Investigation of liquid distribution in gas–solid fluidized beds for fluid cokers

Thermal cracking processes convert larger molecules into smaller, more valuable products, without a catalyst, allowing for transforming residual oils or waste plastics into useful compounds. Fluid coking, a thermal cracking process utilizing a fluidized bed of hot particles, processes approximately 1 million barrels of residual oil daily. This study aims to understand the formation and breakage of wet agglomerates in fluidized beds, which are known to impact the efficiency of thermal cracking by promoting coke formation and fouling. A model is proposed to predict wet agglomerate formation, drying, and breakage. Experiments in a scaled-down cold model of the reactor provided data to validate the model. The study investigated the effects of spray nozzle penetration and the addition of a baffle on agglomerate behaviour. Results indicate that increased nozzle penetration reduces wet agglomerate formation, and adding a baffle increases agglomerate drying time and promotes breakage, reducing the amount of liquid reaching the reactor outlet. The combined approach of optimizing nozzle penetration and adding a baffle significantly improves fluid coker operation by minimizing the detrimental impact of wet agglomerates.