US Patent 7250530 Processes and systems for making phosgene

One process for producing phosgene comprises: introducing a carbon monoxide stream to a metal oxide impregnated activated carbon, reducing a hydrogen sulfide concentration in the carbon monoxide stream to produce a cleaned stream, wherein a cleaned stream hydrogen sulfide concentration is less than or equal to about 20 ppm, and reacting carbon monoxide in the cleaned stream with chlorine to produce phosgene.