Kinetic analysis of biomass pyrolysis using a double distributed activation energy model

Pyrolysis is a fundamental step in thermochemical processes of biomass materials, so a suitable kinetic model is an essential tool to predict the evolution of the resulting products of reaction. However, many difficulties arise in modeling this process step due to the very high number of the involved reactions. In this work, a new double-Gaussian distributed activation energy model was applied in fitting the experimental data of olive residue pyrolysis obtained by thermogravimetric analysis. 2-DAEM formulation considers two sets of parallel reactions occurring and sharing the same pre-exponential factor, but shows different distributions of the activation energy, described by two separate Gaussian distributions that, in turn, grasp the two pyrolysis steps with a high accuracy. Since it is well known that in fitting all the kinetic parameters the pre-exponential factor results highly correlated with the activation energy, the former parameter was separately estimated as a linear combination of the values obtained for the three main biomass components, cellulose, hemicellulose and lignin.