摘要:
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 The formic acid is withdrawn at the bottom end of the column as an azeotrope with water, the azeotrope being in the liquid state or preferably in the vapor state.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Olefinically unsaturated compounds are hydroformylated continuously, the olefin being passed into the lower region of the reactor, under from 1 to 40 bar and at from 50.degree. to 140.degree. C. with the aid of a rhodium complex as a catalyst in a hydroformylation reactor having a liquid reaction zone which occupies about 60-85% of the reactor volume, the gaseous products and reactants being removed from the hydroformylation reactor, the products being isolated and the major part of the remaining gas being recycled to the reactor by the cycle gas method, by a process in which from 20 to 80% by volume of the cycle gas is fed into the hydroformylation reactor above the liquid reaction zone and/or below the liquid surface in the top fourth of the liquid reaction zone.
摘要:
Preparation of C.sub.3 - to C.sub.25 -alkanols by catalytic hydrogenation of corresponding crude C.sub.3 - to C.sub.25 -alkanols, as obtained in the cobalt-catalyzed hydroformylation of C.sub.2 - to C.sub.24 -olefins, by partial 80-95% hydrogenation conversion in a first stage using a silica supported nickel and molybdenum oxide catalyst and then completing the conversion in a second stage using a cobalt catalyst containing copper, manganese, molybdenum and,optionally other activating additives. The process is especially adapted to the economic preparation of C.sub.9 -C.sub.11 - and C.sub.13 -C.sub.15 -alkanols which are used to prepare high-grade plasticizer esters.