The polymerization process comprises polymerizing an olefin monomer and a comonomer in the presence of a polymerization catalyst in a polymerization step conducted in a polymerization reactor in a solvent to produce a solution comprising a polymer of the olefin monomer and the comonomer.
The polymerization process comprises withdrawing an exhaust stream of the solution from the polymerization reactor in a withdrawing step.
The polymerization process comprises separating the exhaust stream to a first primary stream and a primary concentrated solution stream in a first primary separation step, wherein the first primary stream comprises hydrocarbons and polymer.
The polymerization process comprises separating the first primary stream to a second primary stream and a third primary stream in a second primary separation step, wherein the second primary stream comprises dissolved polymer and the third primary stream comprises majority of the hydrocarbons.
The polymerization process comprises cooling the third primary stream to a temperature of −80 to 20° C. in a primary cooling step to obtain a cooled third primary stream.
The polymerization process comprises separating the cooled third primary stream to a fourth primary stream and a fifth primary stream in a third primary separation step, wherein the fourth primary stream comprises hydrocarbons in vapour phase and the fifth primary stream comprises liquid hydrocarbons.
The polymerization process comprises returning the fourth primary stream and the fifth primary stream independently in a primary returning step to a location upstream of the polymerization reactor.