(660i) Purification of Lignocellulosic Hydrolyzate using Flocculant enhanced Depth Filters

For lignocellulosic biorefineries to become economically viable, efficient separation processes must be developed. The removal of lignin-based contaminants prior to fermentation is a major bottleneck for hydrolysate valorization. Fibrous depth filtration is commonly used to remove particles from suspension. Traditional depth filters are ineffective at removing colloidal impurities from hydrolysate streams. To enhance removal efficiency, flocculating polymers are added upstream to aggregate oppositely charged particles. In this experiment, these two operations are integrated. Cationic flocculant poly (diallyldimethylammonium chloride) (PDADMAC) was adsorbed onto the surface of cellulose pulp fibers. The effects of polymer treatment dosage and ratio the of cellulose to PDADMAC were examined. Dynamic light scattering shows the effect on particle size. Zeta potential measurements yield the stability of the suspension. UV/VIS quantified the removal of lignin from the suspension onto the fibers:flocculant complex. The results showed that PDADMAC adsorbed pulp fibers can effectively remove contaminants from aqueous suspensions.