2-08　Changes in the Sulfur Forms of Subbituminous Coals During Oxidation With Peroxides

Abstract

To prepare ultra-low sulfur coal, we have challenged chemical desulfurization of subbituminous coals using two peroxides, hydrogen peroxide and peracetic acid. In the presence of hydrogen peroxide, oxidation was promoted only at 60°C, accompanied by significant carbon loss. On the other hand, treatment with peracetic acid promoted the oxidation of thiophene with low carbon loss. By combining pre-oxidation with peracetic acid treatment and pyrolysis at 400°C, 74% of total sulfur and 72% of thiophene could be removed while recovering approximately 90% of total carbon as char.