Chitosan as a flocculant for pre-hydrolysis liquor of kraft-based dissolving pulp production process

In this work, the flocculation concept was employed to recover the dissolved lignocellulosic materials of industrially produced pre-hydrolysis liquor (PHL) using two different molecular weights of chitosan. The analysis revealed the maximum turbidity of 1000 NTU or 1900 NTU via adding 2.2 mg/g low molecular weight (LMW) or 1.7 mg/g high molecular weight (HMW) chitosan to the PHL, respectively. Also, the maximum furfural removal of 55% or 50% was obtained by adding 0.7 mg/g or 0.5 mg/g LMW or HMW chitosan to the PHL, respectively. The maximum recovery of oligomeric sugars was 20% or 25% by adding 1.5 or 0.5 mg/g LMW or HMW chitosan, while that of lignin was 40% or 35% by applying 2.2 mg/g or 1.7 mg/g LMW or HMW chitosan to the PHL, respectively. The removal of monomeric sugars and acetic acid was rather limited. The particle size and nitrogen analyses were also hired to characterize the properties of the formed complexes.