Abstract: Acyl chlorides are prepared by reacting a carboxylic acid or its anhydride with carbonyl chloride in the presence of a carboxamide of the formula I ##STR1## where R.sup.1 is a radical of the formula ##STR2## R.sup.2 and R.sup.3 are each alkyl of 1 to 9 carbon atoms, R.sup.4 and R.sup.5 are each hydrogen or alkyl of 1 to 9 carbon atoms and the two radicals R.sup.1 and R.sup.2 may furthermore be a hydrocarbon radical which completes the moiety ##STR3## to form a heterocyclic structure, and the stated alkyl and hydrocarbon radicals may furthermore contain substituents which are inert under the reaction conditions.

Abstract: Formamide is prepared continuously from methyl formate and ammonia, pure methanol being recovered, by a process wherein(a) the reaction of methyl formate and ammonia is carried out predominantly in the liquid phase in the upper region of a reaction column R having a total of from 15 to 30 theoretical plates,(b) the methanol formed in this reaction is removed, together with small amounts of formamide, from the column or the evaporator in vaporus form at the level of plates 1-5 (counted from the bottom),(c) the formamide is removed from this methanol/formamide mixture, together with small amounts of methanol, in a distillation column D1 and recycled to R, and(d) the small amounts of methanol contained in the bottom product from R, which substantially consists of formamide and in this column should be at from 110.degree. to 130.degree. C., are separated off in a distillation column D2.

Abstract: Formic acid is recovered, by distillation, from its mixtures with solvents of the general formula I ##STR1## where R.sup.1 is hydrogen, methyl, ethyl or vinyl and R.sup.2 and R.sup.3 are each alkyl, cycloalkyl, aryl or aralkyl, or R.sup.2 and R.sup.3 together form a 1,4- or 1,5-alkylene group, in each case of not more than 8 carbon atoms, with the provisos that the sum of the number of carbon atoms in R.sup.2 and R.sup.3 is 7 to 14 and that only one of these radicals is aryl, by a method in which the distillation is carried out in the presence of a carboxamide II which is selected from the group consisting of formamide, acetamide, propionamide and the same compounds substituted by N-methyl or N,N-dimethyl, and which has a boiling point lower than that of the solvent I.

Abstract: A process for the preparation of acetic acid esters CH.sub.3 --CO--O--R.sup.1 (I, R.sup.1 =an organic radical other than methyl and ethyl) by alkali-catalyzed trans-esterification of an acetic acid ester CH.sub.3 --CO--O--R.sup.2 (II, R.sup.2 =methyl or ethyl) with an alcohol R.sup.1 --OH (III), accompanied by elimination of the alcohol R.sup.2 --OH (IV), wherein(a) the trans-esterification reaction is carried out in the middle section K.sub.M of a distillation column K, the alcohol III being fed as liquid into the upper zone and the ester II into the lower zone of K.sub.M,(b) the alkaline catalyst is introduced into the upper part K.sub.U of K,(c) the alcohol IV, or a mixture of IV and the ester II, is taken off the top of the column,(d) the mixture obtained from (c) (unless the alcohol IV alone is obtained) is separated in the column section K.sub.U or in a stripper column K.sub.S into IV and the azeotrope of II and IV, and the latter is recycled to the lower zone of K.sub.

Abstract: Acid constituents, eg. H.sub.2 S and CO.sub.2 or their mixtures, are removed from industrial gases or natural gases by means of a washing agent which contains the methyl isopropyl ethers of polyethylene glycols. The washing can be carried out with simultaneous drying of the gas, especially in the case of natural gases, since the anhydrous ethers are able to absorb water.

Abstract: A process for the production of anhydrous or substantially anhydrous formic acid by hydrolysis of methyl formate which is carried out in a column having an upper fractionating section, a middle hydrolysis section and a lower extraction section and in which(a) the hydrolysis is carried out in the middle section of the columm, with water and methyl formate in countercurrent,(b) the resulting formic acid is extracted, in the lower section of the column, by means of a carboxylic acid amide which is fed into the lower end of the middle section of the column,(c) the extract phase, consisting in the main of formic acid and the carboxylic acid amide, is distillatively dehydrated, or substantially dehydrated, in the lower section of the column,(d) the methanol and uncovered methyl formate are removed by fractional distillation in the upper section of the column and(e) the pure formic acid or concentrated aqueous formic acid is distilled from the anhydrous or substantially anhydrous extract phase in a second column, le

Abstract: Dimethyl carbonate is obtained pure, from its solutions in methanol, by extractive distillation carried out with a temperature of from 60.degree. C. at the top to 250.degree. C. at the bottom of the column and employing, as the extractant, an aprotic organic liquid which is substantially inert toward dimethyl carbonate, boils at above 100.degree. C. at standard pressure, is miscible with dimethyl carbonate in all proportions and has a dielectric constant .epsilon. of from 4 to 90 and a dipole moment .mu. of from 1.5 to 5 Debye.