GB860673A - Improvements in or relating to the catalytic conversion of alkyl thiophenes - Google Patents

Abstract

Alkyl thiophenes are passed at elevated temperature in contact with a catalyst produced by impregnation of alumina with hydrofluoric acid in aqueous solution, the alumina being in catalytically active form or in a form capable, after impregnation, of conversion to a catalytically active form and being so converted. The alkyl thiophenes may be (a) dealkylated to form lower alkyl thiophenes and/or unsubstituted thiophene, (b) simultaneously dealkylated and alkylated or (c) converted to aromatic hydrocarbons depending on the reaction conditions. The reaction is suitably carried out in the presence of hydrogen. The process may be used for the treatment of fractions containing a mixture of hydrocarbons and alkyl thiophenes such as the mixture of aromatic hydrocarbons and organic sulphur compounds obtained by the solvent extraction of distillation fractions of petroleum origin. In the example, 2-methylthiophene, 3-methylthiophene, 2,5-dimethylthiophene and 2,3,5-trimethylthiophene are contacted with a catalyst consisting of alumina impregnated with hydrofluoric acid to give in each case mixtures of benzene, toluene, thiophene, methylthiophenes and dimethyl thiophenes.