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PDADMAC as a flocculant for lignosulfonate of NSSC pulping process
Author(s) -
Oveissi Farshad,
Sitter Thomas,
Fatehi Pedram
Publication year - 2016
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1002/btpr.2251
Subject(s) - flocculation , chemistry , sulfite , lignosulfonates , chemical engineering , polysaccharide , thermogravimetric analysis , pulp and paper industry , turbidity , lignin , chromatography , organic chemistry , engineering , oceanography , geology
The spent liquor (SL) of neutral sulfite semi‐chemical (NSSC) pulping process contains about 8 wt% lignocelluloses that can be extracted and used in the production of value‐added materials. In this work, a flocculation process followed by centrifugation was considered for isolating lignosulfonate and hemicelluloses from SL. It was observed that, by adding 20 mg/g of polydiallyldimethylammuniom chloride (PDADMAC) with 100,000–200,000 g/mol molecular weight to SL, 45% of lignosulfonate and 39% of hemicelluloses were removed at 30°C. The lignocellulose removal was more efficient for the dual flocculation system of low and high molecular weights PDADMAC than for individual PDADMAC systems. Overall, 49% of lignosulfonate, 47% of hemicelluloses and 97% of turbidity were removed from SL from the dual system when 10 mg/g low molecular weight PDADMAC and 10 mg/g high molecular weight PDADMAC were added to the SL at 30°C, subsequently. The thermogravimetric analysis (TGA) of generated flocs showed that all samples had similar thermal behaviour and 13–16 wt% of flocs remained as ash after burning at 700°C in nitrogen. As the flocs are made of lignocellulosic materials and they are thermally stable, they could be used as fillers in paper board production. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:686–691, 2016