Process and apparatus for the preparation and recovery of maleic anhydride

摘要

An improved process for the preparation and recovery of maleic anhydride in which the recovery of maleic anhydride from a gaseous reaction mixture includes absorbing the maleic anhydride in a solvent and subsequently stripping maleic anhydride from the solvent to obtain crude maleic anhydride product and regenerated absorbing solvent containing polymeric tars and other contaminants. In accordance with the improvement, at least a portion of the regenerated solvent is contacted in an agitated extraction zone with an aqueous liquid extractant to hydrolyze the polymeric tars, transfer water-soluble contaminants to the aqueous extract phase and produce a mixture comprising an aqueous extract phase containing water-soluble contaminants and an organic raffinate phase comprising regenerated absorbing solvent having a reduced concentration of polymeric tars. The aqueous extract and organic raffinate phases are then separated and the organic phase is recycled and used again to absorb maleic anhydride.