Abstract:
The invention relates to a method for producing a supported catalyst, consisting of at least 75 wt. % Al2O3, whose delta- or theta-modified fraction of Al2O3 is at least 1 % of the total Al2O3 fraction and which contains a rhenium compound and optionally a promoter as the active component (A). According to the invention: a) a modified support (T) is produced from a conventional support (T) consisting of at least 75 wt. % of Al2O3, to which a promoter is optionally applied, the delta- or theta-modified fraction of the Al2O3 being at least 1 % of the total Al2O3 fraction, by the calcination of the conventional support (T) at a temperature of between 750 and 1100 DEG C; b) a supported catalyst precursor is produced from the modified support (T) by the application of the active component comprising the rhenium compound (A) to the modified support (T); and c) the supported catalyst precursor is calcinated at a temperature of between 500 and 750 DEG C.
Abstract:
The invention relates to a method for the production of metylamines by means of gas phase reaction from methanol and ammonia as educts in the presence of a heterogeneous catalyst at a pressure in the region of 15 - 30 bars. Said educts are vaporised in one or several heat exchangers (1, 2, 3) in order to overheat an educt gas flow and are subsequently guided to a reactor (4). The educts can be mixed in the inlets of one of the heat exchangers (1, 2, 3) or at one remaining position in a heat exchanger (1, 2, 3). A product gas flow containing monomethylamine, dimethylamine and trimethylamine, in addition to reaction auxiliary products, is removed from the reactor (4). In order to regulate the reactor admission temperature of the educts to a temperature in the region of 360 DEG C - 370 DEG C, the educt gas flow or the product gas flow is guided partially or completely through an adjustable valve (5) enabling the pressure and the condensation temperature to be varied.
Abstract:
Preparation of non-aromatic carbon-carbon double/triple bond compound (A) or its mixtures from another non-aromatic carbon-carbon double/triple bond compound (B), comprises reacting pure (B) with an adsorption agent comprising an aluminum oxide (3 wt.%) and activating at 450-1000[deg]C; and contacting the pure compound (B) with a metathesis catalyst.
Abstract:
Supported catalyst comprising a support (S) in which Al 2 O 3 is present in a proportion of at least 75% by weight and rhenium compounds as active component (A), wherein the maximum of the distribution function of the pore diameters in the mesopore range is at from 0.008 to 0.050 mum.
Abstract:
The invention relates to a method for producing mixtures consisting of diphenylmethane diisocyanates and polyphenylene-polymethylene-polyisocyanates containing a reduced amount of chlorinated secondary products and with a reduced iodine colour index. According to said method, a two-stage reaction of the corresponding mixtures of diphenylmethane-diamines and polyphenylenepolymethylene polyamines with phosgene is carried out in the presence of at least one inert organic solvent at a high temperature. When the phosgenation is complete, the excess phosgene and solvent are separated off and the product of the reaction is treated with heat. The method is characterised in that the mass ratios of phosgene to hydrogen chloride in the detention apparatus in the second stage of phosgenation are simultaneously 10-30:1 in the liquid phase and 1-10:1 in the gas phase.
Abstract:
The invention relates to a supported catalyst consisting of a support (T) comprising at least 75 wt. % Al2O3 and rhenium compounds as the active component (A). According to the invention, the maximum distribution function of the pore diameter lies in the mesopore range between 0.008 and 0.050 ~m.
Abstract:
The invention relates to a process for preparing methylamines by gas-phase reaction of methanol and ammonia as starting materials at a pressure in the range from 15 to 30 bar in the presence of heterogeneous catalyst. The starting materials are vaporized in one or more heat exchangers (1, 2, 3), superheated to produce a feed gas stream and subsequently fed into a reactor (4), with the mixing of the starting materials being able to be carried out in the feed stream to one of the heat exchangers (1, 2, 3) or at any desired position in a heat exchanger (1, 2, 3). A product gas stream comprising monomethylamine, dimethylamine and trimethylamine and also reaction by-products is taken off from the reactor (4). To control the reactor inlet temperature of the starting materials to a temperature in the range from 360° C. to 370° C., all or some of the feed gas stream or the product gas stream is passed through an adjustable valve (5) in order to vary the pressure and thus the condensation temperature.