Abstract: A process for distilling an aqueous NPG mixture comprising NPG, a tertiary amine, water and the adduct of tertiary amine and formic acid (amine formate), said distillation being performed in a distillation column, which comprises drawing off a gaseous stream in the upper region of the column and feeding it to two condensers connected in series, the first condenser being operated in such a way that a portion of the gaseous stream is condensed in the first condenser and the second condenser being operated in such a way that the uncondensed portion of the gaseous stream is essentially fully condensed in the second condenser, the condensed stream from the first condenser being recycled fully or partly as reflux into the column.

Abstract: A process for preparing formic acid by reacting carbon dioxide with hydrogen in a hydrogenation reactor in the presence of a catalyst comprising an element of group 8, 9 or 10 of the Periodic Table, a tertiary amine and a polar solvent to form formic acid-amine adducts which are subsequently dissociated thermally into formic acid and tertiary amine.

Abstract: The present invention relates to a process for preparing formic acid by reacting carbon dioxide (1) with hydrogen (2) in a hydrogenation reactor (I) in the presence of a catalyst comprising an element of group 8, 9 or 10 of the Periodic Table, a tertiary amine comprising at least 12 carbon atoms per molecule and a polar solvent comprising one or more monoalcohols selected from among methanol, ethanol, propanols and butanols, to form formic acid/amine adducts as intermediates which are subsequently thermally dissociated, where a tertiary amine having a boiling point which is at least 5° C. higher than that of formic acid is used and a reaction mixture comprising the polar solvent, the formic acid/amine adducts, the tertiary amine and the catalyst is formed in the reaction in the hydrogenation reactor (I) and is discharged from the reactor as output (3).

Abstract: A process for preparing formic acid by reaction of carbon dioxide (1) with hydrogen (2) in a hydrogenation reactor (I) in the presence of a catalyst comprising an element of group 8, 9 or 10 of the Periodic Table, a tertiary amine comprising at least 12 carbon atoms per molecule and a polar solvent comprising one or more monoalcohols selected from among methanol, ethanol, propanols and butanols, to form formic acid/amine adducts as intermediates which are subsequently thermally dissociated, where the work-up of the output (3) from the hydrogenation reactor (I) is carried out by addition of water so as to increase the distribution coefficient of the catalyst between the upper phase (4) and the lower phase.

Abstract: The present invention relates to a process for distilling an aqueous polymethylol mixture which comprises a polymethylol of the formula (I) (HOCH2)2—C—R2??(I) in which each R is independently a further methylol group or an alkyl group having 1 to 22 carbon atoms or an aryl or aralkyl group having 6 to 22 carbon atoms, a tertiary amine, water and the adduct of tertiary amine and formic acid (amine formate), which comprises performing the distillation in a distillation column which is connected at the bottom to an evaporator, the bottom temperature being above the evaporation temperature of the monoester of formic acid and polymethylol (polymethylol formate) which forms during distillation. The present invention further relates to a composition comprising polymethylol and 1 to 10 000 ppm by weight of polymethylol formate, and to the use thereof.

Abstract: Process for obtaining formic acid by thermal separation of a stream comprising formic acid and a tertiary amine (I), in which a liquid stream comprising formic acid and a tertiary amine (I) in a molar ratio of from 0.5 to 5 is produced by combining tertiary amine (I) and a formic acid source, from 10 to 100% by weight of the secondary components present therein are separated off and formic acid is removed by distillation in a distillation apparatus at a bottom temperature of from 100 to 300° C. and a pressure of from 30 to 3000 hPa abs from the liquid stream obtained, the bottom discharge from the distillation apparatus being separated into two liquid phases and the upper liquid phase being recycled to the formic acid source and the lower liquid phase being recycled for separating off the secondary components and/or to the distillation apparatus.

Abstract: A process for preparing formic acid by reaction of carbon dioxide (1) with hydrogen (2) in a hydrogenation reactor (I) in the presence of a catalyst comprising an element of group 8, 9 or 10 of the Periodic Table, a tertiary amine comprising at least 12 carbon atoms per molecule and a polar solvent comprising one or more monoalcohols selected from among methanol, ethanol, propanols and butanols and also water, to form formic acid/amine adducts as intermediates which are subsequently thermally dissociated, with work-up of the output (3) from the hydrogenation reactor (I) in a plurality of process steps, where a tertiary amine-comprising stream (13) from the work-up is used as selective solvent for the catalyst, is proposed.

Abstract: The present invention relates to a process for purifying crude polymethylol which comprises polymethylol of the formula (I) (HOCH2)2—C—R2 ??(I) in which each R is independently a further methylol group or an alkyl group having 1 to 22 carbon atoms or an aryl or aralkyl group having 6 to 22 carbon atoms, and also hydroxy acid of the formula (IV) in which each R is independently as defined above, which comprises performing the purification in a distillation column, the bottom of the distillation column being connected to an evaporator with a short residence time. The present invention further relates to a composition comprising polymethylol and 1 to 10 000 ppm by weight of an ester of polymethylol and of a hydroxy acid and to the use thereof.

Abstract: The present invention relates to a process for recovering components from a low boiler mixture which is obtained in the distillation of hydrogenation effluents from the preparation of polymethylols, by multistage distillation of the low boiler mixture comprising a tertiary amine, water, methanol, polymethylol of the formula (I) methylolalkanal of the formula (II) alcohol of the formula (III) and an alkanal with a methylene group in the ? position to the carbonyl group, and in which each R is independently a further methylol group or an alkyl group having 1 to 22 carbon atoms or an aryl or aralkyl group having 6 to 22 carbon atoms, a first distillation stage involving separating the low boiler mixture into a higher-boiling, predominantly water-rich fraction and into a lower-boiling aqueous organic fraction comprising the tertiary amine, and the second distillation stage involving separating the aqueous organic fraction from the first distillation stage into a predominantly amine-containing fract

Abstract: Process for preparing formic acid by hydrogenation of carbon dioxide in the presence of a catalyst comprising an element of group 8, 9 or 10 of the Periodic Table, a tertiary amine and a polar solvent at a pressure of from 0.2 to 30 MPa abs and a temperature of from 20 to 200° C. to form two liquid phases, separation of the two liquid phases, wherein the liquid phase (B) enriched with the tertiary amine is recirculated to the hydrogenation reactor and the formic acid/amine adduct from the liquid phase (A) enriched with the formic acid/amine adduct and the polar solvent is thermally dissociated into free formic acid and free tertiary amine in a distillation unit and the tertiary amine liberated in the dissociation and the polar solvent are recirculated to the hydrogenation reactor.

Abstract: The preparation of hydroxypivalaldehyde is effected by aldolizing isobutyraldehyde with formaldehyde and subsequently working up the resulting reaction effluent by distillation, wherein the reaction effluent is fed to a distillation column which is operated at a top pressure in the range from 0.5 to 1.5 bar and in which a two-stage condensation is provided in the top region, in which the vapors are first conducted into a partial condenser operated at a temperature in the range from 50 to 80° C., whose condensate is recycled at least partly into the distillation column, and in which the vapors uncondensed in the partial condenser are fed to a downstream condenser operated at a temperature in the range from ?40 to +30° C., whose condensate is at least partly discharged.

Abstract: The preparation of hydroxypivalaldehyde is effected by aldolizing isobutyraldehyde with formaldehyde and subsequently working up the resulting reaction effluent by distillation, wherein the reaction effluent is fed to a distillation column which is operated at a top pressure in the range from 0.5 to 1.5 bar and in which a two-stage condensation is provided in the top region, in which the vapors are first conducted into a partial condenser operated at a temperature in the range from 50 to 80° C., whose condensate is recycled at least partly into the distillation column, and in which the vapors uncondensed in the partial condenser are fed to a downstream condenser operated at a temperature in the range from ?40 to +30° C., whose condensate is at least partly discharged.

Abstract: A process for catalytically hydrogenating methylolalkanals of the general formula in which R1 and R2 are each independently a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase over a hydrogenation catalyst, which comprises setting a pH of from 7.0 to 9.0 in the hydrogenation effluent by adding at least one tertiary amine, an inorganic base or an inorganic or organic acid to the hydrogenation feed.

Abstract: The invention relates to a process for preparing polymethylol compounds of the formula (I) where the radicals R are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 22 carbon atoms, by condensation of aldehydes having from 2 to 24 carbon atoms with formaldehyde in an aldol reaction using tertiary amines as catalyst to form alkanals of the formula (II) where the radicals R each independently have one of the abovementioned meanings, and subsequent hydrogenation of the latter. The particular inventive feature of this process is that the aldol reaction is carried out using an aqueous formaldehyde solution having a formic acid content of <150 ppm and preferably <100 ppm. In this way of carrying out the process, the formation of by-products can advantageously be prevented in a targeted manner and the yield of the desired polymethylol compound can thereby be increased.

Abstract: Process for the continuous preparation of an amine by reaction of a primary or secondary alcohol, aldehyde and/or ketone with hydrogen and a nitrogen compound selected from the group consisting of ammonia, primary and secondary amines at a temperature in the range from 60 to 300° C.

Abstract: The invention relates to a process for preparing polymethylol compounds of the formula (I) (HOCH2)2—C—R2 ??(I) where the radicals R are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 22 carbon atoms, by condensation of aldehydes having from 2 to 24 carbon atoms with formaldehyde in an aldol reaction using tertiary amines as catalyst to form alkanals of the formula (II) where the radicals R each independently have one of the abovementioned meanings, and subsequent hydrogenation of the latter. The particular inventive feature of this process is that the aldol reaction is carried out using an aqueous formaldehyde solution having a formic acid content of <150 ppm and preferably <100 ppm. In this way of carrying out the process, the formation of by-products can advantageously be prevented in a targeted manner and the yield of the desired polymethylol compound can thereby be increased.

Abstract: Process for the catalytic hydrogenation of methylolalkanals of the general formula where R1 and R2 are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase by means of hydrogen over a hydrogenation catalyst, wherein hydrogen is used in a molar ratio to methylolalkanal of greater than 1.

Abstract: A process is provided for the preparation of polymethylol compounds of formula (I): (HOCH2)2—C—(R)2 , ??(I) in which the radicals R independently of one another are each a further methylol group, an alkyl group having from 1 to 22 C atoms or an aryl or aralkyl group having from 6 to 22 C atoms, by (a) condensing aldehydes having from 2 to 24 C atoms with formaldehyde in an aldol reaction using tertiary amines as a catalyst to give alkanals of formula (II): in which the radicals R independently of one another are each as defined above, (b) then separating, by distillation, the reaction mixture obtained into a bottom product comprising predominantly the compounds of formula II and a low-boiling stream consisting of unconverted or partially converted starting materials, and (c) hydrogenating the distillation bottom, wherein the aldol reaction is carried out with an aqueous formaldehyde solution having a methanol content of 0.35 to 0.

Abstract: Process for the catalytic hydrogenation of methylolalkanals of the general formula where R1 and R2 are each, independently of one another, a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase by means of hydrogen over a hydrogenation catalyst, wherein hydrogen is used in a molar ratio to methylolalkanal of greater than 1.

Abstract: Process for the continuous preparation of an amine by reaction of a primary or secondary alcohol, aldehyde and/or ketone with hydrogen and a nitrogen compound selected from the group consisting of ammonia, primary and secondary amines at a temperature in the range from 60 to 300° C in the presence of a copper-containing catalyst, wherein the catalytically active composition of the catalyst prior to reduction with hydrogen comprises from 20 to 85% by weight of aluminum oxide (Al2O3), zirconium dioxide (ZrO2), titanium dioxide (TiO2) and/or silicon dioxide (SiO2), from 1 to 70% by weight of oxygen-containing compounds of copper, calculated as CuO, from 0 to 50% by weight of oxygen-containing compounds of magnesium, calculated as MgO, oxygen-containing compounds of chromium, calculated as Cr2O3, oxygen-containing compounds of zinc, calculated as ZnO, oxygen-containing compounds of barium, calculated as BaO, and/or oxygen-containing compounds of calcium, calculated as CaO, and less than 30% by weight of oxygen-