Abstract

The physicochemical properties of a waste industrial Со-Мо/Al₂O₃ catalyst for the deep hydrotreating of diesel fuel are studied. IR spectroscopy, thermogravimetry (TG), differential thermal analysis (DTA), and scanning electron microscopy (SEM) are used to establish that the catalyst surface is uniformly coated with a coke film. This soft coke is mostly a mixture of saturated hydrocarbons with a low degree of branching in their structure. The coke is oxidized at temperatures of 190–375°C (soft coke) and 375–525°C (hard coke); its quantitative removal is achieved by means of oxidative calcination in air for 3 h at 550°C. X-ray diffraction, scanning electron microscopy, low-temperature nitrogen adsorption, and chemical analysis are used to show that the waste catalyst undergoes considerable structural transformation with a 7.7% drop in the Mo content and the accumulation of Fe, Ha, and V impurities. As a result of sintering, its specific surface area and total pore volume are reduced by 31.5 and 28.4%, respectively. The obtained data are needed to develop a scheme for its recycling.

中文翻译：

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研究工业废Со-Мо/ Al 2 O 3催化剂对柴油加氢精制的特性

摘要

废工业Со-Мо/ Al ₂ O ₃的理化特性研究了柴油加氢精制催化剂。红外光谱，热重分析（TG），差热分析（​​DTA）和扫描电子显微镜（SEM）用于确定催化剂表面均匀覆盖有焦炭膜。这种软焦炭主要是饱和烃的混合物，其结构中的支化程度较低。焦炭在190–375°C（软焦）和375–525°C（硬焦）的温度下被氧化；通过在空气中于550°C氧化煅烧3小时可实现定量去除。X射线衍射，扫描电子显微镜，低温氮吸附和化学分析表明，废催化剂经历了相当大的结构转变，其中Mo含量下降了7.7％，Fe，Ha和V杂质的积累。烧结的结果是，其比表面积和总孔体积分别减少了31.5％和28.4％。需要获得的数据来制定其回收计划。