Kinetics of Zeolitic Solid Acid-Catalyzed Alkylation of Isobutane with 2-Butene

Currently, the alkylation of isobutane with 2-butene is industrially catalyzed using HF or H₂SO₄, which pose environmental and safety threats due to their toxicity and potential for leakage. An environmentally-benign approach to the alkylation of isobutane with 2-butene involves the use of a solid acid catalyst such as the Y-type zeolite. This catalyst, unfortunately, deactivates rapidly during alkylation. A kinetic analysis of the Y zeolite-catalyzed alkylation reaction has been performed to yield insight into how this deactivation may be minimized. The kinetic study is hindered by the rapid catalyst deactivation, requiring an extrapolation of time dependent data to zero-time. The effective reaction rates can be approximated as being first order in butene concentration for a fixed feed isobutane to olefin ratio. When the reactants and products are in the liquid phase, the reaction is severely diffusion-limited for all practical catalyst particle sizes at a temperature of 100°C.