分批精馏过渡段放持液操作方式

The new mode of operation for slop cut withdrawal in batch distillation, i.e., draining Column liquid holdup at the end of slop cut period, was proposed. And the stopping criterion for the operation was investigated, Experiments were carded out with isopropanol-n-propanol binary system and isopropanol-n-propanol-n-butanol ternary system in a distillation column with a liquid collector installed between the reboiler and the column section, Experimental results in a Ф 45mm batch column show that the proposed policy can overcome the flywheel effect caused by column liquid holdup and thus cut down operation time and energy consumption 31%-61%.     

分批精馏最小过渡馏份量的研究

提出了分批精馏的最小过渡馏份量概念,导出了最小过渡馏份量的计算方法,通过算例分析讨论了塔板数和塔内存液量对最小过渡馏份量的影响。     

分批精馏最小过渡馏分量及过渡馏分脉冲控制法的研究

研究了分批精馏最小过渡馏分量 ,在此基础上针对分批精馏过渡馏分段的特点采用了全回流 全馏出交替进行的脉冲控制法。该法以动态模拟确定了全回流时间 ,统计法确定了全馏出时间。采用正己烷 环己烷物系进行对比实验结果表明 :与传统的恒回流比操作法相比 ,脉冲操作法可明显减少过渡馏分量、缩短操作时间和提高分离效率     

分批精馏中全回流操作的研究

为了研究采用全回流操作完成一定分离任务时所应达到的平衡程度,提出了平衡程度系数概念,并采用乙醇-异丙醇-正丙醇物系对全回流过程中各组分的平衡程度系数在塔内各处的变化及全回流操作终点适宜的平衡程度系数进行实验研究,结果表明,虽然同一时刻不同组分及不同板上的接近平衡程度不同,但实际应用中可只考虑塔顶处关键组分的接近平衡程度,全回流操作终点适宜的平衡程度系数的选取应综合考虑塔板数及操作时间这两方面因素。     

分批间歇萃取精馏技术的进展

对分批问歇萃取精馏技术和进展进行了评述，从分批问歇萃取精馏的操作方式、操作可行性、操作优化等几方面介绍了分批间歇萃取精馏的研究情况，指出存在问题和发展方向。     

分批精馏中的持液作用

分批精馏中持液影响塔内的动态过程,因此许多学者一直致力于分批精馏过程中持液作用的研究,但由于研究缺乏系统性,持液的作用一直是学术上争论的热点.本文提出用全过程分离难度系数关联各参数对分离过程的影响,并建立了分批精馏的恒摩尔持液模型,用全过程的分离难度系数研究了分批精馏的持液作用,结果表明：塔顶持液对分离不利,但塔身持液在一定条件下增多可使所需回流比降低;塔内持液量与釜液量之比为一个因子,当q<0.7时,确定的分批精馏塔存在最佳投料量.采用甲苯-乙苯二元物系对最佳投料量进行了实验验证,实验结果与模拟结果吻合较好.     

间歇精馏新型操作方式的研究进展

本文综述了国内外近年来间歇精馏新型操作方式的研究进展和发展方向,重点介绍了塔顶累积全回流操作、反向间歇精馏塔操作、中间贮罐以及多罐间歇精馏塔操作,阐述了这些新型毛主席匠特点及应用前景。     

分批精馏塔新型操作方式及其应用

对所开发的几种分批精馏塔新型操作方式的基本原理和研究进展作了阐述 ,并介绍了这些新型操作方式在精细化工和制药工业中的应用     

分批精馏模拟技术

综述了当前分批精馏模拟技术的研究进展。介绍了作为目前快捷（ｓｈｏｒｔｃｕｔ） 模型主流的ＦＵＧ快捷模型和ＩＳＣ 快捷模型。与严格模型相比,ＦＵＧ模型和ＩＳＣ 模型具有适应性强、计算量小、计算精度较高的独特优点。     

带有过渡段循环的多元间歇精馏优化计算

采用最大馏出量、最小时间及最大负荷因子作为目标函数,以采出速率作为优化变量,间歇精馏过程采用分段恒回流比操作,利用改进的模拟退火算法进行了带有过渡段循环的三元体系间歇精馏过程的优化。分别获得了3种目标函数下的最优操作条件及最优值,并与文献结果进行了比较。采用改进的模拟退火算法得到的优化计算结果均优于文献值。不同的目标函数下得到的优化操作策略不同,且随着过渡段循环次数的增加精馏过程趋于稳定。     

双回流动态累积间歇精馏全过程的研究

在动态累积间歇精馏塔中,采用双回流动态累积间歇精馏操作对正丙醇-异丙醇二元混合物系进行分离研究。主要考察了操作时间对塔顶整个过程产品浓度、温度变化的影响,并与塔顶回流动态累积间歇精馏操作的分离结果进行了比较,以及过渡馏分阶段操作时间对塔釜正丙醇浓度及温度变化的影响,同时,又对正丙醇的回收进行了研究。结果表明,在同样的产品采出要求条件下,双回流动态累积间歇精馏操作时,随原料中异丙醇含量的增加,所需的操作时间越长,产品的纯度越高,收率越高;操作时间节省166 min,原料中异丙醇质量分数为30%的条件下,所得回收正丙醇的纯度达到91.22%,正丙醇的回收率可达62.93%,原料中异丙醇质量分数别为30%、50%、70%时对应过渡馏分持续时间分别为40、47、58 min;原料中异丙醇质量分数越大,所得回收正丙醇产品的量越少,正丙醇的纯度越低,回收率越小。     

Optimal operation strategy of batch vacuum distillation for sulfuric acid recycling process

Vacuum distillation techniques are widely used in food, biological, pharmaceutical, and wastewater treatment industries. Because of its operation at low temperatures, vacuum distillation prevents the thermal decomposition of materials and alleviates corrosion processes; however, condenser size can be dramatically increased because of reductions in mean temperature differences under the vacuum operation. In batch vacuum distillation processes, vapor generation rate and mean temperature differences are changed with time. In view of these characteristics of batch operation, this paper suggests a novel methodology to minimize the condenser size in batch vacuum distillation processes. The target process is a sulfuric acid recycling system in semiconductor manufacturing plants. In this paper, an equation-oriented dynamic model is established and optimization problem is formulated. By solving the nonlinear programming problem, the condenser size is dramatically reduced when operation time is fixed. In contrast, operation time is greatly shortened when the installed condenser surface area is fixed.     

带有中间贮罐间歇萃取精馏实验研究

使用一个带有中间贮罐的间歇萃取精馏实验装置,以能形成最低共沸物的乙酸乙酯-乙醇体系为分离对象,选用N,N-二甲基甲酰胺(DMF)为萃取剂,实验研究了中间贮罐持液量、中间贮罐持液温度、萃取剂加入速率等操作参数对分离过程的影响。实验结果表明:随着萃取剂流率的增加,中间贮罐持液量也相应增加,组分更易于分离;随着中间贮罐持液量的增加,中间贮罐持液温度也相应升高,且存在最佳分离持液温度;萃取剂流率对分离结果的影响最大,中间贮罐持液温度对分离结果的影响次之,中间贮罐持液量对分离结果的影响最小。     

拟稳态模型用于间歇萃取精馏的数值模拟

Batch extractive distillation (BED) is a special method used in the distillation process by adding a solvent into the batch distillation column to alter the relative volatility of the components and improve the separation. A comprehensive design and simulation method is required due to the complexity of BED. In this study, a quasi-steady-state model for BED is proposed, the derivation and solution of the model are presented. This shortcut model can be used to simulate the composition and temperature of the reboiler, the top and other plates of the column in a batch extractive distillation operation. The calculated values are in good agreement with the experi-mental data. The results show that the quasi-steady-state model is a practical method because of some advantages such as high precision and fast calculation.     

二元提馏式间歇精馏的优化操作与最小汽化总量

理想操作条件下二元提馏式间歇精馏优化操作的汽化总量与最小汽化总量的计算是约束函数优化问题。本文采用罚函数法,将此约束函数优化转变为无约束函数优化,并采用固定双步长因子梯度法数值求解该函数的极值。计算表明:固定双步长因子梯度法具有良好的收敛性,同时,降低分段数较多时,数值截断误差积累对计算结果的影响。二元提馏式间歇精馏优化操作较恒残液组成操作的能耗低的原因如下:在理论板数相对较少(接近二元提馏式间歇精馏恒残液组成操作所需的最少理论板)时,优化操作通过控制再沸比提高了能耗效率;在理论板数相对较多时,优化操作通过控制再沸比,在保证过程的能耗效率较高的同时,可尽可能快地将物料移出系统,减少了精馏过程中塔顶贮槽内液体的混合熵产。通过对计算结果的归纳与外推,得到了理想操作条件下理论板数为无穷多时二元提馏式间歇精馏优化操作再沸比的变化方式以及最小汽化总量的计算公式。     

Optimal operation and tracking control of vapor-recompressed batch distillation

Vapor recompressed batch distillation (VRBD) is an energy-integrated configuration which works on the principle of a heat pump. Operation of such a column is challenging due to unsteady, nonlinear dynamics and strong interplay between separation and energy efficiency. In this paper, a two-step approach is proposed for optimal operation and control of such a column. Initially, an openloop optimal operation policy is generated for maximization of an overall performance index using offline optimization. To this end, three performance indices are proposed to capture interplay between separation and energy efficiency. Subsequently, a model-based output feedback controller is designed to track this optimal performance trajectory. The effectiveness of the proposed approach is demonstrated using a benzene-toluene separation case study wherein it is shown that the proposed approach helps to achieve optimal operation in the presence of operational disturbances.     

间歇萃取精馏过程模拟计算

提出了一种可用于间歇萃取精馏过程模拟计算的快捷模型－准稳态模型，并对该方法的数学模型进行了推导。用此方法对间歇萃取精馏过程中塔顶、塔釜浓度，各塔板温度随时间的变化进行模拟，其结果与实验值吻合较好。它具有计算精度高、计算速度快等优点。