Multi-Gaussian-DAEM-reaction model for thermal decompositions of cellulose, hemicellulose and lignin: Comparison of N2 and CO2 atmosphere

Abstract

Thermal decompositions of three components of biomass (cellulose, hemicellulose and lignin) were studied using nonisothermal thermogravimetric analysis (TGA) under both oxidative and inert atmospheres at a heating rate of 10 K min(-1). The multi-Gaussian-distributed activation energy model (DAEM)-reaction model was first developed to describe thermal decomposition behaviors of three components. Results showed that the presence of CO₂ enhanced the thermal decompositions of three components in high temperature range, but made little difference in low temperature range. Decomposition behaviors under CO₂ were analyzed by the two-stage reaction mechanism corresponding to the pyrolysis process of original materials and the gasification process of char. During gasification stage, CO₂ was reduced to CO, which provided a possibility of a reduction in greenhouse gas emissions. In addition, more CO was produced, and therefore the thermal value of gas was improved. The findings imply that CO₂ gasification technology of biomass has great research significance.

Double Distribution Activation Energy Model as Suitable Tool in Explaining Biomass and Coal Pyrolysis Behavior

“…However, as already noticed in literature [19], regression algorithms show a strong correlation between k0 and E0 leading to a non-uniqueness of kinetic parameters that is called compensation effect [20]. So to overcome this drawback, one choice is to fix k0 at a defined value that must be consistent with the transition-state theory, which indicates values in the range 10 11 -10 16 s −1 [18]. However, to obtain kinetic parameters comparable with the ones reported in the literature, a value of 10 13 s −1 was selected for the biomass [15] and a value of 8 × 10 12 s −1 for the Sulcis coal [21].…”

“…To circumvent such a limitation, in a previous work focused on coal pyrolysis, the authors proposed an extended model able to catch the kinetic parameters of both the steps by including a second Gaussian distribution (2-DAEM) [17]. This multi-Gaussian approach was also used by Zhang et al [18] to model biomass pyrolysis and gasification considering different distribution of activation energy for each class of reactions that share the same pre-exponential factor. In this paper, the multi-Gaussian model is applied to predict the behavior of the selected fuels and the results are compared with those obtained with the single DAEM (1-DAEM).…”

Effect of extractive content on the thermal stability of two wood species from Brazil

“…The pyrolysis process is influenced by many factors, such as heating rate, temperature, pressure residence time, moisture, but is also influenced by the composition of biomass material (Slopiecka et al 2012). So it is important to distinguish the behavior of biomass components for a better understanding of the biomass pyrolysis process (Zhang et al 2014).…”

Properties and Combustion Characteristics of Molded Solid Fuel Particles Prepared by Pyrolytic Gasification or Sawdust Carbonized Carbon

“…304 °C. The main weight loss temperature range of phenol resin was from 300 to 800 °C, and the heat release rate peak appeared at approximately 545 °C (Zhou et al 2011;Zhang et al 2012). These results reveal that adhesive can affect the ignition temperature of MSFs when PGC and adhesives are mixed and molded.…”