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。     

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.     

热集成复杂精馏流程综合的随机最优化方法

This paper addresses the application of stochastic optimization approaches to the synthesis of heat integrated complex distillation system, which is characterized by large-scale combinatorial feature. Conventional and complex columns, thermally coupled (linked) side strippers and side rectifiers as well as heat integration between the different columns axe simultaneously considered. The problem is formulated as an MINLP (mixed-integer nonlinear programming) problem. A simulated annealing algorithm is proposed to deal with the MINLP problem and a shortcut method is applied to evaluate all required design paxameters as well as the total cost function. Two illustrating examples are presented.     

双效精馏流程的节能分析

探讨几种基本的双效精馏装置的流程，并从能源利用的角度研究和分析它们的特点及适用条件。     

复杂二元精馏最小回流比的求算

本文推导出复杂二元精馏塔段最小回流比算式,由此可算出各塔段的最小回流比,其中最大值即为塔的最小回流比,最后举例说明了这种求算。     

基于随机优化的热耦合复杂精馏系统的综合（II）计算举例与分析

应用部分(Ⅰ)提出的模型化方法,对多个5组分混合物分离问题进行了求解,以说明方法的实施和有效性.对不同优化方案的优化结果及其经济性做了比较和分析,基于分析结果,对多组分热耦合复杂精馏流程的经济性和设计规则进行了初步归纳.     

用联合算法模拟复杂精馏过程

提出一个复杂精馏过程的通用数学模型,并采用改进的松弛法与修正的N-R法相结合的联合算法求解该模型。通过对理想物系、非理想物系和Petlyuk塔精馏过程的模拟计算,证明该算法通用性强、可靠性高、收敛速度快,模拟结果与文献及工业实验吻合很好。     

相图分析法对共沸精馏流程的改进

共沸精馏是非理想体系的多组分分离。各个因素之间的关系比较复杂,给流程方案的设计增加了难度。现行的共沸精馏流程长、能量消耗大。本文应用三角相图分析法改进了流程。     

二甲苯精馏装置的流程模拟

应用Pro/II流程模拟软件,对年产1014.3 kt二甲苯精馏装置进行流程模拟.选择合理的热力学模型,模拟分析了精馏的温度和浓度分布以及理论板敷,回流比和能耗的关系.模拟结果与实际操作数据吻合较好,说明该软件在二甲苯精馏装置中的应用是可行的,可用于指导生产和设计.     

热敏物系精馏流程优化

采用大型流程模拟软件PRO/Ⅱ,对高沸点差热敏物系乙醇胺的精馏过程进行了模拟,讨论了塔内浓度分布的特点,提出了增加循环物流、侧线出料的优化流程方案,使MEA塔釜温度从168.8℃降至154.5℃,DEA塔釜温度从192.4℃降至175.7℃,显著降低了釜温,防止了釜液中热敏物料的分解,同时产品纯度保持在99%(质量分数)以上.结果表明,对于高沸点差热敏物系的分离,采用上述优化流程能够有效降低釜温,防止热解,并保证产品纯度要求.     

Synthesis of flowsheets for extractive distillation of azeotropic mixtures

An algorithm for synthesizing extractive distillation flowsheets for separation of complex ternary azeotropic mixtures with different vapor-liquid equilibrium patterns is proposed.Translated from Teoreticheskie Osnovy Khimicheskoi Tekhnologii, Vol. 39, No. 1, 2005, pp. 19–26.Original Russian Text Copyright © 2005 by Ivanova, Timoshenko, Timofeev.     

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.     

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.     

C3选择性加氢热耦合催化精馏流程模拟

针对C₃ 选择性加氢过程中冷剂费用过高问题提出将选择性加氢催化反应器设置在脱乙烷精馏塔的提馏段,并通过原流程的3 个精馏塔的不同热耦合方式所构成的3 种热耦合催化精馏结构;对三热耦合催化精馏结构分别进行严格模拟和评价,表明通过分离和加氢反应的结合增加了加氢反应的转化率,并通过热耦合降低了分离能耗,年度总费用降低显著。模拟结果表明,3 种方案的年度总费用节约效果分别为4.107%、6.420%和10.337%。     

Synthesis of separation flowsheets for multicomponent azeotropic mixtures on the basis of the distillation theory. synthesis: Finding optimal separation flowsheets

A general method based on the presynthesis results is suggested for solving the problem of the synthesis of a number of the most advantageous separation flowsheets. The synthesis of optimal flowsheets can be carried out automatically for mixtures with any number of components and azeotropes. Entrainer selection is discussed, as well as the estimation of the separation cost, with the aim of choosing the optimal variant from several preselected ones.     

Application of a new startup procedure using distributed heating along distillation column

This study proposes the use of distributed heating applied to the sieve trays along distillation columns, aiming to evaluate a new experimental configuration and procedure applied to the startup. Through this new configuration it is expected that the column heating time and energy will be reduced. Due to the characteristics of the process, such as inertia and non-linearity, almost all the process variables change rapidly, which increases the time required to reach the steady state. These factors make the objective of this study even more challenging. Most of the previously published studies on startup involve simulations, whereas the main contribution of this paper is that it provides experimental results. The experiments were carried out on a pilot distillation column with 13 sieve trays processing a binary mixture composed of water and ethanol, with a flow rate of 300 L h^?1 in the fourth tray. It was verified that the use of a heating system which is able to act in a distributed way allows a reduction in the time (40%) and energy (33%) required for the startup procedure, compared to a conventional approach.     

一个用于精馏塔模拟的新模型

A new computational mass transfer model is proposed for simulating the distillation process by solving the fluctuating mass flux for the closure of turbulent mass transfer equation in order to obtain the concentration profile and the separation efficiency of distillation column. The feather of the proposed model is to abandon the conventional way of introducing the turbulent mass transfer diffusivity (dispersion coefficient) to the turbulent mass transfer equation. To verify the validity of the proposed model, a commercial scale packed column and a sieve tray column were simulated and compared with published experimental data. The simulated results were satisfactorily confirmed in both concentration distribution and separation efficiency.     

A boundary value design method for complex demethaniser distillation columns

Typically the number of design options for demethaniser flowsheets, that recover methane from a gas mixture, is large. Repetitive simulations, to evaluate the economic viability of alternatives, do not usually enable a thorough exploration of the variable space for the purposes of process synthesis. More comprehensive process optimisation is facilitated by shortcut design models and a suitable optimisation framework. These optimisation results, applying shortcut models, are useful at the initial design stage, when the range of flowsheet options and operating conditions to be explored is relatively wide.A demethaniser column has many degrees of freedom, including the operating pressure, the location and the order of feeds, the number and duty of side reboilers and the flow rate of the external reflux stream. The complexity of the demethaniser column precludes the use of the Fenske-Underwood-Gilliland shortcut design method. An appropriate design model for the demethaniser is presented for application within an optimisation framework for process synthesis and evaluation. The column design model is computationally relatively undemanding, yet accurate, so should allow evaluation of both energy demand and equipment requirements.The design model presented is a semi-rigorous boundary value method for the design of complex demethaniser columns separating multicomponent mixtures. The method has been implemented within MATLAB and linked to HYSYS for prediction of physical and thermodynamic properties. Industrially relevant examples demonstrate that the results of the proposed design methodology are in good agreement with those of rigorous simulation.