Process for purifying alkanesulfonic acids

US10577312B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Jan SPIELMANN · Mannheim, DE
• Michael Koch · Speyer, DE
• Juergen Wortmann · Ludwigshafen, DE
• Feelly Ruether · Ludwigshafen, DE
• Sabine Weiguny · Freinsheim, DE
• Frieder Borgmeier · Mannheim, DE

Key dates

• Filing date: Nov 8, 2016
• Grant date: Mar 3, 2020
• Expiry date: Nov 8, 2036

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C309/03
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process comprising: (a) distilling a melt comprising crude alkanesulfonic acid to completely or partly remove low boilers, wherein the low boilers are drawn off at the top of a distillation column or of a one-stage evaporation apparatus and a material stream comprising alkanesulfonic acid, high boilers and residual low boilers is withdrawn at the bottom of the distillation column or of the one-stage evaporation apparatus, (b) sending the stream comprising alkanesulfonic acid, high boilers and residual low boilers into a melt crystallization as the starting melt to obtain crystals formed from the alkanesulfonic acid, hydrates of the alkanesulfonic acid or a mixture of both suspended in mother liquor, (c) performing a solid-liquid separation to remove the crystals from the mother liquor, and (d) optionally washing the crystals to remove mother liquor adhering to the crystals.