# A Thermogravimetric Analysis of Biomass Conversion to Biochar: Experimental and Kinetic Modeling
## 1 Introduction
Therefore, biochar produced by the pyrolysis process at temperatures between 400 and 600 \({}^{\circ}\)C has a high fixed carbon content but a low surface area and porosity [26], meanwhile high temperature, low pressure, and high heating rate of the pyrolysis process produces biochar with higher carbon content and a large specific surface area [27]. Biomass consists of hemicelluloses, cellulose, lignin, and small amounts of extractives, which are pyrolyzed at various temperatures and heating rates. The temperature range within which specific components of biomass decompose is as follows: between 200 and 260 \({}^{\circ}\)C, hemicellulose broke down first, followed by cellulose (240 to 350 \({}^{\circ}\)C) and lignin (280 to 500 \({}^{\circ}\)C or higher) [3]. Consequently, a complete understanding of the chemical processes that take place at each stage of the thermochemical degradation of biomass and the influence of process parameters on the structural properties of biochar is necessary. To replicate the pyrolytic processes of biomass at the microscale, thermogravimetric analysis (TGA) is the perfect tool. The application of TGA involves studying changes in materials and products by following patterns related to changes in weight loss with respect to temperature and time [28]. Several studies have investigated biomass pyrolysis of different biomass types using thermogravimetric analysis [29; 30; 31; 32]. A thorough grasp of a biomass feedstock's pyrolysis kinetics is crucial for process design, feasibility analysis, and scalability in industrial applications. Thermogravimetric analysis (TGA) is the most commonly used tool to obtain experimental kinetic data for lignocellulosic biomass pyrolysis [33; 34]. There are two kinds of methods used for the analysis of biomass pyrolysis kinetics: model-fitting and isoconversional methods [35]. The uncertainty in estimating kinetic parameters caused by the use of model-fitting methods can be avoided by the use of isoconversional methods. [PERSON], et al. [36] reviewed the general TGA data processing procedure for isoconversion kinetic analysis of lignocellulosic biomass pyrolysis by using the Friedman isoconversion method. For studying bioresource valorization, different types of mathematical techniques and optimization algorithms have been used in the published literature [37; 38]. An important aspect is the kinetic investigation of biomass decomposition, the essential step that provides data on its energy potential following thermochemical processes [39; 40]. [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] [31] carry out such studies on peach palm seeds (Bactris gasipaes (Kunth)) from the Amazon region. The applied kinetic methods were FWO, KAS, Starink, and Vyazovkin, and the reaction mechanism was determined by the Criado method. There are also kinetic studies on the energy transformation of beech wood biomass [41] as well as Mediterranean biomass [42] using different methods for determining kinetic parameters (activation energy and pre-exponential factor) based on the Kissinger method, isoconversion methods (Kissinger-Akahira-Sunose and Friedman), and other methods based on mathematical models (nonlinear least square minimization and optimization by genetic algorithm) and distributed activation energy model [DAEM]. The KAS method was also used for determination of activation energies from Mushroom Residue Blended with Pine Sawdust/Wheat Straw [43]. [PERSON], et al. [44] used the Coats-Redefern Model to extract kinetic parameters from Tunisian local biomass thermogravimetric data and calculated the activation energy, the pre-exponential factor, and ordinal reaction factor. To understand the details involved in the processing of biomass waste, it is imperative to not only comprehend the stages of the biomass pyrolysis process but also to understand the specifics of the reaction kinetics.