Method and device for producing succinic anhydride through maleic anhydride gas phase hydrogenation

The invention discloses a method and a device for producing succinic anhydride through normal-pressure gas-phase hydrogenation of solvent-free maleic anhydride. The method comprises the following steps: (1) preheating maleic anhydride, gasifying the preheated maleic anhydride, and uniformly mixing the gasified maleic anhydride with hydrogen; (2) injecting maleic anhydride and hydrogen into a hydrogenation reactor, and carrying out double-bond hydrogenation reaction under the action of a hydrogenation catalyst to obtain a reaction product; (3) carrying out heat exchange on the reaction product, and then carrying out gas-liquid separation to obtain a succinic anhydride crude product and circulating hydrogen; (4) fractionating the succinic anhydride crude product to obtain refined succinic anhydride and byproducts thereof; and (5) washing the circulating hydrogen, and removing uncondensed butanedioic anhydride to obtain hydrogen. According to the method disclosed by the invention, expensive organic solvents and