Hoechst Aktiengesellschaft

Heribert Tetzlaff

Hilmar Mildenberger

Bernhard Wojtech

Matthias Krull

Heinz Erpenbach

Siegbert Rittner

Arno Schulz

Winfried Lork

Harald Knorr

Stephen Lachhein

Wolfgang Scheibitz

Georg-Emerich Miess

Eitel Goedicke

Wilhelm Lendle

Joachim Semel

Christoph Porz

Gernot Kremer

Karl-Heinz Schwarz

The invention relates to a process for eliminating adsorbable organic halogen compounds from an aqueous phase, in particular from wastewater or from a process solution, in which the aqueous phase is treated with a nonaqueous extraction medium in a liquid-liquid extraction, which comprises, after the extraction, subjecting the adsorbable organic halogen compounds in the extraction medium to a Wurtz-Fittig reaction. Only small amounts of noncritical products such as NaOH and Hcl, which can be readily removed, are formed in the nonaqueous extraction medium. By means of this process, the cost of the chemicals which conventionally arises in the elimination of the adsorbable organic halogen compounds is considerably decreased.

Process for eliminating adsorbable organic halogen compounds from

The ampholytes are extracted from the reaction solution with a liquid cation exchanger which is immiscible with the acidic aqueous reaction solution, where the cation exchanger is dissolved in at least one organic solvent which is immiscible with water and forms an organic phase with the organic solvent. Subsequently the organic phase which is loaded with the ampholyte is separated from the reaction solution, and then the ampholytes are back-extracted from the organic phase with aqueous solvents. The product losses in the process are low, and the residual salt content is very low.

Process for the extractive removal of phospho- and sulfobetaines from

A large number of customary processes for separating amino acids fails when very polar hydrophilic amino acids with isoelectric points (IEP) which are close to one another are to be fractionated. Mixtures of L-glutamic acid (IEP=3.24) and L-phosphinothricin (IEP=2.6) produced by enzymatic transaminations of the corresponding .alpha.-keto acid have been difficult to separate to date. The invention relates to a process for separating L-phosphinothricin and L-glutamic acid, which comprises carrying out the separation as liquid/liquid extraction with two non-miscible aqueous phases as phase system, where the phase former contained in the phase system is a combination of at least two different water-soluble polymers or of at least one water-soluble salt and one water-soluble polymer, and the extraction is carried out by multistage countercurrent partition on the van Dijck principle.

Process for the extractive separation of L-phosphinothricin and

The invention relates to a process for separating N-methyl-2-pyrrolidone (NMP) from aqueous solutions which are obtained in industry, inter alia, in the production of heat-resistance polymers such as polyamides and polyimides. According to the invention, the extractants used are phenols which are sparingly soluble in water, are aliphatically monosubstituted and/or polysubstituted in the nucleus and have 4 to 16 carbon atoms in the straight-chain or branched, saturated or unsaturated aliphatic radical and have a boiling point which is preferably at least 20.degree.-25.degree. C. above the boiling point of NMP. If necessary, an inert, viscosity-reducing diluent is added.

Process for extracting N-methyl-2-pyrrolidone

In a process for the purification and recovery of a contaminated catalyst solution produced during carbonylation of methanol and/or methyl acetate and/or dimethyl ether and containing carbonyl complexes of rhodium, organic and/or inorganic promoters, undistillable organic impurities and acetic acid, acetic anhydride and ethylidene diacetate, the organic impurities and acetic acid, acetic anhydride and ethylidene diacetate are removed from the contaminatd catalyst solution by extraction at pressures from 35 to 450 bar and temperatures from 0.degree. to 120.degree. C. with a liquefied or supercritical gas, and the phase of the liquefied or supercritical gas is separated from the purified, promoter-containing catalyst solution, the phase of the liquefied or supercritical gas is separated by flash vaporization, the recovered gas is re-employed for extraction, acetic acid, acetic anhydride and ethylidene diacetate are separated off from the component which remains liquid, and are combined with the purified catalyst complex to prepare fresh catalyst solution and, finally, the organic impurities remaining as the residue on separation of the phase of the liquefied or supercritical gas is purged.

Process for the purification and recovery of the contaminated solution

The invention relates to a gentle process for the separation of enol ethers from mixtures containing water-soluble alcohols by extraction, wherein an aqueous solution of a base is used as the extraction agent in a phase ratio of the amounts of the aqueous phase: enol ether/alcohol mixture of at least 0.5:1 and the extraction is carried out in several stages or continuously with a theoretical number of stages of at least two. The process is particularly suitable for separating off enol ethers which readily decompose during distillation.

Process for separating off enol ethers from reaction mixtures containing

A process is disclosed for the separation of halogenated hydrocarbons from concentrated hydrochloric acid, which contains 10 to 37% by weight of hydrogen chloride. The hydrochloric acid is freed from the halogenated hydrocarbons in an extraction with paraffins having more than 7 carbon atoms, or with paraffin waxes having dropping points from 70.degree. to 160.degree. C. or with paraffin/paraffin wax mixtures, preferably in a continuous counterflow extraction or cross-flow extraction.

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Frankfurt am Main, Germany

Heribert Tetzlaff