摘要 |
<p>A continuous process for recycling hydrogen for reuse in making blends of olefin copolymers of high and low molecular weights which comprises copolymerizing ethylene with at least one higher olefin monomer in a solvent in separate reactors in the presence of a coordination catalyst, at least one, but not all, of said reactors containing hydrogen in an amount sufficient to produce low molecular weight copolymer. The resulting solutions of high and low molecular weight copolymers are mixed, unreacted monomers and hydrogen are flashed from the mixture, and the copolymer blend is isolated from the unflashed residue. The flashed gaseous unreacted monomers and hydrogen are circulated together through a staged absorption column under superatmospheric pressure and simultaneously solvent is passed through said column in order to absorb monomer in the solvent and thus separate unabsorbable hydrogen gas from the monomers for recycle to a polymerization reactor in the system for making low molecular weight copolymer component.</p> |