多组分复杂精馏流程的简捷设计法

基于对含多个侧线汽提和／或侧线精馏塔的复杂精馏流程的分析,构造了分离五组分的复杂精馏流程。提出了基于流程水平的多组分侧线汽提和／或侧线精馏塔的复杂精馏流程的设计方法。该法不仅可用于多组分复杂精馏流程的优化设计,并且能为复杂精馏流程的严格模拟提供良好的初值,从而为探讨复杂精馏流程的合成提供有效的途径。     

一种复杂精馏流程的编码表达法

提出一种多组分精馏流程的编码表达法,适用于由简单塔、带有侧线汽提或侧线精馏类型的塔以及Petlyuk类型的塔等单元构造的分离流程.首先根据塔段数和换热器数目之间的关系导出所有可能的分离方案,其次用整数作为编码来产生所有可能的分离任务顺序和换热器方案,最后用二叉树方法建立编码组合与流程结构之间的映射关系,从而实现整个流程的合理表达.同以往的方法比较,本文方法的适用范围更广,可表达更复杂的分离流程,同时简单易行.     

基于随机优化的热耦合复杂精馏系统的综合(Ⅰ)模型化方法

基于随机型最优化策略,针对包含简单塔、带有侧线蒸出及侧线汽提塔的复杂塔、全热耦合（或Petlyuk）塔的热耦合复杂精馏塔系统的综合问题,提出一种模型化方法.针对热耦合复杂精馏流程系统所需塔段数目以及冷凝器和再沸器数目的不确定性,提出了一种分解求解策略,将原问题分解成一系列具有不同塔段数的子问题分别求解;针对流程结构的优化提出一种流程结构的编码表达法,该方法将问题的分离序列结构和热耦合方式分别用两组编码表示,对分离序列的编码采用了数据结构理论中的二叉树排序方法,使流程结构的描述变得更加简便;最后以预分馏塔组分回收率及回流比为连续变量,建立了热耦合复杂精馏系统优化的[JP+1]混合整数非线性规划（MINLP）模型,该模型用改进的模拟退火算法求解,可同时得到优化的流程结构和操作参数.     

1-己烯产品分离工艺优化

针对1－已烯产品的特性，在工艺流程中，利有流程模拟软件Aspen,对不同的分离工艺进行了探讨和研究。在物系分析的基础上，提出了多组分精馏与闪蒸相结合的工艺流程；并对先脱重后脱轻、先脱轻后脱重以及同时脱轻脱重3种可行的分离方案进行了模拟计算，从而确定了最合理的带侧线塔的二塔分离流程。     

基于遗传规划的复杂精馏系统综合

提出了基于遗传规划的复杂精馏系统的综合方法.针对复杂精馏系统特点并结合化工领域知识,对遗传算子进行了改进,给出了一套独特的编码方法和求解策略.算法利用层次化结构来直观地表达复杂分离流程,同时解决了其他随机算法编码在表达精馏过程时的歧意性问题.在不必给定精馏系统超结构的情况下,能够完成可行域的自动搜寻.实例计算表明,基于遗传规划的综合策略可以用于求解复杂精馏系统的最优综合问题,实现了包括侧线塔、完全热偶塔及同时考虑热集成的各种复杂精馏结构的自动搜索寻优.     

低温精馏过程模拟及其分离特性分析(Ⅱ)带有侧线返回进料的低温精馏塔模拟

应用严格的热力学模型研究了带有侧线返回进料的氢同位素低温精馏塔的分离特性.根据氢同位素低温精馏体系的特点，以平衡级模型为基础建立了氢同位素低温精馏稳态模拟模型，确定了模型方程适宜的求解方法.塔的一股侧线出料流股经过一个平衡反应器完成平衡反应后，作为内部进料流股，与原外部进料混合后重新进入精馏塔内进行分离操作.通过对带有侧线返回进料的塔的计算模拟阐明了这一侧线流股对塔分离特性的影响.在平衡反应器内，HD部分分解为H₂和D₂，塔顶产品中H₂的浓度增加了8.635%，塔底D₂的浓度增加了11.327%.     

用于分离三氯氢硅合成过程中主副产品的隔壁塔模拟

以三氯氢硅合成过程中得到的主副产品混合物二氯二氢硅-三氯氢硅-四氯化硅为分离物系,提出采用隔壁塔代替常规精馏序列分离的新工艺.利用Aspen Plus软件对隔壁塔进行模拟,考察回流比、隔板位置、进料位置、侧线采出位置、液相分配比以及气相分配比对塔顶、侧线以及塔釜产品摩尔分数的影响,得到隔壁塔的最佳工艺参数,并通过模拟比较隔壁塔与常规精馏序列分离此混合物的能耗情况.模拟结果表明:当回流比为6、隔板位置为主塔的第8块板和第24块板、进料位置为预分馏塔的第10块板、侧线采出位置为主塔的第15块板、液相分配比为0.21、气相分配比为0.5时,隔壁塔的分离效果最佳,主产品三氯氢硅的摩尔分数为99.999%;相比于常规精馏序列,隔壁塔再沸器节能29.09%以上,冷凝器节能29.48%以上.     

新型精馏-蒸发-热泵集成系统开车过程的操作策略与动态行为

提出了一种新的天然植物多糖提取液的分离流程(DVH):通过在塔底附近引入侧线气相出料,将分离乙醇的精馏过程和浓缩多糖溶液的蒸发过程集成到一个塔设备中完成,再通过热泵(蒸汽喷射泵)在侧线采出蒸汽和再沸器之间实现了热集成,使其比原有流程节约一台蒸发设备,并实现显著的节能效果.使用Aspen Plus软件进行的过程稳态模拟表...     

物系和分离要求对最优三组元精馏结构选择的影响

针对三组分混合物的分离,选取6种不同分离指数的物系,根据多种进料组成和分离要求,对传统的直接分离序列和间接分离序列及其热集成方式、部分热耦合精馏中的侧线精馏和侧线提馏、完全热耦合结构（即隔板塔）进行了模拟与优化设计,并以年度总费用最低为目标选出各种情况下的最优精馏结构。结果表明,分离指数、进料组成及分离要求都对精馏结构的优化选择都有显著影响,热集成精馏、部分热耦合以及完全热耦合精馏结构分别在不同条件下各具有优势。根据分析结果,对影响最优三组元分离精馏结构的因素进行归纳。     

物系和分离要求对最优三组元精馏结构选择的影响

针对三组分混合物的分离,选取6种不同分离指数的物系,根据多种进料组成和分离要求,对传统的直接分离序列和间接分离序列及其热集成方式、部分热耦合精馏中的侧线精馏和侧线提馏、完全热耦合结构(即隔板塔)进行了模拟与优化设计,并以年度总费用最低为目标选出各种情况下的最优精馏结构。结果表明,分离指数、进料组成及分离要求都对精馏结构的优化选择都有显著影响,热集成精馏、部分热耦合以及完全热耦合精馏结构分别在不同条件下各具有优势。根据分析结果,对影响最优三组元分离精馏结构的因素进行归纳。     

Design and synthesis of multicomponent thermally coupled distillation flowsheets

The design and synthesis of thermally coupled distillation flowsheets for separations of five-component mixtures are studied. Four types of possible configurations are identified when simple and complex columns are both considered in a flowsheet. A universal design procedure is developed for design of any types of the identified configurations based on the abstraction of the three basic units in the flowsheets. Two examples demonstrated that this shortcut design method can be used in design of any types of the identified multicomponent thermally coupled distillation flowsheets, as well as give very good initializations for rigorous simulation of such configurations. Moreover, with a proposed computer representation of all the types of the feasible configurations, a synthesis algorithm is developed for synthesizing of multicomponent complex distillation flowsheets with both simple and complex columns. It is practical by the proposed methods for optimal design of multicomponent distillation systems in an extended search space to include the complex distillation flowsheets for industrial problems.     

Extractive Distillation Systems Involving Complex Columns with Partially Coupled Heat and Material Flows

A method based on the representation of flowsheets as graphs is proposed to synthesize flowsheets of extractive distillation of multicomponent azeotropic mixtures in complex columns with partially coupled heat and material flows. It is shown that the flowsheets constructed can provide a significant decrease in the energy consumption for separation because the process becomes structurally closer to thermodynamically reversible distillation.     

Flowsheet synthesis for the extractive distillation of azeotropic mixtures in systems consisting of columns with partially coupled heat and material flows

The earlier proposed flowsheet synthesis methods for the distillation of zeotropic mixtures and the extractive distillation of ternary mixtures using two-product columns is used to develop a flowsheet synthesis method for the extractive distillation with partially coupled heat and material flows. The distillation of azeotropic mixtures with a complex liquid-vapor equilibrium diagram is used to illustrate the feasibility analysis of the flowsheets synthesized by the developed method.     

Synthesis of Optimal Distillation Flowsheets Consisting of Columns with Various Numbers of Sections

Distillation flowsheets consisting of simple columns, both simple columns and complex columns with side streams, and simple column–complex column sequences are considered for zeotropic four-component mixtures. Applicability criteria are suggested for the complex columns.     

Energy-saving technologies of autoextractive distillation of an acetone-chloroform-n-butanol-dimethylformamide mixture

The autoextractive distillation of an azeotropic solvent mixture of acetone, chloroform, n-butanol, and dimethylformamide is considered. A set of flowsheets belonging to different structural classes is synthesized (flowsheets containing two-withdrawal columns and flowsheets involving complex columns with a single side section). The flowsheet that is optimal in energy consumption is revealed, and it is shown that flowsheets with coupled heat and material flows are more efficient than conventional ones.     

Flowsheet Synthesis Strategy for Irreversible Zeotropic Distillation

A strategy is suggested for the synthesis of the set of distillation flowsheets involving complex columns. The strategy is based on the transformation of flowsheets consisting of simple columns.     

Synthesis of partially thermally coupled extractive distillation flowsheets

For sequences involving (i) two-product columns and (ii) partially thermally and materially coupled complexes, algorithms are developed for the exhaustive generation of flowsheets for extractive distillation of n-component mixtures with a single binary azeotrope. The algorithms are aimed at the subsequent development of suitable software. On the basis of the procedure proposed for the construction of extractive distillation flowsheets, catalogues of all flowsheets at n = 2, 3, 4 for case (i) are created. Three recurrence relations are derived for estimating the total number of flowsheets at a specified n, depending on the location of an azeotrope-forming pair in the initial component sequence, when arranged in order of increasing boiling temperatures: at the beginning, end, or strictly inside it.     

Topological analysis of isopower manifolds in distillation

Separation flowsheets for three-, four-, and five-component mixtures are considered. Graphs analysis of the arrangement of feed-composition regions is performed to find the optimum separation flowsheet.     

Process simulator-based optimization of biorefinery downstream processes under the Generalized Disjunctive Programming framework

Downstream processing of biofuels and bio-based chemicals represents a challenging problem for process synthesis and optimization, due to the intrinsic nonideal thermodynamics of the liquid mixtures derived from the (bio) chemical conversion of biomass. In this work, we propose a new interface between the process simulator PRO/II (SimSci, Schneider-Electric) and the optimization environment of GAMS for the structural and parameter optimization of this type of flowsheets with rigorous and detailed models. The optimization problem is formulated within the Generalized Disjunctive Programming (GDP) framework and the solution of the reformulated MINLP problem is approached with a decomposition strategy based on the Outer-Approximation algorithm, where NLP subproblems are solved with the derivative free optimizer belonging to the BzzMath library, and MILP master problems are solved with CPLEX/GAMS. Several validation examples are proposed spanning from the economic optimization of two different distillation columns, the dewatering task of diluted bio-mixtures, up to the distillation sequencing with simultaneous mixed-integer design of each distillation column for a quaternary mixture in the presence of azeotropes.