氯仿萃取分离NMP的工艺流程模拟与分析

本文利用ASPEN PLUS流程模拟软件对NMP萃取塔进行模拟,考察了萃取塔理论级数、操作温度以及溶剂比对脱水塔塔釜废水中NMP含量的影响。结果表明,在一定的进料条件下,萃取塔理论级数为8,操作温度在30℃,溶剂比为2时,脱水塔塔釜废水中NMP含量可以达到工艺指标要求。此外,根据装置实际运行参数调整模型后的计算结果表明,脱水塔釜出料中NMP含量计算结果与实际测定数据最大误差在15 ppm左右,设计模型下的计算结果与实际结果吻合较好。     

苯酚废水萃取工艺的模拟研究

运用流程模拟软件Aspen Plus模拟苯酚废水萃取过程。在所建模型的基础上筛选出合适的萃取剂为1,1,1-三氯乙烷。通过模拟研究了萃取相比、萃取温度、萃取级数等操作条件对萃取结果的影响,为离心萃取机选型及萃取条件的选定提供参考。     

转盘萃取塔在净化湿法磷酸中的应用

在改进型转盘萃取塔中,以磷酸三丁酯（TBP）为萃取剂,航空煤油为稀释剂,对不同浓度的湿法磷酸进行萃取净化,并以蒸馏水为反萃剂对萃取相进行反萃。研究结果表明：转盘萃取塔用于萃取净化湿法磷酸具有良好的适用性,在适宜的操作条件下能取得较好的萃取和反萃效果。实验转盘塔在运行过程中稳定性较好。在该萃取体系下,Ф50mm转盘萃取塔的理论级当量高度约为0．65m。     

基于Aspen Plus的重整液分离塔模拟优化及应用

利用Aspen Plus流程模拟软件,对重整液分离塔进行建模。通过模拟值和实际值的对比,验证了模型与实际工况吻合较好,可以用于指导实际生产。根据生产指标设置约束条件,将回流比、塔顶采出量作为变量,利用优化器搜索塔底热负荷最低的操作条件。根据模拟结果,在实际生产中进行调整,降低了塔底加热蒸汽量,节约了操作费用。     

萃取-精馏耦合工艺处理环丁砜废水的流程模拟

针对聚芳醚树脂聚合过程产生的环丁砜废水的处理,提出了以二氯甲烷为萃取剂的萃取-精馏耦合新工艺。选用NRTL活度系数模型,采用Aspen plus流程模拟软件对萃取-精馏耦合工艺处理环丁砜废水的过程进行模拟研究,并应用灵敏度分析工具分别对萃取塔和精馏塔进行参数优化。模拟结果表明,当萃取塔的平衡级数为7、萃取相比为1∶1、精馏塔的理论板数为5、进料位置为第3块理论板时,废水中环丁砜的浓度从100g/L降至34mg/L,同时得到质量分数为98.31%的环丁砜,环丁砜的回收率达到99.95%,处理后的水和环丁砜都能够满足在聚芳醚树脂生产过程中循环使用的要求。与现有的四效蒸发工艺相比,萃取-精馏耦合工艺的热负荷降低了约37%,具有非常好的工业应用前景。     

萃取与精馏耦合分离苯-甲醇的研究

研究了萃取与精馏耦合法用于苯-甲醇共沸物中的甲醇回收。通过实验手段从萃取剂选择、萃取比及萃取温度变化3个角度对萃取效果进行考察。实验结果表明,水的萃取效果最好,在操作温度35℃下,萃取比1∶1时,甲醇萃取分配系数为40. 0,选择性系数4 260. 8。在此实验数据上,提出以水为萃取剂的萃取与精馏耦合分离工艺流程,并运用流程模拟软件进行3塔连续模拟计算,得到了优化的工艺条件。模拟结果表明,当甲醇塔(T1)理论塔板数为15块、回流比为2,萃取塔(T2)理论塔板数为4块,回收塔(T3)理论塔板数为20块、回流比为2时,可得质量分数在99. 5%以上的苯和甲醇成品。     

醋酸乙烯单体回收单元的流程模拟与优化

采用Aspen Plus流程模拟软件,选取NRTL-HOC模型,对某公司10万t/a聚乙烯醇装置醋酸乙烯单体回收单元进行了全流程模拟,模拟结果与实际值吻合良好。在此基础上,对聚合一塔、聚合二塔和聚合三塔进行模拟优化,分析得到了优化后的工艺参数:聚合一塔汽提甲醇量为46 000 kg/h,聚合二塔混合物进料理论板数为32,聚合二塔萃取水量为19 000 kg/h,聚合三塔侧线采出为塔釜气相采出,聚合三塔回流比为4。在优化条件下,醋酸乙烯产品质量分数达99.95%,聚合二塔萃取水量减少了9.87%,聚合二塔和聚合三塔的总热负荷降低4.84%,节约了萃取水量,降低了能耗。     

丁酮-水共沸物系的萃取分离

采用液液萃取进行丁酮-水共沸物系的分离。测定了三元体系丁酮-水-（1-乙基-3-甲基咪唑醋酸盐）的液液平衡,采用NRTL活度系数方程对液液平衡数据进行回归得到组分间的二元交互作用参数。利用流程模拟软件ChemCAD进行了以离子液体为萃取剂的液液萃取过程的模拟,研究了理论板数、溶剂比（萃取剂摩尔流量和原料摩尔流量的比值）对萃取过程的影响,通过灵敏度分析,获得了优化的操作参数。在最适宜操作条件下,丁酮的摩尔分数可达0.999 4,离子液体经过回收能够直接循环使用。     

加盐萃取-精馏耦合分离甲醇-甲苯的工艺研究

研究了加盐萃取分离甲醇-甲苯共沸体系,考察了盐水种类、用量、质量分数及萃取温度等因素对萃取效果的影响,计算了在各种萃取条件下甲醇和甲苯的分配系数。实验结果表明:CaCl2水溶液的萃取效果最好,在CaCl2水溶液质量分数为0.35、萃取温度40℃、溶剂比(体积比)1.5∶1的条件下,甲醇的分配系数为2.32,选择性系数为18 200。基于以上实验数据,回归得到了萃取液液相平衡常数与萃取温度关联式的模型参数。在此基础上,提出了加盐萃取-精馏耦合分离甲醇-甲苯3塔工艺流程,并利用Aspen Plus软件中的Extract模拟萃取塔、RadFrac模拟精馏塔,选用NRTL-HOC和ELECNRTL热力学模型,对提出的工艺进行模拟计算,得到了合适的工艺操作条件。模拟结果表明:当萃取塔理论板数为5块;甲醇回收塔理论板数为21块、回流比为1.8;甲苯回收塔理论板数为28块、回流比为2.4时,分离得到的甲醇和甲苯的质量分数分别为0.996和0.997。     

新型转盘萃取塔在己内酰胺生产中的应用

探讨了转盘萃取塔在己内酰胺精制中萃取效率的影响因素,影响转盘萃取塔传质性能的主要因素是级间的轴向返混和沟流。介绍了新型转盘萃取塔的设计及其在70 kt/a己内酰胺精制装置中的工业应用效果。与原装置转盘萃取塔的运行情况比较,新型转盘萃取塔内的固定环平面增加了筛孔挡板,能有效抑制转盘萃取塔内的轴向返混,提高转盘萃取塔的传质效率。     

基于Aspen Plus用户模型的甲醇精馏模拟与分析

采用模拟软件Aspen Plus对某厂大型煤化工甲醇四塔精馏过程进行稳态模拟计算和分析,结果表明,应用物性方法 UNIFAC-DMD能有效模拟汽液平衡数据,模拟结果与工厂采集数据吻合良好。进行了常压塔侧线抽提位置分析、回流比对产品各组分浓度影响及精馏塔水力学分析等研究,提供了可行的精馏操作方案。     

工业醋酸脱水过程五元体系非均相共沸精馏的流程模拟

针对以醋酸正丙酯为共沸剂的醋酸脱水过程,考虑醋酸溶剂中未反应的前体对二甲苯以及反应的副产物醋酸甲酯的影响及回收利用,分别选用HOC和UNIQUAC模型来修正体系中五元混合物系的汽液非理想性,通过拟合醋酸甲酯-对二甲苯和醋酸正丙酯-对二甲苯两体系的二元汽液平衡实验数据获得了该两组体系UNIQUAC模型的二元交互作用参数,借助模拟软件Aspen Plus,结合软件内置其他二元体系参数,对工业醋酸脱水塔系包括溶剂脱水塔、PX回收塔、共沸剂回收塔在内的三塔体系进行系统的分析模拟,得到了与工艺数据误差小于±6%的能正确描述工业醋酸脱水塔系操作特性的工艺机理稳态模型,为工业醋酸脱水过程工艺的进一步研究提供理论基础和依据。     

氨盐水碳酸化反应的机理与反应器模型Ⅱ碳化塔反应器/结晶器数学模型

在对碳酸化过程机理和碳化反应动力学进行深入分析和综合描述的基础上，将碳化塔考虑为一多相反应器和多级结晶器，建立了其数学模型。模型全面考虑了化学吸收、反应结晶、流动、传热、传质各物理—化学过程，能够预测和模拟工业碳化塔十几种操作变量对转化率、晶体粒径和产量的影响。通过模型模拟，考察了碳化塔反应器的整体行为，剖析了有关的工业碳酸化过程，提出了相应的工艺改进措施。     

A Simple Way for Implementing Extraction Columns of Infinite Height in Flowsheet Simulators

A surrogate model to implement an extraction column of infinite height in process simulation software is presented. The model consists of three decanters and a few specifications which are easy to implement in commercial process simulators. Using the model, the minimum solvent flow rate and the limiting product compositions are determined. In an example, the surrogate model for the extraction column is combined with standard unit operation models for describing an extraction process with a distillative solvent recycle.     

动态循环提取雷公藤总生物碱的过程研究

雷公藤是一种重要的中药材,其有效成分萜类、生物碱可用于治疗类风湿性关节炎等多种疾病.动态循环提取雷公藤生物碱是雷公藤中药生产中的一个重要工段.今用紫外分光光度法分析总生物碱的含量,测定了雷公藤动态循环提取过程中总生物碱浓度和提取时间的关系.并分析了动态循环提取过程的机理,建立了相应的数学模型,该模型仅含一个参数.模型拟合结果与工业操作数据符合良好,可用于工业动态循环提取过程的模拟和优化.     

Cyanide Recovery from Gold Extraction Process Waste Effluents by Ion Exchange II. Modelling of the Fixed Bed Operation

Abstract

An ion exchange operation in a fixed bed column is tested as a method to recover copper cyanide complexes from gold extraction process waste effluents. With this aim in mind, load and elution breakthrough curves are obtained using the anionic resin Lewatit MP500. A good performance of the resin in the load stage can be deduced from the breakthrough curves obtained in all the assays at two different pHs (12, 8.5). After load step operation, column elution was carried out using NaSCN 1.25 M as eluent. A good elution peak is obtained in all cases, indicating a good performance of the resin and the eluent in this stage. With the aim of testing the design of the industrial operation, a phenomenological model is tested by fitting experimental data to theoretical equations. The model used for the simulation of both steps incorporates axial dispersion, ion exchange equilibrium, and diffusion inside particles described by the linear driving force approximation, as well as taking into account the fact that the resistance to mass transfer controls the kinetics of the ion exchange process. The models are able to simulate the experimental load and elution results reasonably well.     

基于分离系数校正的稀土萃取流程模拟

由于基于稀土萃取机理的流程仿真模型没有考虑萃取槽的萃取效率,导致模型输出的各级组分含量难以符合工业实际工况,为此,本文将机理模型与数据驱动的方法相结合,建立基于分离系数校正的稀土萃取流程模拟。首先,在相对分离系数的稀土萃取流程机理模型的基础上,引入分离系数校正值,实现对稀土萃取机理模型的扩充;其次,运用数据驱动方法,利用斐波那契树优化算法对各级校正值进行优化求解,并使用MATLAB GUI,开发稀土萃取流程模拟系统;最后,结合工业现场实际数据,验证本文流程模拟在工况改变时的动态性能,结果表明本文所建流程模拟符合稀土萃取流程实际工况。     

Dynamic behaviour and simulation of a liquid-liquid extraction column

Dynamic behaviour of a stirred liquid-liquid extraction column was studied experimentally. Various input variables of the column were varied stepwise and the resulting variations in the system and output variables were measured. In addition to experimental work, a computer model was developed on the basis of the dispersion model to simulate the dynamic behaviour of the extractor. This model forms a component program of the dynamic process simulator DIVA, developed at the TU Stuttgart. The experiments showed that the hydrodynamic parameters exhibit no significant dynamic behaviour of their own. Therefore, changes occurring in these parameters closely follow variations in input and system variables. As a result, steady-state relationships for the calculation of flow parameters could be used in the simulation program. The simulator satisfactorily reproduced the experimental results for a number of disturbances. However, this was not always the case. As shown in the following, the model did not take into account the column level controller which, under certain conditions, exerts a very strong influence on the column's dynamic behaviour. As a result, larger differences occurred between experimental and simulated data. This influence on the extractor's dynamic behaviour can, however, be eliminated by a simple modification of the level controller arrangement.     

甲基氯硅烷精馏流程的模拟与优化

采用Aspen plus软件对工业七塔精馏过程进行全流程建模与模拟,优化工艺参数,研究了新的精馏节能工艺。对一甲塔等7个精馏塔采用双因素水平的灵敏度分析,考察了塔釜采出率、回流比、进料位置和塔顶压力对产品浓度和热负荷的影响,确定一甲塔最优的工艺参数：塔釜摩尔采出率为0.92,摩尔回流比为130,塔顶压力为0.18 MPa,总理论板数为400,在210块理论板位置进料。在此基础上,针对高能耗的脱高塔/脱低塔,模拟研究了双效精馏新工艺,新工艺可节省39.70%的年总成本;针对一甲塔模拟研究了热泵精馏新工艺,新工艺可降低41.42%的年总成本。     

A Preliminary Study on Strategies for Optimal Fluid-Bed Drying

ABSTRACT

The degradation of product quality during convective drying depends on the temperature and water concentration history of the panicles and drying time. For improving product quality in combination with acceptable operation costs, optimal control of the operation variables is required.

In this preliminary study the relevance of dynamic optimal operations for batch-wise fluid-bed drying is explored by simulation. Optimal trajectories of operation variables were calculated for a pilot-plant installation by using a model which concerned the drying history of the panicles and the product quality (inactivation of biological active components). The applied objective function was based on an economic criterion combining product quality and operation costs.

Although the advances for the chosen pilot-plant application are moderate, in future studies the potentials and relevance of dynamic optimal operations for drying will be quantified for installations on industrial scale.