Abstract: The invention relates to a process for preparing ethylenediamine by hydrogenation of aminoacetonitrile over a catalyst, wherein the hydrogenation is carried out in a solution comprising aminoacetonitrile, water in a proportion of from 0 to 60% by weight and a solvent and the aminoacetonitrile comprised in the solution is fed into the reaction vessel at a rate which is not greater than the rate at which the aminoacetonitrile reacts with hydrogen in the hydrogenation.

Abstract: The invention relates to a process for preparing an ethylene amine mixture, which comprises hydrogenating an amino nitrile mixture comprising at least 30% by weight of aminoacetonitrile (AAN) and at least 5% by weight of iminodiacetonitrile (IDAN) in the presence of a catalyst. Ethylenediamine (EDA) and/or diethylenetriamine (DETA) and, if appropriate, further ethylene amines can be isolated from the ethylene amine mixtures obtained.

Abstract: The invention relates to a process for preparing tetraethylenepentamine (TEPA) by hydrogenation of diethylenetriaminediacetonitrile (DETDN) over a catalyst. If appropriate, DETDN can also be present as a constituent of an amino nitrile mixture which additionally comprises diethylenetriaminemonoacetonitrile (DETMN).

Abstract: The invention relates to a process for preparing triethylenetetramine (TETA), which comprises hydrogenating ethylenediaminediacetonitrile (EDDN) in the presence of a catalyst and a solvent.

Abstract: The invention relates to a process for preparing an amino nitrile mixture comprising aminoacetonitrile (AAN) and from 5 to 70% by weight of iminodiacetonitrile (IDAN), which comprises heating crude AAN which is largely free of formaldehyde cyanohydrin (FACH-free) at a temperature of from 50 to 150° C.

Abstract: A method for removing acid gases from a fluid stream in which the fluid stream, in contact with an absorption medium in the form of an aqueous amine solution in an absorber, is passed through a first absorption zone and through a second absorption zone, the loaded absorption medium is passed into a first regeneration zone, a part of the resultant partially regenerated absorption medium is passed into the first absorption zone, the other part of the partially regenerated absorption medium is passed into a second regeneration zone, and a part of the resultant regenerated absorption medium is passed into the first absorption zone and the other part of the regenerated absorption medium is passed into the second absorption zone. The method can be carried out with few changes to apparatus of a hot pot plant, the energy requirement for the same performance being no higher than in the hot pot process.

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile, by contacting the vaporous product of the ammoxidation stage directly with a liquid organic solvent (quench), and hydrogenating the phthalonitrile in the resulting quench solution or suspension, wherein the organic solvent is N-methyl-2-pyrrolidone (NMP).

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile and hydrogenating the phthalonitrile, which comprises contacting the vaporus product of the ammoxidation stage directly with a liquid organic solvent or with molten phthalonitrile (quench), partly or fully removing components having a boiling point lower than phthalonitrile (low boilers) from the resulting quench solution or suspention or phthalonitrile melt and, before the hydrogenation, of the phthalonitrile, not removing any products having a boiling point higher than phthalonitrile (high boilers).

Abstract: A process comprising: continuously distilling a crude xylylenediamine in a column to form a pure xylylenediamine and a bottom product, wherein the column comprises a distillation column having a side draw and the distillation column is operated under a reduced pressure and a bottom temperature of 185° C.

Abstract: Process for preparing o-, m- or p-xylylenediamine by hydrogenation of o-, m- or p-phthalonitrile in the presence of a heterogenous catalyst, which comprises feeding a solution of the phthalonitrile in the corresponding isomer of crude xylylenediamine into the hydrogenation reactor, with the crude xylylenediamine having a purity in the range from 85 to 99.7% by weight and a content of higher boilers in the range from 0.3 to 15% by weight.

Abstract: A process for preparing a xylylenediamine by heterogeneously catalyzed hydrogenation of a phthalonitrile, wherein the hydrogenation is carried out in the presence of a cobalt skeletal catalyst, of an alkali metal hydroxide and of an alcohol and/or ether as the solvent, at an absolute pressure in the range from 1 to 100 bar and a temperature in the range from 40 to 150° C.

Abstract: Processes for preparing a xylylenediamine by continuous hydrogenation, wherein the processes comprise: introducing a liquid circulation stream comprising a phthalonitrile and ammonia into a reactor to continuously hydrogenate the phthalonitrile in the presence of a heterogenous catalyst and the ammonia such that a reactor effluent comprising the xylylenediamine is formed; drawing off a portion of the reactor effluent to provide a first recycle stream; mixing at least a portion of the first recycle stream in a mixing unit with liquid ammonia and fresh phthalonitrile in solid or molten form to provide a second recycle stream; and recycling the second recycle stream to the liquid circulation stream, or wherein the second recycle stream and any remaining unmixed portion of the first recycle stream are both recycled to the liquid circulation stream.

Abstract: A process for preparing a xylylenediamine by heterogeneously catalyzed hydrogenation of a phthalonitrile, wherein the hydrogenation is carried out in the presence of a nickel catalyst, of water, of an alkali metal hydroxide and of an ether as a solvent, at an absolute pressure in the range from 1 to 100 bar, at a temperature in the range from 40 to 150° C. and without addition of ammonia.

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile and hydrogenating the phthalonitrile, which comprises contacting the vaporous product of the ammoxidation stage directly with a liquid organic solvent or with molten phthalonitrile (quench), partly or fully removing components having a boiling point lower than phthalonitrile (low boilers) from the resulting quench solution or suspension or phthalonitrile melt and, after the low boiler removal and before the hydrogenation, removing products having a boiling point higher than phthalonitrile (high boilers).

Abstract: The invention relates to a method for producing xylylenediamine, comprising the following steps: ammonoxidation of xylol to form phthalodinitrile and hydrogenation of the phthalodinitrile, whereby the vaporous product of the ammonoxidation stage is directly brought into contact with a liquid organic solvent or with melted phthalodinitrile (quench); constituents having a boiling point lower than that of phthalodinitrile (low boilers) are partially or completely separated out from the obtained quench solution or suspension or phthalodinitrile melt, and; before the hydrogenation of the phthalodinitrile, no products having a boiling point higher than that of phthalodinitrile (high boilers) are separated out.

Abstract: A process for preparing xylylenediamine by continuously hydrogenating liquid phthalonitrile over a heterogeneous catalyst in the presence of liquid ammonia in a reactor, which comprises mixing a stream of a phthalonitrile melt in liquid form by means of a mixer unit with a stream of liquid ammonia and conducting the liquid mixture into the hydrogenation reactor.

Abstract: A process for preparing xylylenediamine by continuously hydrogenating liquid phthalonitrile over a heterogeneous catalyst in the presence of liquid ammonia in a reactor, in which a portion of the reactor effluent is recycled as a liquid circulation stream continuously to the reactor inlet (circulation mode), in which a stream of a phthalonitrile melt in liquid form is conducted by means of a mixer unit into the circulation stream around the hydrogenation reactor, the phthalonitrile conversion in the reactor on single pass being greater than 99%, and the circulation stream consisting to an extent of greater than 93% by weight of liquid ammonia and xylylenediamine and not comprising any further solvent for phthalonitrile.

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile by contacting the vaporous product of this ammoxidation stage directly with a liquid organic solvent (quench), removing products having a boiling point higher than phthalonitrile (high boilers) from the resulting quench solution or suspension and hydrogenating the phthalonitrile, wherein the organic solvent used for the quench is N-methyl-2-pyrrolidone (NMP), after the removal of the high boilers and before the hydrogenation, there is a partial or complete removal of the NMP and/or of products having a boiling point lower than phthalonitrile (low boilers) and the phthalonitrile for the hydrogenation step is dissolved or suspended in an organic solvent or in liquid ammon.

Abstract: In a process for deacidifying a fluid hydrocarbon stream which comprises carbon dioxide (CO2) and/or other acid gases as impurities, the fluid stream is brought into intimate contact with an absorption liquid in an absorption or extraction zone (12), the substantially purified fluid stream and the absorption liquid which is loaded with CO2 and/or other acid gases are separated from one another, and the absorption liquid is subsequently regenerated and then again fed to the absorption extraction zone (12). To regenerate the absorption liquid, the loaded absorption liquid is first expanded in a first low-pressure expansion stage (22) to a pressure of from 1 to 2 bar (absolute). The partially regenerated absorption liquid is then heated in a heat exchanger (20) and then, in a second low-pressure expansion stage (29), again expanded to a pressure of from 1 to 2 bar (absolute).

Abstract: A process for preparing xylylenediamine, comprising the steps of ammoxidizing xylene to phthalonitrile, by contacting the vaporous product of the ammoxidation stage directly with a liquid organic solvent (quench), and hydrogenating the phthalonitrile in the resulting quench solution or suspension, wherein the organic solvent is N-methyl-2-pyrrolidone (NMP).