Abstract: The present invention relates to a method of purifying wastewater by contacting the wastewater which is to be purified with a rod-shaped TiO2 photocatalyst which has a BET surface area of 25 to 200 m2/g, a pore volume of 0.10 to 1.00 ml/g, and a median pore diameter of 0.005 to 0.050 ?m, with irradiation by light, and to the use of such a rod-shaped TiO2 photocatalyst which has a BET surface area of 25 to 200 m2/g, a pore volume of 0.10 to 1.00 ml/g, and a median pore diameter of 0.005 to 0.050 ?m, for purifying wastewater with irradiation by light.

Abstract: The invention relates to a process for preparing an ethylene amine mixture, which comprises hydrogenating an amino nitrile mixture comprising at least two ?-amino nitriles in an amount of at least 5% by weight in each case in the presence of a catalyst and, if appropriate, a solvent.

Abstract: The invention relates to a process for preparing an ethylene amine mixture, which comprises hydrogenating an amino nitrile mixture comprising at least 30% by weight of aminoacetonitrile (AAN) and at least 5% by weight of iminodiacetonitrile (IDAN) in the presence of a catalyst. Ethylenediamine (EDA) and/or diethylenetriamine (DETA) and, if appropriate, further ethylene amines can be isolated from the ethylene amine mixtures obtained.

Abstract: A process for preparing amines of the formula I, by reacting a carbonyl compound of the formula II with an amine of the formula III where R1 and R2 are different and are each an organic radical which has from 1 to 20 carbon atoms and may optionally also comprise heteroatoms, R3 is a C1-C6-alkyl group and R4 is an aryl group which may be partly or fully halogenated and/or may bear from one to three radicals from the group of cyano, nitro, C1-C6-alkyl, C1-C6-haloalkyl, hydroxyl, C1-C6-hydroxyalkyl, C1-C6-alkoxy, C1-C6-haloalkoxy, hydroxycarbonyl, C1-C6-alkoxycarbonyl, C1-C6-alkylamino, di(C1-C6-alkyl)amino, aryl and aryl(C1-C6-alkyl); and * represents the S or R configuration, and ** represents the S and/or R configuration; which comprises performing the reaction in the presence of a heterogeneous imination catalyst, of a hydrogenation catalyst and of hydrogen.

Abstract: Diastereoselective conversion of chiral imines of the formula I to amines of the formula II where the R1 to R4 radicals are each as defined in the description and R1 and R2 are different than one another, by converting the imine of the formula I in the presence of hydrogen and a heterogeneous copper-containing catalyst.

Abstract: A continuous process for producing polyamides, their oligomers or mixtures thereof, if appropriate with further reaction products, comprises reaction of aminonitriles or dinitriles and diamines or mixtures thereof, if appropriate together with further polyamide-forming monomers and/or oligomers, with an aqueous medium composed of aqueous monomer and oligomer extracts obtained from polyamide production by extraction of the polymer with water in a reactor which has a vertical longitudinal axis and through which there is a flow substantially in the longitudinal direction wherein water and/or the aqueous medium are introduced into the reactor at two or more different locations along the vertical longitudinal axis, wherein the aqueous medium is introduced at one or more locations.

Abstract: The invention relates to a process for preparing an ethylene amine mixture, which comprises the following steps: a) crude AAN which is largely free of formaldehyde cyanohydrin (largely FACH-free) is heated at a temperature of from 50 to 150° C. to give an amino nitrile mixture comprising aminoacetonitrile (AAN) and from 5 to 70% by weight of iminodiacetonitrile (DAN), b) hydrogenation of the amino nitrile mixture obtained in step a) in the presence of a catalyst. Ethylenediamine (EDA) and/or diethylenetriamine (DETA) and also, if appropriate, further ethylene amines can be isolated from the ethylene amine mixtures obtained.

Abstract: The invention relates to a process for preparing triethylenetetramine (TETA), which, comprises the following steps: a) reaction of ethylenediamine (EDA) with formaldehyde and hydrocyanic acid (HCN) in a molar ratio of EDA to formaldehyde to HCN of from 1:1.5:1.5 to 1:2:2 to give ethylenediaminediacetonitrile (EDDN), b) hydrogenation of the EDDN obtained in step a) in the presence of a catalyst and a solvent.

Abstract: The invention relates to a process for preparing an ethylene amine mixture, which comprises hydrogenating an amino nitrile mixture comprising at least two ?-amino nitriles in an amount of at least 5% by weight in each case in the presence of a catalyst and, if appropriate, a solvent.

Abstract: The invention relates to a process for preparing ethylenediamine by hydrogenation of aminoacetonitrile over a catalyst, wherein the hydrogenation is carried out in a solution comprising aminoacetonitrile, water in a proportion of from 0 to 60% by weight and a solvent and the aminoacetonitrile comprised in the solution is fed into the reaction vessel at a rate which is not greater than the rate at which the aminoacetonitrile reacts with hydrogen in the hydrogenation.

Abstract: A process for the preparation of benzophenonimine (BPI) of the general formula I where R1 and R2 are C1- to C4-alkoxy, C1- to C2-alkylamine and C2- to C4-dialkylamine and m and n are integers from 0 to 5 and R1 and R2, independently of one another, may be identical or different, by reacting benzophenone (BP) of the general formula II where R1, R2, m and n have the abovementioned meanings, in ammonia and in the presence of titanium dioxide, the titanium dioxide being present substantially in the anatase modification.

Abstract: The invention relates to a process for preparing an ethylene amine mixture, which comprises hydrogenating an amino nitrile mixture comprising at least 30% by weight of aminoacetonitrile (AAN) and at least 5% by weight of iminodiacetonitrile (IDAN) in the presence of a catalyst. Ethylenediamine (EDA) and/or diethylenetriamine (DETA) and, if appropriate, further ethylene amines can be isolated from the ethylene amine mixtures obtained.

Abstract: The invention relates to a process for preparing tetraethylenepentamine (TEPA) by hydrogenation of diethylenetriaminediacetonitrile (DETDN) over a catalyst. If appropriate, DETDN can also be present as a constituent of an amino nitrile mixture which additionally comprises diethylenetriaminemonoacetonitrile (DETMN).

Abstract: The invention relates to a process for preparing triethylenetetramine (TETA), which comprises hydrogenating ethylenediaminediacetonitrile (EDDN) in the presence of a catalyst and a solvent.

Abstract: The invention relates to a process for preparing an amino nitrile mixture comprising aminoacetonitrile (AAN) and from 5 to 70% by weight of iminodiacetonitrile (IDAN), which comprises heating crude AAN which is largely free of formaldehyde cyanohydrin (FACH-free) at a temperature of from 50 to 150° C.

Abstract: Catalysts which are prepared by reducing catalyst precursors which comprise a) cobalt and b) one or more elements of the alkali metal group, of the alkaline earth metal group, of the group consisting of the rare earths or zinc or mixtures thereof, the elements a) and b) being present at least partly in the form of their mixed oxides, and a process for the preparation of these catalysts and the use thereof for the hydrogenation of unsaturated organic compounds. Furthermore, a process for regenerating these catalysts by treatment of the catalyst with a liquid is described.

Abstract: A process for the preparation of benzophenonimine (BPI) of the general formula I where R1 and R2 are C1- to C4-alkoxy, C1- to C2-alkylamine and C2- to C4-dialkylamine and m and n are integers from 0 to 5 and R1 and R2, independently of one another, may be identical or different, by reacting benzophenone (BP) of the general formula II where R1, R2, m and n have the abovementioned meanings, in ammonia and in the presence of titanium dioxide, the titanium dioxide being present substantially in the anatase modification.

Abstract: The present invention relates to a process for preparing an aminoalkyl nitrile by reaction of a corresponding monoamine with a corresponding alkenyl nitrile in a continuous mode of operation, which comprises the steps (a) introduction of the corresponding monoamine into a continuously conveyed reaction stream; (b) introduction of the corresponding alkenyl nitrite into the reaction stream, with this already comprising the aminoalkyl nitrile on addition; (c) reaction of the reaction stream in a first reaction region; and (d) at least partial transfer of the reaction stream into at least one second reaction region for further reaction. The invention further relates to a process for preparing a diamine from the aminoalkyl nitrile, suitable apparatuses for carrying out the processes and their corresponding use.

Abstract: The invention relates to a process for hydrogenating oligonitriles which have at least two nitrile groups in the presence of a catalyst which, before commencement of the hydrogenation, is pretreated by contacting with a compound A which is selected from alkali metal carbonates, alkaline earth metal carbonates, ammonium carbonate, alkali metal hydrogencarbonates, alkaline earth metal hydrogencarbonates, ammonium hydrogencarbonate, alkaline earth metal oxocarbonates, alkali metal carboxylates, alkaline earth metal carboxylates, ammonium carboxylates, alkali metal dihydrogenphosphates, alkaline earth metal dihydrogenphosphates, alkali metal hydrogenphosphates, alkaline earth metal hydrogenphosphates, alkali metal phosphates, alkaline earth metal phosphates and ammonium phosphate, alkali metal acetates, alkaline earth metal acetates, ammonium acetate, alkali metal formiates, alkaline earth metal formiates, ammonium formiate, alkali metal oxalates, alkaline earth metal oxalates and ammonium oxalate.

Abstract: A process for preparing a polyamide by reacting a mixture which comprises a monomer which has a nitrile group and has at least one other functional group capable of forming a carboxamide group, and comprises water, in the presence of titanium dioxide as catalyst, which comprises using titanium dioxide whose BET surface area, determined to the German standard DIN 66 131 volumetrically by the multipoint method, is in the range from 5 to 35 m2/g.