Rohm Gmbh

Rohm Gmbh Chemische Fabrik

Roehm Gmbh Chemische Fabrik

Wilhelm Gruber

Guenter Schroeder

Klaus Langerbeins

Hermann-Josef Siegert

Gunter Schroder

Ernst Bielmeier

Thomas Haeberle

Hans Walter

Franz Schnierle

The present invention relates to a process for the production of methacrylic acid and methacrolein by means of gas phase oxidation of isobutane in the gaseous phase at 250.degree. to 450.degree. C. on molybdenum heteropoly acid catalysts that are made up of CU.sub.a H.sub.b P.sub.c Mo.sub.d V.sub.e O.sub.f heteropoly acid compounds (I), where a=0.1 to 1, b=0 to 7.8, c=0.8 to 1.2, d=9 to 12, e=0.5 to 3, and f depends on the molar numbers a to e, and/or the heteropoly acid H.sub.8 PMo.sub.10 VO.sub.39 (II) or its anhydride PMo.sub.10 VO.sub.35 (III).

Process for producing methacrylic acid and methacrolein by oxidation of

Catalysts having an improved long-term activity behavior in the oxydehydrogenation of, for example, isobutyric acid to methacrylic acid, are prepared from heteropolyacids of molybdenum or from their metal salt derivatives by the concurrent use of a water soluble organic compound which is of low volatility or is practically non-volatile, such as a polymer, followed by calcination of the preparation at 200.degree. C. to 400.degree. C. in the presence of oxygen.

Method for making heteropolyacid catalysts and catalysts made by the

The molybdovanadophosphoric acid H.sub.8 PMo.sub.10 VO.sub.39, its PMo.sub.10 VO.sub.35 anhydride, methods for their preparation, and methods for making methacrylic acid and its esters by oxidation/dehydrogenation wherein the above acid and/or its anhydride is employed as a catalyst.

H.sub.8 PMo.sub.10 VO.sub.39 and its anhydride, PMo.sub.10 VO.sub.35 and

Isobutyric acid is oxidatively dehydrogenated to methacrylic acid by passing a gaseous mixture of isobutyric acid, oxygen, nitrogen and optionally water vapor at temperatures of 300.degree.-450.degree. C. and pressures of 0.5 to 5 bar over a catalyst comprising molybdenum oxide, which also contains vanadium, phosphorous and a metal selected from the group consisting of alkali metals, alkaline earth metals, zinc, silver, aluminum, titanium, lead, manganese, iron, cobalt, nickel and tin, preferably precipitated on a solid silica support and calcined at 200.degree. to 400.degree. C. At conversion levels of 80 to 100% of the isobutyric acid used, a methacrylic acid selectivity of 60 to 74% is attained.

Process for producing methacrylic acid by oxidative dehydration of

In a method for the oxidative dehydrogenation of isobutyric acid in the gas phase, in the presence of oxygen and water vapor at a temperature from 300.degree. C. - 500.degree. C., and in the presence of a solid catalyst, the improvement wherein said catalyst initially consists essentially of at least one member selected from the group consisting of elemental molybdenum, elemental tungsten, molybdenum trioxide, and tungsten trioxide.

Method for the oxidative dehydrogenation of isobutyric acid

In a method for making a carboxylic acid ester by the reaction of the corresponding carboxylic acid amide with a primary alcohol in the presence of a catalyst at elevated temperature, the improvement wherein said catalyst is an at least partially dissolved metal carboxylate or a compound forming a metal carboxylate by reaction in situ with a carboxylic acid, the anion of which metal carboxylate is the anion of said carboxylic acid.

Method of making carboxylic acid esters

In a method for making .alpha.-hydroxy-isobutyramide by the hydration of acetone cyanohydrin in the presence of manganese dioxide as a catalyst, the improvement wherein acetone is added to the reaction mixture.

Method for making .alpha.-hydroxy-isobutyramide from acetone cyanohydrin

An improvement is disclosed of a process for reacting acrylic or methacrylic acid with a vicinal epoxide in the presence of a basic nitrogen compound to produce the corresponding hydroxy ester which comprises carrying out the reaction in the presence of a compound of the formula R--(NO.sub.2) as stabilizer in which R is a linear or branched alkyl or alkenyl or from 1 to 18 carbon atoms.

Hydroxy esters of acrylic and methacrylic acids

A method for making cyanogen chloride which comprises passing an approximately equimolar mixture of dicyan and chlorine over a charcoal catalyst at a temperature between 500.degree.C. and 950.degree.C. at a space velocity between 1000 and 10000 liters, measured at room temperature, per liter of catalyst and per hour.

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Darmstadt, Germany

Wilhelm Gruber