An FCC process for obtaining light olefins comprises contacting a
hydrocarbon feed stream with blended catalyst comprising regenerated
catalyst and coked catalyst. The catalyst has a composition including a
first component and a second component. The second component comprises a
zeolite with no greater than medium pore size wherein the zeolite
comprises at least 1 wt-% of the catalyst composition. The contacting
occurs in a riser to crack hydrocarbons in the feed stream and obtain a
cracked stream containing hydrocarbon products including light olefins
and coked catalyst. The cracked stream is passed out of an end of the
riser such that the hydrocarbon feed stream is in contact with the
blended catalyst in the riser for less than or equal to 2 seconds on
average. The hydrocarbon products including light olefins are separated
from the coked catalyst. The first portion of the coked catalyst is
passed to a regeneration zone in which coke is combusted from the
catalyst to produce a regenerated catalyst. A second portion of the coked
catalyst is blended with the regenerated catalyst and introduced to the
riser. The regenerated catalyst has substantially the same relative
proportions of the first component and the second component as the
blended catalyst that contact the hydrocarbon feed stream.