PREPARATION METHOD OF O-XYLENE-AIR MIXTURE FOR PRODUCTION OF PHTHALIC ANHYDRIDE

摘要

PURPOSE: A method for preparing an o-xylene-air mixture for the production of phthalic anhydride is provided, to allow phthalic anhydride to be produced more stably without danger of explosion. CONSTITUTION: The method comprises the steps of completely evaporating o-xylene(15) in the absence of oxygen; superheating the evaporated o-xylene(18) and mixing the superheated one with air(16); and supplying the obtained mixture to a phthalic anhydride reactor. Preferably the evaporator for o-xylene is a natural-circulation evaporator(7) or a kettle evaporator. Preferably the reaction is carried out with a load of 80-120 g o-xylene/Nm3 air; and the mixing of o-xylene and air is carried out by using a sparger ring mixer. Preferably a steam accumulator(12) is provided in front of the evaporator(7) for o-xylene for supplying the heated steam.