Paraffin alkylation using zeolite catalysts in a slurry reactor: Chemical engineering principles to extend catalyst lifetime

The alkylation of isobutane with 2-butene is carried out using a zeolitic catalyst in a well stirred slurry reactor. Whereas application of Bred bed technology using a solid acid alkylation catalyst has in the past led to catalyst lifetimes in the range of minutes, in this work we report catalyst lifetimes of 5-200 hours using a slurry reactor operated at high olefin conversion. From the experimental and modelling work we show thar the key elements to extend catalyst lifetime appear to be (i) a zeolite (e.g. Beta) with high activity/stability, and high acid site density (low Si/Al ratio) and (ii) a low olefin concentration throughout the reactor, which is achieved by intensive reactor mixing, low to moderate olefin space velocity and a high paraffin to olefin feed ratio.