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:
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:
But-2-enes are obtained from C.sub.4 -hydrocarbon mixtures which contain but-1-ene and may or may not contain but-2-enes by catalytic isomerization of the but-1-ene to but-2-enes in an isomerization zone at elevated temperatures by a process in which the isomerization is carried out in combination with a distillative separation zone, the said hydrocarbon mixture being fed to the isomerization zone and/or distillative separation zone, the isomerization mixture obtained from the isomerization zone is passed into the distillative separation zone, a but-1-ene-containing fraction is removed above the lower third of the distillative separation zone and passed into the isomerization zone, and the but-2-enes or a fraction containing these are or is removed in the lower third of the distillative separation zone.
摘要:
Aldehydes are obtained from the gaseous product of the hydroformylation of olefinically unsaturated compounds using a rhodium catalyst by a process (cf. FIG. 2) in which(a) this gaseous product is introduced, without being cooled or depressured, into a distillation column D,(b) the top fraction from this column is cooled in a condenser K so that the greater part of the aldehydes contained therein is condensed,(c) the condensate is separated, in a separator A, into a gas phase and a liquid phase,(d) the gas phase from A, after waste gas has been separated off, is again brought to the hydroformylation pressure by means of a compressor P, and is returned to the reactor as a recycle gas,(e) the liquid phase from A is returned to D, and(f) the aldehydes are taken off from column D as liquid bottom products and/or as a vaporous side stream.
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:
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:
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:
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.
摘要:
A process for obtaining isobutene from a C.sub.4 -hydrocarbon mixture containing isobutene, by reacting the mixture with a primary alcohol in the presence of an acid condensing agent and decomposing the resulting tertiary ether in the presence of an acid catalyst at an elevated temperature, wherein a primary C.sub.3 - or C.sub.4 -alcohol is used.