带有隔板塔的NFM萃取精馏工艺模拟和优化

运用Aspen Plus模拟软件,采用UNIFAC-Dortmund集团贡献模型估算了UNIQUAC方程中的二元交互作用参数,建立了NFM萃取精馏分离芳烃的过程模拟。模拟结果表明,该模型可以很好地反映装置的实际操作状况。分别考察了溶剂比、溶剂进料温度、溶剂进料位置、回流比等操作参数对萃取精馏塔的分离效果和能耗的影响,以及在保证侧采甲苯纯度的情况下进料位置、侧采位置、气相分配比、液相分配比对隔板塔的能耗影响,获得了NFM芳烃精制新流程中萃取精馏塔和隔板塔的较优操作参数。     

隔板精馏塔分离氯化亚砜的模拟及工艺优化

利用AspenPlus软件对常规的两塔间接序列精馏工艺分离氯化亚砜进行了模拟计算,并提出了一种新型分离工艺—隔板精馏塔工艺。通过对隔板精馏塔的模拟计算,研究了预分离段进料位置、侧线采出位置、回流进料比和分配比对产品纯度和再沸器能耗的影响,结果说明最佳的工艺条件为:预分离段第6块板进料,主塔第55块板采出,回流进料比为4.45,液相分配比为1.60,汽相分配比为1.98。将隔板塔在最佳操作条件下的能耗与常规两塔工艺操作能耗和设备投资进行比较,隔板精馏塔节约冷凝器负荷和再沸器负荷分别为34.62%和34.64%;然后运用专业的设备投资计算软件CAPCOST计算2种工艺设备投资,结果表明,隔板精馏塔新工艺可以降低17.27%的设备投资。综上可知隔板精馏分离氯化亚砜是一种节能、高效的新型分离工艺。     

TFE精馏塔工艺过程的模拟与优化

采用Aspen Plus V11化工流程模拟软件对四氟乙烯(TFE)精馏塔进行模拟,运用UNIFAC基团拆分法对TFE精馏塔进料组分建立物性分析体系。考察了进料板位置、回流比、热负荷和塔顶采出量对塔顶关键组分的影响,并用灵敏度分析工具优化模拟,对精馏塔条件进行优化,得出的较优操作条件可指导实际生产。     

气相进料对隔板精馏塔优化设计的影响

隔板精馏塔（DWC）在节能和节省设备投资方面具有十分突出的优势,隔板精馏塔中隔板位置是重要的设计变量,影响分离效果及能耗,当进料中含有气相时这种影响更加显著。选用苯、甲苯和对二甲苯三元物系,研究了进料的气相分率对隔板位置的影响并确定最优隔板位置。采用严格模拟方法,以年度总费用（TAC）为评价指标,比较不同进料气相分率下隔板塔的经济性,其中气相进料较液相进料TAC最高可节省23.33%。并通过灵敏度分析展示了在进料中含有气相时确定最优隔板位置的重要性。     

气相进料对隔板精馏塔优化设计的影响

隔板精馏塔（DWC）在节能和节省设备投资方面具有十分突出的优势,隔板精馏塔中隔板位置是重要的设计变量,影响分离效果及能耗,当进料中含有气相时这种影响更加显著。选用苯、甲苯和对二甲苯三元物系,研究了进料的气相分率对隔板位置的影响并确定最优隔板位置。采用严格模拟方法,以年度总费用（TAC）为评价指标,比较不同进料气相分率下隔板塔的经济性,其中气相进料较液相进料TAC最高可节省23.33%。并通过灵敏度分析展示了在进料中含有气相时确定最优隔板位置的重要性。     

ASPEN模拟反应精馏生产醋酸甲酯及工业化探讨

采用Aspen Plus软件模拟催化反应精馏生产醋酸甲酯的工艺过程。考察操作压力、醋酸进料位置、回流比和醋酸/甲醇进料比对反应精馏塔塔顶醋酸甲酯纯度的影响。得出反应精馏塔优化操作条件为:操作压力1atm、醋酸在第5块板进料、回流比为1.9、酸醇比为1.6。在模拟计算的基础上,初步探讨工业化装置设计的技术关键点。     

气体分馏装置丙烯精馏塔操作条件的优化

通过利用Aspend Plus软件对丙烯精馏塔进行稳态模拟操作,能够对液泛系数进行76%的修正,由此对不同进料量及不同的进料组进行一定程度的优化操作。由此就能够得出在相同进料的条件之下,最优回流比以及进料的位置是相同的。同时,丙烯精馏塔的分流指标达到了相关的要求,能够有效提升相关操作装置的弹性。     

进料组成改变对隔板塔经济性影响的模拟

完全热耦合精馏相比传统精馏可以减少设备投资和操作费用,可代替传统精馏分离多组分混合物。对隔板塔（完全热耦合精馏塔）用于分离三组分混合物时的可操作性和经济性进行了研究。采用严格模拟方法,针对4种不同的进料组成设计了4种不同的隔板塔,并得出各个隔板塔气相和液相分割比对隔板塔年度总费用（TAC）的关系曲线,研究了当进料组成改变时4种隔板塔的经济性。     

隔壁催化精馏合成乙酸正丙酯模拟研究

提出了用隔壁催化精馏塔合成乙酸正丙酯的生产工艺流程,以隔壁催化精馏塔代替常规乙酸正丙酯反应精馏塔和乙酸正丙酯精制塔。将隔壁催化精馏过程和常规反应精馏生产过程模拟比较,在相同生产能力和产品质量分数要求下,隔壁催化精馏塔可降低能耗15%以上,同时可减少设备投资。对提出的反应隔壁生产乙酸正丙酯的生产流程进行优化,考察了乙酸进料位置、正丙醇进料位置、副塔气相分配比对过程能耗的影响,并得到适宜的生产操作条件。     

连续精馏分离高温费托合成反应水中的含氧有机物

根据高温费托合成反应水的组成特点,采用连续精馏塔对反应水进行初分,以脱除大部分水和有机酸,同时,将非酸类含氧有机物提浓,利于后续化学品分离。首先采用NRTL热力学方法对流程进行了模拟,考察了塔板数、进料位置、回流比等工艺条件对分离结果的影响,得到了最优操作条件,然后采用实验室小型精馏塔对高温费托合成中试副产反应水进行了实验验证。结果表明:塔顶有机物质量分数可提高到75%以上,有机酸质量分数为0;塔釜采出物中非酸有机物质量分数小于0.01%,模拟最优条件为塔板数35块、进料位置为第15块,回流比为4。实验值与模拟值吻合良好。     

隔壁精馏塔应用于空气分离的研究

以空气分离为例,考察了将隔壁精馏塔应用于空气分离的建模与基于年总成本的优化过程。首先对于空分上塔的氩浓度剖面进行了分析,提出了两种应用隔壁精馏塔的可能性,最终选择了带侧线精馏段的隔壁塔。然后考察了空分隔壁精馏塔上塔的各个结构参数与操作参数对其年总成本的影响,在保证产品质量的基础上得到优化的结构参数与操作参数。研究表明,与传统流程相比,将隔壁精馏塔应用于空气分离过程可使年总成本减少7.69%。     

隔板式反应精馏技术的研究进展

隔板式反应精馏技术是一种将隔板式精馏塔和传统反应精馏工艺相结合,反应和分离过程高度强化的复杂技术。简要介绍了隔板式反应精馏技术的特点,并重点论述了该技术在国外的应用以及控制和优化的方法,概述了隔板式反应精馏塔在国内的发展现状,最后指出该技术在节能减排的大环境下将有非常大的发展前景和应用价值。     

分隔壁萃取精馏塔分离醋酸水溶液的模拟

提出了一种新的单塔萃取精馏精制醋酸水溶液的新工艺,该工艺采用分隔壁萃取精馏塔(DWC-E)替代常规萃取精馏流程的萃取精馏塔及溶剂回收塔,不仅节省了设备投资,而且降低了总能耗。利用Aspen Plus模拟软件,对DWC-E塔及常规萃取流程进行了模拟。DWC-E塔的操作条件:塔板数40块,侧线精馏段的板数10块,回流比2,溶剂摩尔比2.5,在此条件下,比较了常规萃取精馏流程与分隔壁精馏塔内温度、液相组成及汽液相流量的变化。结果表明,DWC-E塔比常规的2塔萃取精馏流程节能23.91%。     

Optimal design of mixed acid esterification and isopropanol dehydration systems via incorporation of dividing-wall columns

This study explores the design of a reactive distillation system and that of a heterogeneous azeotropic system by incorporating dividing-wall column (DWC). The first system involves the esterification of mixed acid (acetic acid and propionic acid) with methanol. Simulation studies are carried out for conventional reactive distillation sequence as well as for reactive dividing-wall distillation system. Both systems are optimized by an iterative optimization procedure. Optimal design results show that the reactive dividing-wall system saves steam consumption by 45.2% and reduces total annual costs (TAC) by 34.5%. The second case investigated is a heterogeneous azeotropic distillation system involving dehydration of crude isopropyl alcohol with cyclohexane as entrainer. Two optimal separation systems are generated, including one with a single-dividing wall column and one with a double-dividing wall column. In comparison with an energy-efficient azeotropic distillation sequence containing two stripping columns by Chang et al. (2012) [1], simulation results show that the former two systems can cut steam usage further by 6.0%. The two systems save about 5.4–6.1% in terms of TAC. DWCs prove to be superior to the convention distillation systems with respect to both cost and energy efficiency.     

Synthesis and Analysis of Reactive Dividing-Wall Distillation for Methylal Production

By means of water as an extractant, the two-feed and three-feed reactive distillation production processes of methylal are synthesized and analyzed. The effects of water on the methylal reactive distillation (RD) production is investigated. Thermally coupled two-feed and three-feed reactive dividing-wall columns are proposed and analyzed. The two-feed and three-feed RD processes are compared. The three-feed thermally coupled reactive dividing-wall column (DWC) exhibits an outstanding ability of energy and cost savings. Results from this work could be helpful for further development and application of RD or reactive DWC in methylal production.     

Experimental Investigation of Decentralized Process Control for Reactive Dividing-Wall Columns

The reactive dividing-wall column (RDWC) presents a highly integrated process that enables significant reductions in investment costs and energy consumption. However, the high degree of integration of this apparatus causes numerous interactions between kinetics, vapor-liquid equilibrium, and mass transfer. To ensure a reliable operation of the RDWC, suitable control schemes need to be developed and experimentally validated. A decentralized control scheme for the RDWC is presented and for the first time experimentally investigated on an RDWC pilot plant. A comparison of experimental and simulated data is carried out and shows good agreement.     

Modeling and in-depth analysis of the start-up of dividing-wall columns

Saving potentials of up to 30% in capital and operating costs are the driving forces behind the increase in the application of dividing-wall columns in industry. However, a lack of knowledge still exists when dealing with the start-up of dividing-wall columns, which is inherently a strongly nonlinear process. Here, for the first time the start-up of dividing-wall columns is explored, where the starting point is an empty column at ambient conditions. A model is presented which is capable of predicting the dynamic discrete-continuous changes which are characteristic of dividing-wall columns. The proposed process model takes into account the heat transfer across the dividing wall as well as the vapor distribution below the dividing wall. The degree of accuracy of the model is clearly determined by comparing different simplifications, e.g. a constant vapor distribution ratio equal to the steady-state value. The detailed studies were carried out with strict product specifications so that the influence of process parameters could be quantified. The rigorous process model and the obtained simulation results presented in this study provide a promising basis for developing and applying optimal start-up policies for dividing-wall columns.     

甲醇和三甲氧基硅烷共沸物分离过程模拟和优化

三甲氧基硅烷（trimethoxysilane）是合成功能性有机硅化合物的重要中间体。在以甲醇和硅为原料合成三甲氧基硅烷的工业化生产过程中,过量的甲醇和产物三甲氧基硅烷会形成最高共沸物。本文探究了变压精馏、萃取精馏和隔壁塔萃取精馏三种分离提纯甲醇和三甲氧基硅烷的工艺,以最小年度总费用（TAC）为目标函数,运用混合整数非线性规划（MINLP）对三种流程进行了优化,比较了三种流程的效率和二氧化碳排放量。结果表明,与变压精馏相比,通过隔壁塔萃取精馏分离甲醇与三甲氧基硅烷共沸物具有明显的优势。分离100kmol/h甲醇（摩尔分数50.00%）和三甲氧基硅烷的TAC从198.84万美元/年降低到98.93万美元/年,降幅高达50.25%,效率从8.17%提高到13.82%,二氧化碳排放量从1217.53kg/h减少到684.22kg/h,减少了43.80%。     

乙酰丙酸乙酯的反应精馏模型及隔壁塔节能优化设计

乙酰丙酸乙酯是一种潜在的生物质基平台化合物,在工业上具有很高的应用价值。乙酰丙酸乙酯传统的生产方法主要为间歇反应法,效率较低,产物分离困难且工艺流程较长。因此,本文提出了反应精馏工艺生产乙酰丙酸乙酯,在以中试实验结果为依据的基础上,使用Aspen Plus模拟软件建立了工艺流程,并考察了回流比、进料位置、进料摩尔比以及理论塔板数等关键参数,得到了常规单塔反应精馏工艺生产乙酰丙酸乙酯的最优配置。而后,为了得到纯度大于99.9%的乙酰丙酸乙酯,本文进一步提出了反应精馏双塔精制流程以及反应精馏隔壁塔流程,并通过对两种流程所得到的产品纯度以及能耗的对比,验证了反应精馏隔壁塔工艺生产乙酰丙酸乙酯的有效性以及在节能方面较大的优势。     

Novel design of lubricant-type vacuum distillation process for lube base oils production from hydrocracking tail oil

Dividing-wall columns (DWCs) are widely used in the separation of ternary mixtures, but rarely seen in the separation of petroleum fractions. This work develops two novel and energy-efficient designs of lubricant-type vacuum distillation process (LVDP) for the separation of hydroisomerization fractions (HIF) of a hydrocracking tail oil (HTO). First, the HTO hydroisomerization reaction is investigated in an experimental fixed-bed reactor to achieve the optimum liquid HIF by analyzing the impact of the operating conditions. A LVDP used for HIF separation is proposed and optimized. Subsequently, two thermal coupling intensified technologies, including side-stream (SC) and dividing-wall column (DWC), are combined with the LVDP to develop side-stream vacuum distillation process (SC-LVDP) and dividing-wall column vacuum distillation process (DWC-LVDP). The performance of LVDP, SC-LVDP, and DWC-LVDP are evaluated in terms of energy consumption, capital cost, total annual cost, product yields, and stripping steam consumption. The results demonstrates that the intensified processes, SC-LVDP and DWC-LVDP significantly decreases the energy consumption and capital cost compared with LVDP. DWC-LVDP further decreases in capital cost due to the removal of the side stripper and narrows the overlap between the third lube oils and fourth lube oils. This study attempts to combine DWC structure into the separation of petroleum fractions, and the proposed approach and the results presented provide an incentive for the industrial implementation of high-quality utilization of HTO through intensified LVDP.