UPGRADING OF HEAVY OILS BY CATALYTIC HYDROCRACKING - A BASIC REVIEW

As we approach the era of limited crude oil supplies, catalytic hydroc racking of heavy oils is and will continue to be the center of attenti on for many researchers into the 21st century. The process involves hu ndreds of simultaneous reactions taking place. Hydrocracking is a firs t-order reaction with the kinetic data following a Langmuir-Hinshellwo od approach. Hydrocracking products are more paraffinic and less aroma tic than the feedstock. Fixed bed trickle reactors and backmixed ebula ting bed reactors, usually in series, are widely used in commercial up grading processes. The selection of a suitable catalyst depends on dif ferent factors such as the catalyst activity, acidity, selectivity, li fe, poisons, and pore diffusional limitations. The feed and product qu alities are major elements in the catalyst selection process. Pore dif fusion in the hydrocracking catalyst can greatly effect the reaction r ate. A formulation for the optimum catalyst pore size in heavy petrole ums processing is necessary to achieve high conversion levels.