共查询到18条相似文献,搜索用时 156 毫秒
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醇酸树脂需用高温酯化,能耗大且树脂分子量分布宽,采用固体酸催化,可以降低酯化温度20 ̄40℃,并缩短酯化时间,本文对固体酸在不同多元醇的醇酸树脂品种中的活性,催化酯化工艺特点,分子量分布与非催化酯化工艺对比进行了研究与论述。 相似文献
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本文对以磷钨酸钙为催化剂的酯化反应进行研究。探讨了酯的产率与醇的碳原子数和空间构型的关系。研究表明该催化剂适用于碳原子为5个以上醇的酯化反应,催化活性强,酯的收率高。 相似文献
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将工业上常用的几种强酸性阳离子树脂在己二酸二甲酯合成反应中的催化活性和稳定性进行综合比较,筛选出了适合己二酸二甲酯制备用催化剂。研究了以D001型催化剂合成己二酸二甲酯的工艺。其较优工艺条件为:醇酸物质的量比5:1,催化剂用量8%,反应温度85~90℃,反应时间3.5h,反应酯化率可达到92%。 相似文献
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本文探讨了用无水氯化钙作催化剂合成 9—羟基芴— 9甲酸甲酯的条件。操作简便 ,反应温和无腐蚀 ,减少污染和产品纯化 相似文献
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脂肪酶固定化及催化酯化反应 总被引:11,自引:1,他引:11
本研究报道了利用吸附法和化学键合法将白地霉脂肪酶固定化于五种载体上,用吸附法固定化的脂肪酶保持了高的活性。在有机溶剂中,固定化酶催化了长链脂肪酸与醇的酯化反应,酯化率可达94%。固定化过程并未改变脂肪酶的选择性。固定化脂肪酶可重复使用。 相似文献
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氯化铝-无水氯化钙双催化剂法合成乙酸异戊酯 总被引:1,自引:0,他引:1
无水CaCl2和AlCl3·6H2O都是良好的酯化反应催化剂.Al3 是较强的路易斯酸,无水CaCl2是好的吸水、脱水剂,将二者协同应用于酯化反应中,不仅能有效提高酯化反应产率,而且还可以减少原料消耗. 相似文献
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A. Erdem-Şenatalar E. Erencek A. T. Erciyes 《Journal of the American Oil Chemists' Society》1995,72(8):891-894
The apparent orders of the Lewis acid-catalyzed esterification reactions between castor oil and oleic acid are known to change
with the catalyst used and with the reaction temperature. A mechanism is proposed in this study to explain the variations
(with temperature) in the apparent orders of the cobalt chloride-catalyzed esterification reaction between castor oil and
oleic acid. According to the proposed mechanism, an acid-catalyst intermediate forms in an initial, fast quasi-equilibrium
step, and this intermediate then reacts with the oil to yield the products and to regenerate the catalyst in the rate-determining
second step. A general rate expression, with an acid concentration term and a temperature-dependent constant in the denominator,
is derived from the proposed mechanism and is verified with data obtained at different temperatures. 相似文献
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溶胶-凝胶法负载离子液体[hnmp]HSO_4催化剂在酯化反应中的应用 总被引:1,自引:1,他引:0
由溶胶-凝胶法负载BrÖnsted酸性离子液体N-甲基吡咯烷酮硫酸氢盐([hnmp]HSO4),得到硅胶负载离子液体(SILC)。用SILC作为催化剂,研究了一系列醇酸的酯化反应,在没有带水剂存在下,最高酯收率可以达到69%,TOF可以达到1350 h-1。催化剂重复使用8次未见活性明显降低,具有较好的重复使用性。分析结果表明,离子液体已较好地负载于硅胶上,其中约7%的离子液体与硅胶结合紧密牢固。负载离子液体催化剂的用量明显比纯离子液体催化剂的用量少,有效降低了催化剂成本,有望在固定床反应器中使用。 相似文献
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本文报道了以三氯化铁为催化剂,由乙酰乙酸乙酯与乙二醇反应合成苹果酯的研究,同时研究了催化剂用量、原料配比和反应时间对酯化反应的影响。结果表明:当原料配比为1:1.3,催化剂用量为1.0g,反应时间3.5h时,产物收率可达96%。 相似文献
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Ran Su Xiaosheng Wang Ranjia Li Changchun Yu Hongjun Zhou Aihua Liu Jianli Liu 《American Institute of Chemical Engineers》2023,69(7):e18065
Mo-based catalysts are widely used for the SO2 hydrogenation process. However, the detailed reaction mechanism is still unclear and some details should be further supplemented. In this article, the SO2 hydrogenation processes over the Mo-based catalyst were systematically studied. Several technologies including temperature-programmed experiments, isotope-tracing experiment, fourier transform infrared spectroscopy, and switching experiment were adopted to investigate the reaction steps. The results indicated that during the SO2 hydrogenation process there were three reaction processes containing six steps: First SO2 would adsorb on the active sites, which could start at relatively low temperature. Then the adsorbed SO2 would react with H2 and gradually form elemental sulfur that could be strongly anchored with S atoms of the MoS2 surface. Afterward, the sulfur further reacted with H2 to generate H2S. Alongside with the consumption of S atoms, the sulfur would be reduced and the active sites was recovered, thus starting the next reaction cycle. 相似文献