Developments in upgrading of bitumen by hydropyrolysis

Hydropyrolysis, a short residence time, moderate temperature process, has been under development at the University of Utah for more than a decade. Hydropyrolysis has been shown to produce 90+% liquid product yields from feedstocks containing more than 50% nonvolatile materials. The process results in extremely low coke yields. Detailed studies of the chemistry reveal that hydrogen is responsible for the low coke production through hydrogenation reactions, accelerated cracking and dealkylation reactions, and through kinetic inhibition of bimolecular reactions between aromatics. In the process regime studied, dealkylation reactions, those responsible for cracking of side chains and of ring opening of naphthenoaromatic compounds, are the most rapid. Hydrogen consumption is modest at low gas production levels. A hydrogen balance has been performed as it relates to hydrogenation and dehydrogenation reactions occurring. Results suggest that there may be a limit as to how short a residence time and high a temperature can be utilized and maintain high liquid and low gas yields. Preliminary considerations of a commercial sized plant reveal that costs are reasonable but that gas processing costs must be minimized to ensure profitability.