Methanol-mediated extraction for coal liquid (2) — the effect of phase separation caused by methanol on naphtha fraction derived from Wyoming coal

Abstract

Methanol-mediated extraction, which the authors have developed, was conducted on the naphtha fraction derived from Wyoming coal. When 0.4–1.5 times methanol was added to the feed oil, the mixture formed a two-phase system. The extraction yield of phenol ranged from 86.3% to 99.2% and that of oil fraction ranged from 65.5% to 91.0%. This indicates that the extraction of phenol by methanol only was ineffective. Two extraction methods, extraction with water regardless of the presence of phase separation (method A), and that after separating the formed phase (method B), were conducted to compare the effect of phase separation on the extraction yield and selectivity of phenol. They had no significant differences between two extraction methods. From these results, we concluded that method A is applicable even if phase separation may occur by adding methanol.