Regulating catalyst morphology to boost the stability of Ni–Mo/Al_(2)O_(3) catalyst for ebullated-bed residue hydrotreating

Hydrotreating of vacuum residue by ebullated-bed shows tremendous significance due to more stringent environmental regulations and growing demand for lighter fuels. However, enhancing the catalyst stability still remains as a challenging task. Herein, two Ni–Mo/Al_(2)O_(3) catalysts with distinct morphologies(i.e., spherical and cylindrical) were first designed, and the morphology effect on deactivation was systematically elucidated employing multi-characterizations, such as HRTEM with EDX mapping, electron microprobe analysis, FT-IR, TGA and Raman. It is found that spherical catalyst exhibits superior hydrotreating stability over 1600 h. The carbonaceous deposits on spherical catalyst with less graphite structure are lighter, and the coke weight is also smaller. In addition, the metal deposits uniformly distribute in the spherical catalyst, which is better than the concentrated distribution near the pore mouth for the cylindrical catalyst. Furthermore, the intrinsic reason for the differences was analyzed by the bed expansion experiment. Higher bed expansion rate together with the better mass transfer ability leads to the enhanced performance. This work sheds new light on the design of more efficient industrial hydrotreating catalyst based on morphology effect.

沸腾床蜡油氮化物分析及加氢裂化工艺研究

以常规减压蜡油和沸腾床蜡油为原料,利用高分辨质谱对比了两种原料中氮化物的分子结构及变化规律,在常规减压蜡油中掺炼不同比例的沸腾床蜡油为混合油,并以此为原料进行加氢裂化反应,考察了工艺条件对产物分布及产品性质的影响。实验结果表明,与常规减压蜡油相比,沸腾床蜡油的密度更大,馏程范围较窄,具有更多的大分子烃类物质,组分中的氮化物主要为五环非碱性氮化物,在加氢裂化工艺中脱除难度大。在相同的加氢裂化催化剂体系下,加工混兑沸腾床蜡油的混合油与单独加工常规减压蜡油在产物分布上没有太大变化,产品性质根据混兑比例不同存在差异。

柴油加氢装置改造工艺设计探讨

论述了国内柴油成品油市场的需求放缓使柴油加氢装置急需增产航煤等产品多样化改造的必要性。以多因素的方法为某2.6 Mt/a柴油加氢装置提出了两种改造方案:蜡油加氢处理或中压加氢裂化,并进行了综合分析和优化比选。系统地介绍了该套2.6 Mt/a柴油加氢装置改造为1.85 Mt/a蜡油加氢处理时,装置各部分的改造工艺及设计要点,并着重探讨了分馏部分的工艺流程方案。