REMOVAL OF PHOSGENE FROM OFF-GASES

摘要

To remove phosgene from off-gases, the former is reacted in a washing zone with a liquid which contains or is composed of compounds of the formula <IMAGE> where R1 and R2 are identical or different and are each aliphatic or cycloaliphatic alkyl of 1 to 8 carbons, or R1 and R2 are -(CH2)n- where n is 4 or 5, R3 is hydrogen or aliphatic or cycloaliphatic alkyl of 1 to 6 carbon atoms, or R1 or R2 and R3 are -(CH2)m- where m is 3, 4 or 5. The liquid can be regenerated by the addition of water, and the regenerated liquid can be returned to the washing zone.