摘要:
Disclosed is a method for producing membranes comprising at least one solid layer on one side of a porous support 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:
The invention relates to a method for producing amines by catalytically hydrogenating nitroaromatics and then separating the catalysts from the reaction mixture containing at least one aromatic amine and water. According to the inventive method, the catalysts are separated by means of membrane filtration which is carried out at a pressure of 5 to 50 bar on the side of the suspension, a difference in pressure between the side of the suspension and the side of the permeate of at least 0.3 bar, and a flow rate of 1 to 6 m/s on the side of the suspension.
摘要:
The invention relates to reaction membranes that contain a selective oxidation catalyst disposed on a ceramic membrane that selectively conducts oxide ions and that is composed of (Sr1-xCax)1-yAyMn1-zBzO3-δ, wherein A represents Ba, Pb, Na, K, Y, an element of the lanthanide group or a combination of these elements, B represents Mg, Al, Ga, In, Sn, an element of the 3d or 4d period or a combination of these elements, x is a number of from 0.2 to 0.8, y is a number of from 0 to 0.4, z is a number of from 0 to 0.6 and δ is a number that results from the principle of electroneutrality on the basis of x, y and z. The inventive reaction membranes are suitable for use in oxidative reactions of hydrocarbons in which oxygen is used.
摘要:
Disclosed is a method for the simultaneous preparation of dicarboxylic acids and diamines from (a) polymers based on polyamides made by reacting dicarboxylic acids or derivatives thereof with diamines or (b) compounds containing essentially such polymers, by decomposing these polymers into their constituent monomers by treating the polymers or compounds with a base in an alcoholic solution and subsequently converting electrochemically the dicarboxylic-acid salts thus produced into the corresponding dicarboxylic acids and bases.
摘要:
The invention concerns the electrochemical preparation of dicarboxylic acids by subjecting an aqueous solution containing essentially the alkali-metal salt of a dicarboxylic acid of the general formula (I): HOOC-(CH2)n-COOH, in which n may be an integer from 1 to 8, or mixtures of such dicarboxylic acids, to an electrochemical treatment.
摘要:
Disclosed is a method for processing naphtha, according to which a) naphtha or a stream generated from naphtha in a preprocessing step is divided into a stream A that is stripped of aromatics and a stream B which is enriched with aromatics in a membrane unit, the aromatics concentration in stream A ranging from 2 to 12 percent by weight (step a); b) partial stream A is directed at least in part into a steam cracker (step b); c) partial stream B is directed at least in part into a unit in which said stream B is divided into a stream C or several streams C' C'', C''',..., which has/have a lower aromatics content than stream B, and a stream D or several streams D', D'', D''',..., which has/have a higher aromatics content than stream B, by means of a thermal process (step c); d) stream C or at least one of the streams C', C'', C''' is delivered as a whole or in part to the feed for the steam cracker or directly to the steam cracker (step d).
摘要:
The invention relates to composite membranes comprising at least one porous carrier layer and at least one microporous separating layer, containing at least one MFI-type zeolite. Said separating layer is produced by hydrothermal synthesis. According to the invention, the molar ratio of silicon to aluminium is higher than 120, and the carrier layer contains less than 10 wt. % of aluminium in the elementary or chemically bonded form in a region of at least 100 nm adjacent to the separating layer.
摘要:
The invention relates to a method for converting aromatic nitro compounds into the corresponding amines in the presence of hydrogenation catalysts. Said method is characterized in that hydrogenation catalysts are used in which nickel and platinum are provided on a carrier in the form of an alloy, the atomic ratio between nickel and platinum in said alloy ranging between 30:70 and 70:30.
摘要:
The invention relates to a method for separating a mixture containing a) a monoethylenically unsaturated compound that can be obtained by adding two terminal olefins carrying the functional groups necessary for producing the monoethylenically unsaturated compound containing at least two functional groups, or a saturated compound obtained by hydrogenating one such compound, b) a compound that can be obtained by adding more than two of the terminal olefins cited in a) or a compound obtained by hydrating one such compound, and c) a compound which contains a transition metal, is homogeneous in relation to the mixture, and is suitable as a catalyst for producing a monoethylenically unsaturated compound by adding two terminal olefins carrying the functional groups necessary for producing the monoethylenically unsaturated compound containing at least two functional groups. According to said method, the mixture is separated by means of a semi-permeable membrane, obtaining a permeate and a retentate, in such a way that the weight ratio of constituent b) to constituent c) in the mixture supplied to the semi-permeable membrane is smaller than in the retentate.
摘要:
The invention relates to a method for concentrating an at least partially crystalline solid containing at least one zeolite in a mixture, said mixture containing at least one auxiliary agent, for example a template compound, and the cited solid. The inventive method is characterised in that the mixture is divided into a retentate and a permeate in one step (II) by means of ultrafiltration, the solid content in the retentate being higher than that in the mixture and the solid content in the permeate being lower than that in the mixture. Said method enables auxiliary agents in the permeate, especially template compounds, to be redirected into a crystallisation step (I) which precedes the cited step (II).