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 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: 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 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: 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: COS is selectively removed with respect to CO2 from a hydrocarbonaceous fluid stream which contains CO2 and COS. Examples of the fluid stream include a gas stream, for example natural gas, synthesis gas from heavy oil or heavy residues or refinery gas, or from liquid or liquefied hydrocarbons, for example LPG (Liquefied Petroleum Gas) or NGL (Natural Gas Liquids). The process is carried out by (1) intimately contacting the fluid stream in an absorption or extraction zone with a scrubbing liquor consisting of an aqueous amine solution containing from 1.5 to 5 mol/l of an aliphatic alkanolamine having of from 2 to 12 carbon atoms and from 0.8 to 1.7 mol/l of at least one activator selected from the group consisting of piperazine, methyl piperazine and morpholine, (2) removing the COS essentially completely from the fluid stream, and (3) separating the substantially COS-decontaminated fluid stream and the COS-loaded scrubbing liquor and discharging them from the absorption or extraction zone.

Abstract: The disclosure concerns a process for removing mercaptans from fluid streams comprising same, especially from hydrocarbon gas streams, for example natural gas, synthesis gas from heavy oil or heavy residues or refinery gas, or else from liquid hydrocarbons, for example LPG (liquefied petroleum gas). The invention comprises intimately contacting the fluid stream in an absorption or extraction zone with a scrubbing liquor comprising at least one aliphatic alkanolamine of 2-12 carbon atoms, the amount of wash liquor being supplied to the absorption or extraction zone being sufficient to remove at least CO2 and H2S essentially completely from the fluid stream, and separating the substantially decontaminated fluid stream and the contaminated wash liquor and discharging them from the absorption zone.

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 the purification of tertiary phosphine oxides obtained in a Wittig synthesis as a contaminated by product resulting from the reaction of the corresponding tertiary phosphines, especially triphenylphosphine. The contaminated tertiary phosphine oxides coming from this Wittig synthesis have the formula I ##STR1## in which R.sup.1, R.sup.2, and R.sup.3 denote C.sub.1 -C.sub.12 alkyl, C.sub.5 -G.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.20 aralkyl, or C.sub.7 -C.sub.20 alkylaryl. The contaminated phosphine oxide I or phosphine oxide I-containing mixtures, optionally in an inert solvent, are first caused to react with an inorganic or organic acid at temperatures of from 0.degree. to 150.degree. C. to form a crystallized acid salt. The resulting salt crystals are then treated in a purifying step with water or an inorganic base or an organic base to again form the tertiary phosphine oxide.

Abstract: Triphenylphosphine (TPP) is prepared by reacting triphenylphosphine dichloride (TPPCl.sub.2) with magnesium, aluminum and/or iron in the presence of an inert solvent, employing a TPPCl.sub.2 solution whose content of phosgene, chlorine, diphosgene, hydrogen chloride, thionyl chloride, sulfuryl chloride, phosphorus trichloride, phosphorus oxychloride and/or aliphatic halogen compounds (active chlorine compounds) totals less than 1000 ppm Cl.