Hydrotreating the Whiterocks oil sand bitumen and bitumen-derived liquid (Abstract only)

Conversion of Utah's Uinta Basin bitumens to liquid fuels requires molecular weight reduction of the parent material as well as removal of heteroatoms. Heteroatom reduction of bitumen obtained through solvent extraction of Whiterocks oil sand was investigated. A comparison of the relative processability of Whiterocks bitumen and the bitumen-derived liquid produced by pyrolysis of Whiterocks oil sand in a fluidized bed reactor was assessed. The process variables investigated included temperature (616-712 K) , weight hourly space velocity (0.29-1.38 h"1), and pressure (11.0-17.1 MPa). Significant conversion of bitumen-derived liquid heteroatoms was achieved. However, native bitumen heteroatom removal was limited under similar sets of processing conditions. The refractory nature of the heteroatoms in the native bitumen stems from the higher molecular weight distribution of the uncracked bitumen. Heteroatoms in the native bitumen are unreactive until the moieties that contain them are cracked to reactive lower molecular weight species. Thus, conversion of bitumens to liquid fuels must stress molecular weight reduction prior to heteroatom removal.