基于非平衡级模型的低温甲醇洗流程模拟

对于多级分离过程的模拟通常都采用平衡级模型,而实际化工过程的非理想性使其应用受到了很大限制。本文引入非平衡级模型,采用修正的PSRK物性方法用Aspen plus软件对低温甲醇洗流程的吸收塔及CO2解吸塔进行模拟研究,并将其模拟结果与平衡级模型作对比。该模型下对吸收塔及CO2解吸塔的模拟结果都与设计值吻合很好。并将该流程吸收塔的非平衡级模型计算结果与本文作者教研组前期工作中研究的吸收塔的非平衡级模型结果作对比。研究结果表明,非平衡级模型可以应用于低温甲醇洗流程的模拟计算,为低温甲醇洗流程的设计计算提供了可靠的技术支持。     

基于修正PSRK和RKSWS状态方程的低温甲醇洗吸收塔模拟研究

低温甲醇洗是大型煤化工中常用的气体净化工艺。吸收塔是低温甲醇洗工艺中的核心设备,是整个流程模拟的关键塔。基于PSRK和RKSWS状态方程,修正部分缺省的计算方法,对低温甲醇洗吸收塔进行模拟研究,将模拟结果和运行数据进行对比。结果表明,修正后的PSRK及RKSWS状态方程可应用于低温甲醇洗吸收塔的工艺模拟计算和实际生产操作条件的优化。     

煤制气低温甲醇洗酸性气体吸收模拟与优化

采用Aspen Plus软件,在非平衡级模型的前提下,分别使用不同的物性方法对两酸性气吸收塔进行模拟计算,建立能够较好反映实际状况的酸性气吸收的过程模拟,并在此基础上对酸性气吸收过程进行分析和甲醇流量优化,得到更合理的工艺参数。     

低温甲醇洗吸收塔工艺模拟与过程参数优化

低温甲醇洗汽液平衡数据的测定难度大,而文献报道又极少。利用ASPEN PLUS软件,采用UNIFAC基团贡献法预测该体系汽液平衡,建立了低温甲醇洗吸收塔的过程模拟。模拟结果表明,该模型能够较好地反映该工艺装置的实际操作状况。在此基础上,考查了甲醇流量以及甲醇温度等参数对分离过程的影响,获得了低温甲醇吸收塔的最佳工艺参数。     

低温甲醇洗吸收塔的计算机模拟

应用PRO/II工程模拟软件对某60万t/a煤气化制甲醇项目低温甲醇洗酸性气体吸收塔进行了模拟,通过对比不同热力学模型的模拟结果,明确了H2-CO2-CH3OH三元体系偏离高压和低温条件下的气液平衡是模拟误差较大的原因.将修正后的SRK-SIMSCI热力学模型用于吸收塔的计算,结果表明,该模型能够较好地反映该工艺装置的实际操作状况.     

低温甲醇洗酸性气体吸收塔模拟分析

利用PRO/Ⅱ软件对低温甲醇洗工艺中的酸性气体吸收塔进行了模拟,选用NRTL热力学模型,在成功模拟的基础上对吸收塔的3个操作变量——甲醇温度、甲醇流量、分流分率分别进行了灵敏度分析,并进行了吸收塔液气比的优化分析。     

低温甲醇洗吸收塔模拟及内件优化设计

吸收塔是低温甲醇洗工艺中的核心设备,内件对吸收塔性能至关重要。本文采用规整填料替代以往设计中四溢流塔盘,降低塔径和塔高,以优化设计、节省投资;采用Aspen Plus和DRP软件分别对低温甲醇洗吸收塔工艺参数和塔内件进行模拟和对比;在流程工艺模拟基础上对吸收塔进行水力学计算。模拟计算结果表明,采用规整填料比四溢流塔盘具有优势。     

低温甲醇洗工艺的模拟及扩产改造的研究

某工厂低温甲醇洗工艺原料气分为2股,现有扩产的需求。为实现低温甲醇洗工艺扩产目的,采用Aspen Plus软件基于PSRK物性方法对工艺的实际工况进行了模拟,得到的模拟值与实际值较为符合,从而确定了PSRK为低温甲醇洗工艺模拟的物性方法。在此基础上提出了一种改造方案:新增2台换热器用来预冷原料气;新增氮气汽提塔用来汽提吸收塔甲醇所溶解的酸性气体,甲醇的温度和甲醇中CO2的摩尔分数得以降低,因此甲醇的吸收能力有了明显提高;新增1台进料泵用于输送汽提后的甲醇到吸收塔。同时通过灵敏度分析确定出了改造工艺的最优参数:N2进料量为300 kmol/h,理论板数为7,分流比为0. 020。经过以上改造,各产品流股均符合工艺要求,达到扩产20%的目的。对改造后工艺的操作弹性做进一步分析表明最大扩产幅度可达26%,为实际扩产提供了一定裕度。     

低温甲醇洗吸收塔模拟及内件优化设计

本文采用规整填料替代以往设计中四溢流塔盘、降低塔径和塔高的优化设计。用Aspen Plus和DRP软件分别对低温甲醇洗吸收塔工艺参数和塔内件进行模拟和对比。在流程工艺模拟基础上对吸收塔进行水力学计算。结果表明,采用规整填料比四溢流塔盘具有优势。     

低温甲醇洗系统模拟与分析

介绍了低温甲醇洗系统模拟软件ＲＰＳ。应用本软件对低温甲醇洗系统进行了模拟计算，设计工况的计算结果与设计数据符合良好，实际工况的计算，在生产流程与设计流程有改动、操作条件与设计值偏离较大的情况下，计算结果与现场实测值也符合良好，说明ＲＰＳ软件符合生产实际，可以用于工程设计中的工艺计算、实际生产的模拟分析以及操作条件的优化。     

低温甲醇洗装置在华鲁恒升的应用

介绍低温甲醇洗装置在华鲁恒升3a来的运行状况，分析独具特色的“一头三尾”低温甲醇洗流程的工艺特点，概述操作负荷变化对甲醇洗的影响，并结合实际运行工况提出合理化的操作建议。     

低温甲醇洗气液两相流管线工程设计

以低温甲醇洗无硫富甲醇闪蒸罐到CO2产品塔的两相流管线为例,按照SH/T 3035-2007规定的要求进行计算,通过与工程实践的对比,验证其计算的可行性。总结了低温甲醇洗装置中抑制两相流的三项措施。     

Dynamic modelling of CO2 absorption for post combustion capture in coal-fired power plants

Power generation from fossil fuel-fired power plants is the largest single source of CO₂ emissions. Post combustion capture via chemical absorption is viewed as the most mature CO₂ capture technique. This paper presents a study of the post combustion CO₂ capture with monoethanolamine (MEA) based on dynamic modelling of the process. The aims of the project were to compare two different approaches (the equilibrium-based approach versus the rate-based approach) in modelling the absorber dynamically and to understand the dynamic behaviour of the absorber during part load operation and with disturbances from the stripper. A powerful modelling and simulation tool gPROMS was chosen to implement the proposed work. The study indicates that the rate-based model gives a better prediction of the chemical absorption process than the equilibrium-based model. The dynamic simulation of the absorber indicates normal absorber column operation could be maintained during part load operation by maintaining the ratio of the flow rates of the lean solvent and flue gas to the absorber. Disturbances in the CO₂ loading of the lean solvent to the absorber significantly affect absorber performance. Further work will extend the dynamic modelling to the stripper for whole plant analysis.     

"煤代油"低温甲醇洗工艺流程改造方案的研究

采用低温甲醇洗净化系统模拟软件(RPS)对某化肥厂的低温甲醇洗净化工艺流程的实际运行状况及设备能力进行分析,提出了原料由渣油改为煤后的低温甲醇洗工艺流程改造方案,为"煤代油"改造工程提供了可靠的依据.     

Multi-component reboiled absorber modeling and parametric studies

The steady state operation of an industrial multi-feed, multi-component reboiled absorber column which was previously investigated by Petryschuk (1964) has been simulated by two alternate mathematical models — an equilibrium stage model and a tray efficiency model based on the Murphree tray efficiency concept. Development of the models required the use of a set of physical property estimation procedures which differed from those used by the previous investigator. When subjected to parametric variation studies, both new models successfully reproduce known quantitative and qualitative behavior attributed to the column. The study results demonstrate not only the sensitivity of a simulation of a multicomponent separation process upon physical property estimation procedures, but also indicates the difficulty in model discrimination when plant data of only limited range and accuracy is available.     

双脱单元CO2再吸收塔出口气液夹带现象的治理

Lurqi低温甲醇洗装置白投产运行以来，CO2再吸收塔出口气体夹带大量的甲醇。本文从生产实际的角度出发，分阶段对气液夹带现象进行分析并提出治理措施，既降低了装置的甲醇消耗，也提高了对气液夹带现象的认识，积累了气液夹带治理的宝贵经验。     

Optimisation-based design method for membrane-assisted separation processes

This paper presents a design method for membrane-assisted separation processes based on the concept of process superstructure optimisation, which should be applied to the separation of azeotropic mixtures. The main features of the proposed method are as follows: (i) detailed rate-based modelling of all unit operations; (ii) experimental model identification for membrane separation; (iii) application of an evolutionary algorithm. This method allows the simultaneous determination of optimal process configuration, equipment design and operating conditions for membrane-assisted separation processes.A case study for the separation of a ternary mixture of acetone, isopropyl alcohol and water in a hybrid pervaporation-distillation process is presented using the optimisation-based design method. Detailed rate-based models for the unit operations involved were implemented in a generic process model and necessary membrane model parameters were determined experimentally in a laboratory-scale device for the hydrophilic polymeric membrane Pervap™ 2201D from Sulzer Chemtech. After the identification of an appropriate process superstructure, the process configuration, dimensions of equipment and operating conditions required for the optimal hybrid pervaporation-distillation process were determined simultaneously. The optimisation criterion was the cost for purifying one ton of acetone. The results show that the developed method can be applied successfully for this complex mixed-integer non-linear optimisation problem.     

Equation oriented method for Rectisol wash modeling and analysis☆

Rectisol process is more efficient in comparison with other physical or chemical absorption methods for gas pu-rification. To implement a real time simulation of Rectisol process, thermodynamic model and simulation strat-egy are needed. In this paper, a method of modified statistical associated fluid theory with perturbation theory is used to predict thermodynamic behavior of process. As Rectisol process is a highly heat-integrated process with many loops, a method of equation oriented strategy, sequential quadratic programming, is used as the solver and the process converges perfectly. Then analyses are conducted with this simulator.     

No-estimate short-cut calculation method for absorbers

The commonly-used absorber calculation methods use, as initial profiles, estimates of column temperatures, gas rates etc. This paper describes a new simple calculation method that eliminates the need for estimates for hydrocarbon absorber calculations. Examples involving a wide range of operating conditions are given to illustrate the reliability of the proposed method.