对“恒沸精馏”的质疑

本文通过对“共沸”与“恒沸”概念的分析和由来的追踪,指出了目前化工原理教学中“恒沸精馏”的称谓造成了概念混乱的缺陷和弊端,提出了将有共沸物生成的精馏过程一律称为“共沸精馏”的建议。     

恒沸精馏分离硝基氯苯的研究

提出了采用恒沸真空精馏分离硝基氯苯的新工艺，并通过试验确定了合适的恒沸剂和最佳工艺条件：恒沸剂与原料质量比为0．20：1，回流比为10，为工业化生产提供了可靠的理论依据。     

燃料乙醇热泵恒沸精馏新工艺的研究

为解决传统燃料乙醇生产过程中能耗大的问题，将热泵技术与传统恒沸精馏工艺相结合，开发出热泵恒沸精馏生产新工艺。在分析传统恒沸精馏生产无水酒精工艺方法的基础上，重点分析了燃料乙醇热泵恒沸精馏新工艺的原理、优点和能耗问题。结果表明，热泵恒沸精馏技术节约生产过程能耗56％，显著优于传统恒沸精馏生产工艺。     

浅谈沉降时间对二甲基二氯硅烷水解产物收率的影响

介绍了二甲基二氯硅烷水解反应机理及恒沸酸水解工艺,探讨了恒沸酸水解工艺生产过程中沉降时间对水解物收率的影响。     

恒沸精馏算法的稳定化

<正> 恒沸精馏处理的体系是高度非理想物系,其温度与浓度分布是十分陡峭的,这就使得计算过程对某些操作条件(如回流比、釜底蒸发量)以及自变量初值的微小变化十分敏感,从而造成了恒沸精馏计算的特殊困难性。尤其当存在多种液体或多个解时,计算更为困难。     

间歇恒沸精馏法从异丙醇水溶液中回收异丙醇

采用单塔间歇恒沸精馏法将异丙醇与水分离,从含水１２．６％左右的醇溶液可制得含水小于０．５％的异丙醇产品,醇的回收率达９７．０％。对恒沸剂选择、用量,流程和操作要点作了推荐及说明     

叔丁醇-水-环己烷体系恒沸精馏过程模拟研究

本文运用Aspen plus过程模拟软件模拟计算了叔丁醇-水-环己烷恒沸精馏过程,计算出了各塔板的温度和气液相流量及组成,同时考察了理论塔板数和最小共沸剂流量及全塔热负荷的关系;加料板位置的变化对恒沸精馏塔分离效果的影响;以及设备压强的变化对共沸精馏的影响。     

脱除二甲基二氯硅烷恒沸盐酸水解副产物盐酸中的硅氧烷的方法

概述了脱除二甲基二氯硅烷恒沸盐酸水解副产物盐酸中的硅氧烷的基本方法——活性炭吸附法、聚苯乙烯基树脂吸附法和膜分离法，比较了活性炭吸附法与聚苯乙烯基树脂吸附法的效果，并对如何更好地处理二甲基二氯硅烷恒沸盐酸水解副产物盐酸中的硅氧烷提出了建议。     

1,4-丁二醇分离乙酸甲酯-甲醇二元恒沸物的研究

利用1,4-丁二醇与乙酸甲酯-甲醇二元恒沸物形成三元恒沸物,研究了乙酸甲酯与甲醇恒沸物的分离工艺。实验采用精馏、常压蒸馏、减压蒸馏及冷冻的方法,主要研究了各种方法对甲醇分离的影响,并获得了较佳的工艺条件。研究得出常压蒸馏法可行,乙酸甲酯纯度达到99.7%,收率98.1%,甲醇纯度96.1%,收率95.2%。     

恒再沸比提馏式间歇精馏的最小再沸流比与能耗分析

通过构造一函数,推导出二元恒再沸比提馏式间歇精馏,在理想操作条件下,理论板数趋向无穷多时,瞬时恒浓区变化方式可由此函数值(>0或<0)来判断,完善了二元恒再沸比提馏式间歇精馏最小再沸比计算方法。推导出二元恒残液组成提馏式间歇精馏,在理想操作条件下的最小汽化总量的计算公式。通过对理论板数趋向无穷多时的能耗分析得到,二元提馏式间歇精馏,要求残液中重组分的收率和平均浓度均高时,相对于恒残液组成操作,采用恒再沸比操作能耗较高,其主要原因是低效总能耗（理论板数趋向无穷多时,直接表现为无效总能耗）在总能耗中占比例较大。     

Logic hybrid simulation-optimization algorithm for distillation design

In this paper, we propose a novel algorithm for the rigorous design of distillation columns that integrates a process simulator in a generalized disjunctive programming formulation. The optimal distillation column, or column sequence, is obtained by selecting, for each column section, among a set of column sections with different number of theoretical trays. The selection of thermodynamic models, properties estimation, etc. is all in the simulation environment. All the numerical issues related to the convergence of distillation columns (or column sections) are also maintained in the simulation environment. The model is formulated as a Generalized Disjunctive Programming (GDP) problem and solved using the logic based outer approximation algorithm without MINLP reformulation. Some examples involving from a single column to thermally coupled sequence or extractive distillation shows the performance of the new algorithm.     

多效反应精馏过程生产氯化苄的能量集成

以甲苯氯化生产氯化苄为研究对象,对带侧反应器的反应精馏与精制塔串联工艺(CSRRT)进行研究及能量分析,建立了分段反应精馏与精制塔串联生产氯化苄的新工艺。利用精制塔塔顶蒸汽潜热加热第一段反应精馏塔的塔釜,建立了多效反应精馏(MERD);进一步利用侧反应器的甲苯氯化反应热加热第一段反应精馏塔的塔板物料,建立了多效透热反应精馏(MEDRD)。在相同生产要求下,对3种工艺的能耗进行比较。结果表明,MERD和MEDRD过程实现了能量的优化利用,与CSRRT过程相比,塔釜总再沸器热负荷分别降低16.8%和33.7%。     

微正压精馏塔压力控制方法的研究

研究了采用氮气充压控制精馏塔操作压力的控制方法。氮气充压系统主要由恒压罐、正压罐和负压罐构成,其中恒压罐与精馏塔塔顶相连。首先通过理论比较了氮气充压新方法和传统冷却介质调节法,表明新方法的恒压作用更加快速可靠。试验考察了氮气充压系统的可行性及压力波动调节的灵敏度和可靠性,并且进行了新方法的微正压精馏过程的压力控制试验,结果表明新方法调节灵敏,恒压稳定。     

Optimal retrofit of a side stream column to a dividing wall column for energy efficiency maximization

A side distillation column is widely used to separate multicomponent mixtures into three products. However, this kind of column consumes considerable amounts of energy due to thermodynamic restrictions and the nature of the distillation process. Retrofit of the side distillation column to a dividing wall column (DWC) can result in significant energy savings. This study evaluated a systematic method for optimal retrofit of a side stream column to a DWC. The minimum energy requirement for the separation of a multicomponent mixture was used for a feasibility study. Subsequently, design and optimization was performed using shortcut, rigorous and response surface methodology. One case study was illustrated to demonstrate the proposed methodology. The results showed that the optimal retrofit of a side distillation column to the DWC could not only save a significant amount of energy, but also increase the capacity. This study highlights the potential for retrofitting a side stream column to a DWC from a techno economic point of view.     

Performance and Energy Consumption of Membrane‐Distillation Hybrid Systems for Olefin‐Paraffin Separation

Light olefin and paraffin are commonly separated by energy‐intensive cryogenic distillation. Membrane/distillation hybrid systems constitute an economical alternative separation process. Different configurations of this hybrid system are studied for olefin‐paraffin separation with emphasis on C₃ separation. An approach based on the McCabe‐Thiele method is applied to analyze different process configurations. A facilitated transport membrane is considered as membrane type. Both new column design and augmentation of an existing distillation column by a membrane module are considered. Numerical examples are considered for the separation of propane from propylene through different hybridization shapes with facilitated transport membranes. The energy requirement can be halved using hybrid systems.     

最小有效能损耗的多组分精馏流程优化设计

提出了以有效能损耗最小为目标、同时又考虑热集成的多组分复杂精馏塔序列优化设计新策略。该复杂精馏塔模型:1股进料、2股出料,每块理论板上均可有中间冷凝器或再沸器。复杂精馏过程的设计步骤是:①根据过程有效能最小确定优化塔序列;②对每个塔优化设计出含中间换热器的复杂塔;③考虑多效且允许热集成的复杂精馏流程,以塔压为决策变量,以精馏过程有效能损耗最小为目标,建立并优化设计出一个热集成的复杂精馏流程。一个3组分精馏过程的例子表明所提策略简单有效,可用来指导多组分精馏过程的优化设计。     

Experimental evaluation of a modified fully thermally coupled distillation column

A modified fully thermally coupled distillation column replacing the conventional distillation system is introduced, and its performance is experimentally evaluated for the stable operation of the column. The existing distillation system is modified to an energy-efficient distillation column for the reduction of investment cost and energy requirement. The experiment is conducted for the separation of methanol, ethanol and n-propanol mixture using a 4-in sieve tray column. The temperatures at seven different locations of the column are measured to monitor the column operation, and the measurements indicate that the column is stably operable. The stable operation proves that neither compressor nor pump is necessary for the vapor or liquid flow between tray sections. The experimental result is compared with that of the HYSYS simulation to show how satisfactory the separation is. The modeling of temperature variation provides a successful prediction of the temperature variation.     

Optimization of a reactive distillation process with intermediate condensers for silane production

This work presents a reactive distillation column for the catalytic disproportionation of trichlorosilane to silane which includes three consecutive reversible reactions. This reaction system is however characterized by a large distinction in the boiling points of the components, which make the reactive distillation extremely favored. Nevertheless, the normal reactive distillation column possesses the shortage of high refrigeration requirement. By removing heat at temperature higher than that at the condenser a superstructure representation, rigorous simulations, and optimization problems were combined to derive optimal reactive distillation columns which can realize heat integration between stages and utilities at several refrigeration conditions. An iterative simulation-optimization procedure was proposed to consider temperature changes in stages due to heat integration. The results showed that the installation of two inter-condensers results in the best option with economic savings up to 56%.     

Soft-sensing modeling and intelligent optimal control strategy for distillation yield rate of atmospheric distillation oil refining process

It is a challenge to conserve energy for the large-scale petrochemical enterprises due to complex production process and energy diversification. As critical energy consumption equipment of atmospheric distillation oil refining process, the atmospheric distillation column is paid more attention to save energy. In this paper, the optimal problem of energy utilization efficiency of the atmospheric distillation column is solved by defining a new energy efficiency indicator — the distillation yield rate of unit energy consumption from the perspective of material flow and energy flow, and a soft-sensing model for this new energy efficiency indicator with respect to the multiple working conditions and intelligent optimizing control strategy are suggested for both increasing distillation yield and decreasing energy consumption in oil refining process. It is found that the energy utilization efficiency level of the atmospheric distillation column depends closely on the typical working conditions of the oil refining process, which result by changing the outlet temperature, the overhead temperature, and the bottom liquid level of the atmospheric pressure tower. The fuzzy C-means algorithm is used to classify the typical operation conditions of atmospheric distillation in oil refining process. Furthermore, the LSSVM method optimized with the improved particle swarm optimization is used to model the distillation rate of unit energy consumption. Then online optimization of oil refining process is realized by optimizing the outlet temperature, the overhead temperature with IPSO again. Simulation comparative analyses are made by empirical data to verify the effectiveness of the proposed solution.     

A new approach to distillation column at total reflux

For a distillation column at total reflux, a simulation algorithm is presented, which takes into account the nonideality of both the vapor and liquid phases in addition to the pressure drop at each plate. The solution algorithm based on the Newton-Raphson technique is simple, because this algorithm has only one trial loop and no substitution parts and does not require a large portion of a computer's memory requirements. A numerical example shows the effectiveness of the proposed algorithm.