Process for making tetrahydrofuran and 1,4-butanediol using Pd/Re hydrogenation catalyst
AssigneeE. I. Du Pont de Nemours and Company
InventorsMelinda A. Mabry, William W. Prichard, Stanislaw B. Ziemecki
Life of this patent
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Abstract
Palladium/rhenium-on-carbon catalyst; a method employing said catalyst to produce tetrahydrofuran, 1,4-butanediol or mixtures thereof in selectable ratios from a number of starting reactants; and a method for making the Pd/Re/C catalyst.
Claims30
A method for making tetrahydrofuran, 1,4-butanediol or mixture thereof by hydrogenating a hydrogenating precursor in the presence of a solvent medium and a catalyst on a carbon support, said catalyst comprising about 0.5% to 10% of palladium and about 1% to 10% of rhenium by total weight of supported catalyst, the palladium being present in the form of crystallites having an average size of about 10 nm to 25 nm and the rhenium being present in the form of a highly dispersed phase of crystallites having an average size of less than about 2.5 nm.
A method for making tetrahydrofuran, 1,4-butanediol or mixtures thereof comprising hydrogenating a hydrogenatable precursor in the presence of a solvent medium and a catalyst comprising palladium and rhenium on a carbon support made by the method comprising, in sequence:
- (i) impregnating the carbon support with a source of palladium, said palladium being in solution,
- (ii) removing the solvent, and heating the palladium impregnated carbon at a temperature of about 150.degree. C. to 550.degree. C. under reducing conditions,
- (iii) applying to the palladium impregnated carbon a source of rhenium that is in solution, and
- (iv) removing the solvent.
A method for making tetrahydrofuran, 1,4-butanediol or mixtures thereof comprising hydrogenating a hydrogenatable precursor in the presence of a solvent medium and a catalyst on a carbon support, said catalyst comprising about 0.5% to 10% of palladium and about 1% to 10% of rhenium by total weight, made by the method comprising, in sequence:
- (i) impregnating the carbon support with a source of palladium, said palladium being in solution,
- (ii) removing the solvent and heating the palladium impregnated carbon at a temperature of about 150.degree. C. to 550.degree. C. under reducing conditions,
- (iii) applying to the palladium impregnated carbon a source of rhenium that is in solution, and
- (iv) removing the solvent.
In a method for making tetrahydrofuran, 1,4-butanediol or mixtures thereof from an oxidizable maleic anhydride precursor comprising oxidizing the precursor to form maleic anhydride and reacting the maleic anhydride with hydrogen in the presence of a hydrogenation catalyst, the improvement which comprises:
- (i) collecting the maleic anhydride from the oxidation step in water to form an aqueous solution of maleic acid, and
- (ii) reacting the aqueous solution of maleic acid with hydrogen in the presence of a catalyst on a carbon support, said catalyst comprising about 0.5% to 10% of palladium and about 1% to 10% of rhenium by total weight, the palladium being present in the form of crystallites having an average size of about 10 nm to 25 nm and the rhenium being present in the form of a highly dispersed phase of crystallites having an average size of less than about 2.5 nm.
In a method for making tetrahydrofuran, 1,4-butanediol or mixtures thereof from an oxidizable maleic anhydride precursor comprising oxidizing the precursor to form maleic anhydride and reacting the maleic anhydride with hydrogen in the presence of a hydrogenation catalyst, the improvement which comprises:
- (i) collecting the maleic anhydride from the oxidation step in water to form an aqueous solution of maleic acid, and
- (ii) reacting the aqueous solution of maleic acid with hydrogen in the presence of a catalyst on a carbon support, said catalyst comprising about 0.5% to 10% of palladium and about 1% to 10% of rhenium by total weight, made by the method comprising, in sequence:
- (a) impregnating the carbon support with a source of palladium, said palladium being in solution,
- (b) removing the solvent and heating the palladium impregnated carbon at a temperature of about 150.degree. C. to 550.degree. C. under reducing conditions,
- (c) applying to the palladium impregnated carbon a source of rhenium that is in solution, and
- (d) removing the solvent.
Dependencies are inferred from the claim text.