RECENT DEVELOPMENTS IN FIXED-BED CATALYTIC RESIDUE UPGRADING

Atmospheric or vacuum residue can be converted into valuable distillat es in fixed-bed hydroprocessing units using high reaction temperature, high hydrogen pressure acid low contact time. This paper discusses so me recent developments made to improve the desulfurization level, deni trogenation level, the run length and the conversion level of fixed-be d hydroprocessing units, both from the process and catalyst points of view. These improvements include the development of a multiple swing-r eactor system as well as of complex associations of guard-bed material s and catalysts with particle-size, activity, pore-size and shape grad ings. Synergy between fixed-bed operation and other conversion units h as been studied and revealed that fixed bed residue upgrading technolo gies will play a key role in future refinery schemes in order to estab lish new specifications on gasoline, diesel and fuel. (C) 1998 Elsevie r Science B.V. All rights reserved.