Anna Matala

Estimation of Pyrolysis Model Parameters for Solid Materials Using Thermogravimetric Data

Determination of the material parameters is one of the key challenges of numerical fire simulation attempting to predict, rather than prescribe the heat release rate. In this work, we use common fire simulation software and genetic algorithms to estimate the kinetic reaction parameters for wood components, birch wood, PVC and black PMMA. Parameters are estimated by modelling thermogravimetric experiments and minimizing the error between the experimental and numerical results. The implementation and choice of the parameters for the genetic algorithm as well as the scheme to describe wood pyrolysis are discussed.

Generalized direct method for pyrolysis kinetic parameter estimation and comparison to existing methods

Solid-phase pyrolysis is often modelled using the Arrhenius degradation equation with three unknown parameters: reaction order, activation energy and pre-exponential factor. Since the parameters are model dependent and not directly measurable, several estimation methods have been developed over the years for extracting them from the experimental small-scale data. Lately, the most commonly used methods have been based on optimization and curve fitting. These methods are very efficient for complex problems with multiple reactions but may require significant computational time. Direct (analytic) methods are simpler and faster but often have more restrictions and limited accuracy. This article presents a new, generalized direct method and its performance evaluated along with other commonly used estimation methods. The real usability of the methods is tested also in the presence of small noise.