Optimization of the oxidative fast pyrolysis process of sugarcane straw by TGA and DSC analyses

The objective of this work was to evaluate the influence of the oxygen percentage, heating rate, and total gas flow variables in the pyrolysis process of sugarcane straw through thermogravimetric (TG) and differential scanning calorimetry (DSC) analyses. The experimental conditions of oxygen percentage, heating rate, and total gas flow were optimized using the design of experiments and canonical analysis. The investigated conditions show that to optimize the whole pyrolysis process, the best values for carrying out the process are oxygen concentrations and heating rates around the central level of 10%, and 298 K/min, respectively, where the total gas flow, within the studied constrains, was not statistically significant for the pyrolysis process, according to the regression equations. This condition resulted in approximate values of required heat and percent residual residue of 181.74 kJ/kg and 9.89%, respectively. In addition, the percentage of remaining residue decreases as the heating rate decreases and the percentage of oxygen in the gas mixture increases. The optimum oxygen percentage obtained was also validated by carrying out an autothermal fast pyrolysis in a pilot plant scale.