Method and an arrangement for separating at least one carboxylic acid and furfural from a dilute aqueous mixture thereof

摘要

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.

主权项

1. A method for separating at least one carboxylic acid and furfural simultaneously from a dilute aqueous mixture wherein the total concentration of the carboxylic acids is less than 20% by weight and which further contains as impurities light water soluble polar compounds and/or light hydrocarbons, wherein the method comprises subjecting the dilute aqueous mixture to extraction with at least one methyltetrahydrofuran selected from the group of monomethyltetrahydrofuran and dimethyltetrahydrofuran, forming an extract comprising an organic phase and a raffinate comprising an aqueous phase, and recovering from the extract the at least one carboxylic acid and furfural.