The main objective of this work was to examine the influence of pyrolysis pressure on product yield from wheat straw pyrolysis. The experiments were performed in a tubular reactor at different pressures (10, 20, 30, and 40 psi) with a constant flow rate of nitrogen (50 cc/min) at a temperature of 500 °C. During pyrolysis, the products obtained are oil, gas, and char. The maximum oil yield was 37.6%, obtained at high pressure (40 psi). Liquid product was analyzed using gas chromatography/mass spectrometry (GC-MS). The percentage of bio-oil compounds increased as operating pressure increased. The major components present in the bio-oil were phenols, methoxyphenols, and substituted methoxyphenols such as eugenol and vanillin. The gas products were mainly CO, H 2 , CO 2 , CH 4 , C 2 H 4 , C 2 H 6 , C 4 H 10 , and C 3 's. Char characteristics were measured using scanning electron microscopy (SEM) and ultimate analysis. Van Krevelen diagram shows that the chars obtained from wheat straw pyrolysis have very less H: C and O: C ratios than the raw wheat straw. On the basis of the results of this study, it may be concluded that, within the pressure range studied, 20 psi is the optimum pressure for the pyrolysis of the wheat straw in a tubular reactor with respect to products (char, bio-oil, and gas) yield.

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The distributed activation energy model (DAEM) has been shown to be more descriptive of the pyrolysis reaction than other applicable models. In this study, the temperature dependency of the preexponential factor has been included in the DAEM. The model equation has been solved using Simpson's 1/3 rule, and the kinetic parameters were determined using an optimization method. Simulated annealing method has been used to determine the DAEM kinetic parameters for the nonisothermal pyrolysis of lignin using thermogravimetric analysis (TGA) data. The nonisothermal pyrolysis of lignin was conducted at three different heating rates of 5, 10, and 15 °C/min under nitrogen atmosphere. Predicted results from the optimum kinetic parameters have been compared with the experimental data. The DAEM equation predicts the experimental data very well for different heating rates.

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.