No.72 石炭熱処理時におけるホウ素の放出に及ぼす前処理と添加剤の影響(灰・微量金属(3))

抄録

Boron is one of the most toxic and high volatile elements present in coal. As part of a series of studies carried out on coal cleaning to prevent environmental problems and to promote efficient coal utilization processes, the removal of boron by leaching with water and acetic acid has been investigated. The effects of the addition of ash components, that is, SiO_2, Al_2O_3 and CaO in the control of boron release during pyrolysis and gasification were investigated. Here, 20-60% of boron in coal was removed by leaching the coal with water and acetic acid. Boron leached by water and acetic acid was related to volatiles released from coal in pryrolysis below 1173K. The addition of ash components such as SiO_2 and Al_2O_3 was found to be effective in suppressing the release of boron during pyrolysis at temperatures below and above 1173K, respectively. The addition of CaO to coal was effective in suppressing the release of boron during gasification at 1173K.