TY  - JOUR
AV  - none
TI  - A comparative study on suitability of model-free and model-fitting kinetic methods to non-isothermal degradation of lignocellulosic materials
ID  - scholars14617
KW  - Activation analysis; Bagasse; Cellulosic ethanol; Decomposition; Disintegration; Isotherms; Kinetics; Straw; Thermolysis
KW  -  Isoconversional approach; Ligno-cellulosic fuels; Lignocellulosic material; Lignocellulosic residues; Model fitting techniques; Model-fitting approach; Non-isothermal kinetic; Two dimensional diffusion
KW  -  Activation energy
N2  - The thermal kinetic modeling is crucial for development of sustainable processes where lignocellulosic fuels are a part of chemical system and their thermal degradation eventuates. In this paper, thermal decomposition of three lignocellulosic materials (bagasse, rice husk, and wheat straw) was obtained by the thermogravimetric (TG) technique and kinetics was analyzed by both model-fitting and isoconversional (model-free) methods to compare their effectiveness. Two models selected from each class include Arrhenius and Coatsâ??Redfern (model-fitting), and Kissingerâ??Akahiraâ??Sunose (KAS) and Flynnâ??Wallâ??Ozawa (FWO) (model-free). The formal model-fitting approach simulating the thermal decomposition of solids by assuming a fixed mechanism was found to be unduly facile. However, activation energy (E) values calculated from two model-fitting techniques were considerably different from each other with a percentage difference in the range of 1.36 to 7.65. Particularly, both model-fitting methods predicted different reaction mechanism for thermal disintegration of lignocellulosic materials (two-dimensional diffusion (D2) by Arrhenius and one-dimensional diffusion (D1) by Coatâ??Redfern method). Conversely, the model-free routine offers a transformation of mechanism and activation energy values throughout reaction and is, therefore, more authentic to illustrate the complexity of thermal disintegration of lignocellulosic particles. Based on the model-free kinetic analysis, the lignocellulosic materials may be devised in following order of activation energy: rice husk > bagasse > wheat straw, by both KAS and FWO methods with a percentage difference no more than 0.84 for fractional conversion up to 0.7. Isoconversional approach could be recommended as more realistic and precise for modeling non-isothermal kinetics of lignocellulosic residues compared to model-fitting approach. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
N1  - cited By 18
IS  - 15
PB  - MDPI AG
SN  - 20734360
Y1  - 2021///
VL  - 13
A1  - Mahmood, H.
A1  - Shakeel, A.
A1  - Abdullah, A.
A1  - Khan, M.I.
A1  - Moniruzzaman, M.
JF  - Polymers
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111650509&doi=10.3390%2fpolym13152504&partnerID=40&md5=d415673a0850f4fa88056d712dd5cd21
ER  -