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 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 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 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 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 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 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 preparing biphenols of the general formula I by reaction of monophenols of the general formula II where the radicals R1, R2 and R3 are each, independently of one another, hydrogen, alkyl, aryl or arylalkyl having from 1 to 10 carbon atoms, in the presence of an oxidant in a reactor, wherein a) the reactor comprises no stationary internals which act as baffles, b) a total of not more than 0.6 mol of oxidant is used per one mol of monophenol, and c) the oxidant is introduced either continuously or discontinuously in a plurality of portions over a period of from 10 minutes to 24 hours, with the amount of oxidant introduced per unit time not being constant over the total period of time but instead being varied.

Abstract: A process for continuously preparing a compound which bears at least two functional groups which are each independently selected from the group consisting of nitrile group, carboxylic acid group, carboxylic ester group and carboxamide group.

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.

Abstract: A process for purifying phosphorus chelate ligands by extraction, by using polar extractants.

Abstract: A process for long-term operation of a continuous heterogeneously catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, in which a reaction gas mixture stream comprising the hydrocarbon to be dehydrogenated in a molar starting amount KW is conducted through an overall catalyst bed comprising the total amount M of dehydrogenation catalyst and the deactivation of the overall catalyst bed is counteracted in such a way that, with increasing operating time, the contribution to the conversion in the first third of the total amount M of dehydrogenation catalyst in flow direction decreases, the contribution to the conversion in the last third of the total amount M of dehydrogenation catalyst in flow direction increases, and the contribution to the conversion in the second third of the total amount M of dehydrogenation catalyst in flow direction passes through a maximum.

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 is described for preparing adiponitrile and methylglutaronitrile, characterized by the following process steps: (a) reacting a reactant stream comprising pentenenitriles with hydrogen cyanide in the presence of at least one catalyst and of at least one promoter to obtain a reaction stream which comprises pentenenitriles, the at least one catalyst, catalyst degradation products, the at least one promoter, adiponitrile and methylglutaronitrile, (b) distilling the reaction stream to obtain a stream 3 which is depleted in pentenenitriles and comprises the at least one catalyst, catalyst degradation products, the at least one promoter, adiponitrile and methylglutaronitrile as the bottom product and a stream 4 enriched in pentenenitriles as the top product, (c) extracting the stream 3 using an extractant present in stream 5 to obtain a stream 6 enriched with extractant as the top product which comprises the catalyst, and a stream 7 depleted in extractant as the bottom product which comprises catalyst de

Abstract: A process is described for isomerizing pentenenitrile in a reactant stream, wherein the isomerization is effected over a homogeneously dissolved catalyst.

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 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.