叔丁醇-乙醇-水分离的萃取精馏节能设计与动态控制

针对工业实例分离叔丁醇-乙醇-水三元共沸物,设计了常规三塔萃取精馏(CTCED)及节能型多侧线塔萃取精馏(EDCMR)分离流程.通过稳态优化对2种流程进行对比,基于以年度总费用(TAC)最低为目标的稳态优化后可以得出,多侧线塔萃取精馏流程的TAC比常规三塔萃取精馏流程降低了16.16％.在此基础上,对于多侧线塔萃取精馏...     

热泵及热集成萃取精馏分离异丙醇-水的流程设计与比较

以乙二醇为萃取剂分离异丙醇和水的混合物。为降低能耗、节约成本和减少CO₂排放量，采用热泵和热集成技术强化萃取精馏过程。利用Aspen Plus软件，对常规萃取精馏、热泵萃取精馏和热集成-热泵萃取精馏等工艺进行了模拟和优化。从能耗、年度总费用(TAC)和CO₂排放量等方面对上述工艺进行了评价和比较。结果表明，在相同的设计基础和要求下，压缩机性能系数为10.19的热泵技术能显著降低能耗；与常规萃取精馏相比，热泵萃取精馏方案二节能效率为28%，可减少CO₂排放3.746×10⁶ kg/a，投资回收期为3 a时，TAC可节约0.72×10⁵ USD；充分利用循环萃取剂显热的热集成-热泵萃取精馏更具优势，节能效率达到了35%，可减少CO₂排放8.457×10⁶ kg/a,TAC降低了1.70×10⁵ USD，具有显著的环境效益和经济效益。     

基于先进萃取精馏工艺的乙腈-水共沸物分离过程模拟

以甘油与乙二醇的混合溶剂(摩尔比为6∶1)为萃取剂,分别采用常规萃取精馏(CED)、减压萃取精馏(LPED)、隔壁塔萃取精馏(EDWC)和结合预浓缩段和溶剂回收段的萃取精馏(CPRED)等方法对乙腈 水体系进行精馏分离;并利用Aspen Plus软件对4种工艺流程进行稳态模拟,以年总费用(TAC)最小为目标,采用序贯模块法对各流程的工艺参数进行优化以获得最优结构参数。结果表明：与常规萃取精馏流程的TAC相比,减压萃取精馏的TAC下降了392%,结合预浓缩段和溶剂回收段的萃取精馏的TAC下降了10.57%,而隔壁塔萃取精馏的TAC增加了1003%;从环保角度分析,结合预浓缩段和溶剂回收段合成的萃取精馏流程CO2排放量最少,而隔壁塔萃取精馏流程CO2排放量最多。     

变压精馏和萃取精馏分离乙腈-正丙醇工艺优化

通过乙腈-正丙醇的共沸性质剖析,探索了变压精馏与萃取精馏进行该二元共沸物分离的可行性.利用NRTL方程计算液相的活度系数,其二元相互参数采用实验相平衡数据拟合,通过Aspen Plus对上述2种分离方法开展模拟优化,以年度总费用(T AC)最小为目标函数,得到了2种工艺的优化设计参数.结果表明,采用双塔变压精馏或萃取精馏工艺均能有效地实现乙腈与正丙醇共沸体系的分离,而萃取精馏工艺更适合乙腈和正丙醇的分离.与常规变压精馏工艺相比,热集成变压精馏工艺由于能量集成使得T AC减少了28.2％,主要是操作费用的节省.与热集成变压精馏工艺相比,萃取精馏工艺的总设备折旧费和总操作费用均有一定幅度降低,萃取精馏工艺所需的T AC降低13.9％.     

反应精馏耦合离子液体萃取精馏工艺分离碳酸二甲酯和甲醇联产丙二醇甲醚

采用反应精馏耦合萃取精馏工艺,即反应精馏工艺中引入环氧丙烷反应剂,在消耗部分甲醇的同时,联产高附加值的丙二醇甲醚;萃取精馏工艺中选用离子液体为萃取剂,在实现甲醇-碳酸二甲酯共沸物高效分离的同时进一步降低成本。使用COSMO-RS模型从25种阳离子与25种阴离子的组合中筛选出最优离子液体[HMIM][PF₆],并对体系汽液平衡进行预测,从而设计出合理的分离工艺,使用Aspen Plus V11.0软件模拟并优化工艺流程。通过量子化学计算,利用独立梯度模型及分子表面电荷屏蔽密度分布曲线解释分离机理。模拟结果表明,年总费用相较于常规萃取精馏工艺降低约13.67%。同时,联产丙二醇甲醚带来的额外经济效益为13.4×10⁶$/a。     

[DMIM]DMP萃取精馏分离乙酸甲酯-甲醇共沸物

以离子液体1,3-二甲基咪唑磷酸二甲酯([DMIM]DMP)为萃取剂,精馏分离乙酸甲酯和甲醇共沸物。采用Aspen Plus软件对萃取精馏过程进行了设计和优化。在最佳操作条件下,乙酸甲酯和甲醇的质量分数均在99.5 %以上。与采用二甲基亚砜（DMSO）为萃取剂的工艺相比,[DMIM]DMP工艺具有节能、设备投资低等优势。结果表明以[DMIM]DMP为萃取剂精馏分离乙酸甲酯和甲醇共沸物具有更好的工业应用前景。     

共沸精馏分离生物醇-水混合物的模拟与优化

针对液 液萃取的异丙醇 正丁醇-乙醇 水(IBE H2O)体系,采用共沸精馏方法分离其中的水;并利用化工软件Aspen Plus对发酵产物IBE H2O体系的分离提纯进行流程模拟,设计了精馏流程,筛选了共沸剂,考察了共沸剂的适宜用量,优化了操作条件,得到了精馏流程最优、最经济的操作条件。结果表明：IBE H2O体系分离提纯优选的共沸剂为甲基叔丁基醚(MTBE);最佳精馏流程的共沸剂循环量为58 kmol/h,理论塔板总数为15,进料位置在塔上部第3块塔板处;提纯得到混合醇产品中IBE的摩尔分数可达到99.6%;且此时共沸精馏流程经济最优。     

乙醇-水-l,3-二甲基咪唑磷酸二甲酯盐三组分物系的汽液平衡测定及关联

在101.32 kPa下,用CE-2型Othmer汽液平衡釜测定了乙醇-水-1,3-二甲基咪唑磷酸二甲酯盐([mmim]DMP)物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联。实验结果表明,UNIFAC方程可用于含离子液体物系的汽液平衡的计算;加入离子液体[mmim]DMP使乙醇-水二组分物系的汽液平衡线发生偏离,[mmim]DMP含量越高,汽液平衡线偏离程度越大;[mmim]DMP具有明显的盐析效应,能消除乙醇-水二组分物系的共沸点;[mmim]DMP可作为乙醇-水物系萃取精馏的溶剂。     

丁醇-醋酸丁酯共沸物系萃取精馏萃取剂的分子设计

基于遗传算法思想提出了一种有效的分子设计方法,针对丁醇-醋酸丁酯共沸物系的萃取精馏萃取剂选择问题进行了分子设计,经比较筛选出塔顶产物分别是醋酸丁酯和丁醇时的较佳萃取剂为1,3-丙二醇和硝基丁烷。分别以1,3-丙二醇和硝基丁烷为萃取剂,应用精馏过程模拟软件ProⅡ确定了萃取精馏流程及相应的工艺操作条件;通过对比两种流程的塔设备、能耗、操作条件、产品等方面,认为1,3-丙二醇是分离丁醇-醋酸丁酯共沸物系的较适宜萃取剂。模拟计算结果表明,该分子设计方法是有效的,能为工业生产提供理论基础。     

萃取精馏隔壁塔三种等价模型分离乙腈-水体系流程模拟与优化

采用精馏隔壁塔的三种等价模型,借助Aspen Plus对乙腈-水分离进行了模拟。通过灵敏度分析、TAC分析和能耗分析,研究了不同等价模型在分离共沸体系方面的适用性。结果表明:针对萃取精馏,隔壁塔三种等价模型均可用于模拟分离乙腈-水体系;各模型均体现出节能效果,相较于传统的萃取精馏塔,两塔模型节能12.62%,三塔模型节能22.28%,四塔模型节能14.10%;总费用方面,三塔模型比两塔模型减少11.73%,比四塔减少15.26%。     

变压精馏分离丙酸甲酯-甲醇的节能设计

基于丙酸甲酯-甲醇二元体系的压力敏感特性,以最小年总费用(TAC)作为经济评价指标,对变压精馏分离工艺进行了模拟与优化,并在常规工艺基础上进行了改造,以实现节能的目的。结果表明:常规分离工艺高压进料时,高压塔塔板数为41、回流比为1.5和进料位置为第33块板以及低压塔塔板数为39、回流比为2.0和进料位置为第17块板时TAC最低,为593.00万元/年。将热集成技术应用于常规工艺中,优化后的分离工艺均能实现物系的高效分离。相比于常规变压精馏,部分热集成变压精馏与全热集成变压精馏分别可以节约44.57%与41.94%的能耗,同时可以节约23.84%与32.59%的TAC,主要原因是热量集成使得蒸汽费用与换热器费用降低。优化后的两种工艺分离效果显著,且能耗与TAC均较低,可为工业设计提供理论参考。     

萃取精馏与变压精馏分离甲醇-乙腈共沸物的研究

In the present work, a comparative study of the extractive distillation and pressure swing distillation for methanol-acetonitrile azeotropic separation is performed for the first time. Different separation alternatives, including the conventional extractive distillation, the extractive distillation with vapor or liquid side-stream, the pressure-swing distillation with or without full heat integration, and the heat-pump assisted pressure-swing distillation are rigorously simulated and optimized based on the minimum total annual cost (TAC) via the sequential iterative strategy. The results show that TAC and CO2 emission of the new extractive distillation with vapor side-stream (Vapor-SED) are similar to that of the extractive distillation with liquid side-stream (Liquid-SED). Furthermore, the Vapor-SED and Liquid-SED gives 30.01% and 30.56% reduction in TAC and 23.32% and 23.49% reduction in CO2 emission, respectively, over the most competitive fully heat-integrated PSD configuration. Hence, extractive distillation with vapor or liquid side-stream appears to be better option economically and environmentally for separation of methanol and acetonitrile.     

节能技术在三氯硅烷精馏提纯工艺中的应用

The trichlorosilane (TCS) purification process consumes a significant amount of energy to achieve the high purity requirement for TCS quality (99.9999%). This work proposed a series of energy saving technology to enhance the TCS purification process, including the conventional process, the conventional process coupled with heat-pump (HP), the multi-effect distillation process, and the dividing-wall columns process. All proposed schemes have been conceptually constructed by Aspen Plus. The design and optimization of the processes have been performed by the sensitivity analysis and the response surface methodology. Moreover, the energy consumption and total annual cost (TAC) for these schemes were discussed. The simulation results show that the TAC of the conventional process coupled with the integrated heat pump can reduce 50.5% of energy consumption as compared with the conventional process; the double-effect and three-effect processes can save 15.6% and 33.8% of energy consumption, respectively; the dividing wall column process and that coupled with the heat pump process can reduce by 22.3% and 48.1% of energy consumption, respectively. It can be found that the operating cost can be saved by using the heat pump technology, while the capital cost increases due to the investment in the compressor, when the processes coupled with the heat pump are used. These results demonstrate that the conventional process coupled with the HP technology has advantages over other distillation schemes for TCS purification in terms of the energy saving and economic effects.     

Design and Control of Self-Heat Recuperative Distillation Process for Separation of Close-Boiling Mixtures: n-Butanol and iso-Butanol

In order to explore the advantages of self-heat recuperative distillation(SHRD) process, the design and control of the SHRD process was studied for the separation of n-butanol and iso-butanol mixtures. The economic superiority of SHRD process is presented when a comparison on the total annual cost(TAC) of the conventional distillation process, the vapor recompression distillation process and the SHRD process was made. For the SHRD process, 37.74% and 11.35% savings of TAC can be achieved as compared to the conventional distillation process and vapor recompression distillation process, respectively. The dynamic characteristics of this promising SHRD sequence had been studied, and the dynamic responses demonstrated that 10% changes in both feed flow rate and feed composition can be well handled by the control strategy with dual-temperature control. It is proven that the SHRD system not only can provide economical savings but also can operate normally with good controllability.     

Design,Optimization and Control of Extractive Distillation for Separation of Ethyl Acetate-Ethanol-Water Mixture Using Ionic Liquids

In this work, the process simulation of pressure-swing distillation(PSD) and extractive distillation(ED) using ionic liquid(IL) 1-butyl-3-methylimidazolium acetate([bmim][OAc]) as the entrainer for separation of ethyl acetateethanol-water mixture is performed. The design parameters of the two distillation processes are optimized with the minimum total annual cost(TAC) serving as the objective function. The results show that the TAC saving of ED process is 35.27% in comparison with that of PSD process in the case of achieving the same purity and yield of ethyl acetate.In addition, the dynamic controllability of ED process is further studied. The traditional two-point temperature control structure is proposed for the ED process, and it works pretty well while taking into account the disturbances in both feed rate and feed composition.     

热泵在蒸馏过程中的应用

在常规蒸馏流程中,加热塔底蒸发器所输入的能量大约有 ９５％在塔顶被冷却空气或冷却水带走,一般情况下这部分能量不能得到进一步的回收利用。多年来,人们已采用了多种方法和手段对蒸馏塔的装置和操作进行改进,节约能量 ２％～ ５０％。近年来,人们开始在石油化工装置的蒸馏过程中利用热泵技术降低蒸馏过程的能耗。对气体分馏装置中丙烷──丙烯分离系统的常规蒸馏与热泵蒸馏流程进行比较后发现,热泵蒸馏可比常规蒸馏流程节约能量达 ８０％以上。     

自热回收精馏过程分离正丁醇/异丁醇近沸点混合物的设计与控制研究

为了探索自热回收精馏在分离过程中的优势,以分离正丁醇-异丁醇近沸点混合物体系为例,对自热回收精馏过程的设计与控制过程进行了研究。通过优化设计,求取了传统精馏过程、热泵精馏过程、自热回收精馏过程的年总费用值。结果表明,自热回收精馏过程的年总费用分别比传统精馏、热泵精馏过程节省37.74%、11.35%,因而证明了自热回收精馏过程的经济优势。另外,对该极具潜力的自热回收精馏过程进行了动态研究。当建立双温度控制结构时,自热回收系统能够分别抵抗10%的进料流率与进料组分变化,进料扰动得到了有效的控制。因此,自热回收精馏过程不仅在经济上具有优势,并且显示了良好的可控性。     

基于异丁烯提纯反应精馏的热泵流程模拟及分析

基于异丁烯提纯反应精馏的特点，设计了塔顶蒸汽压缩式的热泵节能流程。利用Aspen Plus软件对全流程进行模拟，并提出了针对部分冷凝流程的热泵精馏模拟策略。从火用分析和技术经济的角度，全面对其进行能耗和经济性分析评价。案例研究结果表明：采用热泵节能技术的反应精馏过程，当压缩比为1.6时，能耗及总费用最低；且与常规反应精馏过程相比，采用热泵节能技术后单位产品能耗降低约87.5%，热力学效率提高32.7百分点，年操作费用下降64.4%，热泵投资回收期为1.5年。     

丙烯精馏塔热泵流程的优化

利用Aspen Plus流程模拟软件,选用RK-SOAVE物性模型和RADFRAC精馏模型,对常规丙烯精馏塔的操作工况进行了模拟.在此基础上,对丙烯精馏塔的2种热泵流程即塔顶蒸汽直接压缩式热泵流程和塔釜液闪蒸再沸式热泵流程进行了模拟计算.结果表明,对于丙烯精馏塔而言采用塔釜液闪蒸再沸式热泵流程更有利.所选热泵精馏流程优化操作参数如下:丙烯精馏塔进料位置为第125块塔板,回流比为16.5,节流阀压力为1.0 MPa.通过对操作参数进行优化,在处理量相同的情况下,可使塔釜液闪蒸再沸式热泵精馏流程压缩机功率降低352.39 kW,辅助冷却器负荷降低31.72 kW.     

溶剂抽提及1-乙基-3-甲基咪唑醋酸盐热溶解聚对羊肠湾次烟煤萃取行为的影响

溶剂萃取是制备超净煤和研究煤分子结构的重要方法之一,对于实现煤资源高效清洁转化具有重要意义。选取中国宁东羊场湾 (YCW) 煤作为研究对象,考察多种溶剂及添加离子液体1 乙基 3 甲基咪唑醋酸盐(［Emim］［AC］)对煤萃取效果的影响。结果表明,煤的萃取产率从大到小的顺序遵循着含氮类、醇类、酮类、烃类的规律。所选取的9种溶剂中,二甲基亚砜对 YCW 煤的萃取产率最高。对于同类溶剂而言,极化率越大,萃取产率越高。研究还发现,离子液体 ［Emim〖DK(〗］［〖DK)〗AC］ 的添加可以显著提高 YCW 煤在溶剂中的萃取产率。此外,离子液体的回收率也可达到915%。