A process for producing a polymer composition comprising the steps (A) to (M) as recited herein, involving the polymerization, in a polymerization reactor of a first polymer, a first stream thereof being passed into a first separator wherein a first liquid phase comprising the polymer and a first vapor phase coexist; withdrawing a first vapor stream and a first concentrated solution stream comprising the polymer from the first separator, passing at least a part of the first vapor stream to a first fractionator; withdrawing a first overhead stream and a first bottom stream from the first fractionator; recovering at least a part of the first overhead stream as a first recycle stream and passing it to the polymerization reactor; passing the first concentrated solution stream from the first separator to a second separator, wherein a second liquid phase comprising the polymer and a second vapor phase coexist; passing at least a part of the second vapor stream to a second fractionator; withdrawing a second overhead stream and a second bottom stream from the second fractionator; recovering at least a part of the second overhead stream as a second recycle stream and passing it to the polymerization reactor; wherein the mass flow rate of the first recycle stream is at least 80% of the mass flow rate of the first vapor stream and the mass flow rate of the second recycle stream is at least 70% of the mass flow rate of the second vapor stream.

This invention relates to a process for forming polymer including: polymerizing a monomer dissolved in a solvent in the presence of a catalyst system under conditions to obtain a first effluent stream including a solution of the polymer and the solvent; heating the first effluent stream in at least one spiral heat exchanger to produce a second effluent stream, where the first effluent stream flows through the spiral heat exchanger in a cross-flow direction relative to spirals of the spiral heat exchanger and performing a separation on the second effluent stream to produce: a third effluent stream including polymer substantially free of the solvent; and a recycle stream including the solvent and unreacted monomer. Processes for devolatilizing a polymer stream are also provided herein.

The present invention relates to a solvent separation apparatus and a waste heat utilization method, and the solvent separation apparatus and the waste heat utilization method according to the present application can reduce the used amount of cooling water and the used amount of steam, in a process of separating a polymer and a solvent.

The present invention relates to a solvent separation apparatus and a waste heat utilization method, and the solvent separation apparatus and the waste heat utilization method according to the present application can reduce the used amount of cooling water and the used amount of steam, in a process of separating a polymer and a solvent.

A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer.

A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer.

A method of separating a polyisoolefin elastomer from non-polymeric components in an organic solvent involves ultrafiltration of a solution of the polyisoolefin elastomer and non-polymeric components in an organic solvent through a semipermeable membrane to substantially retain the polyisoolefin elastomer in a retentate and provide the non-polymeric components in a permeate. Advantageously, stabilizers for the polyisoolefin elastomer are retained in the retentate along with the polyisoolefin elastomer, permeate flux through the membrane is higher as concentration of the polyisoolefin elastomer in the solution increases up to a concentration limit, the separated polyisoolefin elastomer in the retentate has a molecular weight that can be substantially unchanged even when ultrafiltration is conducted at elevated temperature and the amount of polyisoolefin elastomer in the permeate is unmeasurable providing an oligomer-rich permeate uncontaminated by polyisoolefin elastomer.

A process for withdrawing polyolefins from a reactor includes: continuously withdrawing a liquid solution stream from a solution polymerization reactor and passing the liquid solution stream into a low pressure separator; withdrawing a first vapour stream and a first liquid stream from the separator and passing the first vapour stream into a washing column; withdrawing a second vapour stream from the washing column and feeding it via a condenser line to a condenser; cooling the second vapour stream in the condenser so that part of the second vapour stream condenses, producing a condensed second vapour stream and an uncondensed second vapour stream; passing the condensed second vapour stream to an upper part of the washing column via a reflux line; withdrawing a second liquid stream from the washing column and passing at least part of the second liquid stream to the separator via a recycling line; and recovering heat.

A process for withdrawing polyolefins from a reactor includes: continuously withdrawing a liquid solution stream from a solution polymerization reactor and passing the liquid solution stream into a low pressure separator; withdrawing a first vapour stream and a first liquid stream from the separator and passing the first vapour stream into a washing column; withdrawing a second vapour stream from the washing column and feeding it via a condenser line to a condenser; cooling the second vapour stream in the condenser so that part of the second vapour stream condenses, producing a condensed second vapour stream and an uncondensed second vapour stream; passing the condensed second vapour stream to an upper part of the washing column via a reflux line; withdrawing a second liquid stream from the washing column and passing at least part of the second liquid stream to the separator via a recycling line; and recovering heat.

A process for withdrawing polyolefins from a reactor includes: continuously withdrawing a liquid solution stream from a solution polymerization reactor and passing the liquid solution stream into a low pressure separator; withdrawing a first vapour stream and a first liquid stream from the separator and passing the first vapour stream into a washing column; withdrawing a second vapour stream from the washing column and feeding it via a condenser line to a condenser; cooling the second vapour stream in the condenser so that part of the second vapour stream condenses, producing a condensed second vapour stream and an uncondensed second vapour stream; passing the condensed second vapour stream to an upper part of the washing column via a reflux line; withdrawing a second liquid stream from the washing column and passing at least part of the second liquid stream to the separator via a recycling line; and recovering heat.