Method for preparing polymer
Provided is a method of preparing a polymer including: supplying a monomer stream and a solvent stream to a reactor and performing a polymerization reaction to prepare reaction product; supplying a reactor discharge stream to a separation device, separating a gaseous stream including an inert gas in the separation device, and supplying a liquid stream including the reaction product from which the inert gas is removed to a volatilization device; separating a polymer from a lower discharge stream from the volatilization device and supplying an upper discharge stream including an unreacted monomer, a solvent, and an inert gas to a condensation unit; and condensing and separating the unreacted monomer and the solvent in the condensation unit and supplying a gaseous stream to a vacuum unit.
1 . A method of preparing a polymer, the method comprising:
supplying a monomer stream and a solvent stream to a reactor and performing a polymerization reaction to prepare reaction product;
supplying a reactor discharge stream to a separation device, separating a gaseous stream including an inert gas in the separation device, and supplying a liquid stream including the reaction product from which the inert gas is removed to a volatilization device;
separating a polymer from a lower discharge stream from the volatilization device and supplying an upper discharge stream including an unreacted monomer, a solvent, and an inert gas to a condensation unit; and
condensing and separating the unreacted monomer and the solvent in the condensation unit and supplying a gaseous stream to a vacuum unit,
wherein a content of the inert gas in the gaseous stream discharged from the separation device is 80 wt % or more,
wherein a content of the inert gas removed as the gaseous stream in the separation device is 75% to 99% relative to a content of the inert gas included in the reactor discharge stream supplied to the separation device,
wherein a content of the inert gas in a liquid stream discharged from the separation device is 10 ppm to 150 ppm,
wherein the separation device has an operation temperature of 130° C. to 150° C. and an operation pressure of 1.5 kgf/cm 2 g to 3.5 kgf/cm 2 g,
wherein a content of the inert gas in a gaseous stream output from the condensation unit is from 100 ppm to 600 ppm, and
wherein the inert gas is nitrogen.
2 . The method of preparing a polymer of claim 1 , wherein the condensation unit includes two or more condensers.
3 . The method of preparing a polymer of claim 2 ,
wherein the upper discharge stream from the volatilization device is supplied to a first condenser and the unreacted monomer and the solvent are condensed and separated in the first condenser, and the gaseous stream from the first condenser is supplied to a second condenser, and
the unreacted monomer and the solvent are condensed and separated in the second condenser and the gaseous stream from the second condenser is supplied to the vacuum unit.
4 . The method of preparing a polymer of claim 1 , wherein an operation pressure of the volatilization device is 5 torr to 70 torr.
5 . The method of preparing a polymer of claim 1 , wherein the polymer includes an aromatic vinyl-unsaturated nitrile-based copolymer.