A process for recovering paraxylene from a substantially hydrocarbon
feedstock. The recovery comprises cooling the hydrocarbon feedstock in at
least one refrigerated crystallization stage that is indirectly
refrigerated by evaporating at least a portion of a substantially liquid
stream comprising ammonia. The crystallization stage may also be cooled
by an ethylene refrigerant, which has been cooled by heat exchange with a
substantially liquid stream comprising ammonia. The process further
comprises a series of cooling substeps. This invention is also directed
to an ammonia absorption refrigeration process powered by an enthalpy
source from or near a paraxylene recovery unit.