The present invention relates to a process for producing steam using heat recovered from a polymerization reaction. In particular, the present invention relates to a process for producing steam using heat recovered from a polymerization reaction for producing polyolefin, comprising the steps of: thermally contacting said polymerization reaction with a cooling fluid such that the cooling fluid removes heat from said reaction, thermally contacting at least part of said cooling fluid with at least one absorption cycle thereby transferring heat from the cooling fluid to said absorption cycle, using said absorption cycle to produce steam from a condensate, wherein the cooling fluid is used as a hot source for heating at least one evaporator and at least one generator comprised in said at least one absorption cycle. The present invention also relates to a process for cooling a polymerization reaction using a process as described herein. Said invention also relates to a polyolefin producing unit.