关键词: 非均相共沸精馏, 挟带剂, 计算机辅助分子设计, 图论原理, 基团贡献法

Abstract: Heterogeneous azeotropic distillation is an effective technology to separate close boiling point or homogeneous azeotropic mixture.The first step is to select appropriate entrainers.A computer aided molecular design(CAMD)methodology for the entrainer in heterogeneous azeotropic distillation is presented in this study.The CAMD methodology is comprised of three step-by-step stages,which are molecular synthesis,molecular screening and molecular recognition.In the stages of molecular synthesis,groups are pre-selected,the total number and types of the groups for the synthesized molecule are limited,and the automatic combination of groups is completed by using a graph algorithm.In the stages of molecular screening,the basic molecular library is formed by using several limited rules of basic physical properties,such as molecular weight and boiling point.The molecules in the basic molecular library are screened when they form the heterogeneous azeotropic with input components to be separated.As a result,a series of entrainer candidates are listed.In the stages of molecular recognition,the fuzzy comprehensive assessment function,which is composed of several important factors,such as temperature and composition of heterogeneous azeotropic point,and heat of vaporization of entrainer,is used to rank entrainer candidates.Consequently,a group of appropriate entrainers are obtained.For acetic acid-water system and acetonitrile-ethyl acetate system,several better entrainers are obtained.It indicates that the CAMD methodology and the computer procedure is practical and reliable,and the resulting entrainers is the basis for research or conceptual design of heterogeneous azeotropic distillation processes.

Key words: heterogeneous azeotropic distillation, entrainer, computer aided molecular design, graph principle, group contribution method