Effect of O2 on SO2 Reduction with CO or H2 over SnO2−ZrO2 Catalyst

Abstract

To investigate the effect of the O2 content on the direct sulfur recovery process (DSRP) combined with the hot gas desulfurization (HGD) process with the unreacted O2 emitted from the regeneration process, either CO or H2 was used as a reducing agent for the reduction of SO2 over SnO2−ZrO2 catalyst with a Sn/Zr molar ratio of 2/1. Then, the reaction conditions, including temperature, CO (or H2)/SO2 molar ratio, and space velocity, were optimized to maximize the sulfur yield in the presence and absence of 1 vol % O2. The temperature, CO (or H2)/SO2 molar ratio, and space velocity were varied in the ranges of 300−600 °C, 1.0−4.0, and 1000−30000 h−1, respectively. In SO2 reduction using CO with 1 vol % O2, the temperature, CO/SO2 molar ratio, and space velocity for the maximum sulfur yield were 600 °C, 3.5, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 85% and 77%, respectively. In SO2 reduction using H2 with 1 vol % O2, the temperature, H2/SO2 molar ratio, and spa...