Science and technology of novel processes for deep desulfurization of oil refinery streams: A review

Oil refinery related catalysis, particularly hydrodesulfurization (HDS) processes, is viewed as a mature technology and it is often stated that break-throughs are not to be expected. Although this could be a justified compliment to those who developed this area, at the same time it could also stifle potential new ideas. The applicability and perspectives of various desulfurization technologies are evaluated taking into account the requirements of the produced fuels. The progress achieved during recent years in catalysis-based HDS technologies (synthesis of improved catalysts, advanced reactor design, combination of distillation and HDS) and in 'non-HDS' processes of sulfur removal (alkylation, extraction, precipitation, oxidation, and adsorption) is illustrated through a number of examples. The discussed technologies of sulfur removal from the refinery streams lead to a wealth of research topics. Only an integrated approach (catalyst selection, reactor design, process configuration) will lead to novel, efficient desulfurization processes producing fuels with zero sulfur emissions. (C) 2002 Elsevier Science Ltd. All rights reserved.