A catalyst includes a support, where the support includes an external surface, about 60 wt % to about 99 wt % silica, and about 1.0 wt % to about 5.0 wt % alumina. A catalytic layer is disposed within the support adjacent to the external surface, where the catalytic layer further includes Pd, Au, and potassium acetate (KOAc). In the catalyst, (a) the KOAc is from about 60 kg/m.sup.3 to about 150 kg/m.sup.3 of the catalyst; or (b) the catalytic layer has an average thickness from about 50 m to about 150 m; or (c) both (a) and (b). The catalyst also possesses a Brunauer-Emmett-Teller surface area of about 130 m.sup.2/g to about 300 m.sup.2/g and a geometric surface area per packed bed volume from about 550 m.sup.2/m.sup.3 to about 1500 m.sup.2/m.sup.3. The catalyst is highly active for the synthesis of vinyl acetate monomer and exhibits a high selectivity for vinyl acetate monomer.

A catalyst includes a support, where the support includes an external surface, about 60 wt % to about 99 wt % silica, and about 1.0 wt % to about 5.0 wt % alumina. A catalytic layer is disposed within the support adjacent to the external surface, where the catalytic layer further includes Pd, Au, and potassium acetate (KOAc). In the catalyst, (a) the KOAc is from about 60 kg/m.sup.3 to about 150 kg/m.sup.3 of the catalyst; or (b) the catalytic layer has an average thickness from about 50 m to about 150 m; or (c) both (a) and (b). The catalyst also possesses a Brunauer-Emmett-Teller surface area of about 130 m.sup.2/g to about 300 m.sup.2/g and a geometric surface area per packed bed volume from about 550 m.sup.2/m.sup.3 to about 1500 m.sup.2/m.sup.3. The catalyst is highly active for the synthesis of vinyl acetate monomer and exhibits a high selectivity for vinyl acetate monomer.

A method that includes (a) providing a stream containing ethane and oxygen to an ODH reactor; (b) converting a portion of the ethane to ethylene and acetic acid in the ODH reactor to provide a stream containing ethane, ethylene, acetic acid, oxygen and carbon monoxide; (c) separating a portion of the acetic acid from the stream to provide an acetic acid stream and a stream containing ethane, ethylene, oxygen and carbon monoxide; (d) providing the stream to a CO Oxidation Reactor containing a catalyst that includes a group 11 metal to convert carbon monoxide to carbon dioxide and reacting acetylene to produce a stream containing ethane, ethylene and carbon dioxide; and (e) providing a portion of the stream and a portion of the acetic acid stream to a third reactor containing a catalyst that includes a metal selected from group 10 and group 11 metals to produce vinyl acetate.

A method that includes (a) providing a stream containing ethane and oxygen to an ODH reactor; (b) converting a portion of the ethane to ethylene and acetic acid in the ODH reactor to provide a stream containing ethane, ethylene, acetic acid, oxygen and carbon monoxide; (c) separating a portion of the acetic acid from the stream to provide an acetic acid stream and a stream containing ethane, ethylene, oxygen and carbon monoxide; (d) providing the stream to a CO Oxidation Reactor containing a catalyst that includes a group 11 metal to convert carbon monoxide to carbon dioxide and reacting acetylene to produce a stream containing ethane, ethylene and carbon dioxide; and (e) providing a portion of the stream and a portion of the acetic acid stream to a third reactor containing a catalyst that includes a metal selected from group 10 and group 11 metals to produce vinyl acetate.

Fouling of the acetic acid saturator by recycle gas in the continuous gas phase process for manufacture of vinyl acetate is reduced by adding an N-oxyl fouling inhibitor to the saturator and/or at one or more other addition sites in the process, in amounts such that the concentration of N-oxyl compound which accumulates in the saturator bottoms is from 10 to 100 ppm. The amount of N-oxyl compound in the saturator is preferably from 10-50 ppm. The reduction in fouling is evidenced by lessening the lowering of the heat transfer coefficient of the saturator over time.

Fouling of the acetic acid saturator by recycle gas in the continuous gas phase process for manufacture of vinyl acetate is reduced by adding an N-oxyl fouling inhibitor to the saturator and/or at one or more other addition sites in the process, in amounts such that the concentration of N-oxyl compound which accumulates in the saturator bottoms is from 10 to 100 ppm. The amount of N-oxyl compound in the saturator is preferably from 10-50 ppm. The reduction in fouling is evidenced by lessening the lowering of the heat transfer coefficient of the saturator over time.

Fouling of the acetic acid saturator by recycle gas in the continuous gas phase process for manufacture of vinyl acetate is reduced by adding an N-oxyl fouling inhibitor to the saturator and/or at one or more other addition sites in the process, in amounts such that the concentration of N-oxyl compound which accumulates in the saturator bottoms is from 10 to 100 ppm. The amount of N-oxyl compound in the saturator is preferably from 10-50 ppm. The reduction in fouling is evidenced by lessening the lowering of the heat transfer coefficient of the saturator over time.

Purification methods and systems for working up a crude vinyl acetate stream containing vinyl acetate monomer, acetic acid, water, ethyl acetate, and other impurities. Crude vinyl acetate streams are purified with an azeotropic distillation tower using a side draw to remove ethyl acetate and water, and a bottom stream to remove acetic acid from the crude vinyl acetate. The methods and systems move the side draw to a location on the azeotropic distillation tower that maintains a constant water concentration in the bottom product of about 4 to about 15 wt. % and forms a vapor side product. A second distillation tower is used to further purify the vapor side product to obtain water, VAM, ethyl acetate and AA. The system provides easier disposal of ethyl acetate, and cleaner water that can be recycled in the reactor or purification sections of a VAM plant and full recovery of AA.

Purification methods and systems for working up a crude vinyl acetate stream containing vinyl acetate monomer, acetic acid, water, ethyl acetate, and other impurities. Crude vinyl acetate streams are purified with an azeotropic distillation tower using a side draw to remove ethyl acetate and water, and a bottom stream to remove acetic acid from the crude vinyl acetate. The methods and systems move the side draw to a location on the azeotropic distillation tower that maintains a constant water concentration in the bottom product of about 4 to about 15 wt. % and forms a vapor side product. A second distillation tower is used to further purify the vapor side product to obtain water, VAM, ethyl acetate and AA. The system provides easier disposal of ethyl acetate, and cleaner water that can be recycled in the reactor or purification sections of a VAM plant and full recovery of AA.

Process for purification of unreacted vinyl acetate monomers comprising the steps of preliminarily loading an adsorbent agent bed with a mixture comprising an inert gas and fresh vinyl acetate; and feeding said adsorbent agent bed with unreacted vinyl acetate monomers to remove acetic acid.