| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing phosgene, capable of giving the phosgene having good color tone and scarcely containing a main substance causing the corrosion of apparatuses by using carbon monoxide having a dew point of a specific temperature or lower. SOLUTION: This method for producing phosgene comprises reacting chlorine with carbon monoxide. Therein, the carbon monoxide has a dew point of -30 deg.C or lower, especially preferably -50 deg.C or lower. The carbon monoxide is obtained by reacting coke with oxygen, cooling the obtained carbon monoxide at 5 deg.C by the use of a heat exchanger, and then passing the cooled carbon monoxide through an activated alumina-charged tank. In order to reduce carbon tetrachloride and chlorine which corrode apparatuses, the chlorine and the carbon monoxide are reacted in a molar ratio of 1:(1.020 to 1.080), and the chlorine is charged into an activated carbon-charged reaction tower from its two or more chlorine-charging ports, preferably three to six chlorine-charging ports. When the carbon monoxide is recycled, the absorption tower can be downsized, because uncondensed phosgene is reduced. The carbon monoxide is recycled in an amount of 5-99. 5 vol.%. |
