# A Thermogravimetric Analysis of Biomass Conversion to Biochar: Experimental and Kinetic Modeling
## 1 Introduction
The byproducts generated from the apple processing facility mostly comprise pomace produced during juice extraction and peels resulting from the manufacturing of sauces, canned apples, dried rings, and purees [15]. Peels are viewed as substantial waste, while the entire fruit is utilized for consumption or processed into further items post-peeling. The peels are either utilized for feeding purposes or discarded as rubbish [16]. For example, [PERSON], et al. [17] prepared and tested the biochar obtained from apple peels (ACAP) to remove chromium (VI) from an aqueous solution. The results of the research showed that ACAP has an adsorption capacity that is higher than that of commercial activated carbon and can be considered as an efficient, inexpensive, and natural adsorbent for removing chromium (VI) from contaminated wastewater. Another study [18] investigated the preparation of banana peel biochar (BPBC) using a slow pyrolysis method and its use as adsorbent to remove diesel oil from water. The results showed that BPBC exhibited high porosity, thermal stability, and a hydrophobic character, making it a promising adsorbent for oil-water separation and environmental remediation. The adsorption capacity of BPBCfor diesel oil removal was 5.3352 g diesel oil/g adsorbent. Furthermore, banana peel biochar has been shown to be an effective adsorbent for multiple pollutants, including tetracycline, benzoic and salicylic acid, cadmium, As and Pb, Cu, ciprofloxacin and acetaminophen, and bisphenol A and doxycycline [19]. The potential of orange peels as a low-cost adsorbent was examined by [PERSON] et al. [20] on three different pollutant aqueous solutions, methylene blue (MB), tetracycline (TC), and fluorescein sodium (NaFL). The results obtained suggested that the absorbent had excellent adsorption capacity for MB, TC, and NaFL pollutants of 10 mg L\({}^{-1}\), with adsorption rates of 99.17%, 73.5%, and 94.24%, respectively. [PERSON], et al. [21] investigated with good results the biochar derived from orange peels for removing Cu\({}^{2+}\) and Cd\({}^{2+}\) in aqueous media. The bio-adsorbent derived from potato peels is another type of biochar that can interact with heavy metal ions present in water and adsorb them to the surface due to its functional groups. According to [PERSON], et al. [22], under optimal conditions of pH 9, 60 min contact time, 0.5 g of adsorbent, and 10 mg/L of sample concentration, potato peel biochar showed an adsorption efficiency of 61% for removal of various heavy metals such as Co\({}^{+}\), Mg\({}^{+}\), Fe\({}^{+}\), Pb\({}^{+}\), and Cd\({}^{+}\). [PERSON] and [PERSON] [23] prepared modified activated carbons from potato peels as green environmentally friendly adsorbents for the treatment of two drug compounds (dorzolamide and promipexole) from synthetic aqueous effluents. The main advantage of the carbon materials was their reusability, since the biochar that was hydrothermally treated lost just 11% of its adsorption capacity in 20 cycles and the pyrolyzed-treated carbon sample around 35%. Although, as previously presented, biochar obtained from food waste has a huge potential to replace conventional adsorbents such as activated carbon, demonstrating a good large-scale potential application in wastewater remediation; the preparation process is very important because it can influence its adsorption capacity. Carbonization, pyrolysis, hydrothermal liquefaction, and gasification are processes that can be used to produce biochar from a variety of feedstock types, including woody biomass, agricultural biomass, aquatic biomass, food and kitchen wastes, and industrial and urban wastes [24]. Operating parameters such as temperature, heating rate, and reaction time must be closely monitored since they have the potential to alter the chemical and physical characteristics of biochar [25].