Abstract: A process is described for separating mixtures of isomeric pentenenitriles, in which at least one isomer is removed from the mixture, wherein the separation of the substance mixtures of isomeric pentenenitriles is effected distillatively under reduced pressure.

Abstract: A process for extractively removing homogeneously dissolved catalysts from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles with a hydrocarbon H, including performing the steps of a) concentrating the reaction effluent before step b) by distillation at pressures of from 0.1 to 5000 mbar and temperatures of from 10 to 150° C., b) adding a hydrocarbon H to the concentrated reaction effluent to obtain a stream I, and c) feeding stream I, without prior separation of the liquid phases, into an extraction apparatus and extracting it at a temperature T with the hydrocarbon H to obtain a stream II comprising the hydrocarbon H enriched with the catalyst and a stream III having a low catalyst content.

Abstract: The iron-containing catalyst suitable for use as a catalyst contains a) iron or a mixture containing iron and an iron-based compound. The iron has an average crystallite size ranging from 1-35 nm measured by X-ray diffraction.

Abstract: A process for preparing hydrogen cyanide, comprising the provision of gaseous formamide by evaporating liquid formamide in an evaporator (step i)) and the catalytic dehydration of the gaseous formamide (step ii)), and also an apparatus for performing the process according to the invention, comprising at least one microevaporator and a tubular reactor, and the use of a microevaporator for evaporating formamide in a process for preparing hydrogen cyanide from formamide.

Abstract: Method of producing compounds of the general formula XPR2(OR1)??Ia where X is chlorine, bromine or iodine and R1 is an organic radical, by reacting compounds of the general formula X2PR2??II, in which X has the meaning given above and R2 is an organic radical, with compounds of the general formula R1OH??III, in which R1 has the meaning given above, to give a mixture IV, in that a) the postreaction is carried out at a temperature of from 50 to 240° C. and a pressure of from 0.001 to 0.9 bar, b) from the mixture IV the compounds Ia are separated off from the compounds PR2(OR1)2??Ib and, if appropriate, the compounds II and c) compounds Ib and, if appropriate, unreacted compounds II are returned to the synthesis stage.

Abstract: A process for preparing hydrogen cyanide by catalytically dehydrating gaseous formamide in a tubular reactor formed from at least one reaction channel in which the catalytic dehydration proceeds, said reaction channel having an inner surface which is formed from a material having an iron content of ?50% by weight, and no additional catalysts and/or internals being present in the reaction channel, and the at least one reaction channel having a mean hydraulic diameter of from 0.5 to 6 mm, and a reactor with the features specified above and the use of the inventive reactor for preparing hydrogen cyanide by catalytically dehydrating gaseous formamide.

Abstract: An adiponitrile/methylglutaronitrile preparation process includes distilling a reaction stream to obtain stream 3 depleted in pentenenitriles (bottom product) and stream 4 enriched in pentenenitriles (top product); extracting stream 3 obtaining stream 6 enriched with extractant (top product) and stream 7 depleted in extractant (bottom product); distilling stream 6 obtaining stream 8 comprising the catalyst (bottom product) and stream 9 comprising the extractant (top product); distilling stream 7 obtaining stream 10 (bottom product) and stream 11 comprising the extractant (top product); distilling stream 10 obtaining stream 12 comprising catalyst degradation products, at least one promotor, adiponitrile and methylglutaronitrile (bottom product) and stream 13 comprising pentenenitriles (top product); distilling stream 12 obtaining stream 14 comprising catalyst degradation products and the promotor(s) (bottom product) and stream 15 comprising adiponitrile and methylglutaronitrile (top product); distilling stream

Abstract: A process is described for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene, wherein 1,3-butadiene is reacted with hydrogen cyanide in the presence of at least one catalyst and the stream resulting therefrom is purified distillatively, the bottom temperature during the distillation not exceeding 140° C.

Abstract: A process is described for continuously hydrocyanating 1,3-butadiene in the presence of at least one nickel(0) catalyst with chelate ligands, wherein 1,3-butadiene and hydrogen cyanide are used in a molar ratio of from 1.6:1 to 1.1:1.

Abstract: A process for preparing nickel(0)-phosphorus ligand complexes comprising at least one nickel(0) central atom and at least one phosphorus ligand by reacting a nickel(II) compound with a reducing agent in the presence of the ligand to give a reaction mixture, wherein a) the molar reducing agent:nickel(II) compound ratio in the reaction is from 1:1 to 1000:1, calculated as the molar ratio of the redox equivalents, b) the molar phosphorus ligand:nickel(II) compound ratio in the reaction is not more than 30:1, calculated as the molar P atoms:Ni atoms ratio, c) the nickel(0) content in the resulting reaction mixture is not more than 1.3% by weight and d) the resulting reaction mixture is extracted by adding at least one dinitrile and at least one hydrocarbon to form at least two immiscible phases.

Abstract: A process is described for preparing a nickel(0)-phosphorus ligand complex containing at least one nickel(0)central atom and at least one phosphorus ligand, which comprises reducing a nickel(II) halide dried by azeotropic distillation in the presence of at least one phosphorus ligand.

Abstract: A process is described for hydrocyanating 1,3-butadiene over at least one nickel(0) complex having phosphorus ligands as a catalyst, wherein the 1,3-butadiene is used in a mixture with n-butane and the mixture contains from 60 to 90% by volume of 1,3-butadiene and from 40 to 10% by volume of n-butane.

Abstract: Method of producing compounds of the general formula XPR2(OR1)??I a where X is chlorine, bromine or iodine and R1 is an organic radical, by reacting compounds of the general formula X2PR2??II, in which X has the meaning given above and R2 is an organic radical, with compounds of the general formula R1OH??III, in which R1 has the meaning given above, to give a mixture IV, in that a) the postreaction is carried out at a temperature of from 50 to 240° C. and a pressure of from 0.001 to 0.9 bar, b) from the mixture IV the compounds I a are separated off from the compounds PR2(OR1)2??I b and, if appropriate, the compounds II and c) compounds I b and, if appropriate, unreacted compounds II are returned to the synthesis stage.

Abstract: A process is described for isomerizing pentenenitrile in a reactant stream, wherein the isomerization is effected over a heterogeneous catalyst in a distillation column in such a way that, during the isomerization of the isomerization reactant, it is distillatively depleted in relation to the isomerization product in the reaction column of the distillation column.

Abstract: A process for extractively removing nickel(0) complexes having phosphorus ligands from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles by extraction by means of a hydrocarbon, a phase separation of the hydrocarbon and of the nitrile-containing solution into two phases being effected, by feeding at least one polar additive to the hydrocyanation effluent (feedstream) and/or to the extraction stage.

Abstract: A method for producing 3-pentenenitrile by means of the hydrocyanation of 1,3-butadiene, which comprises the following process steps: (b?) distillation of 1,3-butadiene comprising water, 1- and 2-butenes and a stabilizer in a distillation apparatus K4 to obtain a stream 15 as the bottom product, which comprises dried 1,3-butadiene, 1- and 2-butenes and the stabilizer, and a stream 16 as the top product, which comprises an azeotropic 1,3-butadiene/water mixture, condensation of the stream 16 in a condenser W, transfer of the resulting condensate (stream 17) into a phase separation apparatus, recycling of the upper liquid phase (stream 18) consisting of 1,3-butadiene as reflux to the column K4, and discharge of the lower liquid aqueous phase (stream 19), (a) reaction of stream 15 in a reactor R1 with hydrogen cyanide over at least one catalyst (stream 6d) to obtain a stream 1 which comprises 3-pentenenitrile, 2-methyl-3-butenenitrile, the at least one catalyst, unconverted 1,3-butadiene, and 1- and 2-butenes,

Abstract: The invention relates to a method for isomerization of pentene nitrile in an educt flow, wherein isomerization is performed on a homogeneously dissolved catalyst.

Abstract: A process is described for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene, wherein 1,3-butadiene is reacted with hydrogen cyanide in the presence of at least one catalyst and the stream resulting therefrom is purified distillatively, the bottom temperature during the distillation not exceeding 140° C.

Abstract: A system which is suitable as a catalyst for the hydrocyanation of olefinically unsaturated compounds and comprises a) Ni(0) b) a compound which complexes Ni(0) as a ligand and contains trivalent phosphorus, c) a Lewis acid and d) a compound of the formula M Rn where M: Al or Ti R: identical or different monovalent alkoxy radicals, in which case a plurality of alkoxy radicals may be bonded together, and additionally, in the case that M=Al, R may be identical or different monovalent alkyl radicals, in which case a plurality of alkyl radicals may be bonded together or one or more alkyl radicals may be bonded to one or more of the abovementioned alkoxy radicals, n: valency of M, and processes for hydrocyanating an olefinically unsaturated compound in the presence of such a system.

Abstract: A process is described for preparing 3-pentenenitrile, characterized by the following process steps: (a) reacting 1,3-butadiene with hydrogen cyanide over at least one catalyst to obtain a stream 1 which comprises 3-pentenenitrile, 2-methyl-3-butenenitrile, the at least one catalyst and 1,3-butadiene, (b) distilling stream 1 in a column to obtain a high-1,3-butadiene stream 2 as the top product and a low-1,3-butadiene stream 3 as the bottom product which comprises 3-pentenenitrile, the at least one catalyst and 2-methyl-3-butenenitrile, (c) distilling stream 3 in a column to obtain a stream 4 as the top product which comprises 1,3-butadiene, a stream 5 which comprises 3-pentenenitrile and 2-methyl-3-butenenitrile at a side draw of the column, and a stream 6 as the bottom product which comprises the at least one catalyst, (d) distilling stream 5 to obtain a stream 7 as the top product which comprises 2-methyl-3-butenenitrile, and a stream 8 as the bottom product which comprises 3-pentenenitrile.