Patent ID: 6620949
Filing Date: 2003-09-16
Classification: C07C,C07D

Abstract:
A process for the co-production of maleic anhydride and at least one C4 compound selected from the group consisting of butane-1,4-diol, &ggr;-butyrolactone and tetrahydrofuran wherein:maleic anhydride is produced by steps comprising: supplying a source of gaseous oxygen and a hydrocarbon feedstock selected from C4 hydrocarbons and benzene to a catalytic partial oxidation zone which contains a charge of a partial oxidation catalyst capable of effecting the partial oxidation of the hydrocarbon feedstock to form maleic anhydride and which is maintained under catalytic partial oxidation conditions; (ii) recovering from the partial oxidation zone a vaporous reaction effluent stream comprising maleic anhydride, water, unconverted hydrocarbon feedstock, and carbon oxides; (iii) condensing a part of the maleic anhydride present in the vaporous reaction effluent stream in a condensation zone to form a crude maleic anhydride stream; (iv) recovering from the condensation step (iii) a residual vaporous stream containing residual amounts of maleic anhydride; (v) absorbing further maleic anhydride from the residual vaporous stream of step (iv) by absorption in a liquid absorption medium selected from an organic solvent, water, and an aqueous solution; (vi) recovering from the absorption step (v) a loaded liquid absorption medium; and (vii) recovering maleic anhydride from the loaded liquid absorption medium; and wherein:said at least one C4 compound selected from the group consisting of butane-1,4-diol, &ggr;-butyrolactone and tetrahydrofuran is produced by steps comprising: (viii) providing a C4+ hydrogenation feedstock selected from maleic anhydride, maleic acid, dialkyl maleates, and mixtures of two or more thereof; (ix) supplying said C4+ hydrogenation feedstock and hydrogen to a hydrogenation zone which contains a charge of a hydrogenation catalyst effective for catalytic hydrogenation of the C4+ hydrogenation feedstock to yield said at least one C4 product and which is maintained under catalytic hydrogenation conditions; and (x) recovering from the hydrogenation zone a hydrogenation product stream containing said at least one C4 product; wherein crude maleic anhydride condensate of the crude maleic anhydride stream of step (iii) is used as the C4+ hydrogenation feedstock of step (viii) or is used to prepare the C4+ hydrogenation feedstock of step (viii).