摘要:
Process for preparing one or more complexing agents selected from methylglycinediacetic acid, glutamic acid diacetic acid and salts thereofProcess for preparing one or more complexing agents selected from methylglycinediacetic acid, glutamic acid diacetic acid and salts thereof by catalytic dehydrogenation of N,N-bis(2-hydroxyethyl)alanine and/or N,N-bis(2-hydroxyethyl)glutamic acid and/or salts thereof in the presence of alkali metal hydroxide, where a catalyst comprising copper and zirconium dioxide is used, the activation of which is a reduction, wherein the precursor of the catalyst in question has a degree of crystallization K, defined as K = I K · 100 I K + I A , in the range from 0 to 50%.
摘要:
A process for preparing aminopolycarboxylates proceeding from the corresponding polyalkanolamines by oxidative dehydrogenation in the presence of a catalyst comprising 1 to 90% by weight of copper, based on the total weight of the catalyst, using a base, which comprises first performing a partial conversion of the polyalkanolamine to a reaction mixture comprising the aminopolycarboxylate at a temperature in the range from 140 to 180° C. until at least 10 to 90 mol% of the polyalkanolamine has been depleted, and then continuing the conversion at elevated temperature.
摘要:
What is proposed is a process for preparing aminopolycarboxylates proceeding from the corresponding polyalkanolamines by oxidative dehydrogenation in the presence of a catalyst comprising 1 to 90% by weight of copper, based on the total weight of the catalyst, using a base, which comprises first performing a partial conversion of the polyalkanolamine to a reaction mixture comprising the aminopolycarboxylate at a temperature in the range from 140 to 180° C. until at least 10 to 90 mol % of the polyalkanolamine has been depleted, and then continuing the conversion at elevated temperature.
摘要:
A method for isolating methylglycinenitrile-N,N-diacetonitrile (MGDN) from an aqueous mixture comprising MGDN is provided The method comprises cooling the aqueous mixture in one or more steps In one of these steps the mixture is cooled at a cooling rate of at least 20 K/h from a temperature above the solidification point of MGDN to a temperature below the solidification point of MGDN The method is implemented continuously
摘要:
The present invention relates to methods for removing carbon dioxide and, if appropriate, water from breathing air in closed or partially closed systems using a porous metal-organic framework material, such systems having at least one breathing apparatus and also their use and methods for regenerating the porous metal-organic framework material.
摘要:
Dihydroquinacridones, quinacridones and quinacridonequinones are prepared by cyclizing 2,5-dianilino-3,6-dihydroterephthalic acid derivatives or 2,5-dianilinoterephthalic acid derivatives in the liquid or solid state or in solution, in each case in finely divided form, or in the gas phase, in the presence or absence of an oxidizing agent.
摘要:
Aminobenzophenones have the formula ##STR1## where the ring A may be benzofused,X.sup.1 is hydrogen or hydroxysulfonyl,X.sup.2 is hydrogen, hydroxysulfonyl, hydroxysulfonylphenyl, hydroxysulfonylbenzyl or hydroxysulfonylphenylethyl,R.sup.1, R.sup.2 and R.sup.3 are each independently of the others hydrogen, halogen, C.sub.1 -C.sub.12 -alkyl, cyclohexyl or C.sub.1 -C.sub.4 -alkoxy, or one of them may also be the radical of the formula ##STR2## where L is a chemical bond, C.sub.1 -C.sub.4 -alkylene or --O--CH.sub.2 -- and Y.sup.1, Y.sup.2 and Y.sup.3 are each independently of the others hydrogen, halogen, C.sub.1 -C.sub.12 -alkyl or C.sub.1 -C.sub.4 -alkoxy and R.sup.4, X.sup.1, X.sup.2 and the ring A are each as defined above, andR.sup.4 is hydrogen or chlorine,with the proviso that X.sup.1 and X.sup.2 are not both hydrogen, their intermediates having the formula ##STR3## where L is as defined above.
摘要:
In a process for drying microporous, fluid-containing particles, the fluid-containing particles to be dried are fed as a moving bed countercurrently to a drying fluid, the interfacial tension of the fluid being reduced in comparison with the interfacial tension of the fluid at room temperature, at near-critical to supercritical pressure of the fluid, preferably to a value in the range from 0 to {fraction (1/10)}, in particular from 0 to {fraction (1/20)}, of the interfacial tension at room temperature. Furthermore, microporous, three-dimensionally networked particles are prepared by a process comprising preparation of microporous particles containing pore liquid, exchange of the pore liquid in the particles for a fluid and drying of the fluid-containing particles, the exchange and drying being carried out in the moving bed by the countercurrent method.
摘要:
In a process for drying microporous, fluid-containing particles, the heat required for increasing the temperature is supplied by convection by reducing the interfacial tension of the fluid, preferably to 0 to 1/10, in particular to 0 to 1/20, of the interfacial tension of the fluid at room temperature, by appropriately increasing the temperature at from close to the critical pressure to supercritical pressure of the fluid. Furthermore, microporous, three-dimensionally networked particles are prepared by a process in which the drying process is used. In addition, an apparatus is used for carrying out the drying process, the apparatus comprising a pressure container having an inner container and pressure-withstanding outer container and suitable measuring and control apparatuses and pump apparatuses and heat exchangers, the inner container being provided for holding the particles to be dried and a gap being provided between the inner container and the outer container.
摘要:
Hydrophobic silica aerogels obtainable by reacting a waterglass solution with an acid at a pH of from 7.5 to 11, substantially removing ionic constituents from the resulting silica hydrogels by washing with water or dilute aqueous solutions of inorganic bases, while the pH of the hydrogels is kept in the range from 7.5 to 11, displacing the aqueous phase contained in the hydrogel by an alcohol, and subsequent supercritical drying of the resulting alcogels.