三元共沸体系二恶烷-乙醇-水分离方法的研究  

Research on separation of ternary azeotropic system: dioxaneethanol-water

作　　者：刘银川 胡松 胡帅 孙翟宗 杨卫胜 LIU Yinchuan;HU Song;HU Shuai;SUN Zhaizong;YANG Weisheng(Shanghai Research Institute of Petrochemical Technology,SINOPEC,Shanghai 201208,China)

机构地区：[1]中国石油化工股份有限公司上海石油化工研究院

出　　处：《计算机与应用化学》2018年第6期480-489,共10页Computers and Applied Chemistry

摘　　要：二恶烷、乙醇和水三者互溶,相互之间存在二元共沸及三元共沸,且二恶烷和水常压下沸点接近,普通精馏难以分离。本文选取了合适的萃取剂二甲基亚砜（DMSO）,采用萃取精馏从塔顶分离出二恶烷和乙醇,利用加压精馏消除共沸,实现二恶烷和乙醇的分离;萃取精馏塔釜物料经萃取剂回收塔减压精馏从塔釜回收二甲基亚砜,循环至萃取精馏塔中,塔顶分离出水。采用流程模拟软件Aspen Plus对上述流程进行了全流程模拟计算,模拟结果表明：采用上述方法可以实现二恶烷、乙醇和水的分离,分离后二恶烷、乙醇和水的摩尔纯度均达到99%;在此基础上,以萃取精馏塔为例,讨论了理论板数、萃取剂进料位置和进料温度、原料进料位置、溶剂比、回流比对分离效果的影响,完成了全流程工艺参数的优化,利用热集成及双效精馏的方式节省能耗15.8%。The binary and ternary azeotropes exist in dioxane-ethanol-water mixture which is a completely miscible system, and the boiling points of dioxane and water at atmospheric pressure are greatly close. Consequently, it is difficult to separate the components form the mixture by conventional distillation. This work adopted extractive distillation with a suitable extractant-dimethyl sulfoxide （DMSO） to isolate dioxane and ethanol by pressurized distillation at the top of the column. DMSO and water were separated at the bottom of the extractive distillation column and streamed to solvent recovery column to recover the extractant by vacuum distillation, which would be circulated to extractive distillation column; and water was obtained from the top of solvent recovery column. Then the separation process of dioxane-ethanol-water system was simulated by Aspen Plus, and the result demonstrated that the separation of dioxane, ethanol and water can be realized with the mole purity of no less than 99 % for all the components using this method. Meanwhile, the effect of major design parameters of extractive distillation colunm, such as the theoretical tray number, the location of feed, the temperature of solvent, solvent ratio and reflux ratio, on separation was investigated, the whole process parameters were optimized, and the consumed energy was reduced by 15.8 % with heat integration and double effect distillation.

关 键 词：三元共沸 萃取蒸馏 加压精馏 流程模拟 

分 类 号：TQ209[化学工程—有机化工]