ハイパーコール製造における有機溶媒抽出条件の検討

Abstract

Thermal extractions with several polar and non-polar solvents were carried out in order to produce “HyperCoal” (ashless coal) in a high yield. Effects of extraction time and temperature on the extraction yield (HyperCoal yield), and suitable parameters to select coals for HyperCoal production were investigated.We previously reported (Yoshida et al., 2001a) that softening temperature of raw coals is an excellent index for coal giving high extraction yields with Light Cycle Oil (LCO), which is a non-polar and cost-effective solvent. However, in relation to the coal softening, the maximum fluidity did not simply correspond to the extraction yield at 360°C, suggesting that such a high extraction yield can be strongly related to the structural changes occurred at its softening temperature, where thermal relaxation of non-covalent interactions coal actively occurs.Thermal extraction yields with non-polar solvent such as LCO were high for coals around 76 ∼ 81wt% (daf) carbon contents, and the ash content in LCO HyperCoal was 0.03%. In the case of using polar solvent, the extraction yield increased, on the other hand, the amounts of the remained solvent and mineral matters in HyperCoal became larger, compared to the case of non-polar solvent.