Process for the selective production of para-xylene by methylation of toluene in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12 which catalyst has undergone prior treatment with steam to reduce the alpha value thereof to less than about 500 and preferably within the range of less than about 20 but greater than zero.

Selective production of para-xylene

A shell impregnated catalyst for use in the production of vinyl acetate from ethylene, acetic acid and an oxygen containing gas is provided. The catalyst has a productivity of greater than 661 grams of vinyl acetate per hour per liter of catalyst at 150° C. and consists essentially of: (1) a catalyst support having a particle diameter from about 3 to about 7 mm and a pore volume of 0.2 to 1.5 ml per gram (2) palladium and gold distributed in the outermost 1.0 mm thick layer of the catalyst support particles, and (3) from about 3.5 to 9.5% by weight of potassium acetate. The catalyst is characterized by having a gold to palladium weight ratio in the range 0.60 to 1.25.

Catalysts and processes for the manufacture of vinyl acetate

A surface impregnated catalyst consisting essentially of a catalyst support, a palladium-gold alloy distributed in a surface layer of the catalyst support extending less than about 0.5 millimeter from the surface, and alkali metal acetate are provided. The catalyst has substantially higher specific activity than prior art catalysts used for the production of vinyl acetate.

Surface impregnated catalyst

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 manufacture of a Pd/Au/alkali metal catalyst, preferably a fluid bed catalyst used in the production of vinyl acetate comprising impregnating a microspheroidal support with a hydroxy-free metal salt solution of Pd and Au substantially free of barium and halide, reducing said salts to deposit Pd and Au on said support surface and impregnating said support with a halide-free metal salt of an alkali metal (preferably potassium).

Process for the preparation of vinyl acetate catalyst

HIGHLY ACITIVE CATALYSTS FOR THE PREPARATION OF CATALYSTS SUITABLE FOR VINYL ESTER, E.G., VINYL ACETATE, PRODUCTION ARE PREPARED BY TREATING A CATALYST SUPPORT, SIMULTANIOUSLY OR IN EITHER SEQUENCE, WITH OR WITHOUT INTERMEDIATE DRYING, WITH: (A) A SOLUTON OF NOBLE METALS CONTAINING AT LEAST SALTS OF PALLADIUM AND GOLD, AND (B) A SOLUTION CONTAINING COMPOUNDS, E.G., GASES SUCH AS SODIUM HYDROXIDE, WHICH ARE ABLE TO REACT WITH THE NOBLE METAL SALTS OF THE SOLUTION (A) TO FORM WATER INSOLUBLE NOBLE METAL COMPOUNDS; IMPREGNATING THE CATALYST SUPPORT WITH SUCH QUANTITIES OF SOLUTIONS (A) AND (B) CORRESPONDING TO FROM 10 TO 110% OF THE ABSORPTIVE CAPACITY OF THE CATALYST SUPPORT FOR THESE SOLUTIONS; SUBJECTING THE IMPREGNATED CATALYST SUPPORT TO A TIME TEMPERATURE TREATMENT SUCH THAT AT LEAST 95% OF THE IMPREGNATED PALLADIUM AND GOLD ARE TRANSFORMED INTO WATER INSOLUBLE NOBLE METAL COMPOUNDS; REDUCING THE METAL COMPOUNDS TO THE NOBLE METAL WITH A REDUCING AGENT, E.G., ETHYLENE OR HYDRAZINE; REMOVING THE WATER-SOLUBLE COMPOUNDS WHICH ARE CONTAINED IN THE CATALYST BY WASHING BEFORE OR AFTER THE REDUCTION STEP; AND OPTIONALLY TREATING THE RESULTING CATALYST WITH AN ALKALI METAL CARBOXYLATE, E.G., ACETATE, BEFORE OR AFTER THE TREATMENT WITH THE REDUCING AGENT.

Process for the production of catalysts for making vinyl esters

Organic acetates are prepared by reacting an olefine or alkyl benzene with oxygen and acetic acid in the presence of a palladium metal catalyst supported upon aluminium spinel which may contain aluminium oxide. Ethylene, propylene and iso-butylene, and toluene and xylene are mentioned and the support may be impregnated with palladium salt followed by reduction with hydrazine hydrate or hydrogen at high temperatures. Alkali or alkaline earth metal acetates, e.g. sodium, potassium, magnesium or calcium, may also be present. The spinel support is prepared from metals such as lithium, beryllium, magnesium, zinc, and bivalent manganese, iron, cobalt and nickel. Examples describe the preparation of vinyl acetate, allyl acetate, benzyl acetate and benzal diacetate.ALSO:Palladium metal catalysts deposited on a support consisting partly or completely of aluminium spinel which may contain aluminium oxide, are used in the preparation of organic acetates by reacting an olefine or alkyl benzene at elevated temperature with oxygen and acetic acid. The catalyst support is prepared by adding the spinel-forming metals e.g. lithium, beryllium, magnesium, zinc and in the bivalent form, manganese, iron cobalt and nickel, as salts or hydroxides to the aluminium oxide, drying, converting to oxide at from 250-650 DEG C, and finally heating at 900 to 1200 DEG C to form the spinel. The aluminium oxide may be in piece form, or fine-grained and in a modification metal aluminates may be precipitated from aqueous aluminium salt solutions by adding salts of spinel forming metals and heat treating the product. In a further method the aluminium oxide or hydroxide is mixed with spinel-forming metal oxides or hydroxides, ground, shaped and heated to form the spinels. The palladium is deposited e.g. 0.1 to 10.1 by weight by impregnation with a salt solution followed by reduction with hydrozine hydrate, or hydrogen. Alkali or alkaline earth metal acetates e.g. potassium, sodium magnesium or calcium may also be included and the process may use fixed or moving bed catalyses.

Kroenig Dr Walter

Papers

Process for the production of catalysts for making vinyl esters

Process for the production of organic acetates

Recycle of monoolefines to a hydrocarbon pyrolysis process

Verfahren zur Entfernung von Butadien aus Kohlenwasserstoffgemischen, die im wesentlichen aus Kohlenwasserstoffen mit 4 Kohlenstoffatomen bestehen

Verfahren zur selektiven Hydrierung von Pyrolysebenzin oder dessen Fraktionen