Synergism in acetic acid/methanol reactions over ZSM-5 zeolites

Carboxylic acids are readily converted to aromatic hydrocarbons over ZSM-5 zeolites (1). The initial step of the reaction sequence involves oxygen elimination by decarboxylation, decarbonylation and/or dehydration. The residual hydrocarbon moiety is then aromatized, we believe, via classical carbenium ion pathways ( 2 ). The reaction causes rapid catalyst deactivation, which can be alleviated by adding methanol to the feed (3). The synergistic effect of methanol on acetic acid aromatization is the subject of this study.