Grant: Alliance Grants

A prevalent problem associated with the seamless operation of hydrotreating catalytic reactors in the refinery is the issues of fouling and pressure drop growth. These limit the scheduled run lengths of catalytic reactor operation and in severe cases warrant premature shutdowns. The occurrence of submicron metal particles in bitumen-derived gas oils at extremely low concentrations (<100 ppm), can accumulate over extended feed processing times and culminate in significant pressure drop and consequently premature shutdown. Similarly, conjugated olefins can also lead to catalyst deactivation, and fouling in hydrotreater reactors. To gain insight into fouling and the pressure drop profiles associated with hydrotreating of bitumen-derived oils, and to develop appropriate mitigation strategies, a systematic investigation on the fouling mechanism of various foulants present in bitumen-derived gas oils is required. In this proposed work, catalyst fouling, and pressure drop issues due to foulants such as metal fines and conjugated olefins will be studied under industrial conditions in collaboration with Syncrude Canada Ltd. A packed bed hydrotreating reactor that simulates an industrial hydrotreater and actual industrial feeds will be used in studying the issues of foulants. The effects of foulants in the heavy and light gas oils on hydrodesulfurisation and hydrodenitrogenation are also examined. Besides, strategies to minimize foulants deposition on the catalyst bed and reactor body will be investigated by altering the surface acidity of a hydrotreating catalyst, the catalyst pellet morphology, and reactor operating conditions. Additionally, interactive effects of catalyst acidity and process conditions will be investigated along with mathematical modeling of foulants deposition. The proposed outcomes of this project will offer solutions to our industrial partner to mitigate localized zonal fouling, and thus to achieve the desired operating cycle between catalyst regenerations in their Mildred Lake upgrader that produces 350,000 bbl/day of sweet crude oil (SCO) from bitumen oil. In addition, this research will enable other Canadian oil companies to improve the profit margin of SCO production while publishing the project findings.