以先用萃取法分离芳烃,然后再进行络合分离。

Separation and enrichment of n-alkanes from naphtha can reduce the operation cost of catalytic reformer and ethylene plant,optimize feedstock composition and improve production efficiency.Using urea and thiourea as complexing agents,95%(w)ethanol as activating agent,and the mixture of n-octane,isoctane,methylcyclohexane and toluene in different proportions as simulated naphtha for complexing enrichment,the content of each component in complexing phase products and the yield of n-octane were investigated.The results showed that it was feasible to enrich n-alkanes in heavy naphtha by urea thiourea complexation.The optimum reaction conditions of complexation experiment were as follows:the amount of 95%(w)ethanol activation dosage was 80 mL,the amount of simulated naphtha dosage was 60 mL,the mass ratio of urea thiourea was 5021,the complexation temperature was-10℃,and the time was 1 h.Because the presence of a small amount of aromatics has nagative impact on the separation efficiency of n-octane,in industry,aromatic hydrocarbons can be separated by extraction first.