Isoparaffin-olefin alkylation process

A process for isoparaffin-olefin alkylation which comprises the steps of:

• (a) introducing into a reactor fluidizable solid acid zeolite catalyst particles whose largest dimension ranges from 20-2000 microns;
• (b) introducing into the reactor a feed of liquid reactants comprising isoparaffins and olefins at a first isoparaffin to olefin molar ratio of less than 100;
• (c) forming a slurry of said catalyst particles and said feed and circulating said slurry within the reactor such that the isoparaffin reacts with the olefin to produce alkylate product and the isoparaffin to olefin molar ratio of the slurry increases to a value in excess of said first ratio;
• (d) removing a first portion of said slurry which comprises said alkylate product, olefin and isoparaffin, from the reactor and directly recycling said first portion at a rate of at least 5 volume percent of said total reactor volume per minute to mix with the feed and provide an isoparaffin to olefin molar ratio in the reactor of at least 500;
• (e) removing a second portion of the slurry from the reactor and passing said second portion to a separating means to separate alkylate product from the solid catalyst particles;
• and
• (f) regenerating the separated catalyst particles and recycling the regenerated catalyst particles to the reactor.