Abstract:
The invention relates to a method for producing aromatic amines by the catalytic hydration of the corresponding nitro compounds, particularly for producing toluylenediamine by the hydration of dinitrotoluene, characterized in that hydration catalysts are employed, in which a mixture of nickel, palladium and an addition element, selected from the group containing cobalt, iron, vanadium, manganese, chromium, platinum, iridium, gold, bismuth, molybdenum, selenium, tellurium, stannous, and antimony, is present as the active component on a carrier.
Abstract:
The present invention relates to template-free clathrasils, the structure of which contains essentially SiO 2 , wherein the crystals of the clathrasils have the plate-shaped morphology of the layer silicates. The present invention further relates to a method for producing said template-free clathrasils, the use thereof as absorbent, seed crystals for the synthesis of clathrasil membranes of the same zeolite type and in form of dense layers which act as molecular-sieving gas separating membranes.
Abstract:
The present invention relates to a process for separating at least one propylene glycol from a mixture (M) comprising water and said propylene glycol, said process comprising (I) evaporating the mixture in at least two evaporation and/or distillation stages at decreasing operating pressures of the evaporators and/or distillation columns obtaining mixture (M') and mixture (M'); (II) separating the mixture (M') obtained in (I) in at least one further distillation step, obtaining a mixture (M-I) comprising at least 70 wt.-% of water and a mixture (M-II) comprising less than 30 wt.-% of water.
Abstract:
The invention relates to a method for the continuous hydrogenation of unsaturated compounds, according to which particles of a first hydrogenating catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved. According to the invention, the liquid phase is guided through a packed bubble column, in the presence of a hydrogenous gas which is subjected to a first partial hydrogen pressure and is at a first temperature in the parallel flow in the opposite direction to the gravitational force, the substance discharged from the bubble column reactor is subjected to a gas-liquid separation, and the liquid phase is then subjected to a transversal filtration, whereby a retentate and a filtrate are obtained. The retentate is introduced back into the bubble reactor, and the filtrate is guided over a bed of a second hydrogenating catalyst in the presence of a hydrogenous gas subjected to a second hydrogen partial pressure and at a second temperature, the second hydrogen partial pressure being at least 10 bar higher than the first hydrogen partial pressure.
Abstract:
The present invention relates to a process for separating at least one propylene glycol from a mixture (M) comprising water and said propylene glycol, said process comprising (I) evaporating the mixture in at least two evaporation and/or distillation stages at decreasing operating pressures of the evaporators and/or distillation columns obtaining mixture (M') and mixture (M'); (II) separating the mixture (M') obtained in (I) in at least one further distillation step, obtaining a mixture (M-I) comprising at least 70 wt.-% of water and a mixture (M-II) comprising less than 30 wt.-% of water.
Abstract:
The invention relates to a method for the continuous hydrogenation of unsaturated compounds, according to which particles of a first hydrogenating catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved. According to the invention, the liquid phase is guided through a packed bubble column, in the presence of a hydrogenous gas which is subjected to a first partial hydrogen pressure and is at a first temperature in the parallel flow in the opposite direction to the gravitational force, the substance discharged from the bubble column reactor is subjected to a gas-liquid separation, and the liquid phase is then subjected to a transversal filtration, whereby a retentate and a filtrate are obtained. The retentate is introduced back into the bubble reactor, and the filtrate is guided over a bed of a second hydrogenating catalyst in the presence of a hydrogenous gas subjected to a second hydrogen partial pressure and at a second temperature, the second hydrogen partial pressure being at least 10 bar higher than the first hydrogen partial pressure.
Abstract:
Polymer composition comprising a) an oligo- or polyurethane U of the formula (I) wherein k and n independently are numbers from 1 to 100, m is from the range 1-100, (X) is a block of formula (II) and (Y) is a block of the formula (III), (A) is a residue of an aliphatic or aromatic diisocyanate linker, (B) is a residue of a linear oligo- or polysiloxane containing alkanol end groups, and optionally further containing one or more aliphatic ether moieties, and (C) is an aromatic oligo- or polyarylene ether block that is at least partly etherified at its terminal positions with one alkylene glycol unit; or a mixture of such oligo- or polyurethanes; and b) one or more further organic polymers P selected from the group consisting of polyvinyl pyrrolidone, polyvinyl acetates, cellulose acetates, polyacrylonitriles, polyamides, polyole- fines, polyesters, polyarylene ethers, polysulfones, polyethersulfones, polyphenylenesulfones, polycarbonates, polyether ketones, sulfonated polyether ketones, polyamide sul- fones, polyvinylidene fluorides, polyvinylchlorides, polystyrenes and polytetrafluorethylenes, copolymers thereof, and mixtures thereof; preferably selected from the group consisting of polysulfones, polyphenylenes, polyethersulfones, polyvinylidene fluorides, polyamides, cellulose acetate and mixtures thereof.
Abstract:
Process for making a membrane M comprising the following steps: a) preparing a copolymer C, wherein said copolymer C comprises blocks of at least one polyarylene ether A and blocks of polyalkylene oxide PAO, wherein the content of polyethyleneoxide in copolymer C is 30 to 90% by weight and wherein copolymer C is prepared in a solvent L to yield solution S; b) providing a dope solution D comprising at least one polymer P; c) mixing solution S and dope solution D; d) preparing a membrane by bringing the mixture of solution S and dope solution D into contact with at least one coagulating agent.