Conversion of [ 14C]methanol and propane mixtures with H-ZSM-5

Abstract

A mixture of methanol and propanol (2:1 mole ratio) has been converted to C2-C4 gases and gasoline range hydrocarbons with a low (60:1) and high (800:1) Si/Al H-ZSM-5 type zeolite catalyst. In one case the methanol was labeled with 14C and the propanol was unlabeled; in the other instance the labeling was reversed so that propanol was labeled. The data are consistent with the major fraction of the Cn + 1+ hydrocarbons (n = 3 or greater) being derived from the alkylation of the Cn+ hydrocarbons with a C1 species derived from methanol. An alkene oligomerization/cracking reaction pathway is superimposed upon the alkylation reaction pathway and this redistributes the 14C isotope to produce C4, C5 and C7 carbon number groupings which have a relative activity corresponding to a near equilibration of the carbon isotopes.