Relation between sulfurization behavior and mercury vapor capture performance of iron oxide in coal derived fuel gas

摘要

Previously we have reported that H_2S reacts with iron oxide to form FeSx, which captures elemental Hg vapor (Hg~0) as HgS. In this work, we studied the relation between the rate of Hg~0 removal and the rate of sulfidation of iron oxide using a laboratory-scale fixed-bed reactor for the Hg~0 removal and thermo-gravimetric analysis (TGA) for the sulfidation of iron oxides in a temperature range of 60 to 100 deg C. Supported and unsupported iron oxides pre-treated (dried and calcined) at various temperatures were utilized. The relationship between sulfidation and Hg~0 removal is not yet clear. The presence of CO in the feed gas suppressed the weight gain of iron oxide, however the Hg~0 removal capacity was unaffected by the presence of CO. In the case of Fe_2O_3-110 (dried at 110 deg C), generation of COS was confirmed during the removal of Hg~0.