THE CONVERSION OF BUTANES IN HZSM-5

The distribution of products from the conversion of iso- and normal butane on HZSM-5 has been determined from 300 to 550°C over a wide range of conversions. The results clearly indicate that the nature of the products changes significantly in altering both the temperature and conversion conditions. High temperatures and low conversions favor low molecular weight products expected from a protolytic or radical attack on the butane. Reverse conditions favor C3 and higher hydrocarbons. These products are indicative of a classical carbenium ion mechanism. As conditions were changed the transition in mechanism was indicated by the amount of methane produced. For the first time H2 was detected as a primary product in the conversion of normal butane indicating that a tertiary C-H bond is not required for its production. © 1991.