| With the objective of developing a sulfur-producing flue gas desulfurization (SP-FGD) process, effects of O2 and H2O on carbothermal reduction of SO2 by oil sand fluid coke were studied by experiments and thermodynamic analysis. It was observed that the addition of O2 and H2O enhanced SO2 conversion, which was attributed to the reducing gases, CO and H2. Adding O2 and/or H 2O may increase or decrease sulfur yield depending on the availability of SO2. Thermodynamic analysis showed that C/O ratio was a key parameter in controlling equilibrium products of C-O-S and C-O-S-H systems. Results of thermodynamic analysis suggested that gas-solid reactions were slow enough to allow a gas phase equilibrium. Shrinking Core Model (SCM) analysis showed that gas-solid reactions were rate-limiting at 700°C. SEM analysis confirmed the existence of an active layer. Sulfur was found to accumulate in the porous layer. H2O addition had a positive effect on sulfur accumulation. |
