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.

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.

Disclosed is a supported catalyst for the preparation of vinyl acetate monomer, a process for preparing the supported catalyst in tablet or pellet form, and a catalytic process for the manufacturing vinyl acetate using the supported catalyst. Specifically, it is shown that catalyst performance shows a strong dependence on the crush strength of the tableted or pelletized alumina support used in the process to make the catalyst, and that the crush strength of the catalyst is closely related to the porosity of the support. Catalyst activity and selectivity can be enhanced by tailoring the crush strength of the support.

Disclosed is a supported catalyst for the preparation of vinyl acetate monomer, a process for preparing the supported catalyst in tablet or pellet form, and a catalytic process for the manufacturing vinyl acetate using the supported catalyst. Specifically, it is shown that catalyst performance shows a strong dependence on the crush strength of the tableted or pelletized alumina support used in the process to make the catalyst, and that the crush strength of the catalyst is closely related to the porosity of the support. Catalyst activity and selectivity can be enhanced by tailoring the crush strength of the support.

Disclosed is a supported catalyst for the preparation of vinyl acetate monomer, a process for preparing the supported catalyst in tablet or pellet form, and a catalytic process for the manufacturing vinyl acetate using the supported catalyst. Specifically, it is shown that catalyst performance shows a strong dependence on the crush strength of the tableted or pelletized alumina support used in the process to make the catalyst, and that the crush strength of the catalyst is closely related to the porosity of the support. Catalyst activity and selectivity can be enhanced by tailoring the crush strength of the support.

Addition of an N-oxyl compound to points in the VAM synthesis process such that from 10 to 100 ppm of N-oxyl compound is present in the column bottoms of the acetic acid separator markedly reduce fouling in the separator, thus allowing long and efficient VAM production campaigns.

Addition of an N-oxyl compound to points in the VAM synthesis process such that from 10 to 100 ppm of N-oxyl compound is present in the column bottoms of the acetic acid separator markedly reduce fouling in the separator, thus allowing long and efficient VAM production campaigns.

Addition of an N-oxyl compound to points in the VAM synthesis process such that from 10 to 100 ppm of N-oxyl compound is present in the column bottoms of the acetic acid separator markedly reduce fouling in the separator, thus allowing long and efficient VAM production campaigns.

The present teachings disclose contacting an amine salt catalyst with a dicarbonyl compound having an alkylene group between the carbonyl group; adding formaldehyde, paraformaldehyde, or formalin in an amount of about 2:1 to about 3:1 moles of formaldehyde to moles of the dicarbonyl compound to form a mixture; and refluxing the mixture. The process forms a carbonyl-substituted alkene. The process may be performed in the absence of a solvent. The process may form methylene malonates, methylene dimalonates, methylene keto malonamides, methylene diketones, methylene keto esters, and the like.