Characterization and Evaluation of Heavy Gasoline from the RFCC Unit of Zinder Refining Company (SORAZ)

Abstract

Cracked heavy gasoline from SORAZ contains hydrocarbons and trace pollutants that release toxic emissions upon combustion. Ensuring its physicochemical quality is essential for environmental safety and energy performance. This document presents a summary of the study on the characterization and evaluation of gasoline produced by the RFCC unit (fluidized bed catalytic cracking process) using atmospheric residue as feedstock. Gasoline produced from the cracking of atmospheric residue is one of the most important products or light hydrocarbons from both an economic and energy perspective. It generally has a lower molecular weight than that of diesel and atmospheric residue. However, it must possess physicochemical properties (notably octane number) that meet national and international specifications. However, it may contain impurities such as metals, water, sulfur, mercaptan sulfur, etc. It was therefore necessary to ensure the quality of this gasoline and to plan for appropriate additional treatments to be performed at the FCC unit’s outlet. Thus, the main objective of this study was to evaluate the quality of this gasoline through its characterization. This study is particularly relevant in the context of environmental and energy issues. It provided us with a comprehensive understanding of the fuel’s susceptibility to atmospheric pollutants such as SOx, COx, and NOx during combustion, and also allowed us to predict the severity of additional treatments required to reduce emissions of these pollutants, as well as to improve certain of its physicochemical properties, particularly the octane rating. The results of its characterization showed that the average density at 15°C was 730.809 kg/m³, the average mercaptan sulfur content was 9 ppm, the average sulfur content was 640 ppm, the average vapor pressure was 76.47 kPa, and the average octane number was 90.05. This study also showed that the gasoline sample had average contents of 21.8% (v/v), 39.4% (v/v), and 38.8% (v/v) for aromatics, olefins, and saturates, respectively. These results allowed us to conclude that this gasoline is of acceptable quality. However, it cannot be released for sale before undergoing additional treatments such as catalytic reforming to improve its octane number and hydrotreating to reduce its sulfur content in order to limit the production of air pollutants.