Ganiyu Saheed A
Chemistry department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia.
Chem Asian J. 2021 Jun 1;16(11):1307-1323. doi: 10.1002/asia.202100185. Epub 2021 May 3.
It is undisputed that there is a paradigm shift in the global trend of crude oil towards being more sour and heavier than usual light sources. Consequently, the hydrotreating activity becomes a bottleneck with high content of S, N, metals and other impurities than expected. On the other hand, the price of petroleum products lately witnessed instability and fell to the lowest average price (<USD 20) in recent times. In the same vein, the regulation to control the emission of toxic compounds in the atmosphere become stricter as promulgated by various policymakers. In this sense, robust hydrotreating catalysts with characteristics efficient catalytic activity, selectivity and stability are highly desirable. Recently, different approaches have been used to improve and cushion the unprecedented effect emanated from economic, social and environmental challenges posed by heavy and sour crude sources, price instability of the refined products and regulation to lower the sulfur to minimum level or zero parts per millions (ppm). Importantly, the role of support in catalysis cannot be over emphasized, whilst the surface area and porosity, mechanical and thermal stability, dispersion of active metals, acidity/basicity have been greatly improved, the increased activity, stability and selectivity has been observed significantly. In this review, hybrid supports based on aluminosilicates (zeolitic types) and other notable supports from recent literatures were explored and discussed for Ni(Co)Mo(W) supported catalysts for hydrodesulfurization (HDS) activity of heavy organosulfur molecules. The emphasis on the hybrid supports' varied characteristics for HDS of organosulfur molecules, where there are necessities for fast diffusion of reactants and products, better dispersion of MoS crystallites, high surface area and pore volume, and increased acidity of the catalysts are greatly emphasized. Furthermore, the progress made so far on different HDS active phases viz. noble metals, metal phosphides, intermetallic silicides, carbides and iron-zinc are highlighted in this write-up, irrespective of the support composition in the supported catalysts formulations. The need for application of predictive tools, like machine learning (ML) in the design and development of HDS catalysts, and performance evaluation of HDS activity towards achieving better catalytic operation was briefly highlighted. Finally, the review will serve as a summary of scientific efforts in this regards and bridge a gap for the newcomers to investigate the topic in a better way through proper selection and efficient catalysts design.
全球原油趋势正发生范式转变，转向比以往常见轻质原油更酸、更重，这一点无可争议。因此，加氢处理活性成为一个瓶颈，因为硫、氮、金属和其他杂质的含量比预期高。另一方面，近期石油产品价格出现不稳定，降至近期最低平均价格（<20美元）。同样，各政策制定者颁布的控制大气中有毒化合物排放的法规变得更加严格。从这个意义上说，具有高效催化活性、选择性和稳定性等特性的强大加氢处理催化剂是非常需要的。最近，人们采用了不同方法来改善和缓解重质和酸性原油来源、成品油价格不稳定以及将硫含量降至最低水平或百万分之零（ppm）的法规所带来的前所未有的经济、社会和环境挑战影响。重要的是，载体在催化中的作用再怎么强调也不为过，虽然表面积和孔隙率、机械和热稳定性、活性金属的分散性、酸度/碱度都有了很大提高，但活性、稳定性和选择性也显著增加。在本综述中，探讨并讨论了基于硅铝酸盐（沸石类型）的混合载体以及近期文献中其他显著载体，用于负载镍（钴）钼（钨）的催化剂对重有机硫分子进行加氢脱硫（HDS）的活性。重点强调了混合载体对有机硫分子HDS的各种特性，其中反应物和产物快速扩散、MoS微晶更好分散、高表面积和孔体积以及催化剂酸度增加是必要的。此外，本文还强调了到目前为止在不同HDS活性相方面取得的进展，即贵金属、金属磷化物、金属间硅化物、碳化物和铁锌，而不考虑负载型催化剂配方中的载体组成。简要强调了在HDS催化剂的设计和开发中应用预测工具（如机器学习（ML））以及对HDS活性进行性能评估以实现更好催化操作的必要性。最后，本综述将作为这方面科学努力的总结，并为新手通过适当选择和高效催化剂设计更好地研究该主题填补空白。
