Abstract:
The invention relates to a method for producing biphenols of general formula (I) by reacting monophenols of general formula (II), wherein the radicals R1, R2 and R3 independently represent hydrogen, alkyl, aryl or arylalkyl, with 1 - 10 C-atoms, in the presence of an oxidation agent in a reactor. Said method is characterised in that a) the reactor does not contain any stationary integrated components which act as a current agitator, b) a maximum of 0,6 mol of oxidation agents are used per mol of monophenol, and c) the oxidation agent is added in a continuous or discontinuous manner in a plurality of portions within a time span of between 10 min - 24 hours, whereby the amount of oxidation agent which is added per time unit is not constant over the entire tine span, but is varied.
Abstract:
The invention relates to a method for separating hydrogen cyanide from mixtures containing pentenenitrile, by means of the azeotropic distillation of hydrogen cyanide with 1,3-butadiene.
Abstract:
The invention relates to a method for extractive separation of nickel (0) complexes with phosphorous ligands, from a reaction product of a hydrocyanation of unsaturated mononitriles to give dinitriles, by means of extraction with a hydrocarbon, wherein a phase separation of the hydrocarbon and the nitrile-containing solution into two phases occurs, by addition of a polar additive to the reaction product (feed stream) and/or the extraction stage.
Abstract:
A process for the long-term operation of a continuously operated heterogeneous catalyzed partial dehydrogenation of a hydrocarbon to be dehydrogenated, in which a stream of reaction gas mixture containing the hydrocarbon to be dehydrogenated in a molar starting amount HC is passed through a total catalyst bed containing the total amount M of dehydrogenation catalyst and deactivation of the total catalyst bed is counteracted by, as the period of operation increases, the conversion contribution of the first third in the flow direction of the total amount M of dehydrogenation catalyst decreasing, the conversion contribution of the last third in the flow direction of the total amount M of dehydrogenation catalyst increasing and the conversion contribution of the second third in the flow direction of the total amount M of dehydrogenation catalyst going through a maximum.
Abstract:
The invention relates to a method for the extractive separation of homogeneously dissolved catalysts from a reaction product from a hydrocyanation of unsaturated mononitriles to dinitriles, by extraction with a carbon material (K), characterised in that a) a non-polar aprotic liquid (F) is added to the reaction product to give a stream (I) and b) the stream (I) is extracted with a carbon material (K) at a temperature (T), to give a stream (II), containing the carbon material (K), enriched with the catalyst and a stream (III), stripped of catalyst.
Abstract:
The invention relates to a method for hydrocyanation of 1,3-butadiene on at least one nickel(o) complex with phosphor-containing ligands as a catalyst, wherein 1,3-butadiene is used in a mixture with n-butane and the mixture contains 60 - 90 vol. % 1,3-butadiene and 40 -10 vol. % n-butane.
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:
The invention relates to a method for removing water from a mixture containing water and zinc chloride. The invention is characterized in that said mixture containing water and zinc chloride is mixed with an aprotic, polar diluting agent whose boiling point, in the event of non-azeotropic formation of said diluting agent with water under the pressure conditions of the distillation mentioned below, is higher than the boiling point of water and is liquid at the boiling point of water or one azeotrope or heteroazeotrope with water is formed under the pressure and temperature conditions of the distillation mentioned below, and the mixture containing water, zinc chloride and the diluting agent is distilled while removing water or said azeotrope or said heteroazeotrope from this mixture while obtaining a water-free mixture containing zinc chloride and said diluting agent.