Evonik Stockhausen Gmbh

Evonik Degussa Gmbh

Evonik Industries Ag

Harald Plöchinger

Herbert A Gartner

Marc Hager

Hans-Peter Kohler

Daniel Fricker

Jörg Harren

Jorg Harren

Sabine Auernig

Elisabeth Lacker

Herbert Alfons Gartner

Richard Walter

The present invention relates to a continuous process for the production of a superabsorbent polymer comprising providing an acidic liquid aqueous monomer mixture containing dissolved oxygen; continuously feeding the aqueous monomer mixture to a reactor; introducing a source of carbonate or hydrogen carbonate into the aqueous monomer mixture prior to entry into the reactor thereby forming a gas phase comprising carbon dioxide and at least a part of the dissolved oxygen, the gas phase being dispersed in the liquid phase; subjecting the gas/liquid mixture to at least partial phase separation immediately prior to or after entry into the reactor and at least partially removing the separated gaseous phase; subjecting the liquid phase in the reactor to free-radical polymerization to obtain the superabsorbent polymer, and continuously removing the superabsorbent polymer from the reactor.

Continuous process for the production of a superabsorbent polymer

The present invention relates to a process for the production of a superabsorbent polymer comprising preparing an aqueous mixture of monomers selected to provide after polymerization a superabsorbent polymer; feeding said monomer mixture to a reactor; subjecting the aqueous monomer mixture in the reactor to free-radical polymerization to obtain a superabsorbent polymer gel; removing the superabsorbent polymer gel from the reactor; and drying the superabsorbent polymer gel. Where at least one off-gas stream removed from any stage of the process is subjected to scrubbing with a basic aqueous solution prior to venting to obtain an aqueous scrubber solution that is at least partially recycled to any of the above steps of the process.

Process for the production of a superabsorbent polymer

The present invention relates to a process for the production of a superabsorbent polymer comprising preparing an aqueous mixture of monomers selected to provide after polymerization a superabsorbent polymer; feeding said monomer mixture to a reactor; subjecting the aqueous monomer mixture in the reactor to free-radical polymerization to obtain a superabsorbent polymer gel; removing the superabsorbent polymer from the reactor; and working-up the superabsorbent polymer removed from the reactor to obtain a final product, whereby a basic aqueous medium comprising carbonate and/or hydrogen carbonate is fed to the superabsorbent polymer gel.

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Bühl, Germany

Harald Plöchinger