Basf Aktiengesellschaft

Hoechst Aktiengesellschaft

Basf Se Corporation

Hoechst Research & Technology Deutschland Gmbh & Co. Kg

Hoecht Ag

Targar Gmbh

Jens Weiguny

Holger Borchert

Sebastian Storck

Mark Duda

Thomas Gerdau

Cornelia Dobner

Andreas Tenten

Uwe Dingerdissen

Wilhelm Ruppel

Gunther Windecker

Gerd Kaibel

Alexander Weck

Christian Walsdorff

Thomas Krug

Michael Steiniger

Jörg Heilek

Gerald Meyer

Raimund Felder

Ellen Dahlhoff

Kazuhiko Amakawa

Miguel Angel Romero Valle

Nicolas Duyckaerts

Dany Vanden Hautte

Thierry Lurquin

Wolf-Steffen Weiβker

Ralf Freyberger

Thilo Buntrock

Rouven Weiler

Wolf-Steffen Weißker

Processes for decreasing fumaric acid deposits in preparing maleic anhydride by heterogeneously catalyzed oxidation of a hydrocarbon with molecular oxygen. Maleic anhydride is absorbed from the crude mixture in an absorbent in an absorption column and desorbed in a desorption column, the entirety or portion of absorbent depleted in maleic anhydride, for controlled precipitation of fumaric acid, being cooled and/or concentrated by evaporating a portion of absorbent such that the difference between the concentration of fumaric acid in the recycle stream at the outlet of the desorption column under existing conditions and the equilibrium concentration of fumaric acid according to the solubility curve after cooling and/or evaporation of a portion of absorbent is &#x2267;250 ppm by weight, and the fumaric acid precipitated as a solid is removed completely or partly from the absorbent recycling system and the fumaric acid-depleted absorbent is recycled completely or partly to the absorption column.

Process for separating off fumaric acid and other minor components during the production of maleic anhydride

What is described is a process for obtaining maleic anhydride by distillation from a solution of maleic anhydride in a high-boiling absorbent which has been obtained by gas phase oxidation of a hydrocarbon and at least partial absorption of the oxidation products into the absorbent, by The maleic anhydride obtained as a side draw has a low content of acrylic acid and acetic acid.

Process for obtaining maleic anhydride by distillation

A process for preparing a vanadium, phosphorus, and oxygen catalyst precursor for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon having at least four carbon atoms, which comprises

Catalyst-precursor for the production of maleic acid anhydride and method for the production thereof

A process for preparing a vanadium, phosphorus, and oxygen catalyst precursor for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon having at least four carbon atoms, by reacting vanadium pentoxide (I) in the presence of a primary or secondary, noncyclic or cyclic, unbranched or branched, saturated alcohol having from 3 to 6 carbon atoms (II) with a pentavalent or trivalent phosphorus compound (III) in a temperature range from 80 to 160&#xb0; C. with stirring and subsequently filtering the resultant suspension, in which (a) the way in which the phosphorus compound (III) and the vanadium pentoxide (I) are combined in the presence of the alcohol (II), (b) the action of a stirring power of from 0.01 to 0.6 W/kg suspension, and/or (c) the filtration at a temperature from 65&#xb0; C. to 160&#xb0; C. are used to set a filtration resistance &#x3b1;&#xb7;&#x3b7; of &#x3c;50&#xb7;10mPa&#xb7;s/m; a catalyst precursor obtainable from this process; a process for preparing a catalyst from the catalyst precursor; a catalyst obtainable from this process; and a process for preparing maleic anhydride over this catalyst.

Process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of hydrocarbons having at least four carbon atoms by means of oxygen-containing gases at from 350 to 500&#xb0; C. in the presence of a volatile phosphorus compound over a vanadium-, phosphorus- and oxygen-containing catalyst in a shell-and-tube reactor unit having at least one reaction zone cooled by means of a heat transfer medium, in which the temperature and/or the amount of the heat transfer medium flowing into the first (relative to the feed direction) reaction zone are set so that the mean temperature of the heat transfer medium in the first reaction zone T(1zone), which is calculated as the mean of the inflow temperature and the outflow temperature of the heat transfer medium, is in accordance with the formulae (I) and (II)(1zone)&#x2266;(1zone)&#x2212;(1zone)&#x2003;&#x2003;(I)(1zone)&#x2212;(1zone)&#x2266;(1zone)&#x2266;(1zone)+(1zone),&#x2003;&#x2003;(II)where

Method for producing maleic anhydride

Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distanceat an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to &#x2266;5&#xb0; C. at each position in the area of the flow of the catalyst precursor, which lies within the second half/2 of the calcination area, while the local difference in the gas temperature between any positions in the area of the flow of the catalyst precursor, which is located within the second half/2 of the calcination area, amounts to &#x2266;5&#xb0; C.

Method for the production of a catalyst containing vanadium, phosphorus, and oxygen

A catalyst used in a process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon having at least four carbon atoms by means of oxygen-containing gases comprises a catalytically active composition comprising vanadium, phosphorus and oxygen and has a essentially hollow cylindrical structure in which (a) the ratio of the height h to the diameter of the continuous hole d is not more than 1.5 and (b) the ratio of the geometric surface area A to the geometric volume V is at least 2 mm .

Hollow cylindrical catalyst and a method for producing a maleic acid anhydride

In a process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of hydrocarbons having at least four carbon atoms using oxygen-containing gases in the presence of a volatile phosphorus compound over a catalyst comprising vanadium, phosphorus and oxygen in a shell-and-tube reactor unit having at least two successive cooled reaction zones, the temperature of the first reaction zone is from 350 to 450&deg; C. and the temperature of the second and further reaction zones is from 350 to 480&deg; C. and the temperature difference between the hottest reaction zone and the coolest reaction zone is at least 2&deg; C.

Method for producing maleic acid anhydride

Process for the selective preparation of acetic acid using a molybdenum,

The present invention relates to a process for preparing an indene, which involves reacting an indanone with hydrogen in the presence of a catalyst comprising one or more oxides, preferably metal oxides. Preferred oxides comprise elements from groups Ia, IIa, IIa, IVa, Va, VIa, Ib, IIb, IIIb, IVb, Vb, VIb, VIIb and VIII of the Periodic Table, or elements from the lanthanide group.

Process for preparing indenes

The invention relates to a process for the preparation of substituted 3-arylquinazoline-2,4-diones of the formula (I) ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined in claim 1 and Ar is ##STR2## where R.sup.5 to R.sup.9 are as defined in claim 1, by reacting a compound of the formula (II) ##STR3## with a compound Z in the presence of a catalyst, a ligand and a solvent, where Z is

Process for the preparation of substituted 3-arylquinazoline-2,4-diones

The invention relates to a process for the preparation of halobenzaldehydes of the formula (I): ##STR1## in which Hal is fluorine, chlorine, bromine or iodine and z=1, 2, 3 or 4, by catalytic gas-phase oxidation of a substituted toluene of the formula (II), ##STR2## by oxygen, which comprises carrying out the oxidation in the presence of a catalyst of the formula (III)

Process for the preparation of halobenzaldehydes

Process for the preparation of aldehydes by catalytic gas phase hydrogenation of carboxylic acid or their derivatives with the aid of a tin catalyst The invention relates to a process for the preparation of aldehydes by catalytic gas phase hydrogenation of carboxylic acids or carboxylic acid derivatives at elevated temperature, which comprises employing at tin catalyst supplied to an oxidic support material.

Growing community of inventors

Freinsheim, Germany

Jens Weiguny