Patent ID: 6605739
Filing Date: 2003-08-12
Classification: C07C,Y02P

Abstract:
A process for the production of vinyl acetate monomer comprising the steps of:(1) contacting a gaseous feed mixture of ethane or ethylene or ethane/ethylene, steam and a molecular oxygen containing gas in the presence of a first catalyst active for oxidation of ethane, ethylene or ethane/ethylene to produce a selective stream of acetic acid, ethylene, carbon dioxide and water and (2) converting a second feed mixture comprising ethylene, acetic acid and oxygen to vinyl acetate monomer in the presence of a second catalyst active for the production of vinyl acetate, wherein said process does not include an intermediate separation step to remove the CO between the two reaction steps characterized by using a first oxidation catalyst selected from the following catalyst compositions: a catalyst composition comprising the elements Mo, V, Nb, and Pd, in the form of oxides, in the ratio MoaVbNbcPdd wherein: a is 1 to 5; b is 0 to 0.5; c is 0.01 to 0.5; and d is >0 to 0.2; a, b, c, d, represent the relative gram-atom ratios of the elements Mo, V, Nb, and Pd respectively in the catalyst or a catalyst composition comprising the elements Mo, V, Pd, Nb, La and X, in the form of oxides, wherein X is Al, Ga, Si or Ge, in the ratio MoaVbLacPddNbeXf, wherein: a is 1; b is 0.01 to 0.9; c is >0 to 0.2; d is >0 to 0.2; e is >0 to 0.2; f is >0 to 0.3; a, b, c, d, e, f represent the relative gram-atom ratios of the elements Mo, V, La, Pd, Nb, and X respectively in the catalyst or a catalyst composition comprising the elements Mo, V, Nb and X (where X is P, B, Hf, Te, As or mixtures thereof) in the form of an oxide, in the following ratio MoaVbNbcXd wherein: a is 1 to 5; b is >0 to 0.1; c is 0.01 to 0.5; d is >0 to 0.1; a, b, c, d represent the relative gram-atom ratios of the elements Mo, V, Nb, and X respectively in the catalyst or a mixture between the two previous first oxidation catalysts and a catalyst composition comprising the elements Mo, V, Nb, and Pd, in the form of oxides, in the ratio MoaVbNbcPdd wherein: a is 1 to 5; b is 0 to 0.5; c is 0.01 to 0.5; and d is >0 to 0.2; a, b, c, d represent the relative gram-atom ratios of the elements Mo, V, Nb, and Pd respectively in the catalyst.