Study on the effect of degree of polymerization of cellulose on syngas composition based on established higher heating value prediction model

Abstract

The type and proportion of biomass pyrolysis products are determined by both biomass composition and operating conditions. Although the effect of operating conditions has been extensively investigated, the influence of biomass composition, especially the degree of polymerization, has seldom been explored. In this work, cellulose samples with different degrees of polymerization were prepared by soda-oxygen cooking, and the viscosity of the cellulose was determined to obtain the degree of polymerization. Then, an accurate prediction model of the higher heating value of cellulose was successfully established by incorporating the degree of polymerization, and the relative error range was reduced from 13 %-17 % to 0.25 %-1.0 %. Finally, the effect of the degree of polymerization on the gas products of cellulose pyrolysis (H₂, CO, CH₄, CO₂) was explored through process simulation with the help of Gibbs free energy minimization. The results showed that as the increase of the degree of polymerization, the amount of H₂ increased and the amount of CO decreased. This work serves as a preliminary investigation of the effect of the degree of polymerization on cellulose pyrolysis in theory based on thermochemical data. It can be used as a valuable reference for the further study of the effect of degree of polymerization on polymer pyrolysis.