Basf Aktiengesellschaft

Friedrich Sauer

Maximilian Vicari

Hans Hasse

Heinz Auer

Bernd Bessling

Till Adrian

Hans Hammer

Gerhard Wagner

Harald Schwahn

Armin Volker Grenacher

Gerd Kaibel

Dieter Hermeling

Martin Merger

Peter Lechtken

Michael R&ouml;per

Heinrich-Josef Blankertz

Johannes E Schmidt

Karl Fischer

Rainer Ohlinger

Thomas Domschke

Klaus Diehl

Rolf Seubert

Gerhard Borchert

Willi Sch&ouml;nmann

Matthias Fankhaenel

Willy Van Pee

Petra Deckert

Dieter Zimmerling

Rudolf Schmidt

Siegfried Krueger

Horst Brandtstaedter

Hans J Astheimer

Jaak Van Steen

The invention relates to a method for the separation of ascorbic acid from a mixture containing ascorbic acid and-keto-L-gulonic acid in a polar, preferably aqueous solvent, by means of liquid/liquid extraction using an amide. The method preferably also comprises steps for the back-extraction of the ascorbic acid, recycling of the extraction solvent and/or the back extraction solvent and for isolation of the ascorbic acid from the back extraction solvent. The invention further relates to a method for the production of ascorbic acid from KGA and isolation of the ascorbic acid so produced.

Method for the separation of ascorbic acid from a polar solvent containing ascorbic acid and 2-keto-L-gulonic acid

The invention relates to an apparatus and a process for the preparation of anhydrous or substantially anhydrous formic acid. This apparatus is constructed partly or entirely of substantially zirconium-free materials. The extractant employed is a liquid of the general formula I where the radicals Rand Rare alkyl, cycloalkyl, aryl or aralkyl groups, or Rand Rjointly, together with the N atom, form a heterocyclic 5- or 6-membered ring, and only one of the radicals is an aryl group, and where Ris hydrogen or a C&#x2013;C-alkyl group. The apparatus has a synthesis reactor (), a hydrolysis reactor (), three distillation devices () and an extraction device ().

Material for a facility for the production of anhydrous formic acid

The invention relates to a process for obtaining anhydrous or substantially anhydrous formic acid, in which firstly aqueous formic acid is prepared by hydrolysis of methyl formate and is freed from water in the subsequent work-up. The process has the special feature that steam, which is employed for the hydrolysis of methyl formate and for heating a distillation column serving for work-up, is also used as stripping steam for waste-water stripping. The stripped waste water is produced during work-up.

Waste water treatment in a method for producing formic acid which is free of water

The invention relates to a process for obtaining anhydrous or substantially anhydrous formic acid, in which firstly aqueous formic acid is produced by hydrolysis of methyl formate, with the methanol content in the methyl formate having been reduced in advance. The process according to the invention has the special feature that&#x2014;before the hydrolysis of the methyl formate&#x2014;the methanol content of the methanol-containing methyl formate is reduced in a distillation column, this distillation column simultaneously being employed for other separation functions during work-up of the formic acid.

Method for producing anhydrous formic acid

The invention relates to a process for obtaining anhydrous or substantially anhydrous formic acid in which, during the work-up, a compound of the general formula Iwhere the radicals R1 and R2 are alkyl, cycloalkyl, aryl or aralkyl groups, or R1 and R2 jointly, together with the N atom, form a heterocyclic 5- or 6-membered ring, and only one of the radicals is an aryl group, and where R3 is hydrogen or a C1-C4-alkyl group,is employed simultaneously as extractant for formic acid and as antifoam for a distillation process.

Utilization of an extracting agent as antifoaming agent in the production of anhydrous formic acid

Method for hydroformylating olefins having between 20 and 400 carbon atoms

Method for cleaning off-gas flows

Hydroformylation process

A process for isolating triphenylphosphine (TPP) from a triphenylphosphine/aluminum chloride complex dissolved in chlorobenzene by decomplexation, hydrolysis and extraction using water and subsequent separation of the liquid/liquid dispersion, which is composed of a TPP-containing chlorobenzene phase and of an containing Al and Cl compounds aqueous phase, into a TPP-containing chlorobenzene phase and into a TPP-free, aqueous phase, containing Al and Cl compounds, wherein water is dispersed in the chlorobenzene phase in a ratio of 0.6-0.95 kg of water per kg of chlorobenzene solution in a 1st mixing apparatus in such a way that the temperature resulting from the hydrolysis is in the range from 60.degree. to 90.degree. C., the dispersion being carried out with residence times of 5-30 minutes and energy densities of 2-10 kW/m.sup.3, a second dispersion is carried out in a 2nd mixing apparatus with residence times of 5-60 minutes and energy densities of 0.05-0.5 kW/m.sup.3, and the heavier TPP-containing chlorobenzene phase is separated from the lighter TPP-free, aqueous phase containing Al and Cl compounds in a phase separator.

Isolation of triphenylphosphine

Very pure maleic anhydride having a stable color is obtained by fractional distillation of crude maleic anhydride by a method in which the maleic anhydride vapor separated off from low boilers and high boilers is partially condensed so that from 0.5 to 15% by weight of the maleic anydride vapor is separated off from the vapor phase as a liquid precondensate, and the remaining very pure maleic anhydride vapor is then completely condensed.

Obtaining very pure maleic anhydride from crude maleic anhydride

A process for the manufacture of 4,4'-diphenylmethane diisocyanate and a mixture of diphenylmethane diisocyanate isomers containing a controllable amount of uretdione and hydrolizable chlorine which comprises feeding crude MDI to an evaporator, condensing a head fraction in two stages in the presence of an inert gas, feeding the first stage condensate to a distillation column, producing a mixture of diphenylmethane diisocyanate isomers as an overhead, producing 4,4'-diphenylmethane diisocyanate as a side draw, and condensing each of the overhead and side draw in two stages in the presence of an inert gas.

Process for the manufacture of 4,4'-diphenyl-methane diisocyanate and a

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Obersülzen, Germany

Friedrich Sauer