Synergistic Process for High Nitrogen Content Feedstocks Catalytic Cracking: A Case Study of Controlling the Reactions of Nitrogen Compounds in Situ

Abstract

There is currently a growing need to process heavier and tougher feedstocks with increased nitrogen content for fluid catalytic cracking (FCC) units. A coker gas oil with high nitrogen content was catalytically cracked in a pilot-scale riser FCC apparatus under different conditions based on different FCC processes. Then the nitrogen balance and the conversion of saturates, aromatics, resins, and asphaltenes (SARA) were calculated, and the acid amounts of coked catalysts were analyzed by the NH3-TPD method. The results show that in the synergistic process the adsorption of nitrogen-containing species on the catalyst was controlled and more acid sites were available, thus more nitrogen-free hydrocarbons, mainly the saturates, could be cracked, while the nitrogen compounds were enriched in the cracked heavy oil. Furthermore, the compositional and structural identification of nitrogen compounds in cracked heavy oils was carried out by electrospray ionization (ESI) Fourier transform ion cyclotron resonance mas...