Process for producing cationic lignin copolymer under aqueous acid conditions
AssigneesFPInnovations, Lakehead University
InventorsPedram Fatehi, Shoujuan Wang, Jacquelyn Price, Naceur Jemaa, Talat Mahmood, Michael Paleologou
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Abstract
A water-based process was developed for the synthesis of aminated lignin copolymers with high MW, thermal stability and solubility in water over a wide range of p H values. The cationic lignin copolymer described herein comprises: a grafting ratio of (weight of cationic amine compound)/(weight of lignin) of 70 to 200% and a charge density of +1.4-3.0 meq/g. This cationic lignin copolymer can be used as a flocculant in numerous wastewater streams including municipal and industrial systems and sludge dewatering in the pulp & paper, mining and oil industries.
Claims12
A method for preparing a cationic lignin copolymer comprising:
- providing water;
- providing a kraft lignin;
- providing at least one monomer compound, wherein the monomer compound is a cationic amine compound;
- and
- mixing the water, the lignin, and the at least one monomer compound under acidic free radical generating conditions, to polymerize the lignin and at least one monomer compound in aqueous suspension and to produce the cationic lignin copolymer;
- wherein the cationic amine compound is selected from the group consisting of:
- N,N-dimethyldiallyl ammonium chloride (DADMAC);
- N,N′-methylenebisacrylamide;
- [2-(Methacryloyloxy)ethyl] trimethylammonium chloride (METAC), [3-(Methacryloylamino)propyl] trimethylammonium chloride (MAPTAC), [2-(Acryloyloxy)ethyl] trimethyl ammonium chloride (ATAC) and [2-(Methacryloyloxy)ethyl] trimethyl ammonium methyl sulfate (METAM), and
- wherein the cationic lignin copolymer is a flocculant having a molecular weight of 1.3×106 to 1.5×106 g/mol,
- wherein the cationic lignin copolymer is produced free of oxidizing enzymes.
Dependencies are inferred from the claim text.