Process for the preparation of butanediol, butyrolactone and tetrahydrofuran
AssigneeBASF SE
InventorsMichael W. M. Tuck, Philip H. D. Eastland, Andrew G. Hiles, Graham Reed
Life of this patent
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Abstract
Butane-1,4-diol, gamma-butyrolactone or tetrahydrofuran are prepared by vapor phase hydrogenation of a C4-dicarboxylic acid derivative. A maleic anhydride containing vapor stream is contacted in an absorption zone with a first high boiling solvent. A waste gas stream is passed to a scrubbing zone containing a second, higher boiling solvent. The waste gas is purged and the first and second solvents are recovered and recycled. Maleic anhydride is obtained from the absorption zone and converted to a maleic acid diester, which is stripped from the first solvent with hydrogen. The desired products are obtained by hydrogenation.
Claims36
A process for the production of at least one C4 compound selected from butane-1,4-diol, γ-butyrolactone and tetrahydrofuran, which includes the step of hydrogenation in the vapour phase of a C4 dicarboxylic acid derivative in the presence of a heterogeneous hydrogenation catalyst, said C4 dicarboxylic acid derivative being selected from maleic anhydride and di-(C1 to C4 alkyl) esters of a C1 to C4 dicarboxylic acid, which process comprises:
- (a) contacting a vaporous stream containing maleic anhydride vapour, water vapour, and carbon oxides in an absorption zone with a first high boiling solvent having a boiling point at atmospheric pressure which is at least about 30° C. higher than that of maleic anhydride thereby to form a solution of maleic anhydride in the first high boiling solvent;
- (b) recovering from the absorption zone a waste gas stream containing a minor amount of said first high boiling solvent;
- (c) contacting the waste gas stream of step (b) in a scrubbing zone with a second high boiling solvent having a boiling point at atmospheric pressure which is at least 30° C. higher than that of the first high boiling solvent, thereby to form a solution of the first high boiling solvent in the second high boiling solvent and to yield a washed waste gas;
- (d) recovering first high boiling solvent from the solution of step (c) for recycle to step (a);
- (e) recycling residual second high boiling solvent from step
- (d) to step (c);
- (f) purging washed waste gas of step (c);
- (g) converting maleic anhydride in said solution of step (a), if necessary, to said C4 dicarboxylic derivative;
- (h) contacting the solution of said C4 dicarboxylic acid derivative in the first high boiling solvent with a gaseous stream containing hydrogen thereby to strip said C4 dicarboxylic acid derivative therefrom and to form a vaporous stream comprising hydrogen and said C4 dicarboxylic acid derivative;
- (i) contacting material of the vaporous stream of step (h) in a hydrogenation zone under hydrogenation conditions with a heterogeneous hydrogenation catalyst thereby to convert said C4 dicarboxylic acid derivative to at least one C4 compound selected from butane-1,4-diol, γ-butyrolactone and tetrahydrofuran;
- and
- (j) recovering from the hydrogenation zone a product stream containing said at least one C4 compound.
Dependencies are inferred from the claim text.