Basf Aktiengesellschaft

Badische Anilin- & Soda-fabrik Aktiengesellschaft

Heinz Hohenschutz

Max Strohmeyer

Hans Kiefer

Johannes E Schmidt

Rudolf Kummer

Franz Merger

Gerhard Nestler

Gerhard Sandrock

Max Appl

Hans Juergen Nienburg

Eberhard Schaefer

Helmut Walz

Manfred Herr

Josef Gnad

Horst Buelow

Heinrich Elliehausen

Horst Kerber

Hans Moell

Werner Hagen

Werner Sachsze

Juergen Haug

Konrad Rauch

Ludwig Schroff

Dieter Hesse

Guenter Dinkhauser

Hans-Juergen Nienburg

Theo Teutsch

Anhydrous or substantially anhydrous formic acid is prepared by hydrolyzing methyl formate in the presence of a formamide and then obtaining the formic acid from the hydrolysis mixture by distillation, by a method in which the hydrolysis is carried out in the presence of 0.5-3 moles, per mole of methyl formate, of a water-soluble formamide of the general formula I ##STR1## where R.sup.1 and R.sup.2 are each alkyl or together form an alkylene group, giving a 5-membered to 7-membered ring, with the proviso that the sum of the carbon atoms in R.sup.1 and R.sup.2 is 5 or 6 and, in the case of an alkylene group, a carbon atom which is not directly bonded to the N atom can be replaced by an oxygen atom.

Preparation of formic acid

A process for completing the esterification of aliphatic carboxylic acids of 1 to 8 carbon atoms with aliphatic or cycloaliphatic alcohols of 3 to 10 carbon atoms at the boiling point of the alcohol in a column operated with bottom heating, the lower space of the column being free from fitments, the middle space being provided with a packing and the upper space being provided with a packing or other fitments, in which process the water of esterification is driven off at the top of the column by azeotropic distillation, the starting mixture is fed into the side of the column from 5 to 10 m above the liquid level, the ester formed is taken off as liquid from the column bottom, and the column is operated with flooding such that the liquid level is from 6 to 10 m, with the liquid mixture filling the lower column space, which is free from fitments, and the lower part of the packed layer above the said space.

Process for completing the esterification of carboxylic acids with

Formic acid is prepared by hydrolyzing methyl formate, the hydrolysis being carried out in the presence of from 0.5 to 3.0 moles, per mole of methyl formate, of a base which contains tertiary nitrogen atoms, boils at not less than 180.degree. C. under atmospheric pressure and has a pKa from 4 to 9, N-substituted imidazole derivatives being the preferred bases.

Carboxylic acids of the general formula I

Isolation of formic acid from its aqueous solutions

p-alkylphenols are manufactured by continuous reaction of phenol with olefins in the presence of a pulverulent polystyrenesulfonic acid ion exchanger which is suspended in the reaction mixture.

Manufacture of p-alkylphenols

Oxo aldehydes containing iron pentacarbonyl are purified by distilling them in the presence of air.

Purification of oxo aldehydes

Formamide is manufactured continuously from methyl formate and gaseous ammonia. The reaction is carried out in a reactor at from 30 to 90.degree. C, from 5 to 20% by volume of the reactor output is drawn off continuously and fed to the formamide working-up stage, and the remainder of the reactor output is cooled, in an external circuit maintained by means of a pump, to from 25 to 60.degree. C and is mixed with the amount of fresh methyl formate required for steady-state operation, after which the appropriate amount of gaseous ammonia is introduced into the stream of liquid through a jet, by the sucking-jet principle, and the stream of liquid is recycled to the reactor.

Continuous manufacture of formamide

Formic acid is purified by extractive distillation of its aqueous solutions using a basic extractant, followed by distillation of the bottom mixture first obtained, the extractant used being N-formylmorpholine.

Purification of formic acid by extractive distillation

A process for isolating carboxylic acids from residues of the oxo reaction which are obtained as residues, on hydroformylation of ethylene or propylene, optionally after removing a part of the aldehydes produced, subsequent hydrogenation, treatment with aqueous alkali metal hydroxide solutions and subsequent distillation, wherein the residues are acidified with strong mineral acids to a pH of from 2-4, the acidified mixture not containing more than 5 parts by weight of water per part by weight of the carboxylic acids contained in the mixture, the organic phase is then separated off and the carboxylic acids are isolated therefrom by distillation at pressures below 150 mbar. The carboxylic acids obtained can be used as solvents or for the manufacture of esters.

Recovery of carboxylic acids from oxo residues

Formic acid is isolated from mixtures containing formic acid, methyl formate, methanol and water by fractional distillation, the mixture being fed into the upper half of the distillation column and 5 to 15 theoretical plates being maintained above the feed point and 10 to 25 theoretical plates below the feed point. The formic acid is withdrawn at the bottom end of the column as an azeotrope with water, the azeotrope being in the liquid state or preferably in the vapor state.

Recovery of the formic acid/water azeotrope by distillation

Solutions of cobalt carbonyl and cobalt carbonyl hydride in organic solvents are prepared by treating aqueous solutions of cobalt salts with carbon monoxide and hydrogen at a temperature of from 50.degree. to 200.degree.C and a pressure of from 50 to 500 atmospheres in the presence of solvents which are sparingly water-miscible or are water-immiscible and which have a content of cobalt carbonyl, cobalt carbonyl hydride or mixtures thereof, the starting materials and the organic solvents being passed cocurrently through a zone in which a turbulent flow is maintained. The improvement includes using n-butanol as solvent. Solutions of cobalt carbonyl and cobalt carbonyl hydride in n-butanol are suitable as catalyst solutions for oxo syntheses.

Continuous manufacture of solutions of cobalt carbonyl and cobalt

An improvement in the process for the manufacture of predominantly straight-chain aldehydes by hydroformylation of olefinically unsaturated compounds of 2 to 20 carbon atoms with carbon monoxide and hydrogen in which, in a first stage, aqueous cobalt solutions are treated with carbon monoxide and hydrogen at temperatures of 50.degree. to 200.degree.C and pressures of 100 to 400 atmospheres in the presence of active charcoal, zeolites or basic ion exchangers which are charged with cobalt carbonyl, in a second stage cobalt carbonyl-hydride is extracted from the reaction mixtures thus obtained, at temperatures of 20.degree. to 180.degree.C and pressures of 1 to 400 atmospheres, by means of olefinically unsaturated compounds which must be water-insoluble and liquid under the conditions used, the aqueous phase is separated off and the organic phase is transferred to a third stage and in this stage, after introducing olefinically unsaturated compounds if the latter have only been used partially for the extraction, the hydroformylation is carried out at temperatures of 70.degree. to 170.degree.C and pressures of 100 to 400 atmospheres, the improvement being that the extraction in the second stage is carried out as a co-current extraction whilst maintaining turbulent flow.

Manufacture of predominantly straight-chain aldehydes

The formation of an emulsion when working up reaction mixtures containing butyraldehydes and cobalt is avoided by a treatment with gases containing molecular oxygen in an aqueous acid medium at an elevated temperature, at least twice the amount of molecular oxygen stoichiometrically required for the oxidation of the cobalt being used per gram atom of cobalt present in the oxoreaction mixture.

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Mannheim, Germany

Heinz Hohenschutz