Hydropyrolysis of Alberta coal and petroleum residue using calcium oxide catalyst and toluene additive

Abstract

Hydropyrolysis of a mixture of Alberta coal and Athabasca bitumen was carried out in a batch reactor using calcium oxide as an alternate catalyst and the results were compared with those of widely used iron oxide and well-known NiMo/Al 2O 3 catalysts. Most of the reactions were done at temperatures of 500–540°C, residence time of 1 min and hydrogen pressure of 3.4 MPa. Maximum distillable oil (below 523°C) yield of 55 wt% and pitch conversion of 62 wt% were obtained in the presence of CaO or Fe 2O 3 and these values were higher than those without catalyst, although NiMo/Al 2O 3 catalyst gave much higher oil yield and pitch conversion. Catalyst concentration (above 2 wt%) has no consequence upon the distribution of various product fractions. In another study, addition of 15% toluene to the feed in the absence of catalyst led to higher distillable oil yield (68 wt%) and pitch conversion (72 wt%) in the hydroconversion of coal and bitumen mixture. Increase in toluene concentration from 15 to 50 wt% had no positive effect on the product yields.