A new cellulose purification approach for higher degree of polymerization: Modeling, optimization and characterization

•We proposed a new approach in which DP of cellulose is preserved.•Response surface methodology was used for purification modeling.•Purification conditions optimized for highest DP.•TGA, XRD, FT-IR and SEM results shows that proposed method is as good as conventional method. Degree of polymerization (DP) is an important factor which is affected by purification process. In this study, a new purification process is proposed in which cellulose DP is preserved. Response surface methodology (RSM) was used for optimizing the purification conditions. Purification process of biomass at 100°C in 10g/L sodium hydroxide and 30g/L sodium dithionite, is reported as the optimum condition of this treatment. DP, purity, weight reduction and yellowness index were 6012, 98.10%, 8.46% and 25.22 respectively. TGA, IR, XRD and SEM techniques were used to compare both this new approach and conventional purification treatments. The results showed that this proposed purification process can produce cellulose with higher degree of polymerization compare to the conventional method.