No.17 石炭の熱分解及びガス化におけるヒ素及びセレンの動的挙動(灰・微量元素(1))

抄録

Arsenic(As)and selenium(Se)in coal are classified into toxic and high volatile element groups during combustion and gasification. As part of a series of studies carried out on coal cleaning to prevent environmental problems and to promote efficient coal utilization processes, the release behaviors of As and Se during pyrolysis and gasification were investigated. As and Se in coal and char were classified into three groups by sequential leaching method with HCl, HNO_3 and H_2SO_4. In pyrolysis, the release extent of As gradually increased with the increase of temperature, while the release extent of Se drastically increased above 800°C. The release extents of Se and As for coals in pyrolysis below 1200°C were correlated with ash contents. A part of HCl and HNO_3 soluble As in raw coal changed into H_2SO_4 soluble, and HCl and HNO_3 soluble Se in coal released during pyrolysis.