Solution polymerization processes with reduced energy usage

Abstract

An improved solution polymerization process wherein energy consumption is reduced comprising: i) injecting ethylene, solvent, catalyst, α-olefins and hydrogen into at least one reactor to produce a polyethylene in a single liquid phase solution; ii) deactivating the single liquid phase solution; iii) passing the deactivated solution into a vapor/liquid separator forming a bottom stream of polyethylene rich solvent and a gaseous overhead stream; iv) passing not more than 40% of the gaseous overhead stream to distillation; v) condensing the remainder of the gaseous overhead stream to form a recycle stream, while generating low pressure steam; vi) passing the recycle stream through a means for oligomer removal; vii) passing the recycle stream through a lights separator; viii) passing the recycle stream through a purification step; ix) collecting the recycle stream in a recycle drum, passing the recycle stream through a pump and injecting a high pressure recycle stream into said reactors.