Pyrolysis of cocoa shell and its bioenergy potential: evaluating the kinetic triplet, thermodynamic parameters, and evolved gas analysis using TGA-FTIR

Abstract

This study presents the first attempt to focus on the cocoa shell pyrolysis in terms of kinetic triplet, thermodynamic parameters, and evolved volatile analysis using the TGA-FTIR technique. For reliable interpretation of the multistep pyrolysis of cocoa shell, the multiple kinetic triplets were adequately estimated by a combined kinetic procedure using five independent parallel reactions with the Vyazovkin isoconversional method, the compensation effect, and the master plot method. According to the results, the multiple kinetic triplets were able to describe the pyrolysis behavior of the cocoa shell with an accuracy of R 2 > 0.9446 and the pyrolysis mechanisms exhibited different reaction models (n-order and contracting cylinder). Evolved volatile analysis suggested the presence of high-energy compounds (aromatic) and useful chemicals (aldehyde, ketone, esters, ether, and alcohols). The pre-exponential factors for the five pseudo-components of cocoa shell pyrolysis ranged from 2.56 × 10 11 to 8.66 × 10 16 min −1 (derived from the compensation effect method), while the values of E a ranged from 99 to 271 kJ mol −1 . From a comparative analysis, it was found that the results from the compensation effect method ensured the overall kinetic expression to be consistent with the experimental cocoa shell pyrolysis behavior. In contrast, the overall kinetic expression using pre-exponential factors derived from Kissinger's method failed to match the experimental curves. The pyrolytic conversion of cocoa shell into bioenergy appeared as potentially viable (E a -ΔH ≤ 5.5 kJ mol −1 ). The promising findings on the cocoa shell pyrolysis can expand the use of this residue in bioenergy applications, consisting of a great attempt toward its valorization.

Pyrolytic conversion of a novel biomass Ficus natalensis barkcloth: physiochemical and thermo-kinetic analysis

“…However, the interaction of hemicellulose and cellulose has the least role in the complexity of the pyrolysis process and major contribution to the generation and distribution of pyrolytic products [36]. Therefore, the key devolatization of biomass is extensively investigated by scientists for the development of the pyrolytic process and related reactor design which requires a complete explanation of the pyrolysis mechanism [5,31,37].…”

“…It also displays the ultimate data on the reaction mechanism and builds up a numerical model that could describe the process, and also assists in calculating the expenses of the pyrolysis process [4]. The output variables of the kinetic study are kinetic triplet parameters (E a , A, and f(α)/g(α)), which are gained from a combination of non-isothermal TGA information and mathematical methods [5].…”

Pyrolysis Kinetics of Byrsonima crassifolia Stone as Agro-Industrial Waste through Isoconversional Models

“…In fact, this method has been generally used to study the characteristics, thermal behavior, and degradation kinetics of biomass due to its high accuracy and simplicity [ 16 , 17 ]. From this analysis, it is possible to evaluate the kinetic triplet consisting of the apparent activation energy (E A ), pre-exponential factor (A α ), and reaction mechanism or kinetic model, f(α) [ 6 , 18 ] and, in turn, estimate the thermodynamic properties of the process (∆H, ∆G, and ∆S). These parameters are essential for investigating and evaluating the energetic feasibility of a pyrolysis process [ 13 , 18 ].…”

“…In the literature, there are several studies of biomass pyrolysis using various agro-industrial wastes such as avocado stone, Agave salmiana bagasse, and cocoa shell by Sangaré et al [ 18 ], apple pomace by Baray-Guerrero et al [ 19 ], garlic husk by Singh et al [ 20 ], peanut shells by Açıkalın [ 17 ], corn stalk by Cai et al [ 15 ], wheat straw by Mani et al 2010 [ 21 ] and waste sawdust by Mishra & Mohanty [ 5 ], using various kinetic methods. However, the reported results are different for each agro-industrial waste due to different physicochemical characteristics and pyrolytic operating conditions [ 22 ].…”

Responsabilidade socioambiental no contexto educacional: Um estudo de caso sobre o Programa Brasil Reciclado da Faculdade Sul Fluminense

“…As fontes renováveis de energia, como as biomassas lignocelulósicas, têm ganhado destaque devido às suas vantagens ambientais, econômicas e sociais(ARREGI et al, 2018). Em suas diferentes formas, a biomassa é um material rico em carbono que pode ser utilizado como alternativa viável aos combustíveis fósseis, contribuindo para a diversidade da oferta de energia, para a produção de energia sustentável no longo prazo e para a redução da poluição devido à sua neutralidade nas emissões de CO2(ALVES et al, 2020; ANTAR et al, 2021).De acordo com o Balanço Energético Brasileiro (MME, 2021), a biomassa contribui com cerca de 28% da oferta total de energia doméstica do Brasil para aquecimento e necessidades energéticas. Entre as fontes de biomassa de destaque para o setor de bioenergia destacam-se a lenha e o carvão vegetal (ALVES et al, 2020b).…”