Production of caprolactam from adipic acid

A process for preparing a caprolactam product, the process comprising:

• reacting an adipic acid substrate, hydrogen, and ammonia, in the presence of a heterogeneous catalyst comprising at least one metal selected from the group of Ru, Rh, Pt, Pd, Ir, and Os, and mixtures thereof, on a support that is, in the absence of the at least one metal, capable of catalyzing the reaction of the adipic acid substrate and ammonia to produce an amide, and solvent, to convert at least a portion of the adipic acid substrate to the caprolactam product, wherein the adipic acid substrate is a compound of formula I, and wherein the caprolactam product is a compound of formula II
• wherein each R1 and R2 is independently ORa and NH2;
• wherein each Ra is independently selected from the group consisting of hydrogen, alkyl, and a salt-forming ion.

A process for producing caprolactam from adipic acid, the process comprising the steps of:

• a) converting at least a portion of the adipic acid to at least one amide selected from the group of 6-amino-6-oxohexanoic acid and adipamide in the presence of a metal oxide comprising titania, zirconia, or a mixture thereof,
• b) reducing the at least one amide to at least one of aminocaproic acid and aminocaproamide, and
• c) cyclizing at least a portion of the aminocaproic acid and/or aminocaproamide produced from b), above, to caprolactam, wherein at least one of b) and c), above, is carried out in the presence of at least one metal selected from the group of Ru, Pt, Pd, Rh, Ir, and Os.

A catalyst comprising ruthenium and rhenium on a support comprising titania, wherein the catalyst is capable of catalyzing the conversion of adipic acid to caprolactam.