Process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution

US9914112B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Stephan Bauer · Ostercappeln, DE
• Norbert Herfert · Charlotte, US
• Jürgen Freiberg · Lampertheim, DE
• Rudolf Schliwa · Alzenau, DE
• Karl J. Possemiers · Schilde, BE
• Robert Bayer · Sinsheim, DE

Key dates

• Filing date: Jan 14, 2015
• Grant date: Mar 13, 2018
• Expiry date: Jan 14, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L101/14
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for producing water-absorbent polymer particles by polymerizing droplets of a monomer solution in a surrounding heated gas phase in a reactor comprising a gas distributor (3), a reaction zone (5) and a fluidized bed (27), the gas leaving the reactor is treated in a condenser column (12) with an aqueous solution, the treated gas leaving the condenser column (12) is recycled at least partly to the fluidized bed (27), wherein the gas leaving the condenser column (12) comprises from 0.05 to 0.3 kg steam per kg dry gas and the steam content of the gas entering the gas distributor (3) is less than 80% of the steam content of the gas leaving the condenser column (12).