PURPOSE: To prevent oxygen from being mixed with a combustible and volatile organic compound beyond the explosion limits to efficiently recover the organic compound by concurrently purging oxygen remained in a tower with nitrogen in an adsorption process and using nitrogen also for purge gas of a vacuum countercurrent purge regeneration process.
CONSTITUTION: Adsorbers 5a-5c, a blower 2, a vacuum pump 12, a nitrogen holder 22, valves, etc., are installed. In an adsorption process, an organic compound (e.g. aldehyde) is adsorbed with a combustible and volatile organic compound adsorbent (e.g. Na-X type zeolite) and nitrogen and oxygen are discharged outside the adsorbers. In a concurrent purge process, nitrogen flows in parallel to the fluid to scavenge oxygen remained in the adsorbers. Further, in a vacuum countercurrent purge regeneration process, the adsorbers are evacuated in countercurrent to the fluid and then nitrogen flows in the same direction to recover the organic compound. As a result, oxygen is prevented from being mixed with the organic compound beyond the explosion limits.
MORIMOTO TAKASHI
YASUTAKE AKINORI
TSUTAYA HIROYUKI
NOHARA HIROSHI
ISHIZAKI YASUYOSHI
TAKEDA KAZUMI
