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酯化反应中催化剂的研究进展 总被引:2,自引:0,他引:2
酯类物质是一类重要的有机原料,在食品、日用化工及药物生产中被广泛地用作溶剂、香料、防腐剂等精细化工产品或者反应中间体,而酯化反应是制备酯类物质的重要途径。酯化反应通常需在催化剂作用下来完成,本文综述了近年来酯化反应中催化剂应用的研究进展和发展趋势。 相似文献
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《化学工业与工程技术》2017,(2):41-45
传统的酯化反应催化剂如浓硫酸、磷酸、对甲苯磺酸虽然具有较高的催化活性,价廉易得,但存在副反应多、对设备腐蚀严重、能耗大、反应废液处理复杂等缺点。因此,寻找可代替传统催化剂的新型酯化催化剂势在必行。介绍了近年来酯化反应中催化剂研究的进展情况,对相转移催化剂、室温离子液体催化剂、无机盐催化剂、树脂类催化剂、分子筛催化剂、杂多酸催化剂、固体超强酸催化剂等不同催化剂的特点进行了总结,比较了各类催化剂使用过程中的优缺点。提出了酯化反应催化剂未来的研究方向,主要在于开发高效环保型绿色催化剂。 相似文献
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使用2l反应釜,详细考察了自制钛系催化剂和PET酯化反应的相互影响情况,钛系催化剂在较高反应温度和含水量的酯化反应条件下聚合反应活性不降低,同时对酯化反应过程有促进作用,最后介绍了钛系催化剂在工业装置上对酯化反应影响的应用状况。 相似文献
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新型无锑催化剂在聚酯合成中酯化反应动力学研究 总被引:3,自引:0,他引:3
用自制的新型无锑催化剂,主要含有TiO2、钛酸四丁酯,研究了其催化酯化反应的动力学。实验结果表明,在同样的反应条件下,加入自制催化剂与不加催化剂的反应相比,酯化反应活化能有大幅度的降低;酯化反应时间也可缩短39%。 相似文献
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褚小东 《丙烯酸化工与应用》2002,15(3):21-25
用对甲苯磺酸和甲磺酸按一定比例复配作酯化反应催化剂,在釜式反釜内对丁醇和丙烯酸液相酯化反应进行研究,从温度与酯化速率的关系中求出反应级数(n)、反应速度常数(K)和活化能(E),提出了在使用对甲苯磺酸和甲磺酸复配的催化剂时酯化反应动力学模型。 相似文献
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本文主要分析了天然基负栽酸催化剂、无机盐催化剂、阳离子交换树脂催化剂、固体催化剂以及杂多酸催化剂在酯化反应过程中的应用。并且对于酯化反应所需要的条件以及酯化率等相关问题进行了分析。 相似文献
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Butyl-levulinate has been identified as a promising fuel candidate with high oxygen content. Its combustion in diesel engines yields very low soot and NOx emissions. It can be produced by the esterification of butanol and levulinic acid, which themselves are platform chemicals in a biorenewables-based chemical supply chain. Since the equilibrium of esterification limits the conversion in a conventional reactor, reactive distillation can be applied to overcome this limitation. The presence of the high-boiling catalyst sulfuric acid requires a further separation step downstream of the reactive distillation column to recover the catalyst for recycle. Optimal design specifications and an optimal operating point are determined using rigorous flowsheet optimization. The challenging optimization problem is solved by a favorable initialization strategy and continuous reformulation. The design identified has the potential to produce a renewable transportation fuel at reasonable cost. 相似文献
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The uncatalyzed esterification of acetic acid is described in the literature as a typical example of reactive distillation. Many rigorous models were validated using this esterification as an example. Process proposals for the production of pure ethyl acetate from ethanol and acetic acid have been determined using short-cut methods with the assumption of chemical equilibrium only. In this publication, the limitations of this esterification are clarified, using a rigorous model that was developed. The reasons why reactive distillation appears to be unfavorable for this esterification are explained. It is, however, theoretically possible to obtain ethyl acetate in high purity with different variants of the process. Different process variants are examined in this work. Construction variables that are important for the design of reactive columns, such as the number of reactive separation stages and the holdup in the column, are analyzed. Furthermore, the influence of variables dependent on the component system, such as the phase equilibrium of the reactive system and the reaction kinetics on the conversion in the column, are described. It can be shown that the short-cut methods published so far for reactive distillation, which assume chemical equilibrium, are inadequate. 相似文献
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Compared with inorganic chemical heat pumps (CHPs), organic liquid‐gas CHPs are more amenable to be run as a continuous process because the reactants and products can be fed or removed continuously. Therefore, increasing attention has been paid to investigations of CHPs using the organic liquid‐gas reaction system. Relevant research topics involved reaction catalyst, chemical reaction kinetics, reactive distillation, energy efficiency evaluation, economic analysis, etc. Nevertheless, the research on an organic liquid‐gas CHP system is still in the elementary stage. A detailed review on the current research status of catalyst‐assisted CHPs employing an organic liquid‐gas reaction system has been performed. Existing problems are identified and future research directions are proposed. 相似文献
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T.A. Nijhuis A.E.W. BeersF. Kapteijn J.A. Moulijn 《Chemical engineering science》2002,57(9):1627-1632
Solid-acid catalysts are attractive replacements for processes using conventional homogeneous catalysts. In the esterification of an alcohol with a carboxylic acid, however, the side product water strongly inhibits the activity of a solid-acid catalyst. Since an esterification is an equilibrium limited reaction, full conversion is not possible unless one of the products is removed. A novel reactor type, utilizing a solid-acid catalyst coated monolith, is presented in which water can be removed from the liquid reaction mixture by means of reactive stripping. In this manner the inhibition is eliminated and complete conversion can be reached. The advantages of this reactor concept are demonstrated by both experiments and reactor modeling. 相似文献
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An integrated reactive distillation process for biodiesel production is proposed. The reactive separation process consists of two coupled reactive distillation columns (RDCs) considering the kinetically controlled reactions of esterification of the fatty acids (FFA) and the transesterification of glycerides with methanol, respectively. The conceptual design of the reactive distillation columns was performed through the construction of reactive residue curve maps in terms of elements. The design of the esterification reactive distillation column consisted of one reactive zone loaded with Amberlyst 15 catalyst and for the transesterification reactive column two reactive zones loaded with MgO were used. Intensive simulation of the integrated reactive process considering the complex kinetic expressions and the PC-SAFT EOS was performed using the computational environment of Aspen Plus. The final integrated RD process was able to handle more than 1% wt of fatty acid contents in the vegetable oil. However, results showed that the amount of fatty acids in the vegetable oil feed plays a key role on the performance (energy cost, catalyst load, methanol flow rate) of the integrated esterification–transesterification reactive distillation process. 相似文献
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由于稀土元素具有独特的价电子构型,因而含有稀土元素的固体酸碱催化剂通常都具有独特的空间结构和催化性能。本文对稀土固体酸碱催化剂的种类及特点进行了综述,并对其在分别及同时催化酯化和酯交换反应合成生物柴油中的研究进展进行了详细论述;对各类稀土固体酸碱催化剂的优缺点进行了综合比较分析;对各类稀土固体酸碱催化剂具有不同催化活性和稳定性的内在影响原因进行了分析;着重介绍了稀土氧化物的催化反应机理;指出固体酸催化剂已成为经化学催化法合成生物柴油的新发展趋势,如何通过稀土元素掺杂来获得高活性和稳定性的固体酸催化剂,将是今后的一个重要研究方向。 相似文献
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脱水蓖麻油酸酯化改性环氧树脂,将其与二乙醇胺反应,而后产物在光引发剂和活性单体作用下制得UV固化阴极电泳涂料。研究了环氧树脂分子质量、催化剂种类及用量、反应温度对酯化反应的影响,探讨了酯化程度、胺开环率、活性单体的种类及用量对涂料稳定性及涂膜性能的影响。结果表明,选取环氧树脂E-44,酯化温度110℃,催化剂N,N-二甲基苄胺,添加质量分数0.8%~1%,酯化程度35%~40%,胺开环率≥60%,活性单体季戊四醇三丙烯酸酯质量分数15%~20%时,所制备的UV固化阴极电泳涂料涂膜固化快速完全,表面均匀丰满光亮,附着力好,耐溶剂性优。 相似文献