Abstract: A method for tanning a hide wherein said method comprises treating a tannable hide with a tanning composition comprising from 25 to 75% by weight (wt. %) of at least one chromium(III) salt; from 5 to 70% by weight (wt. %) of at least one zeolite having the general formula (1): Mx/n [(AlO2)x(SiO2)y] wH2O, wherein M is an alkali metal cation, a bivalent cation, a trivalent cation or a mixture thereof, n is the valence of the cation, w is the number of water molecules per unit cell, y is a number from 0.8 to 50 and the ratio y to x is ranging from 0.7 to 100, treated with at least one acid selected from the group consisting of a monocarboxylic acid and a polycarboxyic acid; and from 1 to 70 wt. % of at least one aluminium(III) salt; wherein all wt. % are relative to the total weight of the composition (T).

Abstract: The present invention relates to a method and an arrangement for separation and recovery of at least one carboxylic acid and furfural from a dilute aqueous mixture thereof. In the method of the present invention a dilute aqueous mixture comprising at least one carboxylic acid and furfural is extracted with methyltetrahydrofurane, and at least one carboxylic acid and furfural are recovered. The arrangement of the present invention comprises an extraction unit 302 for carrying out extraction of at least one carboxylic acid and furfural from dilute aqueous mixture with methyltetrahydrofuran, connected to distillation unit 307 for carrying out distillation of the extract 305 from the extraction unit 302, and connected to acids distillation unit 320 for carrying out distillation of the bottom stream 308 from the distillation unit 307 to separate at least one carboxylic acid and furfural.

Abstract: The present invention provides a method for purifying and recovering propionic acid from an aqueous mixture containing a fermentation product obtained from a fermentation process using glycerol as substrate, the method comprising optionally acidifying the aqueous mixture to a pH below 4.5, subjecting the aqueous mixture to an extraction with extracting agent containing a heavy extractant and optionally a light extractant as a diluent to obtain an extract comprising the extracting agent and organic acids, and a raffinate comprising water and any unreacted glycerol, and subjecting the extract to vacuum evaporation to separate propionic acid-containing organic acids from the extractant.

Abstract: The present invention provides a method for purifying and recovering propionic acid from an aqueous mixture containing a fermentation product obtained from a fermentation process using glycerol as substrate, the method comprising optionally acidifying the aqueous mixture to a pH below 4.5, subjecting the aqueous mixture to an extraction with extracting agent containing a heavy extractant and optionally a light extractant as a diluent to obtain an extract comprising the extracting agent and organic acids, and a raffinate comprising water and any unreacted glycerol, and subjecting the extract to vacuum evaporation to separate propionic acid-containing organic acids from the extractant.

Abstract: The present invention relates to a method and an arrangement for separation and recovery of at least one carboxylic acid and furfural from a dilute aqueous mixture thereof. In the method of the present invention a dilute aqueous mixture comprising at least one carboxylic acid and furfural is extracted with methyltetrahydrofurane, and at least one carboxylic acid and furfural are recovered. The arrangement of the present invention comprises an extraction unit 302 for carrying out extraction of at least one carboxylic acid and furfural from dilute aqueous mixture with methyltetrahydrofuran, connected to distillation unit 307 for carrying out distillation of the extract 305 from the extraction unit 302, and connected to acids distillation unit 320 for carrying out distillation of the bottom stream 308 from the distillation unit 307 to separate at least one carboxylic acid and furfural.