萃取精馏绿色高效分离共沸物的研究进展

多组分液体混合物特别是共沸物在化工、石油、制药等领域的过程工业中得到广泛应用。节能高效分离共沸物对绿色工业过程的设计和发展具有重要意义。萃取精馏在共沸物分离中发挥着重要作用。这项工作可提供全面的参考，包括萃取精馏、萃取精馏过程设计、萃取精馏耦合过程、萃取精馏优化策略方面的最新进展。首先，讨论了量子化学和分子动力学模拟方法在筛选合适的夹带剂中的应用。其次，阐述了两种不同类型的萃取精馏工艺的设计原理和形式。然后，讨论了通过热集成和强化机制以及萃取精馏与其他特殊精馏过程相结合的能源和经济优化方法，并研究了萃取精馏技术在多组分共沸物分离中的挑战、前景和发展趋势。     

液液萃取-非均相共沸精馏耦合回收正丁酸

正丁酸与水的混合物能够形成最低沸点共沸物,难以用传统精馏分离.在常规非均相共沸精馏基础上,文中提出了更为节能的液液萃取-非均相共沸精馏耦合技术,利用COSMO活度系数模型筛选出合适的溶剂,并探索了混合溶剂萃取精馏分离工艺.采用顺序迭代法优化工艺主要操作参数,使用经济和环境分析方法去评价分离过程的主要性能.单一溶剂液液萃...     

热集成变压精馏分离乙醇-乙腈混合物

以乙醇-乙腈混合物为对象,研究了该体系在实验压力范围内的共沸组成,分析了采用变压精馏工艺分离精制乙醇和乙腈的可行性。通过比较实验压力范围内（101~500 kPa）体系的共沸组成与Aspen Plus模拟软件中计算的体系共沸组成,选择了适合的物性方法。在实验装置上进行了变压精馏法分离精制乙醇、乙腈混合物的实验,重点考察了不同回流比对分离效果的影响,得到了质量分数大于99.5%的乙醇和乙腈产品。 应用Aspen Plus模拟软件对乙醇-乙腈体系的热集成变压精馏过程进行了模拟计算,对比了热集成变压精馏与传统变压精馏的能耗,发现热集成变压精馏节能达35%。     

热耦合技术应用于共沸精馏系统的研究

以异丙醇脱水为例提出了一种热耦合共沸精馏序列的设计和优化方法,应用该方法可以将常规的双塔共沸精馏序列转化为热耦合共沸精馏序列并保证各操作参数的最优值。同时,利用Aspen Plus模拟软件,对异丙醇脱水的常规共沸精馏序列和热耦合共沸精馏序列进行了模拟分析。结果表明,热耦合共沸精馏序列不但提高了热力学效率、降低了能耗,并且能较大幅度地减少CO2排放量。     

苯乙烯装置共沸精馏系统的优化与探讨

从生产操作和节能以及工业化装置的角度,对苯乙烯共沸精馏节能技术的流程以及技术特点进行了详细介绍.其次对此技术方案提出了几点优化措施,包括对后冷器的负荷优化,对乙苯/苯乙烯塔顶控制优化以及对乙苯蒸发系统蒸汽出口控制方案的优化等,通过回收塔顶低温热,能够给苯乙烯装置带来一定经济效益.最后分析了苯乙烯共沸精馏技术优化后的效果,从运行工艺参数和运行稳定性以及节能效果、经济效益几方面进行了对比,指出苯乙烯共沸精馏节能技术具有很大的实际应用价值,对苯乙烯装置的可持续发展具有重要意义.     

共沸精馏分离乙醇-异丙醇

为了分离乙醇-异丙醇混合物,研究了共沸精馏在乙醇-异丙醇物系中的应用。根据共沸剂的选取原则选定出1-己烯作为共沸精馏分离乙醇-异丙醇混合物的共沸剂,使用ASPEN模拟软件模拟连续和间歇共沸精馏分离乙醇-异丙醇工艺流程,并通过间歇共沸精馏实验考察了所选共沸剂的分离效果。结果表明：使用1-己烯作为共沸剂能成功的分离乙醇-异丙醇混合物;采用有30块理论板的填料塔,回流比为25,共沸剂1-己烯与乙醇的质量比为4∶1,塔釜异丙醇的质量分数达到99.77%。     

共沸精馏技术研究及应用进展

本文综述了共沸精馏的特点、分类、共沸剂的选择及相关国内外研究进展。根据所形成的共沸物是否能分离为不互溶的两个液相,共沸精馏可分为均相共沸精馏和非均相共沸精馏。综述了近年国内外共沸精馏技术的应用研究和进展。特别指出在含有少量难分离共沸/近沸杂质的分离方法,具有可行性强,可靠性高等优势,是共沸精馏技术发展的一个重要方向。     

塔釜回流共沸精馏技术的研究

通过-个具有塔釜回流的精馏塔实验装置,以正己烷为共沸剂,从操作时间、回流比的控制、共沸剂的用量及实际应用等方面对塔釜回流共沸精馏技术分离乙醇-水共沸混合物进行了实验研究.研究结果表明:塔釜回流共沸精馏技术与常规共沸精馏技术相比,在其他操作参效相同,回流比大于3时,塔釜回流得到的产品纯度和收率有明显提高;达到同样的产品纯度和收率,塔釜回流所用的共沸剂量减少;但塔釜回流的操作时间延长.塔釜回流改善了常规的操作方式在生产应用上的不足.是一种很有应用前景的分离新技术.     

具有最低共沸点难分离物系变压精馏分离

变压精馏是根据物系压力改变引起液体混合物共沸点组成变化,进而使共沸物系得以分离的一种有效分离方法。具有最低共沸点的液体混合物分离是化工过程中常见的分离难题。本文在热力学分析基础上研究了四氢呋喃与乙醇、环己烷与苯混合物这类典型的最低共沸液体混合物的变压精馏可行性,提出变压精馏分离四氢呋喃-乙醇液体混合物工艺流程,以NRTL-RK为物性计算方法,利用Aspen Plus模拟软件对变压精馏分离工艺过程进行分析及模拟,并对工艺参数进行优化。结果表明:在常压塔和8atm高压塔组成的双塔流程中变压精馏能将四氢呋喃-乙醇最低共沸混合物进行较好的分离,指出本文提出的研究方法可为具有最低共沸点液体混合物分离工艺的建立提供更加有效的指导。     

四氢呋喃-乙醇变压精馏分离

共沸混合物分离是化工过程中常见的分离难题。变压精馏是根据物系压力改变而使液体混合物共沸点组成发生变化,进而使共沸物系得以分离的一种有效分离方法。在热力学分析基础上,提出了四氢呋喃-乙醇液体混合物变压精馏分离双塔工艺流程。以NRTL-RK为物性计算方法,利用Aspen Plus模拟软件对变压精馏分离工艺过程进行分析及模拟,并对工艺参数进行优化。研究结果表明:在常压塔和0.8 MPa高压塔组成的双塔流程中变压精馏可将四氢呋喃-乙醇最低共沸混合物进行较好的分离。     

Research advances in thermally coupled intensification technology for special distillation

In the production and separation process of petroleum, medicine, chemical industry and other industries, it is often accompanied by the production of azeotropic or similar boiling point mixtures. Its high-efficiency and energy-saving separation is a prerequisite for industrial clean production and sustainable development. Special distillation as an effective separation method attracts substantial attention from researchers. However, special distillation is a process with high-energy consumption. Therefore, the development of intensification technology for special distillation with low costs and reliable performance is of great significance for the economy and energy sustainable development. According to the heat and mass transfer laws of special distillation, this work introduces the research advances of thermally coupled distillation, dividing wall column, side-stream distillation, organic Rankine cycle, heat pump and different pressure thermally coupled technologies in energy saving special distillation process from the intensification principles and retrofitting technologies. In addition, this work outlines the challenge and opportunity of intensification technology to provide references of the theoretical research and application to special distillation.     

Distillation technology – still young and full of breakthrough opportunities

Throughout history, distillation has been the most widespread separation method. However, despite its simplicity and flexibility, distillation still remains very energy inefficient. Novel distillation concepts based on process intensification, can deliver major benefits, not just in terms of significantly lower energy use, but also in reducing capital investment and improving eco‐efficiency. While very likely to remain the separation technology of choice for the next decades, there is no doubt that distillation technology needs to make radical changes in order to meet the demands of the energy‐conscious modern society. This article aims to show that in spite of its long age, distillation technology is still young and full of breakthrough opportunities. Moreover, it provides a broad overview of the recent developments in distillation based on process intensification principles, for example heat pump assisted distillation (e.g. vapor compression or compression–resorption), heat‐integrated distillation column, membrane distillation, HiGee distillation, cyclic distillation, thermally coupled distillation systems (Petlyuk), dividing‐wall column, and reactive distillation. These developments as well as the future perspectives of distillation are discussed in the context of changes towards a more energy efficient and sustainable chemical process industry. Several key examples are also included to illustrate the astonishing potential of these new distillation concepts to significantly reduce the capital and operating cost at industrial scale. © 2013 Society of Chemical Industry     

裂解C_5馏分分离技术的研究进展

简要介绍了C5馏分的用途以及国内外C5馏分分离技术的研究进展,叙述了几种主要分离工艺流程的特点和近年来开发的一些新技术,如在节能降耗和提高经济效益方面具有很大潜力的热耦精馏、热集成、化学吸收及膜分离等方法,展望了C5馏分分离技术在工艺优化、节能、开发新型萃取溶剂等方面的前景。     

Reduction of Energy Consumption and Greenhouse Gas Emissions in a Plant for the Separation of Amines

The chemical industry comprises of the companies that produce industrial chemicals. It is central to the modern world economy, converting raw materials into more than 70 000 different products. However, environmental regulations and the risk of climate change are putting pressure on the chemical industry to minimize greenhouse gas emissions. In this work, we use the concept of process intensification (using thermally coupled distillation) to reduce energy consumption and CO₂ emissions in a plant for the separation of amines. The results show that the use of thermally coupled distillation sequences can be related to a reduction in energy consumption, greenhouse gas emissions, and good theoretical control properties in the re‐designed plant.     

精馏技术研究进展与工业应用

精馏是化学工业中应用最广泛的关键共性技术,广泛应用于石油、化工、化肥、制药、环境保护等行业。精馏具有应用广泛、技术成熟等优点,但存在设备投资大、分离能耗高等问题,因此研究开发新型高效传质元件、开发新型节能精馏技术,具有重要的社会意义和经济价值。本文从精馏塔类型、流体力学性能、传质性能、塔器大型化、过程节能、过程强化等方面,介绍了精馏技术的研究进展与工业应用。对于板式塔,从气液两相流动状态、压降、漏液和雾沫夹带方面研究了塔板的流体力学性能;对于填料塔,从压降、液泛和持液量方面研究了填料塔的流体力学性能,但目前的研究仍以经验关联式为主,缺乏严谨的的理论模型。对于气液两相的传质性能研究,简述了气液两相传质理论,但科学、精准的传质模型尚未提出。对于塔器大型化的应用研究,介绍了塔板、气液分布器和支撑装置等大型化关键技术的工业应用。从精馏过程典型节能技术、耦合节能技术、流程节能技术、低温余热回收和特殊精馏等方面,介绍了精馏过程节能与强化的应用进展。文章最后对精馏过程的传质、强化和集成进行了展望。     

丁二烯分离装置热偶精馏的操作特性

以丁二烯分离装置为对象，对热偶精馏ＴＣＳ－Ｒ用于非理想体系的操作特性和节能效果进行了模拟分析与研究。根据分离要求确定主塔最小馏出的液量后，热偶精馏ＴＣＳ－Ｒ的分离能力和节能效果受汽相连接流股流率的影响最大，其次为汽相连接流股的抽出位置。丁二烯分离装置中应用热偶精馏ＴＣＳ－Ｒ后可以在满足分离要求的前提下节能４０％左右。在此基础上，对这种偶合塔计算了主塔底乙烯基乙炔含量变化对汽相连接流率变化的灵敏度。     

Feasibility study of a thermally coupled reactive distillation process for biodiesel production

Biodiesel fuel represents an interesting alternative as a clean and renewable substitute of fossil fuels. A typical biodiesel production process involves the use of a catalyst, which implies high energy consumptions for the separation of the catalyst and the by-products of the reaction, including those of undesirable side reactions (such as the saponification reaction). A recently proposed process involves the use of short-chain alcohols at supercritical conditions, avoiding the use of a catalyst and the occurrence of the saponification reaction. This process requires fewer pieces of equipment than the conventional one, but its high energy requirements and the need of special materials that support the reaction conditions makes the main product, biodiesel fuel, more expensive than petroleum diesel. In this work, a modification of the supercritical process for the production of biodiesel fuel is proposed. Two alternatives are proposed. The process involves the use of either reactive distillation or thermally coupled reactive distillation. Simulations have been carried out by using the Aspen One™ process simulator to demonstrate the feasibility of such alternatives to produce biodiesel with methanol at high pressure conditions. A design method for the thermally coupled system is also proposed. Both systems have been tested and the results indicate favorable energy performance when compared to the original scheme. Furthermore, the thermally coupled system shows lower energy consumptions than the reactive distillation column.     

内部热耦合空分塔的节能优化分析

内部热耦合精馏是迄今为止所提出的节能效果最好,而唯一没有商业化的节能技术。将内部热耦合技术用于空分塔,可以带来良好的节能效果。根据低温空气分离过程以及三组分精馏的特点,提出了一种新的内部热耦合空分精馏塔优化模型。在优化模型基础上,对热耦合塔进行了深入的节能优化与分析,并且与常规空分仿真结果进行了比较分析,压缩机能耗下降20.75%,产值增加17.46%,单位产值能耗下降32.53%。内部热耦合空分塔的提取率以及能耗均优于常规热耦合空分塔,节能效果显著。     

Effect of Recycle Streams on the Closed-Loop Dynamics of Thermally Coupled Distillation Sequences

The effects of thermal links on the closed-loop dynamics of thermally coupled distillation sequences for the separation of quaternary mixtures have been studied in this work by using rigorous dynamic simulations. The incorporation of thermal links into conventional distillation sequences can lower the energy consumption up to 40% without introducing additional control problems to the resulting thermally coupled distillation sequences. In some cases, the thermally coupled distillation sequences outperformed the dynamic behavior of the conventional distillation sequences for set point tracking. This result is important to establish that thermally coupled distillation sequences not only can have significant energy savings but also good dynamic properties.