Abstract: Methods of online cleaning of heat exchangers at elevated temperatures are provided. Cleaning of the heat exchanger is achieved through an increasing heat exchanger effluent temperature of a polymer solution together with operating under optimized process conditions provided by a phase diagram constructed for the polymer solution. The separation of polymer from unreacted monomers and solvent in the polymer solution is carried out by raising the temperature of the polymer solution as reactor effluent flowing through the heat exchanger. Then, subsequently and by reducing pressure of the heat exchanger effluent, the polymer solution separates into two liquid phases.

Abstract: Methods of online cleaning of heat exchangers at elevated temperatures are provided. Cleaning of the heat exchanger is achieved through an increasing heat exchanger effluent temperature of a polymer solution together with operating under optimized process conditions provided by a phase diagram constructed for the polymer solution. The separation of polymer from unreacted monomers and solvent in the polymer solution is carried out by raising the temperature of the polymer solution as reactor effluent flowing through the heat exchanger. Then, subsequently and by reducing pressure of the heat exchanger effluent, the polymer solution separates into two liquid phases.

Abstract: Described herein are methods for continuous solution polymerization. The method may comprise polymerizing one or more monomers and comonomers in the presence of a solvent in a polymerization reactor to produce a polymer solution; determining the composition of the polymer solution exiting the polymerization reactor in an on-line fashion; determining at least one of the critical pressure or critical temperature; comparing the critical pressure and/or critical temperature to the actual temperature of the polymer solution and the actual pressure of the polymer solution; heating or cooling the polymer solution to a temperature within 50° C. of the critical temperature; and passing the polymer solution through a pressure letdown valve into a liquid-liquid separator, where the pressure of the polymer solution is reduced or raised to a pressure within 50 psig of the critical pressure to induce a separation of the polymer solution into two liquid phases.

Abstract: Described herein are methods for continuous solution polymerization. The method may comprise polymerizing one or more monomers and comonomers in the presence of a solvent in a polymerization reactor to produce a polymer solution; determining the composition of the polymer solution exiting the polymerization reactor in an on-line fashion; determining at least one of the critical pressure or critical temperature; comparing the critical pressure and/or critical temperature to the actual temperature of the polymer solution and the actual pressure of the polymer solution; heating or cooling the polymer solution to a temperature within 50° C. of the critical temperature; and passing the polymer solution through a pressure letdown valve into a liquid-liquid separator, where the pressure of the polymer solution is reduced or raised to a pressure within 50 psig of the critical pressure to induce a separation of the polymer solution into two liquid phases.