Entrained-Flow Gasification of Oil Sand Coke with Coal: Assessment of Operating Variables and Blending Ratio via Response Surface Methodology

Abstract

Co-gasification of oil sand fluid coke with sub-bituminous coal was performed in an entrained-flow gasifier. The underlying objective of this work was to assess the combined effects of the operating variables (i.e., temperature and oxygen and steam concentrations) and coal/coke blending ratio in an entrained-flow gasification process, where the focus was to quantify the relationships between the response variables and vital operating factors. With a view to the shortcomings of the classical “one-factor-at-a-time” method in identification of the effect of experimental factors and their interactions, a statistical design of the experiment based on response surface methodology (RSM) was used. The response variables used in this work were H2, CO, H2/CO ratio, gasification efficiency, and carbon conversion. Experiments were conducted over a temperature range of 1000–1400 °C, using steam and oxygen to carbon weight ratios of 0.9–4.3 and 0–0.4, respectively, equivalent to 15–50 vol % steam and 0–3 vol % oxygen in N2 carrier gas. All of the response variables were successfully fitted to either a two-factor interaction or quadratic model. Using RSM, the effects of individual operating factors and their interactions were categorically determined, which were not otherwise possible by the classical design of experiment methodology. Using the resultant response variable correlations, H2 production was optimized as a function of the temperature, steam and oxygen concentration, and different blending ratios. The full potentiality of Canadian oil sand coke for entrained-flow gasification was successfully investigated via RSM. The results of this work, however, are only applicable to entrained-flow gasification systems.