Basf Aktiengesellschaft

Basf Se Corporation

Ulrich Rauh

Ulrich Hammon

Volker Schliephake

Gerhard Nestler

Toni Dockner

Helmut Lermer

Armin Schraut

Wolfgang Pies

Klaus Joachim Müller-Engel

Jürgen Schröder

Karl Gerhard Baur

Ulrich Annen

Herbert Exner

Michael Fried

Peter Schlemmer

Jochen Meschke

A continuously operated heterogeneously catalyzed gas-phase partial oxidation of at least one organic compound in an oxidation reactor is operated safely by a process in which an explosion diagram for the feed gas mixture is deposited as the basis of a cut-out mechanism in a computer.

Safe operation of a continuous heterogeneously catalyzed gas-phase partial oxidation of at least one organic compound

Higher (meth)acrylates IV are prepared by transesterification of a lower (meth)acrylate I with a higher alcohol ROH in the presence of a stabilizer or stabilizer mixture and of a catalyst or catalyst mixture, by a process in which the liberated lower alkanol ROH is separated off and is fed at least partly to the preparation of the lower (meth)acrylate I.

Method for producing (meth)acrylic acid esters

A method for measuring the temperature of fluid masses being treated in a tubular reactor apparatus which comprises carrying out the treatment in reactor apparatus comprises at least two same-type tubular reactors which are filled with solid particles, at least one tubular reactor containing a temperature measuring unit, the tubular reactors being designed such that both the ratio of the mass of the solid particles to the free cross-sectional area of the respective tubular reactor and the pressure drop measured by an inert gas being conducted transversely to the free cross-sectional area are each substantially identical across the respective tubular reactor. The apparatus is suitable for treating fluid masses while generating or consuming thermal energy, the temperature being measured.

Temperature measurements in tubular reactors during treatment of fluid masses

In a process for the disposal of low, mediun, and high-boiling secondary components formed during the preparation of (meth)acrylic acid the gaseous low-boiling secondary components are burned, whilst low-boiling and medium-boiling secondary components that are dissolved in water optionally together with high-boiling secondary components treated with solvent are added.

Method for removing by-products obtained when producing acrylic acid or methacrylic acids

A reactor apparatus comprises at least two same-type tubular reactors which are filled with solid particles, at least one tubular reactor containing a temperature measuring unit, the tubular reactors being designed such that both the ratio of the mass of the solid particles to the free cross-sectional area of the respective tubular reactor and the pressure drop measured by an inert gas being conducted transversely to the free cross-sectional area are identical across the respective tubular reactor. The apparatus is suitable for treating fluid masses while generating or consuming thermal energy, the temperature being measured.

Apparatus for measuring temperatures in tubular reactors

A process for the preparation of C.sub.1 -C.sub.4 -alkyl esters of (meth)acrylic acid from esters of the formula I ##STR1## and in case from esters of the formula (II) ##STR2## where R.sup.1 is hydrogen or --CH.sub.3,

Preparation of alkyl esters of (meth)acrylic acid

In a process for the separation by rectification of unsaturated carboxylic acids from solvents in which the acids were absorbed after the synthesis reaction, the rectification is briefly interrupted and the rectification column is flushed with a basic solution. The interruption is carried out at regular time intervals. The basic solution used is an aqueous solution of alkali metal and/or alkaline earth metal hydroxide, preferably NaOH, KOH, Ca(OH).sub.2 or their anhydrous oxides; alkaline polar organic solvents as amines or amides can be used, too.

Separation by rectification of unsaturated carboxylic acids from solvents

A diester of (meth)acrylic acid with a C.sub.4 -C.sub.6 -alkanediol is separated from a mixture which essentially consists of the C.sub.4 -C.sub.6 -alkanediol, the monoester of (meth)acrylic acid with the C.sub.4 -C.sub.6 -alkanediol and the diester of (meth)acrylic acid with the C.sub.4 -C.sub.6 -alkanediol by extraction with an organic solvent in the presence of water, by a process in which the diester-containing mixture is added continuously in the middle section of an extraction column and in addition water and the organic extracting agent are passed continuously countercurrent in the extraction column.

Separation of a diester of (meth)acrylic acid with a C.sub.4 -C.sub.6

A process for the separation of a mono(meth)acrylate of a C.sub.4 -C.sub.6 alkanediol from an aqueous solution containing a mono(meth)acrylate of a C.sub.4 -C.sub.6 alkanediol and the said C.sub.4 -C.sub.6 alkanediol, by extraction with an organic solvent, in which the extracting agent used is an organic solvent selected from the group comprising esters of C.sub.1 -C.sub.4 alkanecarboxylic acids and C.sub.1 -C.sub.5 alkanols, single and mixed dialkyl ethers having from 4 to 8 C atoms, and mixtures of such organic solvents.

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Limburgerhof, Germany

Ulrich Rauh