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在四元催化体系间歇釜式反应的基础上,本文对乙烯齐聚的连续化反应进行了系统研究,设计并安装了一套连续化反应装置,包括预反应器,反应器和闪蒸后处理装置。在连续化反应装置上,分别考察了催化剂进料速度,反应压力和催化剂浓度对然齐聚连续化反应的影响,同时获得了连续化反应的最佳反应条件。经过研究发现,该四元催化剂体系的间歇釜式反应的最佳反应条件,也同时是连续化反应的最佳反应条件,齐聚反应的催化活性,C的选择性 相似文献
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《化工进展》2017,(5)
以异丙胺为核合成了一种1.0代聚酰胺-胺型超支化大分子骨架,并进一步与水杨醛和六水合氯化镍通过"一锅法"合成了一种具有新型支链结构的超支化水杨醛亚胺镍系催化剂。采用FTIR、~1H NMR和ESI-MS表征方法证明了合成产物的结构与理论结构相符。在甲基铝氧烷为助催化剂、甲苯为溶剂的催化体系内确定了催化乙烯齐聚的最佳反应条件,在Al/Ni摩尔比1000、反应温度25℃、反应压力0.5MPa、反应时间30min的条件下,催化乙烯齐聚的活性达3.8×10~5g Olig/(mol Ni·h),齐聚产物主要是C8及以下烯烃,含量高达99%。在相同条件下,通过对比不同骨架结构的超支化镍配合物,初步确定了超支化镍配合物催化乙烯齐聚反应体系催化性能的影响因素。 相似文献
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采用过渡金属配合物催化乙烯齐聚是制备α-烯烃的一条重要工艺路线,部分催化体系已进入了中试和工业化生产阶段,但近年来的研究工作表明,一些过渡金属催化剂在甲苯溶剂中的齐聚产物可直接与甲苯发生Friedel-Crafts烷基化反应,这将为烷基苯的生产开辟一条新的途径。综述了近年来乙烯齐聚过程中发生Friedel-Crafts烷基化反应的研究进展,详细阐述了催化剂的结构、催化体系、工艺条件等对烷基化反应及烷基化产物分布的影响。同时,给出了乙烯齐聚中Friedel-Crafts烷基化反应的反应过程,对设计可催化乙烯齐聚制备混合烷基苯的催化剂具有重要的意义。 相似文献
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采用1.0G超支化大分子(1.0G)、3-取代水杨醛和NiCl2·6H2O为原料,依次经席夫碱反应和络合反应合成了3种新型具有不同取代基位阻的超支化水杨醛亚胺配体及其镍系催化剂,利用红外光谱(FTIR)、核磁共振氢谱(1H NMR)、紫外光谱(UV-vis)、电喷雾质谱(ESI-MS)及电感耦合等离子体质谱(ICP-MS)等方法对合成出产物的结构进行表征。考察了配体空间位阻、溶剂种类、助催化剂种类及反应条件对催化乙烯齐聚性能的影响。研究结果表明,配体空间位阻对催化乙烯齐聚性能有较大的影响,当以甲苯为溶剂、甲基铝氧烷(MAO)为助催化剂,在最佳反应条件下,超支化邻苯基水杨醛亚胺镍系催化剂催化乙烯齐聚的活性为2.81×105g/(mol Ni·h),对高碳烯烃(C10+)的选择性为34.28%。此外,在超支化水杨醛亚胺镍系催化剂催化性能评价的基础上,对其催化乙烯齐聚的机理进行研究。 相似文献
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以环氧乙烷和无水乙醇为原料,以负载KOH的5A分子筛为催化剂,在连续操作的膜反应器中合成乙二醇单乙醚.考察了反应温度、KOH负载量及空时对乙醇转化率和乙二醇单乙醚选择性的影响.结果表明,以KOH负载质量分数为17.6%的5A分子筛作为催化剂,在110 ℃和空时2 h的条件下反应,乙二醇单乙醚的选择性达到了88.81%.通过膜反应器与间歇釜式反应器对比实验发现,膜反应器中乙二醇单乙醚的选择性明显高于间歇釜式反应器. 相似文献
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在釜式反应器中研究了氨基磺酸催化甲醛和甲酸甲酯偶联反应,考察了反应温度、反应时间、原料配比和催化剂用量等因素对乙醇酸甲酯和甲氧基乙酸甲酯生成量的影响,最佳反应条件为: 反应温度150~160 ℃,反应时间4 h,n(甲醛):n(甲酸甲酯)=05,在此条件下得到最大的乙醇酸甲酯和甲氧基乙酸甲酯的生成量,总生成量达到2134 mmol·(g-cat)-1。与其他催化剂的性能进行对比发现,氨基磺酸对催化甲醛和甲酸甲酯偶联反应显示出较好的催化性能。 相似文献
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HarmP. Dijkstra Niek Ronde GerardP.M. vanKlink Dieter Vogt Gerard vanKoten 《Advanced Synthesis \u0026amp; Catalysis》2003,345(3):364-369
A shape‐persistent nanosize dodecakis(NCN‐PdII‐aqua) complex ( 4b ) was applied as a homogeneous catalyst in the double Michael reaction between methyl vinyl ketone and ethyl α‐cyanoacetate under continuous reaction conditions in a nanofiltration membrane reactor. Due to its macromolecular dimensions, the catalyst is retained in the reactor (R=99.5% determined by ICP‐AAS) during catalysis. In addition, the catalyst was found to be stable under the continuous reaction conditions as a constant activity was obtained at prolonged reaction times (26 h, 65 exchanged reactor volumes). The turnover number of the catalyst was thus increased by a factor greater than 40 from 80 (batch) up to >3000 mol/mol Pd. Further development of this technology will allow an increase of the number of (industrial) catalytic processes in which homogeneous catalysts are applied. 相似文献
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在连续搅拌和分水条件下,研究了复合硫酸盐(Fe2(SO4)3-K2SO4)催化乙酸与正丁醇的反应。通过正交实验考查了催化剂用量、反应物配比、反应时间等因素对反应的影响。结果表明,其最优条件是:固定乙酸用量0.10mol,催化剂用量1.50g,醇酸物质的量比1.8∶1,反应时间2h,乙酸正丁酯的酯化率可达98.4%;另外,该催化剂具有制备方便,催化活性好,环境污染小等优点。 相似文献
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Egidio Viola Alessandro BlasiVito Valerio Ivan GuidiFrancesco Zimbardi Giacobbe BraccioGirolamo Giordano 《Catalysis Today》2012,179(1):185-190
Three solid catalysts have been tested in the transesterification of fried oils: CaO, SrO, K3PO4. For CaO and SrO the different efficiency, between their use as powder or granules, has been examined. Another investigated aspect has been the catalytic activity at different catalyst loadings and recycles. At the end granules have been employed in a catalytic bed reactor, comparing results with batch systems. Results have shown that using catalyst as granule does not affect the yields after 3 h of reaction. The use of the catalytic bed reactor has given the possibility to perform the transesterification maintaining the catalyst separated from the reactants, without loss of efficiency; in fact the comparison between trials in batch reactor and in catalytic bed system has not shown differences in yields. After 3 h of reaction, at 65 °C, 5 wt% of catalyst, we have had the following FAME yields: 92% for CaO, 86% for SrO, 78% for K3PO4. The transesterification reaction has shown a sensitive influence respect to K3PO4 granules amount used; in fact the yield has reached the 85% using 10 wt% of catalyst. The reutilization of the catalyst, without regeneration, has shown a loss of efficiency of about 10-20% in decreasing yield. 相似文献
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采用自制的负载钛催化体系[TiCl4/MgCl2-AlEt3],合成了聚1-丁烯与少量丙烯的釜内合金。考察了反应温度、反应时间、催化剂加入量、丙烯与1-丁烯共聚时间等肘催化活性和合金等规度的影响。从而确定了该材料的最佳生产条件。实验结果表明Ti/Bt值约为2.2×10^-5,Al/Ti为200左右时,催化剂的催化活性相对较高。升高温度和延长反应时间同样可以提高催化活性及增大合金中的丙烯单元含量。同时还对合金进行了结构表征。 相似文献
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Raquel P. Rocha Diogo F. M. Santos Olívia Salomé M. P. Soares Adrián M. T. Silva Manuel Fernando R. Pereira José L. Figueiredo 《Topics in Catalysis》2018,61(18-19):1957-1966
This work shows a promising N-doped carbon catalyst for the oxidation of oxalic acid by catalytic wet oxidation, which is able to compete with the traditional noble metal and metal oxide catalysts used in the process. After preliminary studies conducted in batch mode, the catalytic performance of the metal-free carbon nanotubes, both in powder form and supported on a macrostructured carrier (a cordierite monolith), was evaluated under continuous operating conditions. The ability of the N-functionalities to promote activation and chemisorption of oxygen led not only to fast oxalic acid mineralization under batch mode (5 min of reaction to reach full mineralization), but also to good performance under continuous operation (more than 90% conversion of oxalic acid in the steady state, using the powder and around 55% using the catalyst immobilized on a honeycomb cordierite monolith). 相似文献
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保护与脱保护是医药中间体等精细化工领域中较为常见的一种有机合成策略。常用的保护基主要有苄基与苄氧羰基,通常可利用催化加氢法将其脱除。采用高压加氢间歇釜工艺存在气液传质效率低,操作安全性差,氢解效率低等问题。采用连续微反应加氢技术进行非均相催化加氢脱保护,可以利用其较高的气液传质效率和平推流特性实现高选择性脱保护,并显著缩短反应时间。本文阐述了连续微反应加氢技术在脱保护反应中的优点及其在药物中间体合成中的实际应用,并介绍了催化剂与溶剂对脱保护反应的影响。最后对连续微反应加氢技术在脱保护中的应用进行了展望。 相似文献
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The realuminated H-mordenite catalysts (HM1-4) treated with different concentrations of NaOH and NaAlO2 aqueous solutions were prepared, and characterized by inductively coupled plasma (ICP), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR) and temperature-programmed desorption of ammonia, They are of lower Si/Al ratio and higher acid amount while keeping a high relative crystallinity. Their catalytic performances were evaluated with the liquid-phase tert-butylation of toluene with tert-butyl alcohol in a 100 ml stainless steel batch reactor equipped with a stirrer. HM2 zeolite catalyst, obtained by treating HM in 0.1 mol•L-1 NaOH followed by 0.05 mol•L-1 NaAlO2 aqueous solution, shows a higher catalytic activity because of its highest acid amount. For HM2 catalyst the influences of reaction conditions on catalytic performance were investigated. The conversion of toluene is 50.3% and the selectivity of p-tert-butyltoluene is 74.7% at a temperature of 180°C, 2 of molar ratio of tert-butyl alcohol to toluene, 4h of reaction time and 0.2 of M(catalyst)/M(toluene). 相似文献
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乳酸乙酯具有无毒、溶解性好、不易挥发、有果香气味等特点,是极具开发价值和应用前景的"绿色溶剂"。由于乳酸乙酯的特性,国内外学者渐渐致力于开发更高效更环保的制备方法。连续流化催化精馏是利用乳酸和乙醇酯化、粉末状大孔强酸性交换树脂作为催化剂,随反应物流动的连续催化精馏方式,是一种更优的高效而环保的乳酸乙酯生产方式。首次利用连续流化催化精馏制备乳酸乙酯,并旨在研究连续流化催化精馏与间歇精馏制备乳酸乙酯的对比来突出前者的优势,对连续流化催化精馏的产物进行精馏提纯,得到更高纯度的乳酸乙酯,为连续流化催化精馏制备乳酸乙酯的优势提供了可靠的理论依据,并在食品工业等高纯度要求的工业中的运用起到了推进作用。 相似文献