采用沉淀-空气氧化法制备煤担载型高分散铁基催化剂(Fe/C),并引入第二金属镍得到Fe-Ni/C催化剂。采用XRD,HRTEM,SEM-mapping等分析了催化剂的晶相组成、形貌特征及活性金属在煤上的分散状态,高压釜实验对比了两种催化剂在煤重油加氢共...采用沉淀-空气氧化法制备煤担载型高分散铁基催化剂(Fe/C),并引入第二金属镍得到Fe-Ni/C催化剂。采用XRD,HRTEM,SEM-mapping等分析了催化剂的晶相组成、形貌特征及活性金属在煤上的分散状态,高压釜实验对比了两种催化剂在煤重油加氢共炼反应中的催化活性,分析了反应后固体残渣的微观形貌。结果表明,Fe/C催化剂的主要活性成分为α-FeOOH和γ-FeOOH,引入镍后则生成了混晶相Fe 0.67 Ni 0.33 OOH,Fe、Ni活性金属在载体煤表面分布均匀。两种催化剂作用下的干基无灰煤转化率均高于97%,但Fe-Ni/C催化剂作用下产物分散性更好。固体残渣的SEM照片对比表明Fe/C催化剂体系中生成了较多球形焦炭,而Fe-Ni/C催化剂较强的加氢作用能有效抑制共炼体系中裂解中间产物的缩合生焦,在得到较高煤转化率的同时能有效降低固体残渣的粒径。展开更多
采用单因素和正交实验,考察了沙生灌木沙柳在苯酚和四氢萘混合供氢溶剂中液化的反应时间、反应温度、催化剂用量、苯酚用量和四氢萘用量等工艺参数对液化产物残渣率的影响,得到沙柳在混合溶剂中的最优化工艺是:反应温度120℃,反应时间2...采用单因素和正交实验,考察了沙生灌木沙柳在苯酚和四氢萘混合供氢溶剂中液化的反应时间、反应温度、催化剂用量、苯酚用量和四氢萘用量等工艺参数对液化产物残渣率的影响,得到沙柳在混合溶剂中的最优化工艺是:反应温度120℃,反应时间2 h,催化剂(98%的浓硫酸)1 m L,苯酚15 g,四氢萘5 m L,此条件下的液化率可达97.51%。各因素影响次序为:反应温度>反应时间>催化剂用量>四氢萘用量>苯酚用量。不同反应时间下的沙柳液化液体产物红外谱图表明,在反应时间30 min前产生新峰,在30 min后谱图特征相同;固体残渣红外谱图表明,沙柳组分中的木质素和半纤维素首先发生了降解,木质素结构单元中的酚醚键断裂先于木质素芳香核之间的碳碳键的断裂,且液化反应的最终固体残渣中含有吡喃糖环和缔合羟基;液化固体残渣热重分析表明,产物中的有机质随液化的进行逐步减少,且热分解反应分为2个阶段,表现出明显的阶段性。展开更多
In this research,a solid 1%Li/Ca-La mixed oxide catalyst was prepared using co-precipitation method followed by wet impregnation.The prepared catalyst was used in the transesterification reaction of canola oil and met...In this research,a solid 1%Li/Ca-La mixed oxide catalyst was prepared using co-precipitation method followed by wet impregnation.The prepared catalyst was used in the transesterification reaction of canola oil and methanol for biodiesel synthesis.The effects of calcination and reaction temperatures were investigated on the activity of the catalyst.In addition,rate of the reaction was studied through a kinetic model for which parameters were determined.Surface properties and structure of the catalyst were characterized through the powder X-ray diffraction(XRD),thermogravimetry/derivative thermogravimetry(TG/DTG),and Fourier transform infrared spectroscopy analysis.All these emphasized that the performance of the catalyst corresponded to the generation of the active sites and their thermal activation.展开更多
文摘采用沉淀-空气氧化法制备煤担载型高分散铁基催化剂(Fe/C),并引入第二金属镍得到Fe-Ni/C催化剂。采用XRD,HRTEM,SEM-mapping等分析了催化剂的晶相组成、形貌特征及活性金属在煤上的分散状态,高压釜实验对比了两种催化剂在煤重油加氢共炼反应中的催化活性,分析了反应后固体残渣的微观形貌。结果表明,Fe/C催化剂的主要活性成分为α-FeOOH和γ-FeOOH,引入镍后则生成了混晶相Fe 0.67 Ni 0.33 OOH,Fe、Ni活性金属在载体煤表面分布均匀。两种催化剂作用下的干基无灰煤转化率均高于97%,但Fe-Ni/C催化剂作用下产物分散性更好。固体残渣的SEM照片对比表明Fe/C催化剂体系中生成了较多球形焦炭,而Fe-Ni/C催化剂较强的加氢作用能有效抑制共炼体系中裂解中间产物的缩合生焦,在得到较高煤转化率的同时能有效降低固体残渣的粒径。
文摘采用单因素和正交实验,考察了沙生灌木沙柳在苯酚和四氢萘混合供氢溶剂中液化的反应时间、反应温度、催化剂用量、苯酚用量和四氢萘用量等工艺参数对液化产物残渣率的影响,得到沙柳在混合溶剂中的最优化工艺是:反应温度120℃,反应时间2 h,催化剂(98%的浓硫酸)1 m L,苯酚15 g,四氢萘5 m L,此条件下的液化率可达97.51%。各因素影响次序为:反应温度>反应时间>催化剂用量>四氢萘用量>苯酚用量。不同反应时间下的沙柳液化液体产物红外谱图表明,在反应时间30 min前产生新峰,在30 min后谱图特征相同;固体残渣红外谱图表明,沙柳组分中的木质素和半纤维素首先发生了降解,木质素结构单元中的酚醚键断裂先于木质素芳香核之间的碳碳键的断裂,且液化反应的最终固体残渣中含有吡喃糖环和缔合羟基;液化固体残渣热重分析表明,产物中的有机质随液化的进行逐步减少,且热分解反应分为2个阶段,表现出明显的阶段性。
基金supported by the Iran National Science Foundation(INSF)
文摘In this research,a solid 1%Li/Ca-La mixed oxide catalyst was prepared using co-precipitation method followed by wet impregnation.The prepared catalyst was used in the transesterification reaction of canola oil and methanol for biodiesel synthesis.The effects of calcination and reaction temperatures were investigated on the activity of the catalyst.In addition,rate of the reaction was studied through a kinetic model for which parameters were determined.Surface properties and structure of the catalyst were characterized through the powder X-ray diffraction(XRD),thermogravimetry/derivative thermogravimetry(TG/DTG),and Fourier transform infrared spectroscopy analysis.All these emphasized that the performance of the catalyst corresponded to the generation of the active sites and their thermal activation.
