Verfahren zur Gewinnung von aromatischen Kohlenwasserstoffen aus aromatenreichen OElen mit einem hohen Gehalt an ungesaettigten Verbindungen

1,261,977. Recovering aromatics. RUTGERSWERKE A.G. 15 Dec., 1969 [19 Dec., 1968], No. 61047/69. Heading C5E. Aromatic hydrocarbons are recovered from oils and residues rich in aromatics and also containing unsaturated compounds by subjecting the oil or residue to (1) heat treatment at elevated pressure, and then (2) evaporation by pressure decrease. The evaporated vapours are fractionated into appropriate aromatic fractions. The heat treatment is suitably at 300-500‹ C. for 10-60 minutes at 4-30 atmospheres pressure, and polymers formed from unsaturated compounds are quickly removed from the distillation apparatus with the sump product. In Example 1, an aromatic-rich residual oil from benzene pyrolysis to ethylene is heated under 4-10 atmospheres pressure for 45 minutes to a final temperature of 380‹ C., and then after pressure decrease is fractionated to give 4% light oil, 17% naphthalene oil, 21% alkyl naphthalene oil, 15% anthracene oil and 42% pitch. The further recovery of naphthalene, anthracene and phenanthrene is referred to, and the yields and purities of the products are compared with those from a similar fractionation without heat pretreatment.