Patent ID: 7632913

Claim:
A reactor system for producing polycarbonate, the reactor system comprising one or more reactant vessels, an oligomerization reactor, a first pressure control device, a preheater, a second pressure control device, a distributor, and a flash tank, wherein the one or more reactant vessels contain reactants comprising a melt transesterification catalyst, a dihydroxy compound, and an activated diaryl carbonate, wherein the reactor system is connected in the following configuration: (i) the one or more reactant vessels connected to the oligomerization reactor, (ii) the first pressure control device disposed between and connecting the outlet of the oligomerization reactor and the inlet of the preheater, (iii) the second pressure control device disposed between and connecting the outlet of the preheater and the distributor, (iv) the distributor disposed at the inlet to the flash tank, whereby the pressure in the preheater is controllable at a pressure intermediate between the pressure in the oligomerization reactor and the flash tank.