Valorization of decationized newsprint to levulinic acid

Abstract

As of today, most chemical products are fossil-based. The environmental concerns of fossil resources due to their constant misuse have led to the exploration of bio-based alternatives. Biomass comprising industrial and municipal wastes, agricultural residues, forest residues, and natural herbaceous plants can favorably replace fossil fuel to produce chemicals. In this study, softwood and hardwood pulps were used to synthesize levulinic acid. Prior to a dilute acid hydrolysis step, the wood pulps were decationized overnight with 0.2 M HCl. The effects of the major reaction conditions including reaction temperature, time, and HCl concentration on the yield of levulinic acid was studied via a central composite design. Levulinic acid yields from softwood and hardwood pulps reached 50.30 and 68.85 mol%, respectively, at optimum reaction conditions. When newsprints were tested using the optimized parameters for softwood and hardwood conversion, levulinic acid yields of 66.25 and 79.65 mol% were obtained, respectively. A kinetic model was developed to predict the yields of glucose, hydroxymethylfurfural, and levulinic acid from the HCl-pretreated newsprint. The analysis of the kinetic parameters and the results of the response surface methodology experiments provided optimized conditions for levulinic acid production.