Abstract: The invention relates to a multistage process for the continuous preparation of organic, distillable isocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic amines with urea and alcohols to liberate ammonia and form low molecular weight monomeric urethanes and thermal dissociation of the latter, in which by-products formed are at least partly utilized.

Abstract: The invention relates to a multistage process for the continuous preparation of organic, distillable isocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic amines with urea and alcohols to liberate ammonia and form low molecular weight monomeric urethanes and thermal dissociation of the latter, in which by-products formed are at least partly utilized.

Abstract: A catalyst comprising nickel on a TiO2 support is obtainable by coprecipitation of nickel and at least one further metal selected from among Si, Zr, Hf, alkaline earth metals, Y, La and Ce, and optionally at least one dopant metal selected from groups 5 to 11 of the Periodic Table of the Elements, from a solution in which the corresponding metal salts are present onto a particulate TiO2 support, subsequent drying, calcination and reduction and optionally passivation to give the nickel-containing catalyst. It is used, in particular, for the hydrogenation of nitroaromatic compounds.

Abstract: The invention relates to a process for distillatively preparing TDA from a reactant stream comprising TDA, high boilers and low boilers in a dividing wall column in which a dividing wall is disposed in the longitudinal direction of the column to form an upper combined column region (2), a lower combined column region (3), a feed section (4) having a rectifying section (5) and stripping section (6), and also a withdrawal section (7) having a rectifying section (9) and stripping section (8), which comprises the following steps: a. feeding the reactant stream (13) into the feed section (4) of the dividing wall column (1); b. drawing off a low boiler fraction via the top of the column (11); c. drawing off TDA via a side draw (14) in the withdrawal section (7) of the dividing wall column (1); d. drawing off a low boiler fraction via the bottom of the column (12).

Abstract: The invention relates to a process for distillatively preparing TDA from a reactant stream comprising TDA, high boilers and low boilers in a dividing wall column in which a dividing wall is disposed in the longitudinal direction of the column to form an upper combined column region (2), a lower combined column region (3), a feed section (4) having a rectifying section (5) and stripping section (6), and also a withdrawal section (7) having a rectifying section (9) and stripping section (8), which comprises the following steps: a. feeding the reactant stream (13) into the feed section (4) of the dividing wall column (1); b. drawing off a low boiler fraction via the top of the column (11); c. drawing off TDA via a side draw (14) in the withdrawal section (7) of the dividing wall column (1); d. drawing off a low boiler fraction via the bottom of the column (12).

Abstract: Liquid organic compounds are hydrogenated by a process in which the hydrogen present in the reactor contains proportions of at least one gas which is inert in the hydrogenation reaction.

Abstract: A catalyst comprising nickel on a TiO2 support is obtainable by coprecipitation of

Abstract: Liquid organic compounds are hydrogenated by a process in which the hydrogen present in the reactor contains proportions of at least one gas which is inert in the hydrogenation reaction.

Abstract: In a process for preparing amines, in which at least one compound containing at least one nitro group is reacted with hydrogen in the presence of a supported catalyst comprising, as catalytically active metal, nickel, if desired together with at least one metal of transition group I, V, VI and/or VIII, the reduced and stabilized supported catalyst comprises nickel crystallites having a bimodal nickel crystallite size distribution having maxima at 30-80 Angstrom and 81-150 Angstrom on a support comprising ZrO.sub.2, ZrO.sub.2 --HfO.sub.2 and/or SiO.sub.2 --ZrO.sub.2 and/or SiO.sub.2 --ZrO.sub.2 --HfO.sub.2 and in the reduced and passivated state has a nickel content of 60-80 percent by mass, an SiO.sub.2 content of 0-20 percent by mass, a ZrO.sub.2 content of 0-40 percent by mass, an HfO.sub.2 content of 0-4 percent by mass and after further reduction for one hour at 100.degree. C. has a degree of reduction of at least 70%.