Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Bayer Aktiengesellschaft

Degussa Aktiengesellschaft

Gerd Schreyer

Helmut Waldmann

Gunter Prescher

Werner Schwarze

Heinz Friedrich

Helmut Beschke

Rolf Wirthwein

Werner Heimberger

Otto Weiberg

Wulf Schwerdtel

Hermann Seifert

Wolfgang Swodenk

Friedrich Bittner

Friedhelm Geiger

Heinz Kolb

Heinz Haschke

Axel Kleemann

Heribert Offermanns

Paul Scherberich

Friedrich Asinger

Klaus Hentschel

Wolfgang Weigert

Klaus-Peter Muller

Helmut Suchsland

Willi Hofen

Karl-Hermann Reissinger

Wolf-Dieter Pfeifer

Wolfgang Heim

Peter K Kleinschmit

Herbert Klenk

Horst Weigel

Wolfgang Leuchtenberger

Gerhard Morlock

Wolfgang Merk

Theodor Lussling

Carl Voigt

Hermann Schmitt

Herbert Tanner

Jorg Hensel

Jorg Krekel

Gerd Siekmann

Gunter Giesselmann

Franz-Ludwig Dahm

Rolf Ackermann

Ferdinand Theissen

Hans Schaefer

Wilhelm Alfons Schuler

Gregor Schuster

Anne Rindfuss

Ludwig-Karl Schworzer

Manfred Kruger

Rudolf Vanheertum

Wolf Dieter Pfeifer

Gerhard Sperka

Georg Franz

Horst Hillenbrand

Gerhard Bach

Ullrich Gora

The residual gases obtained in the production of cyanuric chloride having a pressure of 1-5 bar (absolute) preferably 1-4 bar, are worked up by leading them into the lower portion of a column, reacted in the column with at least the equivalent amount of hydrogen cyanide to form cyanogen chloride and led in countercurrent flow to the water charged to the upper portion of the column whereupon the aqueous solution of cyanogen chloride formed is withdrawn from the lower portion of the column and preferably is returned into the production portion of the plant for recovery of the cyanogen chloride while the purified waste gas of the column leaves in the upper portion of the column.

Working up of the residual gases resulting from the production of

In order to be independent of the situation in regard to methane and natural gas and at the same time to obtain a heating gas there is employed in the hydrocyanic acid-methane-ammonia process (the BMA process) in place of methane an alkanol or alkanediol having 2-4 carbon atoms, preferably ethyl alcohol, and this is reacted with ammonia in a C:N ratio of 0.8:1 to 2:1. Optionally additional hydrogen can be present.

Process for the production of hydrogen cyanide

There is provided an apparatus for bringing into contact liquids at least one of which is viscous, the apparatus consisting essentially of a tubular container, a first nozzle from introducing a liquid in the upper portion of the container, at least one other nozzle lower than the first nozzle for introducing a different liquid, the tubular container being closeable at the tap thereof and downward from said other nozzle being constricted breast shaped to form a discharge opening, said other nozzles are preferably of polished steel, said other nozzles consist essentially of at least one tangential spray means arranged in at least one row, said other nozzles being slightly above said constriction and being directed in the direction of the upper closeable device or said first nozzle and wherein the discharge opening can discharge into another container which is permanently or detachably connected to the tubular container, said further container can be provided with means for establishing reduced pressure or superatmospheric pressure.

Apparatus for bringing liquids in contact

A process for the preparation of .epsilon.-caprolactone comprising:

Preparation of .epsilon.-caprolactone

Nicotinamide is prepared from nicotinonitrile by hydrolysis at 120.degree. to 200.degree. C. employing alkali hydroxide.

Process for the production of nicotinamide

Methionine and potassium are recovered from the recycling solution of the potassium carbonate-methionine process by concentrating the mother liquor after the methionine precipitation and with cooling carbonating the mother liquor.

Process for the recovery of methionine and potassium bicarbonate

Suspension or solutions of cyanuric chloride in water containing organic solvents are prepared at high mixing velocities and low temperatures with resulting low degree of hydrolysis by introducing liquid cyanuric chloride through a nozzle in the upper portion of the mixing apparatus in countercurrent flow to upwardly flowing solvent introduced from at least one lower nozzle above a breast shaped constriction in the lower, open portion of the apparatus. In this way the chamber walls are always covered with an unbroken layer of liquid. The process can be carried out at normal, reduced or elevated pressure. At reduced pressure by evaporation of the solvent there is simultaneously a cooling of the system.

Process for the production of suspension or solutions of cyanuric

Finely divided suspensions of cyanuric chloride in organic solvents which are practically water free are prepared at high mixing velocities and low temperatures by introducing liquid cyanuric chloride through a nozzle in the upper portion of the mixing apparatus in countercurrent flow to upwardly flowing solvent introduced from at least one lower nozzle above a breast shaped constriction in the lower open portion of the apparatus. In this way the chamber walls are always covered with an unbroken layer of liquid. The process can be carried out at normal, reduced or elevated pressure. At reduced pressure by evaporation of the solvent there is simultaneously a cooling of the system.

Process for the production of suspension or solution of cyanuric

Pyridine and 3-methylpyridine prepared by the catalytic reaction of acrolein or a mixture of acetaldehyde and acrolein with ammonia is recovered from the gas mixture formed by cooling the gas mixture and working up the condensate separated in the cooling. The gaseous mixture is first cooled to a temperature between 40.degree. and about 80.degree. C. and then cooled to a temperature between about 10.degree. and below 40.degree. C.

Process for the recovery of pyridine and 3-methylpyridine

Glycidyl methacrylate is produced by transesterifying methyl methacrylate with glycidol in the presence of a polymerization inhibitor and a transesterification catalyst in which the catalyst is a salt of formula MeX where Me is an alkali metal ion and X is a cyanide, cyanate or thiocyanate ion.

Process for the production of glycidyl methacrylate

Catalysts used in the epoxidation or hydroxylation of water soluble olefinic compound with hydrogenperoxide are recovered by separating the catalyst as a distillation residue, the distillation residue is introduced into an inert material which is in whirling movement, e.g., as a fluidized bed, the organic compounds contained in the distillation residue are burned with oxygen or oxygen containing gases whereupon the catalyst compound separated on the inert whirling material together with the portion of the catalyst compound which accumulates in the solids separator connected at the outlet of the reactor is dissolved in water and the solution obtained again used for epoxidation or hydroxylation.

Process for the recovery of catalysts in the epoxidation and

Pyridine and 3-methyl pyridine are prepared by reacting acrolein with ammonia in the gas phase on a catalyst in a fluidized bed. The acrolein and ammonia are introduced separately in gaseous form into the reactor.

Process for the production of pyridine and 3-methyl pyridine

Process for isolating propylene glycol diacarboxylates in the preparation of propylene oxide by reaction of propylene with a solution of percarboxylic acid in an organic solvent, the boiling point of which is lower than that of the carboxylic acid which corresponds to the percarboxylic acid used as the epoxidizing agent, and higher than that of propylene oxide, separation, by distillation, of the reaction mixture which essentially contains propylene oxide, the carboxylic acid corresponding to the percarboxylic acid used as the epoxidizing agent and one or more of the by-products propyleneglycol, propylene glycol monocarboxylate and propylene glycol dicarboxylate as well as propylene and the organic solvent, into a fraction containing propylene oxide and propylene and a fraction containing the carboxylic acid, the by-products mentioned and the organic solvent and further separation of the fractions into the individual components by distillation. The fraction containing the carboxylic acid, one or more of the by-products propylene glycol, propylene glycol monocarboxylate and propylene glycol dicarboxylate, and the organic solvent is distilled in a column at pressures of 1.5 to 6 bars and with an average residence time of 10 to 90 minutes in the sump. The organic solvent is removed as the top product and the carboxylic acid and the corresponding propylene glycol dicarboxylate is obtained as the sump product. From the sump product the propylene glycol dicarboxylate is isolated in a manner which is in itself known.

Process for isolating propylene glycol diesters in the preparation of

Pure racemic acid (dl-tartaric acid) and meso tartaric acid are produced by reaction of an alkali maleate with aqueous hydrogen peroxide in the presence of an alkali tungstate in a process wherein the molar ratio of hydrogen peroxide to maleic acid is greater than 1:1 and the alkali salt of cis-epoxysuccinic acid formed together with the alkali tungstate, in a given case after destroying the excess hydrogen peroxide, are converted to free cis-epoxysuccinic acid and free tungstic acid by leading them over a strongly acidic cation exchanger, whereupon the hydrolysis of the free cis-epoxysuccinic acid to racemic acid and meso-tartaric acid can take place either in the presence of or the absence of the free tungstic acid, whereby the tungstic acid in the case of catalyst free hydrolysis before, and in the case of catalyst containing hydrolysis after this hydrolysis is removed with an anion exchanger and the racemic acid is then in known manner crystallized out of the tungstic acid free hydrolysis mixture by lowering the temperature in a given case with evaporation of water, whereupon the meso-tartaric acid remains in the mother liquor, and there is recovered from the mother liquor either by crystallization or by evaporation to dryness, in a given case in admixture with racemic acid, unreacted cis-epoxysuccinic acid and maleic acid, while the anion exchanger laden with the tungstic acid is regenerated in known manner with dilute aqueous alkali and, in a given case, the resulting solution of alkali tungstate, eventually after treatment with activated carbon is returned directly into the epoxidation step. There is also disclosed a process for the separation of maleic acid from synthetic tartaric acid containing maleic acid in which an aqueous solution of the crude tartaric acid which can also still contain the catalyst used, is led over a basic anion exchanger which is present in the hydroxyl or tartrate form.

Process for the production of pure racemic acid and mesotartaric acid

Nicotinamide is recovered from the reaction mixture resulting from the hydrolysis of nicotinonitrile at elevated temperature by converting the nicotinamide into a melt while removing the solvent.

Process for the recovery of nicotinamide

Growing community of inventors

Hanau, Germany

Gerd Schreyer