Insight into Pyrolysis Kinetics of Lignocellulosic Biomass: Isoconversional Kinetic Analysis by the Modified Friedman Method

Abstract

Isoconversional methods are commonly used to process the thermogravimetric analysis (TGA) data and to simultaneously obtain the effective activation energies for lignocellulosic biomass pyrolysis. However, the widely used isoconversional methods may lead to some systematic problems, for example, numerical instability for the Friedman method and significant errors in the kinetic parameters for the Flynn−Wall−Ozawa and Kissinger−Akahira−Sunose methods. To avoid the above problems, a modified Friedman isoconversional method has been developed in this work to accurately determine effective activation energies for solid-state reactions, such as biomass pyrolysis reactions. Through processing theoretically simulated data of strongly varying activation energy, the modified method applying for narrow intervals of conversion degree was proven to be capable of calculating the conversion dependence of activation energy accurately and reducing the effect of data noise. The modified Friedman isoconversional method was employed to process the non-isothermal TGA data of wheat straw pyrolysis at heating rates of 2.5, 5, 10, and 20 K min −1 and the kinetic data of beech sawdust pyrolysis at 5, 10, and 20 K min −1 from the literature. The results showed that the effective activation energies for the pyrolysis of wheat straw and beech sawdust varied significantly with the degree of conversion (in the conversion range from 0.05 to 0.85, the effective activation energies for wheat straw pyrolysis varied from 154 to 379 kJ mol −1 , while 155−316 kJ mol −1 was reported for beech sawdust pyrolysis).

Production of polyurethane elastomer from highly reactive acetic acid lignin‐derived polyols with reduced molecular weights

“…S4). The apparent activation energy (E a ) of different cross‐linking degrees was obtained by the calculated slopes of the equations (see the supplementary material) 40,41 …”

Industrial biochar systems for atmospheric carbon removal: a review

“…Model fitting techniques are, in general, not recommended by the international confederation for thermal analysis and calorimetry (ICTAC) kinetics committee due to the uncertainty related to the determination of kinetic parameters (Vyazovkin et al 2011). The most common model-free methods reported in the literature include the single-step reaction method ASTM E-698, integral iso-conversional methods such as Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose and Friedman's differential iso-conversional method (Osman et al 2020b, c;Akor et al 2021;Mishra and Mohanty 2018;Luo et al 2020;Bonilla et al 2019). In general, all methods carry various drawbacks and may lead to errors and inaccuracies in computing kinetic parameters if mishandled (Vyazovkin et al 2011;Luo et al 2020).…”

“…The most common model-free methods reported in the literature include the single-step reaction method ASTM E-698, integral iso-conversional methods such as Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose and Friedman's differential iso-conversional method (Osman et al 2020b, c;Akor et al 2021;Mishra and Mohanty 2018;Luo et al 2020;Bonilla et al 2019). In general, all methods carry various drawbacks and may lead to errors and inaccuracies in computing kinetic parameters if mishandled (Vyazovkin et al 2011;Luo et al 2020). Various kinetic modelling software can be utilized for accurate analysis, such as advanced kinetics and technology solutions (AKTS) (Osman et al 2020b, c;Akor et al 2021), or kinetics neo software.…”

Kavun çekirdeği pirolizine ait kinetik parametrelerin ve termodinamik özelliklerin belirlenmesi

“…Flynn-Wall-Ozawa (FWO) yöntemi Denklem (7)'nin geliştirilmesiyle elde edilen FWO yönteminin denklemi aşağıda verilmiştir [31].…”