Abstract: The invention relates to a process for working up water containing 4,4?-dichlorodiphenyl sulfoxide and/or 4,4?-dichlorodiphenyl sulfone as impurities, comprising: (a) mixing the water containing 4,4?-dichlorodiphenyl sulfoxide and/or 4,4?-dichlorodiphenyl sulfone as impurities with an organic solvent in which 4,4?-dichlorodiphenyl sulfoxide and/or 4,4?-dichlorodiphenyl sulfone have a solubility of at least 0.5 wt % based on the amount of 4,4?-dichlorodiphenyl sulfoxide and/or 4, 4?-dichlorodiphenyl sulfone and organic solvent at 20° C., which forms a two-phase system with water and which can be stripped from water with a stripping gas and subsequently separating the obtained mixture into an aqueous phase and an organic phase, and (b) stripping the organic solvent from the aqueous phase with a stripping gas.

Abstract: The invention relates to a process for purifying 4,4?-dichlorodiphenyl sulfone comprising: (a) providing a suspension comprising particulate 4,4?-dichlorodiphenyl sulfone in carboxylic acid, (b) carrying out a solid-liquid separation of the suspension to obtain residual moisture containing 4,4?-dichlorodiphenyl sulfone and a carboxylic acid comprising filtrate, (c) washing the residual moisture containing 4,4?-dichlorodiphenyl sulfone with an aqueous base and then with water, (d) mixing the aqueous base after being used for washing with a strong acid, or mixing the aqueous base after being used for washing, the carboxylic acid comprising filtrate and a strong acid, (e) carrying out a phase separation in which an aqueous phase and an organic phase comprising the carboxylic acid are obtained.

Abstract: The present invention is directed to a method of purifying a protein of interest from the particulate matter of a fermentation broth comprising the step of purifying the protein of interest from the particulate matter of the fermentation broth, wherein the step of purifying the protein of interest from the particulate matter of the fermentation broth comprises one or more washing steps, which comprises contacting the particulate matter with a washing solution comprising one or more conditions that favor the solubilization of the protein of interest and/or the desorption of the protein of interest from the particulate matter.

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) dis

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) dis

Abstract: The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the single or multiple performance of the following wash stage (a): (a) contacting the crude aromatic nitro compound (N-in) with an aqueous phase (W-res) and then separating the phases to obtain an organic phase (N-res) and an aqueous phase (W-res), wherein at least one demulsifier (D) is present in one or more of the wash stages (a).

Abstract: A process for purifying an aqueous glyoxal solution comprising at least one acid by extractive acid removal, comprising i) mixing and dispersion of the aqueous glyoxal solution with an ion exchanger solution comprising a tertiary amine and an organic solvent, ii) phase separation and removal of the ion exchanger solution laden with the acid from the aqueous glyoxal solution, and iii) regeneration of the ion exchanger solution by contacting with a basic compound for neutralization of the acid and removal of the basic compound, iv) mixing and dispersion of the ion exchanger solution with water to obtain a dispersion of water and ion exchanger solution, v) Phase separation and removal of the aqueous phase from the ion exchanger solution in such a way that the content of the aqueous phase of the regenerated ion exchanger solution is <1% by weight, and recycling of the ion exchanger solution into step i).

Abstract: A method for producing 3-pentenenitrile is provided that includes: (a) isomerizing an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerization catalyst to form a stream (1), which contains the isomerization catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distilling the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerization catalyst(s); (c) distilling the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2); (d) distilling stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the he

Abstract: Processes for obtaining aromatic hydrocarbons from a hydrocarbon mixture a1. Mixture a1 is extractively distilled with extractive solvent a2 producing mixture bl comprising solvent a2, aromatic hydrocarbons and high boilers, and nonaromatic hydrocarbon mixture b2. Mixture b1 is distilled to aromatic hydrocarbon c1 and solvent comprising high boilers c2. Substream dl is removed from c2 and c2 is recycled to extractive distillation. Substream d1 is extracted with water producing aqueous phase e1 and organic phase e2. Aqueous phase e1 is distilled and purified solvent a2 is recovered and recycled into extractive distillation of mixture b1. Substream e2? is removed from organic phase e2 and recycled into extractive distillation of mixture b1. The amount of organic phase e2? is such that when d1 comprising solvent, high boilers, water and circulated stream e2? is dispersed, aqueous extract phase e1, forms a disperse phase and organic phase e2 a continuous phase.

Abstract: The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the following wash stages (a1) and (a2), where each of stages (a1) and (a2) may be performed once or more than once in succession: (a1) contacting the crude aromatic nitro compound (N1-in) with a first aqueous phase (W1-in) comprising at least one base (B) and then separating the phases to obtain an organic phase (N1-res)and an aqueous phase (W1-res); and then (a2) contacting the organic phase (N1-res) obtained in stage (a1) with a second aqueous phase (W2-in) and then separating the phases to obtain a purified organic phase (N2-res) and at least one aqueous phase (W2-res), the aqueous phase used (W2-in) having a pH of 6 to 9.

Abstract: The invention relates to a process for purifying crude aromatic nitro compounds which originate from the nitration of aromatic compounds, comprising the single or multiple performance of the following wash stage (a): (a) contacting the crude aromatic nitro compound (N-in) with an aqueous phase (W-res) and then separating the phases to obtain an organic phase (N-res) and an aqueous phase (W-res), wherein at least one demulsifier (D) is present in one or more of the wash stages (a).

Abstract: Processes for obtaining aromatic hydrocarbons from a hydrocarbon mixture comprising aromatic and nonaromatic hydrocarbons and high boilers comprising: (A) providing a hydrocarbon mixture a1 and an extractive solvent a2, (B) extractively distilling the mixture a1 with the extractive solvent to obtain a mixture b1 of extractive solvent, the aromatic hydrocarbons, and high boilers, (C) distilling the mixture b1 to one or more fractions c1 comprising aromatic hydrocarbons and the extractive solvent c2 comprising high boilers, (D) removing a substream d1 from the extractive solvent c2, (E) extracting the substream d1 of the extractive solvent with water to obtain an aqueous extract phase e1 essentially free of high boilers and an organic phase e2 comprising the high boilers, (F) distilling the aqueous extract phase e1 and recovering the extractive solvent a2. Step (E) is preceded by a distillation in which a fraction of very high-boiling hydrocarbons is removed from substream d1.

Abstract: A method for producing 3-pentenenitrile is provided that includes: (a) isomerizing an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerisation catalyst to form a stream (1), which contains the isomerisation catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distilling the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerisation catalyst(s); (c) distilling the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2); (d) distilling stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the he

Abstract: The present invention relates to a process for preparing formic acid by reacting carbon dioxide (1) with hydrogen (2) in a hydrogenation reactor (I) in the presence of a catalyst comprising an element of group 8, 9 or 10 of the Periodic Table, a tertiary amine comprising at least 12 carbon atoms per molecule and a polar solvent comprising one or more monoalcohols selected from among methanol, ethanol, propanols and butanols, to form formic acid/amine adducts as intermediates which are subsequently thermally dissociated, where a tertiary amine having a boiling point which is at least 5° C. higher than that of formic acid is used and a reaction mixture comprising the polar solvent, the formic acid/amine adducts, the tertiary amine and the catalyst is formed in the reaction in the hydrogenation reactor (I) and is discharged from the reactor as output (3).

Abstract: A process for purifying an aqueous glyoxal solution comprising at least one acid by extractive acid removal, comprising i) mixing and dispersion of the aqueous glyoxal solution with an ion exchanger solution comprising a tertiary amine and an organic solvent, ii) phase separation and removal of the ion exchanger solution laden with the acid from the aqueous glyoxal solution, and iii) regeneration of the ion exchanger solution by contacting with a basic compound for neutralization of the acid and removal of the basic compound, iv) mixing and dispersion of the ion exchanger solution with water to obtain a dispersion of water and ion exchanger solution, v) Phase separation and removal of the aqueous phase from the ion exchanger solution in such a way that the content of the aqueous phase of the regenerated ion exchanger solution is <1% by weight, and recycling of the ion exchanger solution into step i).

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 invention relates to a process for obtaining aromatic hydrocarbons selected from benzene, toluene, xylene and ethylbenzene mixtures thereof from a hydrocarbon mixture which additionally comprises nonaromatic hydrocarbons and high boilers, comprising the steps of (A) providing a hydrocarbon mixture a1 and an extractive solvent a2 composed of N-formylmorpholine, (B) extractively distilling the hydrocarbon mixture a1 with the extractive solvent to obtain a mixture b1 of extractive solvent and the aromatic hydrocarbons, said mixture comprising high boilers, and a mixture b2 comprising nonaromatic hydrocarbons, (C) distilling the mixture b1 of extractive solvent and aromatic hydrocarbons obtained in step (B) to obtain one or more fractions c1 composed of aromatic hydrocarbons and the extractive solvent c2 which comprises high boilers, (D) removing a substream d1 from the extractive solvent c2 and recycling the extractive solvent c2 into the extractive distillation (B), (E) extracting the substream d1 of the ex

Abstract: The invention relates to a process for obtaining aromatic hydrocarbons selected from benzene, toluene, xylene and ethylbenzene and mixtures thereof from a hydrocarbon mixture which additionally comprises nonaromatic hydrocarbons and high boilers, comprising the steps of (A) providing a hydrocarbon mixture a1 and an extractive solvent a2 composed of N-formylmorpholine, (B) extractively distilling the hydrocarbon mixture a1 with the extractive solvent to obtain a mixture b1 of extractive solvent and the aromatic hydrocarbons, said mixture comprising high boilers, and a mixture b2 comprising nonaromatic hydrocarbons, (C) distilling the mixture b1 of extractive solvent and aromatic hydrocarbons obtained in step (B) to obtain one or more fractions c1 composed of aromatic hydrocarbons and the extractive solvent c2 which comprises high boilers, (D) removing a substream d1 from the extractive solvent c2 and recycling the extractive solvent c2 into the extractive distillation (B), (E) extracting the substream d1 of th

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: 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