Basf Aktiengesellschaft

Basf Corporation

Bernhard Otto

Thomas Fetzer

Hermann Wistuba

Matthias Rauls

Gert Buerger

Wolfgang Buechele

Volker Schumacher

Bernd Bruchmann

Michael Hesse

Klaus Harth

Dietrich Scherzer

Wilhelm Ruppel

Matthias Irgang

Dieter Baumann

Roland Minges

Peter Keller

Michael Baier

Wolfgang Heider

Otto Hofstadt

Eckhart Wagner

Siegmund Pohl

Wilfried Seyfert

Siegfried Bechtel

Richard Van Gelder

Gert B&uuml;rger

Christoph Gahn

Paul Pijl

Udo Setzer

Joachim Borgwart

Willy Van Pee

Paul Jacobs

Emil Roth

Gert Burger

A copper-containing catalyst of the composition of N O contains a compound of the formula M Al O , where M is Cu or a mixture of Cu and Zn and/or Mg and x is from 0.8 to 1.5. The novel catalyst is used in a process for the catalytic decomposition of pure N O or N O contained in gas mixtures, at elevated temperatures.

High-temperature stabile catalysts for decomposing N2O

Dicarboxylic acid crystals are prepared from a solution containing at least one organic dicarboxylic acid in a process in which at least one anionic polyelectrolyte having a molecular weight of at least 2000 is added to the solution before or during the crystallization.

Dicarboxylic acid crystallizates

In a process and an apparatus for avoiding encrustations in reactors or crystallizers ( ), such as industrial crystallizers for suspensions ( ), points of incidence ( ) for the excitation of ultrasonic oscillations by sonotrodes ( ) which are connected to electromechanical converters ( ) are provided on the walls ( ) and on the base ( ) of the crystallizer ( ). The ultrasonic frequency is generated at high-frequency generators ( ).

Reduction of encrustation of crystallization processes

Mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (raw MDI) having a reduced iodine color number and a reduced chlorine content are prepared by reacting the corresponding mixtures of diphenylmethanediamines and polyphenylpolymethylenepolyamines with phosgene in the presence of at least one inert organic solvent at elevated temperature, and then, after phosgenation is complete, incorporating into the reaction mixture, in the presence or absence of the phosgene, a mixture of water and at least one monohydric or polyhydric polyoxyalkylene alcohol, preferably having a functionality of from 2 to 3, and advantageously having a hydroxyl number of from 20 to 1800, in an effective amount which advantageously comprises from more than 0.01 to 0.3% by weight of water (i) and from 0.5 to 5% by weight of a polyoxyalkylene alcohol (ii), in each case based on the weight of raw MDI, then removing the excess phosgene or the phosgene residues still present and the inert organic solvent, if desired adding to the reaction product up to 5% by weight, based on the weight of raw MDI, of at least one antioxidant based on phenol and/or aryl phosphite and thermally treating the reaction mixture.

Preparation of mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates having a reduced iodine color number and a reduced chlorine content

Catalysts prepared by combining M--Al.sub.2 O.sub.4 where M is an element of Group Ib, VIIb or VIII of the Periodic Table of the Elements with tin, lead, an element of group IIa or IIb of the Periodic Table of the Elements as oxide or salt or in elemental form and calcining at 300-1300.degree. C. under 0.1-200 bar and the process for preparing them.

Catalyst with fine-particle dispersion of the active component

Method of removing nitrogen oxides from a gas flow

Process for the catalytic decomposition of dinitrogen monoxide in a gas

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Limburgerhof, Germany

Bernhard Otto