Patent ID: 6986833

Claim:
A process for fractionating an amine-containing mixture which comprises at least one amine, water, low-boilers and optionally high-boilers, having step, (iii) and (iv) and optionally step (v): (iii) extracting the amine-containing mixture with sodium hydroxide solution, to obtain an aqueous, sodium-hydroxide-containing first phase, and an aqueous-organic second phase which contains amine, low-boilers and, where present, high-boilers, (iv) distilling the aqueous-organic second phase in a distillation column having a stripping part and an enrichment part, to obtain essentially anhydrous amine as bottom-phase take off or sidestream takeoff in the stripping part of the distillation column, an amine-water azeotrope as sidestream takeoff in the enrichment part of the column and a low-boiler fraction as overhead takeoff, and recycling the amine-water azeotrope to the extraction step (iii), and (v) optionally further purifying or fractionating the essentially anhydrous amine.