Cyclone fouling in fluid cokers: model development and adsorption experiments

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The worldwide trend of light crude oil depletion due to increasing energy demands led to the viability and profitability of bitumen processing and upgrading. Global energy demand is expected to increase 48% by 2040. Although renewable energy sources are increasing, fossil fuels are anticipated to account for over 75% of the world's energy needs through 2040. Canada is a major source of liquid fossil fuels with 166 billion barrels of recoverable reserves in the oil sands. Fluid Coker reactors are used to upgrade bitumen into lighter products by injection onto a fluidized bed reactor of hot coke particles, required for the thermal cracking reactions. Fouling in the cyclones above the fluidized bed reduces the flow area in the gas outlet tubes, increasing the reactor and burner pressures. This pressure buildup requires a reduced feed rate due to the burner blower's maximum output, eventually leading to a shut-down. The main objective of the proposed research is to improve the unit reliability by proposing fouling mitigation strategies in the reactor cyclones using two research approaches. The first will develop a phenomenological model to predict cyclone fouling based on relevant fluid dynamic characteristics, vapour phase reactions, and vapour-liquid thermodynamic characteristics. The model will be used to predict the relative impacts of proposed mitigation strategies on areas of interest in the Fluid Coker reactors. The second approach will measure hydrocarbon vapour adsorption in a high temperature well-mixed batch system to determine the impact of coke surface characteristics. These measurements will establish the kinetics of hydrocarbon adsorption as well as the impact of molecular weight on preferential adsorption. The successful completion of this project will generate relevant experimental data and modeling methods to mitigate Fluid Coker cyclone fouling. Two MESc students will be trained during the project and will develop highly relevant skills to work in Canada's oil and energy industries. Lastly, when the process life cycle is considered, improved Fluid Coker energy efficiencies have a beneficial effect by reducing carbon dioxide emissions and economic loss.