摘要:
A process is disclosed for the continuous preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine) in high yield and high purity from 3-cyano-3,5,5-trimethylcyclohexanone (isophoronenitrile) by aminating hydrogenation with hydrogen and ammonia in the presence of a fixed bed catalyst. The aminating hydrogenation is carried out by allowing a mixture of isophoronenitrile, ammonia and a C.sub.1 -C.sub.3 -alcohol, in the presence of hydrogen, to trickle over a trickle bed reactor provided with a Co and/or Ru fixed bed catalyst, at 3 to 8 MPa and at a temperature of 40.degree. to 150.degree. C., preferably 90 to 130.degree. C., and working up the reaction mixture by distillation. Preferably, a high-boiling by-product fraction, containing a bicyclic amidine, is added to the mixture to be hydrogenated, thereby appreciably increasing the yield.
摘要:
A process is described for the simultaneous production of 1,2- and 1,3-propanediol from glycerol. The process involves the reaction stages (a) dehydration of glycerol by feeding a gaseous glycerol-water mixture with 10 to 40 wt % glycerol at 250.degree. to 340.degree. C. over a solid catalyst with an H.sub.0 value (Hammett acidity function) of less than 2, preferably between -3 and -8.2, (b) hydration of the acrolein contained in the reaction mixture of stage (a), and (c) catalytic hydrogenation of the reaction mixture, containing 3-hydroxypropionaldehyde and hydroxyacetone, of stage (b). Two valuable products, namely 1,2- and 1,3-propanediol, can be obtained simultaneously and in high total yield from glycerol in a simple process.
摘要:
A process for the production of 1,3-propanediol by heterogeneously catalyzed hydrogenation of 3-hydroxypropionaldehyde in an aqueous solution at 30 to 180° C., at a hydrogenation pressure of 5 to 300 bar and a pH value of 2.5 to 7.0, wherein ruthenium on an oxide support is used as the catalyst.
摘要:
This invention relates to a process for the production of primary and/or secondary amines from oxo compounds by catalytic imination of the oxo compound with ammonia or a primary amine and subsequent hydrogenation. Imination proceeds according to the invention in the presence of a novel imination catalyst, namely an organopolysiloxane containing sulphonate groups. This imination catalyst is distinguished by elevated activity. The process is in particular suitable for the production of isophorone diamine from isophorone nitrile, wherein it has proved possible to reduce the content of secondary products and to increase yield.
摘要:
1,3-propanediol (PD) is obtained by hydration of acrolein to 3-hydroxypropionaldehyde (HPA) with subsequent catalytic hydrogenation; 3,3'-oxybis-1-propanol (OD) occurs as a yield-reducing by-product. Disclosed is a process which increases the 1,3-propanediol yield. The OD which is separated by distillation during treatment of the reaction mixture containing PD and OD is treated in aqueous solution at from 100 to 300.degree. C. with an acid solid catalyst, in particular an acid zeolite, and the reaction mixture from which the solid catalyst has been removed is returned into the treatment stage of the reaction mixture containing PD and OD.
摘要:
A process is disclosed for the preparation of 3-hydroxyalkanals having 3 to 12 carbon atoms, in particular 3 or 4 carbon atoms, by hydration of the underlying 2-alkenals with water in a homogeneous phase in the presence of an acid catalyst. The previously known hydration using mineral acids or carboxylic acids as catalyst results in low volume/time yields and/or low selectivities. These disadvantages can be avoided by using in the present invention, as catalyst, a dissolved acid-base buffer which results in a pH of from 2 to 5 in the reaction mixture; the acid component and corresponding base of which are present in a total quantity of from 0.5 to 40% by weight in the reaction mixture. The preferred buffers composed of a lower monobasic carboxylic acid and a tertiary amine can easily be recycled.
摘要:
A reactor for performing endothermic catalytic reactions is disclosed formed of a monolithic counterflow reactor with parallel heating and reaction channels. The internal walls of the reaction channels are coated with a catalyst for the catalytic reaction to be performed, while the internal walls of the heating channels have a catalyst for the catalytic combustion of a fuel gas/air mixture.
摘要:
A process for preparing 3-hydroxyalkanals having 3 to 12 carbon atoms by hydration of 2-alkenals with homogeneous catalysis, by using as catalyst a compound corresponding to the formula ##STR1## wherein: z denotes H, C.sub.1 - to C.sub.6 -alkyl, --CH.sub.2 --CH(CH.sub.3) --Y' or --(CH.sub.2).sub.o --Y'R denotes H, C.sub.1 - to C.sub.6 -alkyl, benzyl, phenyl, .omega.-hydroxy --C.sub.1 - to C.sub.6 -alkyl, --CH.sub.2 --CH(CH.sub.3)--Y' or --(CH.sub.2).sub.o --Y'Y and Y' are identical or different and denote --COOH, --P(O) (OH).sub.2, --OH, pyridyl, or --P(O) (CH.sub.2 OH)OH, wherein the acid functional group may be present partly in the form of its alkali metal salt, alkaline-earth salt or ammonium saltn denotes 1, 2, 3, 4, 5 or 6 where Y is --COOH, --P(O) (OH).sub.2, pyridyl or --P(O) (CH.sub.2 OH) OH; 2 or 3 where Y is --OHo denotes 1, 2, 3, 4, 5 or 6 where Y' is --COOH, --P(O) (OH).sub.2, pyridyl or --P(O) (CH.sub.2 OH)OH; 0, 2 or 3 where Y' is --OH.
摘要:
A method of producing cyanopyridines by means of the catalytic reaction of methylpyridines with ammonia and oxygen at elevated temperature using catalysts consisting of compounds of the elements antimony, vanadium, silicon, titanium and oxygen and compounds of one or more of the alkali metals as well as a method of producing the catalysts and the catalysts themselves.
摘要:
A method of producing cyanopyridines by means of the catalytic reaction of methylpyridines with ammonia and oxygen at elevated temperature using catalysts consisting of compounds of the elements antimony, vanadium, silicon, titanium and oxygen and compounds of one or more of the alkali metals as well as a method of producing the catalysts and the catalysts themselves.