METHOD FOR PRODUCING UNSATURATED NITRILE

摘要

PROBLEM TO BE SOLVED: To provide a method for producing unsaturated nitrile, in which clogging of a heat exchanger arranged on an outlet line of a reactor and clogging of a quick cooling tower arranged in the downstream of the heat exchanger can be prevented.SOLUTION: The method for producing unsaturated nitrile by an ammoxidation reaction comprises the steps of: feeding a gaseous raw material containing at least one selected from the group consisting of alkane, olefin and alcohol to a catalyst-packed reactor to advance the ammoxidation reaction in the reactor; introducing the reaction product gas produced by the ammoxidation reaction into a heat exchanger to cool the introduced reaction product gas; and introducing the reaction product gas cooled in the heat exchanger into a quick cooling tower to cool the introduced reaction product gas. A liquid or a gas of 110°C or higher temperature is used as a cooling medium for cooling the reaction product gas in the heat exchanger. The quick cooling tower is an empty tower having no packed layer, or has a packed layer having 1.5 m or less height or 90% or higher void volume.