加盐萃取-精馏耦合分离苯-环己烷共沸物  

Separation of benzene-cyclohexane azeotrope by combined process of extraction with salt and distillation

作　　者：董红星[1] 王晓宇[1] 杨晓光[1] 

机构地区：[1]哈尔滨工程大学材料科学与化学工程学院,黑龙江哈尔滨150001

出　　处：《化学工程》2009年第4期1-3,48,共4页Chemical Engineering(China)

基　　金：黑龙江省自然科学基金资助项目(E-200808);哈尔滨工程大学基础研究基金项目(mzj07053)

摘　　要：采用N,N-二甲基甲酰胺(DMF)+硫氰酸钾(KSCN)萃取分离苯-环己烷共沸物,并用常规间歇精馏处理富含苯的萃取液。考察了不同溶剂与原料液的体积比、盐质量分数对该体系分配系数及选择系数的影响,并进行了多级错、逆流萃取实验及精馏实验。实验结果表明:7级错流萃取可得摩尔分数大于97%(脱溶剂摩尔分数)的环己烷;5级逆流可得摩尔分数大于75%(脱溶剂摩尔分数)的环己烷;精馏后的萃取液,苯摩尔分数可达98%以上,DMF+KSCN摩尔分数可达96%以上。加盐萃取-精馏耦合分离苯-环己烷共沸物可得到令人满意的分离效果,是一种绿色节能的新方法。The extraction with N, N-dimethylformamide （DMF） ＋ potassium thiocyanate （KSCN） was carried out to separate benzene-cyclohexane azeotrope, and routine batch distillation was used to deal with the extract containing more benzene. The effects of different volume ratios of solvent to feed solution and the mass fraction of salt were researched on partition coefficient and selectivity coefficient. The experiments were conducted for multistage cross/counter current extraction and distillation. The experimental results show that after seven-stage cross-current extraction, the mole fraction of cyclohexane is more than 97% （without solvent）; after five-stage counter-current extraction, the mole fraction of cyclohexane is more than 75% （without solvent）. The mole fractions of benzene and DMF ＋ KSCN are more than 98% and 96% respectively in the rectified extract. The separation of benzene-cyclohexane azeotrope by combined extraction process with salt and distillation can get a satisfactory result and is a new green energy-saving method.

关 键 词：加盐萃取 精馏 苯-环己烷共沸物 DMF+KSCN新溶剂 

分 类 号：TQ202[化学工程—有机化工]