Analysis of the oxidation reactivity of carbonaceous materials using thermogravimetric analysis

Differences between combustion and oxy-combustion of corn and corn–rape blend using thermogravimetric analysis

“…This behaviour was previously described by the other authors in the literature [48,58] in terms of lignin content. The obtained activation energies are in accordance with the results previously reported for several bioresidues [5,17,24,[30][31][32][33]41,48,50,54,59,60], considering that the oxy-combustion processes generally disfavour chemical reactions. The pre-exponential factors and orders of reaction are in accordance with the previous results [5,[30][31][32][33]54,59,60].…”

“…The rate of heterogeneous solid-state reactions can be generally described by where α is the conversion degree or fraction of the material combusted, t is the time, k(T) is a temperature-dependent constant and f(α) is the reaction model, which describes the dependence of the reaction rate on the extent of reaction. The mathematical description of the data for a single-step solid-state decomposition is usually defined in terms of a kinetic triplet [30]: the activation energy, E; the Arrhenius parameter, A; and an algebraic expression of the kinetic model as a function of the fractional conversion α, f(α). These terms can be related to experimental data as follows:…”

“…However, the sample requires some amount of time to reach the experimental temperature in this type of experiment [14,24], which is a drawback that non-isothermal methods do not account for. Model-fitting mathematical approaches were the original and most popular, especially for isothermal experiments, but they have lost popularity to isoconversional methods, which can compute kinetic parameters without modelling assumptions [30][31][32][33]. Model-free isoconversional methods allow E to be estimated as a function of α without pre-fixing the reaction model.…”

“…In this case, Doyle's approximation was used for f(α) [15,16,22,39,[40][41][42], which involves measuring the temperatures corresponding to fixed values of α from experiments at different heating rates [30].…”

Biomass pyrolysis kinetics: A comparative critical review with relevant agricultural residue case studies

“…It should be noted as a point of clarity that there are other so-called "modified Coats-Redfern" methods in the literature, but they cannot be considered isoconversional because they still require the selection of a reaction order. These alternative "modified Coats-Redfern" formulations often involve a regression analysis of one or more of the kinetic triplet parameters [162,163]. One such "modified" method [163] reported errors for E a estimates that are an order of magnitude lower than those obtained from isoconversional techniques.…”