Abstract: In a process for preparing phthalic anhydride by catalytic gas-phase oxidation of o-xylene or naphthalene or o-xylene/naphthalene mixtures with a gas comprising molecular oxygen over a coated catalyst comprising an inert, nonporous support material on which a catalytically active composition comprising titanium dioxide and vanadium pentoxide is applied in layer form, a catalyst whose catalytically active composition comprises from 3 to 6% by weight of vanadium pentoxide, calculated as V2O5, from 0.3 to 0.5% by weight of a cesium compound, calculated as Cs, and the remainder to 100% by weight of titanium dioxide in the anatase modification is used in the presence or absence of a coated catalyst, differing therefrom, for the catalytic gas-phase oxidation of o-xylene or naphthalene or o-xylene/naphthalene mixtures and, in the presence of such a second catalyst, the latter is used in a combined bed with the catalyst of the above composition in the reactor.

Abstract: A process for the preparation of methyl formate by reacting methanol and carbon monoxide in the presence of an alkali metal alcoholate or alkaline earth metal alcoholate at from 30.degree. to 150.degree. C. and from 50 to 300 bar, wherein a nonionic complexing agent is used to bind the alkali metal cations or alkaline earth metal cations.

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: 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