GB858649A - Transalkylation of aromatic hydrocarbons - Google Patents

Abstract

High molecular weight alkyl aromatic hydrocarbons are prepared by reacting in the liquid phase at 50-150 DEG C. in the presence of aluminium chloride and hydrogen chloride an alkylatable aromatic hydrocarbon, 0,05-1,5 mols of a secondary or tertiary alkyl benzene per mol of aromatic hydrocarbon and 0,05-5 mols of a straight chain paraffin per mol of aromatic hydrocarbon to obtain a high molecular weight alkyl aromatic hydrocarbon and a low molecular weight paraffin, the alkyl benzene having the formula ARR1 C-CHR2R3 where R is a methyl radical and R1, R2 and R3 are hydrogen, methyl or ethyl and the paraffin having the formula R4 CH2 R5 where R4 and R5 ar straight chain alkyl groups or R4 may be hydrogen, the total number of carbon atoms in R4 and R5 being 10-30. The aromatic hydrocarbon may be benzene, toluene, a xylene, ethylbenzene, cumene, naphthalene, alpha- or betamethylnaphthalene, diphenyl or aromatics in hydrocarbon fractions. The alkyl benzene is preferably tertiary butyl benzene but cumene, tertiary amyl benzene, 2-ethyl-2-phenylbutane, 2, 3-dimethyl-2-phenylbutane, and 2-methyl-2-phenylpentane can be used. Alternatively it may be formed in situ by adding to the reactants isobutylene, propene, 2-methylbutene-1, 2-ethylbutene-2, 2, 3-dimethylbutene-1, or -2 or 2-methylpentene-1. Suitable paraffins may be derived from waxes, pale oils, fuel oils or kerosene which may contain tertiary carbon atoms or normal hexadecane. Reaction times of 1-8 hours may be used and the low molecular weight paraffin is preferably removed as it is formed.