共查询到19条相似文献,搜索用时 93 毫秒
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采用浸渍法制备了固体碱催化剂硅酸钠/二氧化锆(Na2SiO3/ZrO2),并用其催化大豆油制备生物柴油。考察了催化剂焙烧温度、催化剂焙烧时间、硅与锆物质的量比、醇油物质的量比和催化剂用量等因素对生物柴油产率的影响。X射线衍射(XRD)表征结果显示,引入硅酸钠可调变催化剂中二氧化锆的晶相组成。对催化剂的性能测试表明,当催化剂焙烧温度为600 ℃、催化剂焙烧时间为3 h、硅与锆物质的量比为4、醇油物质的量比为7、催化剂用量(催化剂占大豆油的质量)为3%时,生物柴油的产率最高为92.5%。 相似文献
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采用浸渍法,将KOH负载在新型载体氧化锆上,通过高温煅烧得到了固体碱催化剂。探讨了制备条件对催化剂催化酯交换反应活性的影响,获得了催化剂的最佳制备条件,以大豆油和甲醇为原料研究并优化了催化酯交换反应制备生物柴油的工艺条件。结果表明,固体碱催化剂KOH/ZrO2的最佳制备条件为:KOH负载量20%,煅烧温度600℃,煅烧时间2 h。固体碱催化剂催化酯交换反应的最优反应条件为:醇油比9:1,反应温度75℃,反应时间3 h,催化剂用量4.0%。各因素对产率影响的大小为:醇油摩尔比 > 反应温度 > 反应时间 > 催化剂用量。 相似文献
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用浸渍法制备了KF/Al2O3负载催化剂,并将负载催化剂用于菜籽油与甲醇酯交换合成生物柴油的研究。考查了不同负载量、不同煅烧温度对催化剂活性的影响,肯定了KF/Al2O3催化剂存在产生强碱位,并利用GC-MS对生物柴油进行了检测。结果表明,生物柴油的主要成分为油酸甲酯,其含量达到50%以上。 相似文献
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棉籽油酯交换制备生物柴油固体碱催化过程研究 总被引:23,自引:0,他引:23
生物柴油(脂肪酸甲酯)可以由棉籽油与甲醇在碱催化剂的作用下通过酯交换反应制得.本实验通过高温煅烧氢氧化镁、碳酸钙及镁-铝水滑石得到了相应的固体碱催化剂MgO、CaO及MgO-Al2O3,并对催化剂活性进行评价.实验结果表明,CaO及MgO-Al2O3具有较高的酯交换反应活性:在230℃,醇油摩尔比12:1及催化剂用量为棉籽油2%(wt)的条件下,反应3 h后,甲酯的收率达到90%以上.CO2-TPD实验结果表明,CaO 及MgO-Al2O3具有较强和较多的碱性位,而催化剂的活性与碱强度及碱性位数量直接相关. 相似文献
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Carla Cristina C.M. Silva Mariana M.V.M. Souza Donato A.G. Aranda 《Fuel Processing Technology》2010,91(2):205-4157
Esters of fatty acids, derived from vegetable oils or animal fats, and known as biodiesel, are a promising alternative diesel fuel regarding the limited resources of fossil fuels and the environmental concerns. In this work, methanolysis of soybean oil was investigated using Mg-Al hydrotalcites as heterogeneous catalyst, evaluating the effect of Mg/Al ratio on the basicity and catalytic activity for biodiesel production. The catalysts were prepared with Al/(Mg + Al) molar ratios of 0.20, 0.25 and 0.33, and characterized by X-ray diffraction (XRD), textural analysis (BET method) and temperature-programmed desorption of CO2 (CO2-TPD). When the reaction was carried out at 230 °C with a methanol:soybean oil molar ratio of 13:1, a reaction time of 1 h and a catalyst loading of 5 wt.%, the oil conversion was 90% for the sample with Al/(Mg + Al) ratio of 0.33. This sample was the only one to show basic sites of medium strength. We also investigated the reuse of this catalyst, the effect of calcination temperature and made a comparison between refined and acidic oil. 相似文献
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Karel Komers Jaroslav Machek Radek Stloukal 《European Journal of Lipid Science and Technology》2001,103(6):359-362
The composition of the solutions of solid KOH in methanol has been measured by means of determinating the content of water in the equilibrium mixture. The dependence of the equilibrium reaction extent ζ1 and the concentration equilibrium constant Kc on the ratio of the initial amounts of methanol and KOH containing 0.164 and 16.27 wt‐% of water are determined and theoretically described. The concentration of CH3O¯ ions can be calculated with these results. This value is very important for the course of the alkaline catalyzed methanolysis of rapeseed oil to biodiesel, because the methoxide ions are the true catalyst of such a transesterification. 相似文献
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Karel Komers Radek Stloukal Jaroslav Machek Frantiek Skopal Alena Komersov 《European Journal of Lipid Science and Technology》1998,100(11):507-512
The enumeration of the analytical methods used in the production of biodiesel from rapeseed oil and methanol catalyzed by KOH and published till 1997 is given. Some of our original methods for individual or simultaneous determination of the main components in the reaction mixture are described. All these methods can be also used to analyse the non-equilibrium complex and heterogeneous mixture. 相似文献
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制备了含铝5%的负载型AI/SiO2多相催化剂,以其为催化剂,采用改进型无溶剂法工艺合成环氧大豆油。优化工艺条件为:反应时间4h,大豆油:甲酸(85%):H202(30%)=1:0.2:0.92(体积比).催化剂用量为2.0g,反应温度40。60℃,所得产品色泽浅,环氧值高(〉6.5%),产品质量优于国家标准,催化剂可重复使用,再生容易,无腐蚀,对环境友好。 相似文献