Abstract
Hydrodenitrogenation (HDN) of heavy oil fractions is of interst and importance for upgrading the heavy oil because it is a means for removing basic heterocyclic nitrogen compounds which can poison acidic catalysts used in cracking and refining.The emerging synthetic fuels industry provides a second motivating factor for nitrogen removal: the need for minimizing NOx formation during the combustion of coal and shale oil liquids.HDN is accomplished by the use of conventional hydrodesulfurization technology with a slight-ly modified catalyst at higher temperatures and pressures and lower space velocities.In order to development for more effective processes, some work has been carried out with model compounds to gain information on key mechanistic steps and to find some leads towards cat-alyst improvements.The recent studies of HDN of carbazole and acridine suggest that, after the hydrogenation of aromatic rings, HDN of the hydrogenated heterocyclic ring is accelated.This supports the conclusion that the hydrogen consumption for HDN is larger than for hydrodesulfurization.
