Process for the preparation of ketene

摘要

In this process for the preparation of ketene by the thermal, catalytic cracking of acetic acid under reduced pressure, the hot cracked gases are cooled to approx. 0 DEG to -10 DEG C. and, in the course thereof, water, unreacted acetic acid and acetic anhydride are condensed. The quantity of acetic acid employed for the thermal cracking reaction should be 0.5 to 2.5 txhours-1xm-3, relative to the volume V of a shell-and-tube heat exchanger through which the cracked gas is passed. The pressure drop in the tubular heat exchanger should be 50 to 150 mbars and the surface/volume ratio should be 60 to 120 m-1.