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醋酸纤维素固定化脂肪酶催化猪油合成单甘酯 总被引:6,自引:0,他引:6
以醋酸纤维素固定化猪胰脂肪酶催化猪油甘油解反应合成单甘酯,反应温度在猪油熔点附近(32℃),甘油与酶摩尔比为4:1,甘油含水量为4%,反应在20h达到平衡,可获得单甘酯的最高产率,为50.05%。 相似文献
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酶催化合成高纯度甘油中碳酸单酯 总被引:3,自引:0,他引:3
研究了无溶剂体系中脂肪酶LRI催化合成甘油中碳酸单酯(MG)。得到适宜的反应条件为:反应温度57℃,n(酸)∶n(甘油)=1∶1 1,加酶量100U/g(酸),甘油初始含水量w(H2O)=12%,封闭物系反应4h转敞开物系反应6h。产物中甘油中碳酸单酯质量分数w(MG)=42 20%。将n(酸)∶n(甘油)降低至1∶9,反应时间缩短至4h,粗产物经脱甘油和脱酸处理,可获得高纯度甘油中碳酸单酯。纯化后产品中基本不含游离酸及甘油,其中甘油中碳酸单酯质量分数w(MG)=73 65%。过量加入的甘油全部可以回收利用,其平衡转化率降低不超过2%。 相似文献
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以γ-Al2O3为载体,通过等体积浸渍法制备了负载型KI/γ-Al2O3催化剂,并通过二氧化碳、环氧丙烷和甘油合成甘油碳酸酯反应评价其催化活性,结果发现,KI负载量为1.5 mmol/g时具有最高的活性和稳定性。催化剂使用4次后,其活性没有明显降低。同时考察了反应温度、反应时间、反应压力和反应物摩尔比对反应的影响。在最佳反应条件下(环氧丙烷为0.3 mol,甘油为0.1 mol,反应温度为130℃,反应时间为2 h,反应压力为5.0 MPa),甘油的转化率为58.5%,甘油碳酸酯的产率为54.6%。 相似文献
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Investigation on a green synthetic approach for glycerol carbonate: The reaction of glycerol with urea
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以甘油和尿素为原料,探讨了低甘油含量的甘油碳酸酯环境友好的合成工艺。考察了催化剂的结构、反应条件等因素对甘油转化率的影响,结果表明在390 ℃煅烧3 h的硫酸锌催化效果最好。采用甘油与尿素反应后再与碳酸酯反应的偶合反应方式,所得甘油碳酸酯中甘油的含量仅为0.6%,降低了合成成本。 相似文献
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以不同碱金属(铵)卤化物为催化剂,考察了其在二氧化碳与甘油合成甘油碳酸酯反应中的活性。采用环氧丙烷为溶剂及耦合剂,极大提高了反应的转化率。实验结果发现碘化物具有较好的催化活性。以碘化铯为催化剂,考察了反应温度、反应时间、反应压力、反应物摩尔比和催化剂用量对反应结果的影响。在最佳反应条件下(环氧丙烷0.3 mol,甘油0.1 mol,反应温度120℃,反应时间1.5 h,反应压力3.0 MPa,催化剂用量0.15 g),甘油的转化率为86.5%,甘油碳酸酯的产率为81.6%。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献