Patent ID: 8409539

Claim:
A process for preparing phosgene by gas-phase reaction of carbon monoxide and chlorine in the presence of a solid catalyst in one or more cylindrical reactors which has/have a bundle of parallel catalyst tubes which are aligned in the longitudinal direction of the reactor and whose ends are fixed in tube plates which have discharge holes therein, with a cap at each end of the reactor and deflection plates which are aligned perpendicular to the longitudinal direction of the reactor in the intermediate space between the catalyst tubes and leave free passages located alternately opposite one another on the interior wall of the reactor, and a compensator positioned in the reactor wall and ports or part-ring channels provided on the reactor wall for the introduction and discharge of the heat transfer medium and the openings of these ports or part-ring channels to the interior of the reactor have a circular or rectangular cross-section and an opening ratio in the range from 5 to 50%, the process consisting essentially of: charging the catalyst tubes with the solid catalyst, passing a gaseous reaction mixture comprising the carbon monoxide and the chlorine from one end of the reactor via one cap through the catalyst tubes, discharging the gaseous reaction mixture from the opposite end of the reactor via the second cap, and passing a liquid heat transfer medium through the intermediate space around the catalyst tubes, wherein the reactor (the reactors) for carrying out the process has/have no tubes in the region of the passages.