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 producing cyclohexenone derivatives of general formula (I), wherein R 1 represents hydrogen or OH; R 2 represents (Ia), comprising the following steps: (a) hydrolyzing a cyclohexenol compound of formula (II), wherein R 3 represents hydrogen and R 4 represents C 1 -C 6 -alkoxy or R 3 and R 4 represent vicinal hydroxy groups, which carry a common acetal protective group or a ketone protective group, R 5 represents (IIa), and R 6 represents a protected hydroxy group, in the absence of an organic solvent and in the presence of an acid catalyst; and; (b) extracting the reaction mixture by using a polar extracting agent.
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) distilling stream 5 to obtain a stream 6 as the bottom product which comprises 3-pentenenitrile and a stream 7 as the top product which comprises 2-methyl-3-butenenitrile.
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:
Procedimientos para la separacion extractiva de complejos de níquel (0) con ligandos y/o ligandos libres fosforados del producto de una reaccion de hidrocianacion de mononitrilos insaturados para obtener dinitrilos por extraccion mediante un hidrocarburo, donde se lleva a cabo la separacion de fases del hidrocarburo y del producto de la reaccion en dos fases, a una temperatura T (en sC) caracterizado porque el contenido de complejos de níquel (0) con ligandos fosforados y/o ligandos libres fosforados del producto de la reaccion de hidrocianacion es, segun la temperatura T, de por lo menos y % en peso, y es independiente de la temperatura T, como máximo de 60% en peso, siendo dado el valor numérico del contenido mínimo y por la ecuacion y = 0,5 ò T l 20 y T debe usarse en la ecuacion como valor numérico adimensional.
Abstract:
The invention relates to a method for the separation of ascorbic acid from a mixture containing ascorbic acid and 2-keto-L-gulonic acid in a polar, preferably aqueous solvent, by means of liquid/liquid extraction using an amide. The method preferably also comprises steps for the back-extraction of the ascorbic acid, recycling of the extraction solvent and/or the back extraction solvent and for isolation of the ascorbic acid from the back extraction solvent. The invention further relates to a method for the production of ascorbic acid from KGA and isolation of the ascorbic acid so produced.
Abstract:
The invention relates to a method for the separation of ascorbic acid from a mixture containing ascorbic acid and 2-keto-L-gulonic acid in a polar, preferably aqueous solvent, by means of liquid/liquid extraction using an amide. The method preferably also comprises steps for the back-extraction of the ascorbic acid, recycling of the extraction solvent and/or the back extraction solvent and for isolation of the ascorbic acid from the back extraction solvent. The invention further relates to a method for the production of ascorbic acid from KGA and isolation of the ascorbic acid so produced.
Abstract:
The invention relates to a method for the separation of ascorbic acid from a mixture containing ascorbic acid and 2-keto-L-gulonic acid in a polar, preferably aqueous solvent, by means of liquid/liquid extraction using an amide. The method preferably also comprises steps for the back-extraction of the ascorbic acid, recycling of the extraction solvent and/or the back extraction solvent and for isolation of the ascorbic acid from the back extraction solvent. The invention further relates to a method for the production of ascorbic acid from KGA and isolation of the ascorbic acid so produced.