Reaction kinetics and particle agglomeration studies in support of heavy oil and bio-oil upgrading

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Diminishing conventional crude oil reserves have led to increased production from unconventional resources, such as bitumen from the Canadian oil sands and fuels converted from biomass. In Canada, an estimated 168 billion barrels are recoverable from the oil sands using available technologies, while increasing biofuel research throughout the world reflects environmental concerns due to greenhouse gas emissions, advantages of energy diversification, and declining conventional fossil fuel reserves. Bio-oils produced from biomass conversion processes have the following inferior properties compared to conventional fuels: higher oxygen content, reduced heating value, greater viscosity, and chemical instability. Both bitumen and bio-oils require upgrading processes to produce valuable fuels and chemicals similar to those obtained from conventional crude oils. The shift to heavy oil and residue upgrading makes it pertinent to advance the understanding of particle agglomeration in fluidized bed reactors. Interparticle liquid bridging is known to occur in Fluid Cokers and potentially in hydroprocessors, where both reactors are currently used for heavy oil and residue upgrading. Particle agglomeration reduces heat and mass transfer, augments reactor fouling, and can lead to defluidization. By carefully selecting the continuous and dispersed liquid phases, the impacts of relevant phase physical properties (e.g., liquid viscosities, particle size, dispersed liquid concentration, particle wettability) on agglomeration severity and the overall fluid dynamics in a slurry bubble column configurations will be investigated. These experimental studies will provide predictive capabilities and mitigation strategies for agglomerate formation in upgrading reactors. A parallel and complementary objective is to study the hydrodeoxygenation kinetics of bio-oils produced via pyrolysis. The previous bio-oil upgrading pathway occurs at elevated temperatures (300 to 500°C), high hydrogen pressures (5 to 20 MPa), and typically in the presence of a catalyst, consequently sharing similarities with hydroprocessing. Fixed bed upgrading systems have been primarily studied, where commonly reported issues are catalyst poisoning, coke formation, and reactor plugging. A fluidized configuration will be evaluated to address these concerns due to the improved mixing characteristics and the potential for semi-continuous catalyst addition/removal. Reaction kinetics will be investigated using a unique fluidized and induction heated microreactor to identify the optimal reaction conditions (i.e., temperature, hydrogen pressure, catalyst size and composition). Promising kinetic data for bio-oil hydrodeoxygenation in a fluidized configuration could lead to the scale-up of an innovative upgrading reactor, a necessary processing step for biofuel production in future biorefineries.