Kinetics of the Pyrolysis of Lignin Using Thermogravimetric and Differential Scanning Calorimetry Methods

Abstract

The thermal behavior of a hardwood lignin found in Eastern Canada was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Kinetic parameters were determined for pyrolysis of lignin from room temperature to 300 at 15 °C·min−1. The maximum rate of thermal destruction of lignin occurred between 246−259 °C. The DSC thermogram of lignin showed an endothermic peak at approximately 113 °C. The kinetic model was applied, and the activation energy for the lignin was calculated. The weight loss data showed first order decomposition with Arrhenius behavior. The activation energy value obtained for lignin was in the range of 8−68 kcal·mol−1. The results showed that the kinetic model fitted the data well in the specific range of temperatures. The present model was also compared with the experimental data available in the literature, and the comparisons of E a values are tabulated.

Experimental investigation of a sequential process for the fractionation of sweet sorghum bagasse

“…The glass transition temperature of a polymer is a function of the molecular weight, moisture content and its crystallinity [43]. The T g of the samples tested was found as about 85-95°C, and it is in good agreement with the results reported in literature [44]. The shoulder at around 300-400°C in the thermogram can be attributed to the polysaccharide content in the samples.…”

Butyration of Lignosulfonate with Butyric Anhydride in the Presence of Choline Chloride

“…Figure 9 shows the linear regression curves of the LS samples in the fast pyrolysis stage, each of which had a favorable correlation coefficient (greater than 0.9978), demonstrating that the order of the reaction selected was appropriate. As can be seen in Table 3, the activation energies of the butyrated LS products were within the range of 78.1 to 105.0 KJ/mol during the fast pyrolysis stage, higher than indicated by the results described in other works (8 to 68 KJ/mol) (Murugan et al 2008). This may be because different species of lignin were used and because of the erroneous assumption by other researchers that the thermal degradation of lignin follows first-order reaction kinetics (Jiang et al 2010).…”

Changes of wood cell walls in response to hygro-mechanical steam treatment

“…In general, cells of earlywood possess larger lumen with thin and a less-dense cell wall than latewood. Since the radial compression treatment was carried out at a temperature of 160 • C, which was higher than the glass transition temperatures of both hemicellulose and lignin (Hillis & Rozsa, 1978Murugan, Mahinpey, Johnson, & Wilson, 2008), the enhanced mobility of hemicellulose and lignin molecules within and between the fibres, leads to a more deformed structure. Due to the high deformation of the earlywood cell walls probably additional pores in different sizes (mesopore or micropore) were formed in these thin-wall cells of earlywood.…”