(99d) Upgrading of Athabasca Oilsands Bitumen by Low Temperature Natural Zeolite Cracking

Synthesized or acidified minerals, particularly clays, have been found to effectively break heavy petroleum resources such as gas oil. However, the application of natural zeolites (NZs) as cracking catalysts and/or adsorbents for oilsands bitumen is a novel approach. Canadian oilsands bitumen, the majority of which is in Alberta, represents approximately 15% of the proven global crude oil resources, and is an extremely valuable source of energy for North America. However, the density, viscosity, contaminant content, and residue fraction of the bitumen recovered from these sands are much higher than those of conventional crude oil due to the presence of large molecules such as asphaltenes. Our studies show that acidified NZs such as clinoptilolite from Saint Clouds, New Mexico and Ca-chabazite from Bowie, Arizona can be developed as very effective reagents for cracking of oilsands bitumen. Low-cost NZs, particularly clinoptilolites, are present globally in large natural deposits. NZ-cracked oilsands bitumen products are highly recoverable (up to ~84%) using light hydrocarbons such as pentane, which indicates substantial conversion of heavier fractions to lighter components. Boiling point distribution and viscosity measurements of the products demonstrate that NZ catalyzed cracking results in much less viscous low boiling point products compared to those produced from pure thermal treatment, or analogous catalytic treatment using the standard petroleum cracking agent, zeolite Y. An additional benefit of using NZs for oilsands bitumen processing is that they function as strong adsorbents to facilitate removal of contaminant heteroatoms such as vanadium (up to ~80%) and nitrogen (up to ~38%). Based on our findings we envision a NZ-based alternative to traditional primary upgrading processes for bitumen, that operates at lower temperatures, improves the transportability of bitumen, and simultaneously removes contaminants, reducing processing steps. This study investigates the efficacy of NZ catalyzed cracking for conversion of heavy fractions of Athabasca oilsands bitumen. Boiling point distribution, average molecular weight and viscosity of the catalytically cracked samples are compared with baseline values for raw and thermally cracked bitumen samples.