基于有效能分析的复杂精馏塔优化设计

提出了以有效能消耗最小为目标的复杂精馏塔优化设计新方法。给出了精馏塔优化设计模型及最佳进料位置、适宜理论板数NT、塔内换热器简约的确定方法,并以两组分正庚烷和乙苯的混合物为例进行设计与讨论。优化后的精馏塔含有中间换热器,与传统的简单塔有本质的区别,平衡线和操作线均处于相对平均的位置,更节能。     

热集成复杂精馏系统综合的研究

将夹点分析法应用于热集成复杂精馏系统综合的换热网络设计中,避免了以换热网络结构作为独立变量,建立了一个以预分馏塔组分回收率、回流比及操作压力为连续变量,以分离序列和热耦合方式为离散变量的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。对多个五组分混合物分离问题进行了求解,并对不同优化方案的优化结果及其经济性作了比较和分析,结果表明采用热集成复杂精馏塔流程可以显著地降低系统的总费用,还表明该方法是求解热集成复杂精馏系统综合问题的有效方法。     

A simple synthesis method for studying thermally integrated distillation sequences

In this paper an improved method for studying processes for separation of multicomponent mixtures is presented. A thermodynamically oriented procedure was developed for the analysis and synthesis of the best heat‐integrated distillation system. Systematic ranking of possible schemes was used in order to verify the best structure of a heat‐integrated distillation system. An integrability criterion was introduced for the selection of the most promising heat‐integrated sequences. Distillation columns were studied according to their ability for heat integration. The proposed selection of possible distillation columns sequences using rising integrability criteria gave a good approximation of the best heat‐integrated distillation column sequences according to their total annual cost. Computational simulation of the process and pinch analysis were used for thermodynamic optimization of energy consumption. The method is illustrated with five‐ and six‐component example problems.     

一种通用的反应蒸馏塔综合与设计方法

反应精馏是反应过程和分离过程耦合为一体的单元操作,已成为当今研究的重要领域。然而,到目前为止并没有一套通用简便的方法去指导反应精馏过程的综合与设计,严重限制了它的广泛应用。本文在过程强化原理的基础上提出了一种反应蒸馏塔通用的综合与设计方法,并利用2种反应蒸馏系统来评价所提出的设计策略。结果表明,该综合设计方法可以简便高效地搜索出反应蒸馏塔的最优结构,适用于不同类型的反应蒸馏塔的综合与设计。     

中间换热器及热泵对复杂塔处理能力的影响

为了研究复杂精馏塔扩容改造,文中运用流程模拟软件及Liu与Jobson提出的面积利用率曲线(FUA曲线)研究了安装中间冷凝器、中间再沸器及热泵对复杂精馏塔处理能力的影响.由模拟及计算结果可得基础工况的FUA曲线,根据该曲线形状可以确定:当复杂精馏塔处理量增加时,哪些塔板将成为其处理能力提高时的“瓶颈”;中间换热器及热泵...     

催化精馏分解过氧化氢异丙苯制苯酚模拟计算

强酸性大孔树脂催化过氧化氢异丙苯(CHP)分解反应制苯酚是一个快速反应,需要用丙酮对进料CHP进行稀释,且反应过程要注意及时移出热量。依据该反应特点,设计催化精馏分解CHP制苯酚,应用Aspen Plus过程模拟软件进行了模拟计算。操作压力增大转化率下降而热负荷增大;回流比增大转化率开始增大,但一定程度后处于恒定;CHP进料位置越低转化率越低;而丙酮进料位置对转化率影响很小;停留时间增加,转化率开始增加而后维持一恒定值,但再沸器热负荷降低。计算结果对催化精馏分解CHP制苯酚工艺设计具有参考价值。     

侧反应器反应精馏方法生产醋酸甲酯的模拟

采用强酸性阳离子交换树脂催化醋酸与甲醇反应精馏生成醋酸甲酯,可避免硫酸作为催化剂的不足。但该非均相催化反应受平衡限制,且达到平衡时间较长,采用传统反应精馏塔难以提供足够反应空间。文中设计侧反应器与精馏塔耦合新工艺,采用Aspen Plus软件模拟研究了侧反应器数量、位置,原料进料位置,回流比,醇酸比等对反应精馏过程的影响。结果表明,当装置具有7个侧反应器,反应器间隔4块板,在优化的操作条件下,醋酸甲酯质量分数可达99.1%。     

Synthesis of optimal thermal membrane distillation networks

Thermal membrane distillation (TMD) is an emerging separation method which involves simultaneous heat and mass transfer through a hydrophobic semipermeable membrane. Traditionally, studies of this technology have focused on the performance of individual modules. Because of purity and recovery requirements, multiple TMD modules may be used in various configurations including series, parallel, and combinations. Furthermore, there may be a need to reroute streams from one module to another or to recycle a stream to the same unit. The objective is to develop a systematic approach to synthesize an optimal TMD network. A structural representation is developed to embed potential configurations of interest. A mathematical formulation is developed to transform the design problem into an optimization task that seeks to minimize the cost of the system. Two case studies are presented to illustrate the applicability of the developed approach and its merit over conventional design scenarios. © 2014 American Institute of Chemical Engineers AIChE J, 61: 448–463, 2015     

IDEAS approach to process network synthesis: minimum utility cost for complex distillation networks

This work aims at quantifying the minimum utility cost necessary to complete a given separation task using vapor-liquid equilibrium (distillation) operations. The Infinite DimEnsionAl State-space (IDEAS) process is introduced as a new paradigm for this process synthesis activity. The IDEAS conceptual framework includes all possible process configurations, and yields mathematical programs that are convex (linear), thereby guaranteeing the global optimality of the obtained solution.A case study, on nitrogen/oxygen mixture separation, is employed to illustrate the power of the proposed approach. The obtained IDEAS designs are compared with the corresponding McCabe-Thiele (conventional) minimum utility designs, and are shown to be as much as 50% more thermodynamically and economically efficient.     

复杂精馏系统的合成研究

通过建立精馏换热网络线性规划模型,快速确定最小公用工程量(或费用)的精馏流程和操作参数,使精馏系统的合成问题简化,最后通过文献中的算例验证了模型的可行性。     

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。     

Rigorous design of distillation columns using surrogate models based on Kriging interpolation

The economic design of a distillation column or distillation sequences is a challenging problem that has been addressed by superstructure approaches. However, these methods have not been widely used because they lead to mixed‐integer nonlinear programs that are hard to solve, and require complex initialization procedures. In this article, we propose to address this challenging problem by substituting the distillation columns by Kriging‐based surrogate models generated via state of the art distillation models. We study different columns with increasing difficulty, and show that it is possible to get accurate Kriging‐based surrogate models. The optimization strategy ensures that convergence to a local optimum is guaranteed for numerical noise‐free models. For distillation columns (slightly noisy systems), Karush–Kuhn–Tucker optimality conditions cannot be tested directly on the actual model, but still we can guarantee a local minimum in a trust region of the surrogate model that contains the actual local minimum. © 2015 American Institute of Chemical Engineers AIChE J, 61: 2169–2187, 2015     

流程模拟软件Aspen Plus在精馏塔设计中的应用

以Aspen Plus流程模拟软件对精馏塔进行了简捷设计和严格核算,对精馏塔设计的影响因素进行了分析,并对精馏塔的经济核算进行了初步说明。     

MINLP synthesis of optimal cooling networks

A mixed-integer nonlinear programming (MINLP) algorithm for the synthesis of cooling networks is presented. As opposed to previous models in which the minimization of utility consumption has been formulated, the algorithm considers simultaneously the capital cost for the coolers and the utility costs. The strategy is based on a superstructure that allows bypass and splitting of utility streams. Also, the superstructure considers a combination of arrangements in series and in parallel that allows for an efficient use of cooling streams. The typical arrangement of cooling networks in parallel usually conducts to higher total costs. Also, it is shown that the use of minimum amounts of cold utilities does not necessarily conduct to the minimum total cost. Three case studies are used to show the application of the proposed method.     

Graphical design and analysis of thermally coupled sidestream columns using column profile maps and temperature collocation

A systematical procedure is presented to design thermally coupled sidestream units like side rectifiers and side strippers are presented in this article. The method combines the column profile map technique to assess topological characteristics of the specific configuration with temperature collocation to rigorously ensure a realizable column design, without making assumptions with regard to the phase equilibrium or product specifications. The proposed methodology offers a unique graphical insight into the challenging problem of thermally coupled column synthesis. Techniques are presented for highlighting superior designs or eliminating inferior ones, based on vapor flow rate, number of stages, and thermodynamic efficiency. Design parameters such as the feed and side‐draw trays that may require insight or experience are products of the procedure. Design solutions obtained using this methodology can be used to initialize the state of the art process flow sheeting tool, AspenPlus?, which typically leads to fast convergence to the desired product purities without further adjustments. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

精馏塔设备的设计与节能研究进展

精馏过程是化工过程中最耗能的过程之一。本文总结了常规精馏塔,反应精馏塔以及分隔壁精馏塔这几种类型精馏塔的研究进展。常规精馏塔的研究仍在进行,并主要体现在算法的改进与新算法的提出,以及常规精馏塔在化工高等教学的重要作用上,指出了反应精馏塔和分隔壁精馏塔是近几年精馏塔设计方面的研究热点,如反应精馏塔的模型、求解方法等,分隔壁精馏塔是一种全新的概念因而并未系统化,但却能够明显节省设备投资,并具有良好的节能前景,尤其是在与反应精馏结合后效果特别明显。文章最后对精馏塔的未来研究方向进行了展望。     

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。     

异丁烷精馏过程的模拟优化及热力学分析

针对工业上对异丁烷纯度要求以及精馏分离过程能耗较大等特点,首先对要分离的C3和C4混合物体系深入分析,建立了异丁烷精馏新工艺方案,应用流程模拟软件Aspen Plus进行设计,采用严格计算模块和SRK热力学方法。目前,模拟过程准确性的关键在于热力学模型的选用上,为了解决这一问题,提出了对现场实测数据进行热力学一致性原则检验,并与SRK模型数据进行比较以验证其准确性。通过设计规定与灵敏度分析工具来优化操作参数,并对结果进行了热力学分析。研究结果表明:最合适的工艺方案为精馏塔理论塔板数为93,三股原料分别在第24,28,46块板位置进料,质量回流比为7.0,分离效果可达到塔顶异丁烷质量分数大于98.5%,热力学效率达到50.072%。模拟和优化结果表明新工艺方案效果较佳,为实际生产提供了准确的依据。     

氯乙烯精馏过程的模拟与分析

采用Aspen Plus通用模拟软件模拟计算了氯乙烯双塔精馏过程,得到了适宜的操作参数,对氯乙烯的工业生产具有一定的指导意义。