双溶剂口的双釜间歇萃取精馏过程分析.docx

中文摘要
间歇萃取精馏是分离共沸物或近沸物的一种方法,由于它结合了问歇精馏和萃取精馏的优点,特别适用于化工、制药、溶剂回收等产量小、品种多的行业, 因此间歇萃取精馏近年来已成为非常活跃的研究和开发领域。
针对常规间歇萃取精馏存在的塔釜温度变化较大、初始投料量受容积限制、弹性较小等缺点,本文提出了双溶剂进口的双釜间歇萃取精馏流程。在这种新的操作方式中,有一个釜作为原料釜,另一个作为溶剂回收釜。混有溶剂的塔内液相直接流入中间储罐,储罐间歇地向溶剂回收釜转移液体,液体经简单蒸馏后, 汽相返回原料釜,而富含溶剂的液相取出作为回收的溶剂从塔中回收溶剂入口加入塔中。在自行设计的①89X2000,填充①3X30环填料的不锈钢间歇萃取精馏塔上进行实验;分析塔顶馏分浓度、塔釜温度,并与单溶剂口的双釜间歇萃取精馏方式在相同操作参数下对比了溶剂使用量、产率和产品浓度。实验结果表明新的操作方式具有塔釜温度稳定、操作控制方便、节省溶剂使用量、收率提高等优点。
论文建立了双釜间歇萃取精馏过程的平衡级恒摩尔持液模型,并使用改进的两点隐含法对非线性刚性方程组求解。模拟计算结果与实验数据对比,两者吻合较好,表明了模型的可靠性。
关键词:间歇萃取精馏双溶剂进口双釜刚性微分方程组
ABSTRACT
Batch extractive distillation(BED)is used to separate azeotrope or the mixture ol which the relative volatility is close to it has both advantages ofbatch distillation and extractive distillation,batch extractive distillation is ing increasingly important to the production of small scale and high value products like fine chemicals and pharmaceuticals·
This paper proposes a new mode of batch extractive distillation which has two
stills and two solvent inlets tO e the disadvantages existing in the regular batch extractive distillation such as volume limitation of still,the wide range of temperature change of feed still,less flexible and SO the new mode there ar e
two stills:one is an additional as the solvent recovery still while the other is kept as
the feed the process,liquid mixture containing solvent downwards from c01umn flows directly into the middle storage middle tank transfers liquid tO the solvent still in the solvent still by simple distillation,vapor 舶m it returns feed still;and the residual liquid contains more solvent as recovery soIvenLt intr-0duted from solvent inlet into out expedments in 089× 2000 batch distillation facility which filled with 03×30 packing in column·
Analyzing the top fraction concentration,still temperature;and contracting results with single inlets BED mode’S in the same operation parameters on solvent usage, product yie