Abstract: A process is described for preparing adiponitrile by hydrocyanating 1,3-butadiene over a catalyst, by, in a first process step, hydrocyanating 1,3-butadiene to 3-pentenenitrile over at least one nickel(0) catalyst, and, in a second process step, hydrocyanating 3-pentenenitrile to adiponitrile over at least one nickel(0) catalyst with addition of at least one Lewis acid, wherein at least one of the at least one nickel(0) catalysts used in the particular process steps is transferred into the other process step.

Abstract: The invention relates to phosphinite phosphites I of formula 1, 2, 3, 4, 5 or 6 and mixtures thereof, wherein R1, R2, R4 independently represent an alkyl or alkylene group with 1 to 8 carbon atoms, provided that at least one of the groups R1, R2, R4 is different from H; R5 to R22 independently represent H, an alkyl or alkylene group with 1 to 8 carbon atoms; R3 is H, methyl or ethyl; X is F, Cl or CF3, if n=1 or 2 and X is H, if n=0.

Abstract: A process is described for removing hydrogen cyanide from mixtures comprising pentenenitrile, wherein the removal is effected by an azeotropic distillation of hydrogen cyanide with 1,3-butadiene.

Abstract: The disclosure relates to a process for purifying crude caprolactam. The process involves converting a first mixture of 6-amino capronitrile and water to a second mixture of caprolactam ammonia, water, high boilers and low boilers using a catalyst. The ammonia is removed from the second mixture to obtain a third mixture. Water is removed from the third mixture to give crude caprolactam, high boiler and low boilers. Purified caprolactam is then obtained by a series of distillation steps.

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 for dewatering hydrocyanic acid by distillation, which includes distilling crude hydrocyanic acid containing from 50 to 99.9% by weight of HCN, from 0.1 to 40% by weight of water, from 0 to 15% by weight of carbon oxides and optionally from 0.01 to 1% by weight of an involatile stabilizer, at a pressure of from 1 bar to 2.5 bar, a bottom temperature of from 100° C. to 130° C. and a top temperature of from 25° C. to 54° C., in the absence of a volatile stabilizer, in a distillation column to obtain a top draw stream containing purified, anhydrous hydrocyanic acid and carbon oxides and a bottom draw stream including water and, optionally, the involatile stabilizer.

Abstract: A process is described for preparing 3-pentenenitrile, characterized by the following process steps: (a) isomerizing a reactant stream which comprises 2-methyl-3-butenenitrile over at least one dissolved or dispersed isomerization catalyst to give a stream 1 which comprises the at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, (b) distilling stream 1 to obtain a stream 2 as the top product which comprises 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, and a stream 3 as the bottom product which comprises the at least one isomerization catalyst, (c) distilling stream 2 to obtain a stream 4 as the top product which, compared to stream 2, is enriched in (Z)-2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in stream 2, and a stream 5 as the bottom product which, compared to stream 2, is enriched in 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in stream 2, (d) di

Abstract: A process for extractively removing nickel(0) complexes having phosphorus ligands and/or free 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 reaction effluent into two phases being effected at a temperature T (in ° C.), wherein the content of nickel(0) complexes having phosphorus ligands and/or free phosphorus ligands in the reaction effluent of the hydrocyanation, depending on the temperature T, is at least y % by weight and, irrespective of the temperature T, is a maximum of 60% by weight, where the numerical value of the minimum content y is given by the equation y=0.5·T+20 and T is to be used in the equation as a dimensionless numerical value.

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: A process is described for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene with hydrogen cyanide over at least one catalyst, wherein the 1,3-butadiene and/or hydrogen cyanide is contacted with at least one microporous solid before the reaction.

Abstract: A process is described for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene in the presence of at least one catalyst, wherein the reaction is carried out in a loop reactor having external pumped circulation and jet nozzle for driving the internal circulation.

Abstract: A process is described for removing hydrogen cyanide from mixtures comprising pentenenitrile, wherein the removal is effected by an azeotropic distillation of hydrogen cyanide with 1,3-butadiene.

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 is described for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene in the presence of at least one catalyst, wherein unhydrocyanated 1,3-butadiene is removed from the effluent of the hydrocyanation and recycled into the process, and the recycled 1,3-butadiene is monitored for the content of hydrogen cyanide.

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.

Abstract: A process is described for preparing adiponitrile by hydrocyanating 1,3-butadiene over a catalyst, by, in a first process step, hydrocyanating 1,3-butadiene to 3-pentenenitrile over at least one nickel(0) catalyst, and, in a second process step, hydrocyanating 3-pentenenitrile to adiponitrile over at least one nickel(0) catalyst with addition of at least one Lewis acid, wherein at least one of the at least one nickel(0) catalysts used in the particular process steps is transferred into the other process step.

Abstract: A process for the removal of water from a mixture comprising water and zinc chloride, which comprises adding to said mixture comprising water and zinc chloride an aprotic, polar diluent whose boiling point in the case where an azeotrope is not formed between said diluent and water under the pressure conditions of the distillation mentioned below is higher than the boiling point of water and which is in liquid form at this boiling point of water or which forms an azeotrope or heteroazeotrope with water under the pressure and temperature conditions of the distillation mentioned below, and distilling the mixture comprising water, zinc chloride and the diluent with removal of water or said azeotrope or said heteroazeotrope from this mixture, giving an anhydrous mixture comprising zinc chloride and said diluent.

Abstract: A process for reducing the level of an aliphatic monounsaturated amine (IV) in a mixture (V) containing an aminonitrile (I) or a diamine (II) or a dinitrile (III) or mixtures thereof as well as said mine (IV) by a) reacting said mixture (V) with an anionic nucleophile (VI) which contains a nucleophilic atom selected from the group consisting of oxygen, nitrogen and sulfur, which is capable of taking up an H+ ion to form an acid having a pKa value in the range from 7 to 11, as measured in water at 25° C., and which has a relative nucleophilicity, as measured in methyl perchlorate/methanol at 25° C., in the range from 3.4 to 4.7 when said nucleophilic atom is oxygen, in the range from 4.5 to 5.8 when said nucleophilic atom is nitrogen, and in the range from 5.5 to 6.8 when said nucleophilic atom is sulfur, in an amount in the range from 0.01 to 10 mol per mole of said amine (IV) in said mixture (V) at a temperature in the range from 50 to 200° C.

Abstract: A process for isomerizing cis-2-pentenenitrile to trans-3-pentenenitrile in the presence of aluminum oxide as a catalyst, wherein the aluminum oxide has a BET surface area of at least 50 m2/g.

Abstract: A process for extractively removing homogeneously dissolved catalysts from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles, by extraction by means of a hydrocarbon H, which comprises a) adding a nonpolar aprotic liquid L to the reaction effluent to obtain a stream I, and b) extracting the stream I 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.