摘要:
The present invention relates to template-free clathrasils whose framework comprises essentially SiO2, wherein the crystals of the clathrasils have the platelet-like morphology of a sheet silicate. The present invention further relates to a process for preparing these template-free clathrasils and also to their use as absorbent, as seed crystals for the synthesis of clathrasil membranes of the same zeolite type and in the form of dense layers which function as gas separation membranes having a molecular sieving action.
摘要:
A process continuously hydrogenating unsaturated compounds, in which particles of a first hydrogenation catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved, the liquid phase, in the presence of a hydrogenous gas at a first partial hydrogen pressure and at a first temperature, is conducted through a packed bubble column reactor in cocurrent counter to the direction of gravity, the effluent from the bubble column reactor is sent to a gas-liquid separation, the liquid phase is sent to a crossfiltration to obtain a retentate and a filtrate, the retentate is recycled into the bubble column reactor and the filtrate, in the presence of a hydrogenous gas at a second partial hydrogen pressure and at a second temperature, is passed over a bed of a second hydrogenation catalyst, the second partial hydrogen pressure is at least 10 bar higher than the first partial hydrogen pressure.
摘要:
Composite membranes comprising at least one porous substrate layer and at least one microporous separation layer, comprising at least one zeolite of the MFI type, are described, the separation layer being produced by a hydrothermal synthesis in which the molar ratio of silicon to aluminum is greater than 120 and the separation layer contains less than 10% by weight of aluminum in elemental or chemically bound form in a zone of at least 100 nm adjacent to the separation layer.
摘要:
The present invention relates to a process for preparing an aqueous polymer dispersion by free-radical emulsion polymerization of a monomer mixture which comprises N,N-diethylaminoethyl methacrylate, to the polymer dispersion obtainable by this process, and to the use thereof.
摘要:
The invention relates to an improved method for the production of D-pantothenic acid and/or salts thereof and use thereof as adjunct for animal feedstuffs.
摘要:
The present invention relates to a process for the preparation of nanoparticulate zinc oxide in the form of aqueous suspensions or in the form of pulverulent solid. Furthermore, the invention relates to the use of zinc oxide particles and suspensions prepared in this way in cosmetic sunscreen preparations, as stabilizer in plastics, in paints, in coatings and as antimicrobial active ingredient.
摘要:
A process for the preparation of aqueous solutions of glucans having a β-1,3-glycosidically-linked main chain and side groups having a β-1,6-glycosidic bond by fermentation of fungal strains. The fungal strains secrete the glucans into the fermentation broth, in an aqueous culture medium, and the separation of the glucans from the fermentation broth is effected using asymmetrical filter membranes.
摘要:
A method of preparing a finely divided emulsion from a crude emulsion is proposed where the crude emulsion is forced through a porous membrane, wherein the porous membrane is constructed from two or more superimposed layers which differ in pore diameter.
摘要:
A method for producing membranes which contain at least one solid layer on one side of a porous substrate by treating the side of the support, which is to be coated, with a synthetic solution that forms the solid layer. The inventive method is characterized in that the space located behind the side of the porous support, which is not to be coated, is filled with an inert fluid during the production of the solid layer on the porous support, “behind” being from the perspective of the support. The pressure and/or the temperature of the fluid is/are selected such that the synthetic solution is essentially prevented from entering in contact with the side of the porous support, which is not to be coated.
摘要:
A process is described for continuously hydrogenating unsaturated compounds, in which particles of a first hydrogenation catalyst are suspended in a liquid phase in which an unsaturated compound is dissolved, the liquid phase, in the presence of a hydrogenous gas at a first partial hydrogen pressure and at a first temperature, is conducted through a packed bubble column reactor in cocurrent counter to the direction of gravity, the effluent from the bubble column reactor is sent to a gas-liquid separation, the liquid phase is sent to a crossfiltration to obtain a retentate and a filtrate, the retentate is recycled into the bubble column reactor and the filtrate, in the presence of a hydrogenous gas at a second partial hydrogen pressure and at a second temperature, is passed over a bed of a second hydrogenation catalyst, wherein the second partial hydrogen pressure is at least 10 bar higher than the first partial hydrogen pressure.