Hydrodenitrogenation Catalysis

Catalytic hydrodenitrogenation (HDN) is a process in which organonitrogen compounds are removed from hydrocarbon feedstocks to produce processible, stable, and environmentally acceptable liquid fuels and lube base stocks. When coupled with hydrodesul-furization (HDS), this process is commonly referred to as “hydro-treating,” which is an integral part of oil refining. While it has long been recognized that HDN is more difficult than HDS, the former has historically been of little concern to the refiners because of the comparatively small quantities of nitrogen compounds present in conventional petroleum stocks. This situation, however, will certainly change because of the growing need to process heavy and low-quality stocks, and the anticipated need to upgrade syncrudes, both of which are rich in highly refractory nitrogen compounds. At present, conventional HDS catalyst technology is adapted for HDN, despite the fact that it is not ideally suited for nitrogen removal. In recent years there has been considerable interest in the development of more effective HDN catalysts, as witnessed by the rapidly expanding patent literature in this area.