Column for concentrating phthalic anhydride

US6884324B2 · kind B2 · utility

Assignee

• Lurgi GmbH · DE

Inventors

• Thomas Gutermuth · Maintal, DE
• Helmuth Domes · Obertshausen, DE

Key dates

• Filing date: Jan 21, 2003
• Grant date: Apr 26, 2005
• Expiry date: Mar 23, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D307/89
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

To improve the columns used so far for producing phthalic anhydride, and to make them less expensive and easier to install, it is proposed that in the column for concentrating phthalic anhydride two distillation stages are arranged, wherein the removal of the low-boiling components of the crude phthalic anhydride by distillation is effected in the first distillation stage (2) and the separation of the high-boiling components from the pure phthalic anhydride is effected in the second distillation stage (3), both distillation stages being arranged side by side and being separated from each other by a vertical wall (4), and that the bottom (7) of the first distillation stage (2) is connected with the bottom (10) of the second distillation stage (3).