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对羟基苯甲酸丁酯的合成及催化剂的选择 总被引:2,自引:0,他引:2
对以正丁醇和对羟基苯甲酸为原料合成对羟基苯甲酸丁酯的催化剂及反应条件进行了研究。硫酸氢钠是合成对羟基苯甲酸丁酯的一个新型、良好的催化剂。最佳反应条件为:醇酸摩尔比为4:1,催化剂用量为对羟基苯甲酸质量的5%,反应时间为4h。上述条件下对羟基苯甲酸丁酯的收率为91%。 相似文献
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超强酸La~(3+)-SO_4~(2-)TiO_2合成对羟基苯甲酸丁酯 总被引:3,自引:0,他引:3
以稀土固体超强酸La3 + SO42 - TiO2 为催化剂,以对羟基苯甲酸与正丁醇为原料催化合成对羟基苯甲酸丁酯,研究了原料量比、催化剂用量和反应时间诸因素对产品收率的影响。试验结果表明:La3 + SO42 - TiO2 是合成对羟基苯甲酸丁酯的良好催化剂,在n(丁醇) n(对羟基苯甲酸) =4 0 ,催化剂的用量为对羟基苯甲酸质量的3 5 % ,反应时间4 0h ,反应温度12 0℃~130℃,对羟基苯甲酸丁酯的收率达到92 7%。 相似文献
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采用溶胶-液相法制备了H3PW12O40/TiO2复合催化剂,用FT-IR分析方法对催化剂进行了结构表征。以对羟基苯甲酸和正丁醇为原料合成了对羟基苯甲酸丁酯,考察了反应物配比、催化剂用量、反应时间及催化剂的重复使用性能对产品收率的影响。实验结果表明,合成对羟基苯甲酸丁酯的较优反应条件为:对羟基苯甲酸0.1 mol,n(对羟基苯甲酸)∶n(正丁醇)=1.0∶5.0(摩尔比),催化剂的用量为1.2 g,反应时间4.0 h。上述条件下,对羟基苯甲酸丁酯的收率可达85.0%以上。 相似文献
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对利用油酸氧化制取壬二酸进行了较为系统的探索。在 50℃ ,pH =2 .5,适宜催化剂条件下 ,壬二酸的收率提高到 60 %,且反应条件温和 ,具备工业生产的价值。 相似文献
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Sheshan Bhimrao Meshram Omkar S Kushwaha Palle Ravinder Reddy Gaurav Bhattacharjee Rajnish Kumar 《中国化学工程学报》2019,27(9):2148-2156
Gas hydrate reserves are potential source of clean energy having low molecular weight hydrocarbons trapped in water cages. In this work, we report how organic compounds of different chain lengths and hydrophilicities when used in small concentration may modify hydrate growth and either act as hydrate inhibitors or promoters. Hydrate promoters foster the hydrate growth kinetics and are used in novel applications such as methane storage as solidified natural gas, desalination of sea water and gas separation. On the other hand, gas hydrate inhibitors are used in oil and gas pipelines to alter the rate at which gas hydrate nucleates and grows. Inhibitors such as methanol and ethanol which form strong hydrogen bond with water have been traditionally used as hydrate inhibitors. However, due to relatively high volatility a significant portion of these inhibitors ends up in gas stream and brings further complexity to the safe transportation of natural gas. In this study, organic additives such as oxalic acid, succinic acid and L-aspartic acid (all three) having—COOH group(s) with aspartic acid having an additional—NH2 group, are investigated for gas hydrate promotion/inhibition behavior. These compounds are polar in nature and thus have significant solubility in liquid water; the presence of weak acidic and water loving (carboxylic/amine groups) moieties makes these organic acids an excellent candidate for further study. This study would pave ways to identify a novel(read better) promoter/inhibitor for gas hydrate formation. Suitable thermodynamic conditions were generated in a stirred tank reactor coupled with cooling system; comparison of gas hydrate formation kinetics with and without additives were carried out to identify the effect of these acids on the formation and growth of hydrates. The possible mechanisms by which these additives inhibit or promote the hydrate growth are also discussed. 相似文献
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Varying concentrations of free docosa-4,7,10,13,16-pentaenoic acid or its CoA ester were incubated with a given variable concentration
of 1-14C-linoleate or 1-14C-α-linolenate as either the free fatty acid or the CoA ester, microsomal enzymes, and the appropriate cofactors for fatty
acid desaturation. The results obtained were compared to the effects of docosa-4,7,10,13,16,19-hexaenoyl CoA when incubated
in a similar manner in the presence of the labeled substrates. Both feedback and crossed inhibition effects were observed;
these inhibition effects may play a role in the regulation of polyunsaturated fatty acid biosynthesis. 相似文献
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Conclusions Experimental data are given which indicate that the cationic initiation of caprolactam, which is initiated by acid esters of H3PO4 with lower alcohols, is analogous to the reaction in the presence of hydrogen halide acids, and not to that in the presence of acidic polyethylene glycol phosphates.The catalytic activity of the low-molecular-weight phosphates decreases with increase in the size of the alcoholic radical.Translated from Khimicheskie Volokna, No. 2, pp. 27–29, March–April, 1984. 相似文献