Anthracene separation from anthracene oil - by pref. two-step crystallisation with methanol diluent and solvent extn. with methyl-pyrrolidone

摘要

Anthracene is sepd. from coal tar-anthracene oil by (i) crystallisation with MeOH as diluent, followed by (II) solvent extn. of crude anthracene, pref. with N-Me pyrrolidone. Crystallisation can take place in 1 or 2 steps, by treating the anthracene oil, at 20-90 (40-70) deg.C, with 5-20 wt.%, w.r.t. anthracene oil, of MeOH and cooling for 1-5 (1-2) hrs. For solvent extn., the crystals are mixed with 50-200 wt.%, w.r.t. crude anthracene, of N-Me pyrrolidone, at 10-60 deg.C. The anthracene obtd. is at least 95 wt.% pure and can be processed to anthraquinone.