The present invention relates to a process and apparatus for the
production of light olefins comprising olefins having from 2 to 3 carbon
atoms per molecule from a feedstock containing heavier olefins. An
intermediate cut from a fractionation column is used as olefinic feed to
an olefin cracking process preferably after undergoing selective
hydrogenation of diolefins. In one embodiment, a liquid side draw from a
fractionation column is selectively hydrogenated and then returned to the
fractionation column from which a vapor side draw containing olefins is
cracked in the olefin cracking reactor.