Process for the production of sap
AssigneeList AG
InventorsSahbl Belkhiria, Pierre Fleury, Ibrahim Al-Alim
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Abstract
A continuous process for the production of dried superabsorbent polymers (SAPs) the polymerization reaction is carried out either in an initially homogenous aqueous monomer solution (bulk aqueous solution polymerization) or in a heterogeneous water-in-oil reactant mixture (reverse phase suspension or emulsion polymerization) within a continuous closed polymerization reactor, then the resulting polymer gel is dried within a continuous moved bed in a closed dryer, avoiding the needs of standard intermediate maturity tank(s).
Claims22
(canceled)
A method according to claim 22, wherein the moving bed closed dryer comprises an agitated vessel having at least one agitating shaft, wherein the shaft is heated to increase the heat transfer and drying efficiency of the dryer.
A method according to claim 22, wherein maturity of the polymer is carried out in a first zone of the closed dryer.
A method according to claim 22, including mixing into at least one of the closed polymerization reactor and the closed dryer an additive selected from the group consisting of monomers, comonomers solvents, and mixtures thereof.
A method according to claim 22, including recycling to at least one of the closed polymerization reactor and the closed dryer the dried SAP fines.
A method according to claim 22, including equipping at least one of the closed polymerization reactor and the closed dryer with condensing and recycling systems of residual reactants, solvents and additives.
A method according to claim 22, wherein at least one of a pressure lock chamber and a gel cutting system is located between the closed polymerization reactor and the closed dryer.
A method according to claim 22, wherein the polymer gel leaving the closed polymerization reactor is mixed in a mixer with at least one additive for improving free-flowing properties before entering the closed dryer.
A method according to 22, wherein the dried SAP fines exiting the closed dryer are partly cooled during their passage through a jacketed continuous discharge system.
(canceled)
A continuous process for the production of dried superabsorbent polymers (SAPs) comprising:
- carrying out a polymerization reaction in a closed polymerization reactor to form a polymer gel, wherein the polymerization reaction is selected from the group consisting of (1) bulk aqueous solution polymerization and (2) suspension polymerization;
- drying the resulting polymer gel on a continuously moving bed in a closed dryer;
- and
- discharging dried SAP fines.
Dependencies are inferred from the claim text.