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991.
Lu-Lu Wang Yang Zhang Fan Zhang Ruijiang Feng 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(18):2770-2776
Morpholine basic ionic liquid was synthesized with N-methyl morpholine, N-butyl bromide, and KOH by two-step method and was used to catalyze the transesterification of soybean oil with methanol to biodiesel. The structure of the catalyst were examined by 1H nuclear magnetic resonance. The effects of the molar ratio of methanol to oil, reaction temperature, and amount of catalyst on the biodiesel yield were investigated. Optimized biodiesel yield of 94.5% was achieved with catalyst amount of 3.0 wt%, and methanol to soybean oil molar ratio of 14:1 at reaction temperature of 60 °C for 6 h. The catalyst has maintained sustained activity after being employed to six cycles. The prepared biodiesel component was analyzed by gas chromatography-mass spectrometry (GC-MS) and the results showed that the biodiesel comprised of hexadecanoic acid methyl ester, 10, 13-octadecadienoic acid methyl ester, 9-octadecenoic acid methyl ester, and octadecanoic acid methyl ester, illustrating that fatty acids of soybean oil were converted completely. 相似文献
992.
Ayhan Demirbas 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(13):1890-1897
Transesterifications of grain of corn oil samples in KOH catalytic and in supercritical methanol were studied without using any catalyst. Biodiesel, an alternative biodegradable diesel fuel, is derived from triglycerides by transesterification with methanol and ethanol. The transesterification reaction is affected by the molar ratio of glycerides to alcohol, catalysts, reaction temperature, reaction time and free fatty acids and water content of oils or fats. It was observed that increasing the reaction temperature, especially to supercritical temperatures, had a favorable influence on methyl ester (biodiesel) conversion. The molar ratio of methanol to corn germ oil is also one of the most important variables affecting the yield of methyl esters. Higher molar ratios result in greater ester production in a shorter time. In the transesterification, free fatty acids and water always produce negative effects, since the presence of free fatty acids and water causes soap formation, consumes catalysts, and reduces catalyst effectiveness, all of which result in a low conversion. 相似文献
993.
Theethawat Singhasiri 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(19):2799-2808
The optimum conditions for biodiesel production by the transesterification of waste oil form the pork grilling process in the food factory in Udon Thani, Thailand, using NaOH and KOH as catalysts, has been investigated. A Box–Behnken Design (BBD) followed by a Response Surface Methodology (RSM) with 30 runs was used to assess the significance of three factors: the methanol to oil molar ratio, the amount of NaOH and KOH used, and the reaction time required to achieve the optimum percent fatty acid methyl ester (%FAME). The measured %FAME following transesterification using NaOH as a catalyst was an optimum 95.6% with a methanol to oil molar ratio of 12.2:1, a NaOH percentage mass fraction of 0.49% and a reaction time of 63 min. Using KOH as a catalyst, the %FAME was an optimum 93.0% with a methanol to oil molar ratio of 12:1, a KOH percentage mass fraction of 0.61% and a reaction time of 72 min. The coefficient of determination (R2) for regression equations were 98.55% and 93.99%, respectively. The probability value (P<0.05) demonstrated a very good significance for the regression model. The physicochemical properties of the biodiesel obtained from the waste oil met the ASTM 6751 biodiesel standard, illustrating that waste oil from the pork grilling process can be used as a raw material for biodiesel production by transesterification. 相似文献
994.
M. I. Senoymak 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(21):3139-3143
In this study, simultaneous transesterification and esterification of high acid value sunflower oil to fatty acid methyl esters was studied using Amberlyst 46 as a heterogeneous catalyst. The influence of reaction conditions such as molar ratio of methanol/oil, reaction time, and reaction temperature was investigated. The highest fatty acids methyl esters yield of 75.8% was obtained in presence of 6 wt% oleic acid content under reaction conditions of 20 wt% Amberlyst 46 catalyst amount, 6/1 methanol/oil molar ratio, reaction temperature of 130°C, and reaction time of 10 h. 相似文献
995.
探讨了酸浸-水解法分离提取丙烯腈废催化剂中铋、镍的工艺条件, 采用先酸浸后水解的方法, 利用硝酸铋的水解特性实现酸浸液中铋、镍的分离。研究结果表明, 在温度80 ℃、反应时间1.5 h、酸浓度3 mol/L、液固比5的最优酸浸条件下, 铋、镍浸出率分别为97.49%和81.81%; 在温度80 ℃、水解时间60 min、液液比8的最优水解条件下, 水解沉淀中铋提取率为89.57%, 水解液中镍提取率为94.86%; 铋、镍的总回收率均可达75%以上。水解沉淀的Bi/Ni值从原料的0.297增大到136.76, 水解液的Ni/Bi值从原料的3.37降低到0.007, 有效实现了铋与镍的分离。 相似文献
996.
本文主要探讨国内外铂族金属尾气净化催化剂最新的研发及应用进展,通过供需数据分析近年来铂族金属在汽车尾气净化催化剂领域的应用情况,通过国内外文献及专利技术揭示铂族金属在汽车尾气净化催化剂领域的研发动向,重点分析了近年来如何减少使用铂族金属和如何提高催化性能的相关技术,此外还涉及到载体、蜂窝结构、捕集器、过渡金属氧化物、柴油尾气净化、尾气催化剂回收和对生物圈的影响等方面的研发进展。从研发技术趋势来看,铂族金属在汽车尾气催化净化剂方面的应用与研发更多的倾向于资源的合理应用、高效利用、以及尽可能的降低成本等方面,采取的措施包括比较昂贵的铂被较廉价的钯等替代、强化对铂族金属的性能活化、改善气体扩散性、设计合理的结构(包括比表面、孔径和孔体积等)、粒径的合理设置等方面。未来铂在个体汽车尾气净化催化剂上的用量将进一步减少,其他金属(如过渡金属氧化物)在协同铂族金属尽可能发挥催化活性的同时减少铂族金属的用量,以求在成本和效率方面找到最佳平衡点。 相似文献
997.
采用等体积浸渍法制备了La2O3改性的Ni/SiO2催化剂,考察了La2O3的引入方法对Ni/SiO2催化剂催化间二硝基苯加氢制间苯二胺反应性能的影响,并采用XRD、TPR和XPS等表征技术对催化剂的物化性质进行了研究.结果表明,La2O3的添加顺序对Ni/SiO2催化剂的物化性质和加氢性能影响非常明显.当镧以先于镍浸渍方式引入时,将大大削弱载体与镍物种之间的相互作用,镍晶粒度变小,分散度增加,催化剂的活性显著提高,间二硝基苯转化率和间苯二胺收率分别达到97.1%和93.5%.在以镍和镧共浸方式制备的催化剂中,La2O3的存在也使Ni/SiO2催化剂的反应性能有所改善,但效果没有镧先于镍浸渍方式突出.当以先浸镍后浸镧的方式加入助剂时,催化剂中的镍晶粒增大,分散性变差,催化剂的活性大幅度下降. 相似文献
998.
999.
1000.
甲烷氧化偶联制乙烯工艺研究进展 总被引:3,自引:0,他引:3
甲烷氧化偶联(OCM)途径是通过一步法获取乙烯,是现有乙烯生产中最为简捷的工艺。本文综述了该工艺催化剂系统、反应机理、工艺开发研究的新进展,并探讨了OCM过程面临的关键问题有催化剂的选择、反应器和反应流程的设计和反应温度的控制。 相似文献