Energy potential and thermogravimetric study of pyrolysis kinetics of biomass wastes

Thermokinetic study of macadamia carpel pyrolysis using thermogravimetric analysis

“…[52,53] The carpel of macadamia showed a high O/C ratio (1.07) because of the high oxygen content, which decreases the calorific value of the biomass and its potential products. [45] The H/C ratio observed (0.12) is very low, since the hydrogen content is 5.46%, indicating a high carbonization and aromaticity of biomass degree, favourable for fuel production. [55] The small amounts of nitrogen (1.24%) observed in the biomass indicates that the formation of harmful oxides (NOx) from its volatile products combustion will also be low, [56] implying low levels of environmental pollution.…”

“…The isoconversional models based on Equation ( 7) and the Arrhenius relationship require no knowledge of reaction models beforehand, being referred to as model-free methods. [44] Thus, the kinetic parameters were calculated from the slope of different linear model plots using the TGA data, from room temperature to 1273.15 K. [45] The isoconversional models used in this study were Ozawa, [23] Kissinger-Akahira-Sunose (KAS), [46] modified Starink, [47] and Kissinger. [48] Their respective equations are shown in Table 2, where β is the heating rate (K Á min À1 ), Ea is the activation energy (J Á mol À1 ), R is the universal gas constant (8.314 J K À1 mol À1 ), / is the conversion, and A is the pre-exponential factor (s À1 ).…”

“…[52,54] The negative effects of the ashes include fouling and agglomeration issues in the reactors. [45] It was observed that the macadamia carpel has a relatively low AC (14.31%) with a nonsignificant percentage, which indicates that a potential high-quality bio-oil can be produced from it. Ultimate analysis revealed that the contents of carbon and hydrogen are considered high for lignocellulosic biomass and contribute to the calorific value.…”

Non-isothermal kinetics: best-fitting empirical models instead of model-free methods

“…They deal with the kinetics of organic samples with highly complex chemical composition. A few recent works on similarly complex samples are also listed from the Journal of Thermal Analysis and Calorimetry [7][8][9][10][11][12][13][14]. Many further references can be found in the work of Cai et al [6] which is an overview of the application of the isoconversional methods for biomass pyrolysis till 2017.…”

“…It assumes one pool of reactants for which the reactivity varies as the reaction proceeds. However, most of the samples of practical interest contains more than one sort of reacting species, as it was the case in the studies [4][5][6][7][8][9][10][11][12][13][14] as well as in the nearly 100 works reviewed by Cai et al [6]. Each species has its own reacted fraction, its own reactivity parameters, and its own concentration in the sample.…”