Basf Se Corporation

Josef Macht

Cornelia Katharina Dobner

Ulrich Hammon

Klaus Joachim Mueller-Engel

Christian Walsdorff

Holger Borchert

Frank Rosowski

Claus Hechler

Andreas Raichle

Catharina Horstmann

Klaus Joachim Müller-Engel

Ortmund Lang

Andrey Karpov

Marvin Kramp

Cathrin Alexandra Welker-Nieuwoudt

Stefan Lipp

Matthias Wilhelm Meier

Gregor Grackiewicz

Yunfei Zhou

Markus Gitter

The invention relates to an oxidation catalyst comprising at least one inorganic, oxidic or ceramic, shaped support body having a BET surface area of less than 0.5 m/g, based on the support, which is at least partly coated with a catalytically active multielement oxide, the catalyst being precious metal-free and the shaped support body having the form of a saddle whose saddle surface is curved oppositely in the two principal directions, to a process for producing it, to its use in various catalytic gas phase oxidations, and to corresponding processes for catalytic gas phase oxidation.

Oxidation catalyst with saddle-shaped support body

A hollow cylindrical shaped catalyst body for gas phase oxidation of an alkene to an &#x3b1;,&#x3b2;-unsaturated aldehyde and/or an &#x3b1;,&#x3b2;-unsaturated carboxylic acid comprises a compacted multimetal oxide having an external diameter ED, an internal diameter ID and a height H, wherein ED is in the range from 3.5 to 4.5 mm; the ratio q=ID/ED is in the range from 0.4 to 0.55; and the ratio p=H/ED is in the range from 0.5 to 1. The shaped catalyst body is mechanically stable and catalyzes the partial oxidation of an alkene to the products of value with high selectivity. It provides a sufficiently high catalyst mass density of the catalyst bed and good long-term stability with acceptable pressure drop.

Mechanically stable hollow cylindrical shaped catalyst bodies for gas phase oxidation of an alkene to an unsaturated aldehyde and/or an unsaturated carboxylic acid

What is described is a catalyst for preparation of an &#x3b1;,&#x3b2;-unsaturated carboxylic acid by gas phase oxidation of an &#x3b1;,&#x3b2;-unsaturated aldehyde, comprising a shaped support body with an active composition applied thereto, wherein the active composition coverage q is at most 0.3 mg/mm, where Q is the active composition content of the catalyst in % by weight and Sis the specific geometric surface area of the shaped support body in mm/mg. Also described are a process for preparing the catalyst and a process for preparing an &#x3b1;,&#x3b2;-unsaturated carboxylic acid by gas phase oxidation of an &#x3b1;,&#x3b2;-unsaturated aldehyde over a fixed catalyst bed comprising a bed of the catalyst. The catalyst, with constantly high conversion of acrolein, reduces overoxidation to COand increases the selectivity of acrylic acid formation.

Catalyst for preparation of an unsaturated carboxylic acid by gas phase oxidation of an unsaturated aldehyde

An &#x3b1;,&#x3b2;-unsaturated aldehyde and/or an &#x3b1;,&#x3b2;-unsaturated carboxylic acid are prepared by gas phase oxidation of alkene with molecular oxygen over a fixed catalyst bed comprising a bed of hollow cylindrical shaped catalyst bodies having a multimetal oxide active composition. The fixed catalyst bed comprises at least three successive reaction zones; the highest local temperature in the fixed catalyst bed does not occur in the reaction zone closest to the reactor outlet; the highest local temperature in the fixed catalyst bed does not occur in the reaction zone closest to the reactor inlet; and the value WT=(ED&#x2212;ID)/2 in the reaction zone in which the highest local temperature in the fixed catalyst bed occurs is lower than in the other reaction zones, in which ED is the external diameter and ID is the internal diameter of the shaped catalyst body. The yield of the products of value is enhanced in this way.

Process for preparing an unsaturated aldehyde and/or an unsaturated carboxylic acid

An eggshell catalyst consisting of a hollow cylindrical support body of length 2 to 10 mm, external diameter 4 to 10 mm and wall thickness 1 to 4 mm, and an eggshell, applied to the outer surface of the support body, of catalytically active oxide material of the general formula I,MoVWCuXXO&#x2003;&#x2003;(I)in which the variables are each defined as follows:

Eggshell catalyst consisting of a hollow cylindrical support body and a catalytically active oxide material applied to the outer surface of the support body

A process for producing a catalytically active composition being a mixture of a multielement oxide comprising the elements Mo and V and at least one oxide of molybdenum, in which spray drying of an aqueous solution or of an aqueous suspension of starting compounds comprising the elements of the multielement oxide produces a spray powder P, a pulverulent oxide of molybdenum and optionally shaping assistants are added thereto, shaped bodies are shaped from the resulting mixture and these are converted to the catalytically active composition by thermal treatment.

Process for producing a catalytically active composition being a mixture of a  multielement oxide comprising the elements Mo and V and at least one oxide of molybdenum

Mo-, Bi- and Fe-comprising multimetal oxide compositions of the general stoichiometry I,MoBiCoFeKSiO&#x2003;&#x2003;(I),

Mo-, Bi- and Fe-comprising multimetal oxide compositions

A process for long-term operation of a heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, in which the propene present in the reaction gas input mixture is partially oxidized as this gas mixture passes through the fixed catalyst bed which is accommodated in two spatially successive temperature zones A, B, and, in long-term operation, as a measure to counteract the reduction in the quality of the fixed catalyst bed, the temperature of at least one of the two temperature zones is increased such that the difference T&#x2212;Tbecomes increasingly greater, where Tis the temperature of temperature zone B, and Tthe temperature of temperature zone A.

Process for long-term operation of a heterogeneously catalyzed partial gas phase oxidation of propene to acrolein

A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide which comprises the element Mo, the elements Bi and/or V and one or more of the elements Co, Ni, Fe, Cu and alkali metals, in which sources of the different elements are used to obtain a finely divided mixture which is coarsened to a powder by press agglomeration, the coarsened powder is used to form, by press agglomeration, shaped bodies V which are separated into undamaged shaped bodies Vand into damaged shaped bodies V, the undamaged shaped bodies Vare converted by thermal treatment to the shaped catalyst bodies K, and the damaged shaped bodies Vare comminuted and recycled into the obtaining of the finely divided mixture.

Process for continuously producing geometric shaped catalyst bodies K

A process for preparing (meth)acrolein by heterogeneously catalyzed gas phase partial oxidation of a precursor compound, in which the reaction gas mixture which comprises at least 3% by volume of precursor compound is passed through a fresh fixed catalyst bed whose active material is a multielement oxide which comprises the elements Mo, Fe and Bi and at least one of the elements Ni and Co, and the fixed catalyst bed is loaded with at least 40 l (STP)/l&#xb7;h of precursor compound, and the precursor compound is converted to an extent of at least 90 mol %, wherein, over the first 8000 operating hours, during X=10 to 500 operating hours, the highest temperature of the reaction gas mixture in the fixed catalyst bed is 400 to 450&#xb0; C. and, during the remaining 8000&#x2212;X operating hours, is 300 to &#x3c;400&#xb0; C., and the loading of the fixed catalyst bed with organic precursor compound, averaged over the time, for the X=10 to 500 operating hours is greater than for the 8000&#x2212;X operating hours.

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Mannheim, Germany

Josef Macht