催化重整集总动力学模型研究进展

催化重整集总动力学建模为重整工艺模拟和优化提供理论基础,模型为模拟重整反应过程,预测产品分布和产品性质提供计算工具。从催化重整集总动力学模型的集总划分、建模数据来源、参数估算以及重整流程模拟等方面,综述模型的发展历程和现状,并展望催化重整集总动力学模型的研究前景。重整模型越来越倾向于开发连续再生装置模型以及不断优化算法,更加的精细化、精确化,不仅能够降低生产成本,更能满足各种环保和生产要求。     

催化重整集总动力学模型的建立及其在线应用

按照集总理论的指导原则,在原17集总反应网络的基础上,提出了一种包含20个集总组分、31个反应的催化重整动力学模型.该模型进一步细分了八碳芳烃组分,并考虑了烷烃组分的所有加氢裂化反应.在某工业连续重整装置上的验证结果表明,所建立的20集总模型可以精确地模拟包括八碳芳烃4个异构体在内的反应产物组成;与原17集总模型相比,裂化产物的预测精度明显提高.随后,采用特定的在线预测和校正策略,将该模型用于在线预测此连续重整过程的总芳烃收率、各芳烃组分收率以及重整油辛烷值,在进料和反应操作条件较大的变化范围内,在线预测趋势和预测精度均令人满意.总芳烃收率和重整油辛烷值的平均预测偏差仅分别为0.52 %和0.36,与离线模拟精度相当.     

催化重整装置模拟研究综述

详细介绍目前国内外在催化重整装置建模和计算机稳态模拟方面的研究现状及进展，对20世纪50年代末以来主要的几种催化重整集总动力学模型进行了比较研究，并对模型方程的求解算法，以及模型中有关的关键动力学参数，催化剂因子，装置因数等参数估计问题进行了探讨，最后简单介绍目前主要的几种重整模拟软件的功能特点和应用情况。     

催化重整装置反应器的建模与仿真

针对催化重整装置的流程模拟,基于集总理论与催化重整反应机理,提出了一种反应器的模型。该模型的反应网络较全面地考虑了烷烃、环烷烃及芳烃之间的反应关系,覆盖了重整反应过程中的大部分反应。为了降低参数估计的难度,通过合理假设将待估参数数量减少至99个,并将复杂的反应网络依据碳原子数划分为C₆~C₁₁₊六个反应子网络,再采用BFGS算法与SQP算法相结合的分组迭代估计方法以降低参数估计的误差。通过催化重整装置的模拟计算对模型进行了验证,结果表明,模型能够对反应产物组成进行较准确的预测,可满足现代工业应用对模型精度的需求。     

ASPEN PLUS在尾气吸收装置流程模拟中的应用

介绍ASPEN PLUS工艺计算软件的用法和特点;在尾气吸收装置流程模拟过程中,ASPEN PLUS的应用方法以及流程模拟步骤的介绍。     

催化重整集总动力学模型(Ⅰ)模型的建立

根据集总指导原则,从催化重整的反应机理出发,建立了十六集总催化重整动力学模型.该模型不仅简单可行,且能适用于不同生产方案的重整反应,具有较强的适用性和良好的拟合性.     

催化重整集总动力学模型(Ⅰ)模型的建立

根据集总指导原则,从催化重整的反应机理出发,建立了十六集总催化重整动力学模型.该模型不仅简单可行,且能适用于不同生产方案的重整反应,具有较强的适用性和良好的拟合性.     

基于差分进化算法和HYSYS机理模型的催化重整过程优化

选取催化重整18集总31反应集总动力学模型,以流程模拟软件HYSYS为工具,建立了催化重整机理模型。以最大化芳烃产率为优化目标,以4个反应器入口温度为决策变量,建立了过程优化模型。利用差分进化算法求解该优化问题,并利用可行性规则处理约束。仿真结果表明,芳烃产率有较大提高,证实了差分进化算法的有效性。     

催化重整反应38集总动力学模型及其在连续催化重整中的应用

根据集总理论和催化重整的反应机理,基于工业连续重整装置,提出了一个包含38个集总组分、86个反应催化重整反应动力学模型。该模型将重整物料按碳原子数集总为C6～C11+组分,相同碳原子数的物料又划分为正构烷烃、异构烷烃、五元环烷烃、六元环烷烃和芳烃,裂化产物细分为C1～C5组分。通过合理简化,确定了86个待估模型参数,并在工业现场数据的基础上,利用分层策略与BFGS算法对其进行了估计。通过对某炼厂连续重整反应器的模拟计算对该模型进行了验证,计算值与实际值吻合较好,表明该模型具有较好的可靠性与准确性,达到了工业应用的要求。将模型用于芳烃收率的预测,在较大的时间跨度内,精度与趋势均令人满意。最后,利用该模型对芳烃收率进行了优化计算,经优化后芳烃收率提高0.17%,该结果可为连续重整装置的优化操作提供参考。     

基于18集总动力学模型的连续重整反应装置建模与仿真

针对连续重整反应过程较为复杂、化学反应的耦合性强及参数估计难度较大的问题,提出了一种包含18个集总组分,27个反应的新型催化重整动力学模型。该模型在符合催化重整反应机理与集总理论划分原则的基础上,通过合理集总划分降低参数估计难度。新模型将8碳芳烃组分细分为二甲苯和乙苯2个集总,并将正烷烃、异烷烃分别集总,采用BFGS算法求解相应的模型参数。结果表明,该模型可以较为准确的预测出各芳烃产率,预测结果符合现代工业对模型的要求。     

工业级催化重整装置的全流程模拟与优化

1 INTRODUCTION Catalytic naphtha reforming is a very important process for producing high octane gasoline, aromatic feedstock and hydrogen in petroleum-refining and petrochemical industries[1]. To design new plants and optimize the existing ones, an appropriate mathema- tical model for simulating the industrial catalytic re-forming process is needed[2,3]. The naphtha used as catalytic reforming feed-stock is very complex usually consisting of about three hundred hydrocarbons with carbon nu…     

基于集成建模方法的乙二醇全流程模拟

乙二醇生产流程是一个包含十几个精馏塔和固定床催化反应器的长流程。由于流程长且反应催化剂影响不易确定等因素,乙二醇生产过程的全流程模拟十分困难。基于ASPEN PLUS软件平台,集成支持向量机、优化算法、机理建模等多种方法,建立了乙二醇的全流程模型。通过采集并处理实际生产的工业数据,采用优化算法进行模型的智能校正,进一步完善了模型的性能。乙二醇全流程模型模拟结果与实际工业过程数据相符,能够满足工业建模的要求。     

A generalized framework for computing bifurcation diagrams using process simulation programs

Interest in discovering multiple steady-state solutions for reaction and separation processes grew exponentially in the 1990s. Process simulators like ASPEN PLUS, CHEMCAD, HYSYS, and PRO/II are designed to obtain at best one solution. Simulation programs can find multiple solutions only by the expenditure of much effort. Here, a bifurcation technique using arclength continuation is presented that can be incorporated as an add-in subroutine to a simulation program to automatically trace a solution path, including turning points, to obtain multiple solutions with respect to a user-selected parameter. The technique is illustrated with applications to the ASPEN PLUS process simulator. The algorithms are based on a predictor–corrector implementation where the predictors reside in add-in FORTRAN routines and the existing nonlinear equation solvers in ASPEN PLUS equipment models serve as the correctors. Furthermore, the existing physical property packages in ASPEN PLUS are also utilized. The method was tested successfully on an adiabatic CSTR example using the ASPEN RCSTR model, and homogeneous azeotropic, heterogeneous azeotropic, and reactive distillation examples using the ASPEN RADFRAC model. Two of these examples are presented here. In all four examples, the range of the selected bifurcation parameter covers a region that produces three multiple solutions.     

乙烯装置制冷系统模拟及优化

以化工流程模拟软件ASPEN PLUS为应用平台,建立了能良好描述裂解气在冷箱中预冷、在脱甲烷塔中分离和制冷系统工艺模型。应用该模型对扬子乙烯装置老区制冷系统进行了流程模拟、参数灵敏度分析和过程优化;研究了甲烷和乙烯冷剂分配、相同和不同温度级乙烯冷剂分配对乙烯损失的影响,以及相应操作参数的优化调整;找到了现有制冷系统的用能瓶颈;解决了工艺操作参数的优化问题;实现了装置高负荷工况下的经济运行。     

SIMULATION OF A MEDIATED ELECTROCHEMICAL PROCESS

Mediated electrosynthesis is a cyclic process involving electrochemical generation of a redox agent and use of that agent to effect a chemical reaction. This process is applicable to a large number of mediators and chemical substrates. Cerium in particular is an excellent mediator for syntheses of aldehydes and quinones. An ASPEN PLUS process and cost model is presented for the cerium mediated electrosynthesis of 1,4-naphthoquinone from naphthalene. The process involves two-phase reaction, phase separation, liquid-liquid extraction, electrochemical oxidation, and crystallization. The ASPEN PLUS simulator, however, does not include a module for the separation of organic and aqueous electrolyte solutions. Therefore, a liquid-liquid extractor block is developed based on distribution coefficients. The extractor model also accounts for phase entrainments. Stream compositions are controlled by maintaining fixed ratios of component mass flows. Finally, an extremely tight tolerance is required to account for minute quantities of organics in the aqueous stream. The use of the model to identify economically interesting operating conditions is demonstrated.     

SIMULATION OF A MEDIATED ELECTROCHEMICAL PROCESS

Mediated electrosynthesis is a cyclic process involving electrochemical generation of a redox agent and use of that agent to effect a chemical reaction. This process is applicable to a large number of mediators and chemical substrates. Cerium in particular is an excellent mediator for syntheses of aldehydes and quinones. An ASPEN PLUS process and cost model is presented for the cerium mediated electrosynthesis of 1,4-naphthoquinone from naphthalene. The process involves two-phase reaction, phase separation, liquid-liquid extraction, electrochemical oxidation, and crystallization. The ASPEN PLUS simulator, however, does not include a module for the separation of organic and aqueous electrolyte solutions. Therefore, a liquid-liquid extractor block is developed based on distribution coefficients. The extractor model also accounts for phase entrainments. Stream compositions are controlled by maintaining fixed ratios of component mass flows. Finally, an extremely tight tolerance is required to account for minute quantities of organics in the aqueous stream. The use of the model to identify economically interesting operating conditions is demonstrated.     

基于ASPEN PLUS软件的湿法烟气脱硫模型

笔者利用大型化工流程软件ASPEN PLUS对火电厂烟气湿法脱硫工艺进行了模拟,介绍了模拟过程中物流、单元操作模块的选取和灵敏度分析、设计规定的计算方法。模拟结果表明脱硫效率随着液气比和钙硫比的增加而增加,随着烟气流速的增加而降低,其结论与原始设计数据较为吻合,建立的模型对优化设计具有一定的指导意义。     

环氧乙烷精制塔的模拟与分析

利用ASPENPLUS化工流程模拟软件中的RADFRAC模型对环氧乙烷精制塔进行了模拟计算。通过比较,选用NRTL-RK方程来计算液相活度系数,所得模拟结果与实际生产值基本吻合,获得了和设计值一致的数据。通过对精制塔的回流量、进料位置和侧线采出位置等参数对环氧乙烷精制塔影响的深入研究,提出了最优的操作方案,获得了对高纯度环氧乙烷具有指导意义的相关工艺数据,达到了增效降耗的目的。