Hydrocracking – Industrial Processes

Abstract

Hydrocracking can be used to accomplish several different processing objectives, treating feeds ranging from residual oils to naphtha and producing lighter products with lower sulfur and nitrogen content. The choice of process configuration depends on the feed and processing objective. Once‐through, single‐stage, two‐stage, separate hydrotreater and reverse‐flow process flowsheets are described. In all cases the reactor selection must address the issues of fluid distribution, heat removal, pressure drop, catalyst deactivation, and bed plugging. Common approaches to gas separation and product recovery are also described. Commercially licensed processes including H‐Oil, IFP hydrocracking, Isocracking, LC‐Fining, moderate pressure hydrocracking, Shell hydrocracking, and Unicracking are described with reference to the generic flowsheets. Relevant engineering issues such as fluid distribution, quench zone design, mercaptan recombination, heavy polynuclear aromatics control, heat integration, metallurgy considerations, process safety, and hydrogen management are discussed in detail. Approximate correlations for estimation of process utility requirements and capital investment are given.