Celanese International Corporation

Hoechst Celanese Corporation

Other

Philip M Colling

Ioan Nicolau

Leland R Johnson

Jerry A Broussard

Adolfo Aguilo

Michael A Loewenstein

Raul A Hauser Luna

Ethylene is a commodity chemical used as a reactant in the production of vinyl acetate. Ethylene is relatively expensive thus making its recovery and re-use in the process encouraged. The present invention provides a method for the recovery of ethylene from the inert gas purge stream from the reactor loop in a vapor-phase process for making vinyl acetate. The method of the present invention includes the steps of contacting the inert gas purge stream containing ethylene with acetic acid in an absorption vessel; discharging a stream containing acetic acid and ethylene from one aspect of the absorption vessel; separating the ethylene from the acetic acid in the stream by contacting the stream with ethylene gas in a scrubber column; and recovering ethylene from a top portion of the scrubber column. The method may also include the step of recycling the recovered ethylene to the reactor loop for further use.

Ethylene recovery system

A catalyst for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid comprising a porous support on the porous surfaces of which is deposited catalytically effective amounts of metallic palladium and gold, and cupric acetate. Use of this catalyst results in a reaction having a relatively low selectivity to carbon dioxide.

Vinyl acetate catalyst comprising metallic palladium and gold, and cupric acetate

Synthesying vinyl acetate utilizing a catalyst for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid comprising a porous support on the porous surfaces of which is deposited metallic copper in a zone surrounded by deposits of catalytically effective amounts of metallic palladium and gold, neither of which is substantially intermingled with said copper.

Vinyl acetate production using a catalyst comprising palladium and gold

A catalyst for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid as reactants comprising a porous support on the porous surfaces of which is deposited catalytically effective amounts of metallic palladium and gold, copper as the free metal or cupric acetate, and a fourth metal selected from the group consisting of magnesium calcium, barium, and zirconium, as its oxide or mixture of oxide and free metal.

Vinyl acetate production using a catalyst comprising palladium, gold,

Vinyl acetate catalyst comprising palladium, gold, copper and any of

A method is provided to manufacture a palladium-gold catalyst by separately impregnating and fixing the palladium and gold and reducing the fixed solids to free metal on a suitable support useful for vinyl acetate manufacture from ethylene and acetic acid.

Vinyl acetate catalyst preparation method

A process for the production of vinyl acetate (VA) by reaction in the vapor phase of ethylene, oxygen and acetic acid as reactants, comprising passing at a temperature sufficient to initiate the reaction, a feed gas comprising said reactants and continuously or intermittently containing liquid acetic acid and/or non-volatile components, through a filter and distribution bed of inert material having throughout its volume substantial intercommunicating open spaces among the solid portions, and thence through a plurality of tubes each containing a bed of catalyst for the reaction, and withdrawing a product gas comprising VA. The filter and distribution bed acts to filter out the liquid acetic acid and/or non-volatile components and distribute more evenly the feed gas into the tubes.

Production of vinyl acetate in a catalytic reactor equipped with filter

A catalyst for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid comprising a porous support on the porous surfaces of which is deposited metallic copper in a zone surrounded by deposits of catalytically effective amounts of metallic palladium and gold, neither of which is substantially intermingled with said copper. Methods for preparing the catalyst and for synthesizing vinyl acetate utilizing the catalyst are also disclosed.

Vinyl acetate catalyst comprising palladium and gold deposited on a

Vinyl acetate catalyst comprising metallic palladium and gold and cupric

A catalyst for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid as reactants comprising a porous support on the porous surfaces of which is deposited catalytically effective amounts of metallic palladium and gold and a third metal selected from the group consisting of magnesium calcium, barium, zirconium and cerium, as its oxide or mixture of oxide and metal, said catalyst having been prepared by either of two specified methods (A) or (B). Use of the catalyst results in a reaction of relatively high activity and/or low heavy ends selectivity.

Process for preparing vinyl acetate utilizing a catalyst comprising

A catalyst particularly useful in the preparation of unsaturated esters such as the reaction of ethylene, oxygen and acetic acid in a vapor phase to form vinyl acetate. The catalyst comprises a honeycomb carrier coated with silica and containing palladium and gold throughout the silica coat. Such catalysts show reduced pressure drop and a high space time yield for vinyl acetate.

Honeycomb catalyst for vinyl acetate synthesis

A process is disclosed for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid as reactants comprising contacting said reactants and a non-halogen containing copper compound with a catalyst comprising a porous support on the porous surfaces of which is deposited catalytically effective amounts of metallic palladium, gold and copper. During the process to prepare vinyl acetate, a stream of alkali metal acetate is preferably passed over the catalyst. The process results in higher vinyl acetate selectivity and productivity due to lower CO.sub.2 selectivity during the life of the catalyst, and/or longer catalyst life.

Vinyl acetate process utilizing a palladium-gold-copper catalyst

This invention provides a supported palladium-gold catalyst for vinyl acetate production from ethylene, acetic acid and oxygen. All of the reactants employed in the catalyst preparation are potassium salt compounds which are essentially sodium-free. A preferred invention palladium-gold catalyst provides exceptional improvement of carbon dioxide selectivity in vinyl acetate production.

Palladium-gold catalyst for vinyl acetate production

A method of preparing a catalyst particularly useful in the reaction of ethylene, oxygen and acetic acid in the vapor phase to form vinyl acetate comprises impregnating a porous support with water soluble salts of palladium and gold, fixing the palladium and gold on the support as water insoluble compounds by immersing the impregnated support in a reactive solution and tumbling the impregnated support in the reactive solution for at least 1/2 hour to begin precipitation of the insoluble compounds and completing precipitation of the insoluble compounds on the support and reducing the insoluble compounds to free palladium and gold. The catalysts prepared in this manner have been shown to provide improvement with respect to reduced selectivity to CO.sub.2 during the vinyl acetate forming reaction.

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Corpus Christi, TX, United States of America

Philip M Colling