Thermochemical Conversion Processes Research Articles

Economic Performance of Small-Scale Fast Pyrolysis Process of Coproducing Liquid Smoke Food Flavoring and Biofuels

Biomass fast pyrolysis is a thermochemical conversion process to produce biofuels. However, the aqueous portion of pyrolysis liquid is usually considered a low-value product. This aqueous liquid ca...

A stochastic biomass blending problem in decentralized supply chains

AbstractBlending biomass materials of different physical or chemical properties provides an opportunity to adjust the quality of the feedstock to meet the specifications of the conversion platform. We propose a model which identifies the right mix of biomass to optimize the performance of the thermochemical conversion process at the minimum cost. This is a chance‐constraint programming (CCP) model which takes into account the stochastic nature of biomass quality. The proposed CCP model ensures that process requirements, which are impacted by physical and chemical properties of biomass, are met most of the time. We consider two problem settings, a centralized and a decentralized supply chain. We propose a mixed‐integer linear program to model the blending problem in the centralized setting and a bilevel program to model the blending problem in the decentralized setting. We use the sample average approximation method to approximate the chance constraints, and propose solution algorithms to solve this approximation. We develop a case study for South Carolina using data provided by the Billion Ton Study. Based on our results, the blends identified consist mainly of pine and softwood residues. The blends identified and the suppliers selected by both models are different. The cost of the centralized supply chain is 2%–6% lower. The implications of these results are twofold. First, these results could lead to improved collaborations in the supply chain. Second, these results provide an estimate of the approximation error from assuming centralized decision making in the supply chain.

Tunable Syngas Production from Biomass: Synergistic Effect of Steam, Ni-Cao Catalyst, and Biochar

The acquisition of tunable syngas through the inherently separated generation of high purity H2 and CO from biomass will further establish the role of biomass-derived syngas as a versatile platform for liquid fuels and value-added chemical synthesis. The influence of steam, Ni-CaO catalyst, and biochar on the tunable syngas generated from sewage sludge via a two-stage sorption-enhanced (TSSE) thermochemical conversion process was studied in this study. The presence of steam and Ni-CaO catalyst shows unprecedented performance in enhancing the H2 generation at the first stage, and the control experiments indicate that the steam performs a higher selectivity to H2 than the Ni-CaO catalyst. The introduction of biochar supplements carbon source for CO production, remarkably promoting the CO generation at the second stage, which could be further pronounced by the addition of Ni-CaO catalyst. A synergistic effect of steam, Ni-CaO catalyst, and biochar contributes to a significant enhancement in H2 and CO generation with an inherently separated generation of H2 (88.2 vol% of purity) and CO (55.6 vol% of purity). And the combined use of steam, Ni-CaO catalyst, and biochar could lead to a superior syngas quality with high LHVsyngas and energy recovery efficiency.

Selection criteria of municipal solid wastes for thermo-chemical conversion processes by using proximate and ultimate analysis

Municipal solid waste (MSW) is mostly known as garbage or trash which is generated due to day-to-day life human activities. It is the commercial, medical and residential waste generated in a particular area or municipal either in solid or semi-solid form, excluding industrial hazardous wastes. These wastes create environmental pollution in land, water and air, hence, the proper disposal of MSW is a challenging factor globally. This paper presents MSW disposal process using thermo-chemical processes such as combustion, gasification and pyrolysis. The best thermo-chemical process for its individual waste can be formulated by using selection criteria from proximate and ultimate analysis. For the analysis purpose, 28 different types of MSW were collected and found that 13 samples are good for combustion while six samples and five samples are good for gasification and pyrolysis respectively. The MSW collected are in the categories of hospital wastes, domestic/household wastes, industrial/constructional wastes, institutional/school wastes and shop/hotel wastes.

Selection criteria of municipal solid wastes for thermo-chemical conversion processes by using proximate and ultimate analysis

Selection criteria of municipal solid wastes for thermo-chemical conversion processes by using proximate and ultimate analysis

Kinetic analysis and pyrolysis behavior of low-value waste lignocellulosic biomass for its bioenergy potential using thermogravimetric analyzer

A substantial amount of renewable feedstocks study has been dedicated to bio-fuel and biochemical generation, preferably thermochemical conversion processes such as pyrolysis. In this work, the physicochemical study, pyrolysis behaviouer and kinetic parameters of Cascabela thevetia (SK) Delonix regia (SG) and Manilkara zapota (CK) seeds were tested in the thermogravimetric analysis (TGA) at three rates of heating (10–50 °C min−1) to estimate its bioenergy potential. Further, the kinetic constraints were investigated by using model-free approaches, namely Kissinger-Akahira Sunose (KAS), Friedman model (FM), Cots-Redfern model (CR), Distributed Activation Energy Model (DAEM), Ozawa-Flynn-Wall (OFW), and Vyazovkin method (VZ). Characterization study of applied biomass showed an attendance of extensive amount of volatile matter (73.15–75.24%), carbon content (50.12–55.02%), heating value (20.52–25.12 MJ kg−1), and lower ash content (2.20–3.15%) and nitrogen content (3.01–5.10%). Further, DSC inspection of applied biomass recognized that biomass decayed under the endothermic process during the heating process. The average activation energy for CK, SG, and SK was originated to be 157.81, 150.90, 166.28 kJ mol−1 for KAS, 164.55, 166.59, 177.05 kJ mol−1 for OFW, 168.47, 166.05, 185.22 kJ mol−1 for FM, 194.87, 157.87, 199.74 kJ mol−1 for DEAM and 168.75, 158.86, 102.28 kJ mol−1 for VZ respectively. Additionally, CR model yields 49.99, 35, 38.71 kJ mol−1 at n = 1 and 34.79, 29.18, 27.7 kJ mol−1 at n ≠ 1 for CK, SG, and SK, respectively. Finally, the variation between activation energy and enthalpy of reaction showed promising product formation. In contrast, Gibbs free energy and higher heating value (HHV) of biomass exhibited its potential for energy and fuel production.

Numerical estimation of the thermal stability boundaries for the process of thermochemical conversion processes of biomass in quasi-equilibrium approximation

The stationary process of pyrolysis and gasification of plant biomass in a wide range of conditions is considered. The reaction rate in a multicomponent system is a complex function of composition and temperature. To simplify the calculations, we use the approximation of the brutto-reaction: it is supposed that a slow reaction of thermal decomposition of biomass proceeds in the reaction zone with first order kinetics and Arrhenius dependence on temperature. Gas phase reactions rates are considered to be high enough to apply the quasi-equilibrium approximation. Calculations make it possible to estimate the temperature values at the boundary of thermal stability and the position of this boundary for different residence times of biofuel in the reaction zone.

Influence of Ca(OH)2 on ash melting behaviour of woody biomass

Woody biomass is a renewable source offering high potential for production of bio-fuels, -chemicals and -energy. During the outdoor storage of biomass biodegradation processes take place, which leads to mass reduction up to 30 wt%. To avoid these mass losses, the biomass was mixed with Ca(OH)2 in different ratios. To ensure, that this additive does not negatively influence further thermo-chemical conversion of biomass (e.g. by fluidized bed combustion), the spruce and poplar ash with and without additive was tested using ash melting microscopy. It was demonstrated that all the characteristic temperatures (DT, HT, FT) were significantly higher than the thermo-chemical conversion process temperatures in a fluidized bed. Thus it could be pointed out that the addition of Ca(OH)2 does not negatively influence ash melting behaviour, ash melting temperature respectively.

Developments in waste tyre thermochemical conversion processes: gasification, pyrolysis and liquefaction.

Fossil fuels, particularly crude oil, have proven to be a source of energy to households, transportation and power industries over the past decades. This natural reserve is diminishing at an alarming rate with crude oil having reserves to last the earth for the next half a century. As a result, researchers are constantly seeking remedial technologies to close this gap. Thermochemical conversion processes such as pyrolysis, gasification and liquefaction (PGL) offer an alternative solution to mitigating the world's high reliance on crude oil. These processes can be employed to provide energy, fuel and high-end value-added products. This paper aims to highlight all the research and development advancements and trends that have been made over the past three decades while employing waste tyres and other feedstock. In addition, the prominent countries and their associated researchers who have made novel discoveries in the field of thermochemical conversion are extensively discussed. The research findings show that significant research outputs such as the utilization of vast types of feed materials, the reaction mechanisms, the factors affecting the processes, and the application of the different end-products for thermochemical processes are well documented in the literature. Also, the collected data showed that significant advancements have been achieved in developing PGL technologies. The following conclusions were drawn: (i) PGL technologies show a generally increasing percentage interest from 1990 to 2020, (ii) many authors have identified the end-products obtained from waste feedstocks, such as; waste tyres, biomass, plastics, food waste, microalgae and animal manure to yield promising application benefits, (iii) China has shown the greatest interest in investing into waste to energy initiatives and has demonstrated the vast applications of waste derived products and, (iv) employing waste tyres as a feedstock has shown potential for producing high-end value products in their crude form or refined form. Some of the shortcomings identified during the study are the modest interest shown by most African regions as well as the lack of regulatory frameworks developed by certain countries.

Impact of torrefaction process temperature on the energy content and chemical composition of stool tree (Alstonia congenisis Engl) woody biomass

Torrefaction process temperature has been identified as one important factor that can enhance energy content of Alstonia congenisis wood-dust biomass. Wood biomass, being the principal feedstock for solid fuel needs to be subjected to optimum process conditions that will increase its energy content. Therefore, physico-chemical analyses were carried out both on the torrefied and untorrefied samples of Alstonia congenisis wood-dust biomass in order to understand effects of torrefaction treatment on chemical and energy compositions of the biomass. Torrefaction was performed at varying process temperatures of 200 ​°C, 250 ​°C and 300 ​°C under a resident time of 45 ​min with an improvised laboratory scale torrefier designed with steel container. The results showed thattorrefied samples were remarkably different in colour compared to the untorrefied. It was observed that as the process temperature increases, the higher heating value (HHV) increased and energy yield decreased. The thermal stability of lignin, cellulose and hemicellulose was discovered to be in the following order: hemicellulose ˂ cellulose ˂ lignin. The fixed carbon and ash contents increased with increase in temperature. The result of elemental composition showed that torrefaction enhanced the fuel properties of the Wood-dust. Grindability and hydrophobicity tests indicated that torrefaction process increased the fragility and water-hating properties of the biomass. The observed decrease in moisture content greatly improved the fuel properties of the biomass as solid fuel. Hence, torrefaction process was confirmed as a value-added thermo-chemical conversion process for Alstonia congenisis wood dust biomass.

Теплотехнические характеристики процесса пиролиза отработанных шин

A significant annual growth in the number of spent car tires creates a serious environmental problem and calls for the need to continue searching for efficient resource-saving methods of their recycling. There is a growing number of efforts aimed at studying waste tire thermochemical conversion processes, including their pyrolysis to obtain valuable products, including a solid fraction (coke residue), liquid hydrocarbon fraction (pyrolysis oil), and noncondensable gaseous fraction (pyrolysis gas). Commercial and pilot pyrolysis plants and reactors are reviewed. A rotating drum reactor, shaft and screw reactors are the most promising solutions for implementing a continuous process. The development of new resource-saving solutions for the pyrolysis of waste tire requires knowledge of the thermal characteristics of this process, including information on the material and heat flows in the pyrolysis reactor. The composition and thermal properties of waste tire, as well as specific outputs, composition and fuel properties of pyrolysis product material flows, including pyrolysis gas, pyrolysis oil and coke residue, are presented. Information on the pyrolysis plant or reactor heat balance structure is either absent or incomplete. Based on the data available in the literature, the heat balance of a commercial pyrolysis plant equipped with screw reactors characterized by a specific thermal destruction heat of 0.640 MJ/(kg of tires) is drawn up and studied. The numerical analysis results correlate with the data published for the commercial-grade plant. Information on the pyrolysis chamber heat balance structure is correct enough for use in engineering practice. It has been found that the specific heat consumption for the pyrolysis process is 2.269 MJ/(kg of tires). This value can be used in numerically analyzing pyrolysis plants equipped with other designs of pyrolysis reactors.

Thermochemical conversion characteristics of a single wood pellet in a convective low‐temperature air environment

In this study, the thermochemical conversion process of a single wood pellet under low temperature (350°C-650°C) isothermal heating is investigated to identify the outstanding low-temperature ignition and combustion characteristics for heat generation, particularly during the preheating stages in the furnace. The thermal behavior of wood powder was analyzed using thermogravimetric/Fourier transform infrared spectroscopy. The suspended single pellet combustion phenomenon under a convective hot air stream was also explored. The results showed that the wood primarily decomposed in a range from 240°C to 520°C, and low-temperature ignition was found at 293°C due to heterogeneous oxidation. For pellet combustion, an outstanding heterogeneous-induced homogeneous combustion phenomenon occurred when the stream temperature was higher than 350°C. In contrast, the ignition mechanism shifted to volatile auto-ignite mode at 650°C due to the interplay of fuel devolatilization and oxygen diffusion. The pellet temperature evolution was measured, and the results revealed a maximum heating rate of 6.61-16.95 K/s under a stream temperature ranging from 350°C to 650°C. The weight loss evolution showed three stages during the entire heating process, and the average activation energy (13.12 kJ/mol) was obtained. Char combustion was found favorable to CO production for gaseous emissions, but the burning of volatiles tended to convert fuel into CO2. Finally, a simplified reaction scheme based on different onset temperatures, including pyrolysis, heterogeneous/homogeneous oxidation, and heterogeneous gasification was proposed to illustrate a potential thermochemical conversion route for further utilization.

Characterization of hydrochar and process water from the hydrothermal carbonization of Refuse Derived Fuel

In this study, hydrothermal carbonization (HTC) was used as a thermochemical conversion process to upgrade Refuse Derived Fuel (RDF). The effect of process temperature (250 °C, 275 °C and 300 °C), residence time (30 min and 120 min), and RDF-to-water ratio (1:15 and 1:5) on the main characteristics of the produced hydrochars and process waters was assessed. The HTC process yielded hydrochars with enhanced fuel properties when compared to the original feedstock, namely higher carbon content and heating value. The hydrochars also presented reduced oxygen and ash contents. The hydrochar produced at 300 °C for 120 min presented the lowest ash content (3.3 wt%, db) whereas the highest heating value was found for the hydrochar obtained at 275 °C for 120 min (28.1 MJ/kg, db). The HTC process was also responsible for a significant reduction in chlorine concentration, showing dechlorination efficiencies between 69.2 and 77.9%. However, the HTC process generated acidic process waters with high COD values (maximum 27.2 gO2/L), which need to be further managed or valorized. Energy calculations were also performed, revealing that lower water amounts, lower temperatures, and longer residence times, represent optimal conditions for higher hydrochar yields and consequently good process efficiencies.

Bio-oil production from Moringa oleifera Lam. residue through fixed-bed pyrolysis

The thermal degradation of lignocellulosic materials is one of the most promising approaches for obtaining energy sources and chemical products. In this study, the chemical and thermochemical characterization of Moringa oleifera Lam. seeds and residues showed that biomass can potentially be used to produce energy through a thermochemical conversion process. The seeds and biomasses of Moringa oleifera Lam. were submitted to pyrolysis, the main method of thermochemical conversion. Pyrolysis reactions were conducted in a stainless steel fixed-bed reactor under atmospheric nitrogen pressure, temperatures of 500–600 °C and N2 gas flow of 1 and 3 mL min−1. The calorific value of the biomass ranged from 17 to 21 MJ/kg. The results obtained in the optimization of the pyrolysis conditions in a fixed-bed reactor, the temperature of 600 °C, and N2 flow of 1 mL min−1, were selected. The chromatographic analysis (GC/MS) of the bio-oil allowed the identification and semi-quantification of the different chemical classes present in the bio-oils (acids, phenols, oleonitriles, hydrocarbons, aromatics, ketones, aldehydes, ether, amines, amides, alcohol). High content of carboxylic acids (superior values 70%) was observed for the seeds and mechanical residue, and a high content of phenolic and nitrogen compounds, with 43% in both cases, for the Soxhlet residue. The moringa residues can be considered as a productive source of bioproducts, significantly reducing the harmful effects of chemicals originating from fossil fuels, while minimizing the disposal of waste into the environment.

Solar-Driven Chemical Looping Methane Reforming Using ZnO Oxygen Carrier for Syngas and Zn Production in a Cavity-Type Solar Reactor

Converting sunlight into chemical fuels and metal commodities, via solar thermochemical conversion processes, is an attractive prospect for the long-term storage of renewable energy. In this study, the combined methane reforming and ZnO reduction in a single reaction for co-production of hydrogen-rich syngas and metallic Zn was demonstrated in a flexible solar thermochemical reactor prototype, driven by highly concentrated sunlight. Using solar energy as the process heat source in chemical-looping methane reforming with the ZnO/Zn oxygen carrier is a means to reduce the dependence on conventional energy resources and to reduce emissions of CO2 and other pollutants, while upgrading the calorific value of the feedstock for the production of energy-intensive and high-value chemical fuels and materials. On-sun experiments were carried out with different operating parameters including operating temperatures (800–1000 °C), inlet methane flow-rates (0.1–0.4 NL/min), and inlet ZnO feeding-rates (0.5–1.0 g/min) both in batch and continuous modes under reduced (0.15 and 0.45 bar) and atmospheric pressures (0.90 bar), thereby demonstrating solar reactor flexibility and reliability. As a result, increasing the temperature promoted net ZnO conversion at the expense of favored methane cracking reaction, which can be lowered by decreasing pressure to vacuum conditions. Diminishing total pressure improved the net ZnO conversion but favored CO2 yield due to insufficient gas residence time. Rising ZnO feeding rate under a constant over-stoichiometric CH4/ZnO molar ratio of 1.5 enhanced ZnO and methane consumption rates, which promoted Zn and syngas yields. However, an excessively high ZnO feeding rate may be detrimental, as ZnO could accumulate when the ZnO feeding rate is higher than the ZnO consumption rate. In comparison, continuous operation demonstrated greater performance regarding higher ZnO conversion (XZnO) and lower methane cracking than batch operation. High-purity metallic Zn with a well-crystallized structure and of micrometric size was produced from both batch and continuous tests under vacuum and atmospheric pressures, demonstrating suitable reactor performance for the solar thermochemical methane-driven ZnO reduction process. The produced Zn metal can be further re-oxidized with H2O or CO2 in an exothermic reaction to produce pure H2 or CO by chemical-looping.

Kinetic study of carbonaceous deposit formation and catalyst deactivation in hydrotreating of fast pyrolysis bio-oil

Fast pyrolysis of biomass followed by hydrotreating of bio-oil is considered to be a promising thermochemical conversion process of biomass to liquid fuel. Catalytic hydrotreating converts the crude bio-oil from biomass pyrolysis into liquid intermediates with reduced oxygen content, and low viscosity and acidity. However, effective lifetime of catalyst can be significantly reduced by coking which has been recognized as the main cause of catalyst deactivation during the hydrotreating process. In this study, similar phenomenon has been observed but the catalyst deposit was different from the reported coke and thus a new term of carbonaceous deposit is introduced. Kinetics of the carbonaceous deposit formation and its characteristics have been investigated for hydrotreating of bio-oil derived from fast pyrolysis of rice husk using commercial HTB-45 Ni-based catalyst. A mathematical model for the hydrotreating process, which is based on key chemical reactions and consists of ordinary differential equations (ODEs), has been developed and solved with the kinetic parameters being obtained from the experiments. Results of this study are helpful for better understanding and optimization of the catalytic upgrading of fast pyrolysis bio-oil.

Physico-chemical Characterization of sewage sludge for thermochemical conversion processes

ABSTRACT Thermochemical conversion of sewage sludge has the advantage of being a ‘waste to energy option’ enabling sustainable waste disposal. Among the different methods of waste to energy conversion, the thermochemical route has many advantages over the other methods, such as high reduction in volume of feedstock and lower process time. However, sewage sludge is a non-conventional type of biomass whose characteristics and behavior under various operating conditions are quite different from the conventional type of biomasses because of its distinct composition. The various complex reactions occurring during the thermochemical conversion process depend on the physical and chemical properties of the feedstock. It is essential to have a proper understanding of the physical as well as chemical characteristics of feedstock for better processing and utilization. Accurate and reliable information about the feedstock is required for the design, operation, and optimization of the thermochemical conversion processes. Detailed studies on lignocellulosic biomasses are available in the literature, but only limited works are reported on non-lignocellulosic biomasses such as sewage sludge. This paper provides a comprehensive analysis of physical and chemical characteristics of sewage sludge influencing the thermochemical conversion processes. The results for furnace-dried sludge showed that the volatile matter (49.82% by weight), fixed carbon (7.46% by weight) and higher heating value of sewage sludge (12.26 MJ/kg) samples are comparable to that of conventional biomasses. However, higher moisture and ash contents, presence of heavy metals, sulfur, and acidic oxides revealed its distinct nature and indicated the need for additional primary processing and additives for its suitability in thermochemical conversion.

Thermochemical conversion routes of hydrogen production from organic biomass: processes, challenges and limitations

Hydrogen production from various organic biomass via thermochemical process is considered as a promising and economical viable technique. The advantages of this process are higher product yield and flexibility with current available facilities than other hydrogen production methods. Nowadays, large-scale hydrogen production from various biomass is the challenging process. Still, few thermochemical conversion process are yet in developing stage and there are several issues need to be solved for its successful pilot-scale operation, for example fluctuation equipment cost, availability of feedstocks, practical barriers, and public reception. Most of the researchers have strongly recommend that organic biomass is a suitable and predominant source of feedstock for hydrogen production. But, an extensive energy is required for the thermochemical conversion technologies to produce hydrogen rich syngas, due to extremely endothermic effect. In future, more research is required to reduce the emission of greenhouse gas and hydrogen production cost. In addition to this, certain mathematical modeling is required to reduce process energy demand. Detailed techno economic investigations are required to prior implementation of large-scale reactor. This review focuses on various thermochemical conversion technologies and their potential ways of hydrogen production using various organic biomass as a feedstock, challenges, and limitations associated with the process.

Phytotoxicity of hydrochars obtained by hydrothermal carbonization of manure-based digestate

The management of digestate, the main by-product of the anaerobic digestion (AD) process, is one of the most serious environmental issues. Although digestate is used on arable land as a fertilizer, it can have a negative impact on the environment due to nitrate leaching into the groundwater and ammonia volatilization into the atmosphere, with high economic and environmental disposal costs. Therefore, hydrothermal carbonization (HTC), a thermochemical biomass conversion process, could represent a sustainable and efficient alternative for digestate management. Hydrochar, the solid product of the HTC process, has been recently proposed as a plant growing medium in soilless culture systems (SCS). Here, using cow manure digestate as feedstock, we investigated the influence of the HTC process reaction temperature (180, 220 and 250 °C) and residence time (1 and 3 h) on the physical-chemical properties (pH, electrical conductivity, and mineral element concentrations) of the resulting hydrochars. Furthermore, in order to fully valorize hydrochar as a growing medium, their possible phytotoxic effects and those of their water extracts (prepared at two different concentrations and at different pHs) were tested in germination tests with cress seeds (Lepidium sativum L.). Concentrations of nutrients, heavy metals, organic acids, sugars and furan compounds were determined in the water extracts. Characterization analysis of these hydrochars revealed that they can be distinguished from each other by their physical-chemical properties, which were significantly affected by the two process parameters. Specifically, the HTC temperature had a greater effect on the composition of hydrochars than the residence time. Germination tests found hydrochar water extracts to show significantly lower phytotoxicity than the hydrochars themselves. Notably, the phytotoxic effect of the extracts decreased with increasing extraction ratio and decreasing pH. The chromatographic characterization of extracts identified the presence of potential phytotoxins, such as furan compounds (i.e., hydroxymethylfurfural and furfural). However, before using hydrochars as potential and innovative growing media for plants, their phytotoxicity should be limited, for example through their dilution with other substrates. Overall, AD-HTC coupling could represent a valuable eco-sustainable expedient in the field of biomasses, green economy and waste conversion and, therefore, further investigations in this direction are necessary.

In-situ investigation of coal particle fragmentation induced by thermal stress and numerical analysis of the main influencing factors

Particle fragmentation influences thermochemical coal conversion processes in different ways, which is of great significance for process design and control. Different mechanisms are proposed for fragmentation characterization, but direct and substantial optical evidence supporting these theories is rarely reported. In the present study, the fragmentation process of two anthracites with low volatiles is investigated in-situ with the aid of an optical system. The observed fragmentation phenomenon confirms that the thermal stress is the main driving force for the fragmentation of the investigated anthracite particles. Together with a model analysis, a fragmentation pattern different from previous reports is proposed. The tensile stress causes the particles to fragment from the center. Fine particles are produced by multiple tensile failure rather than by the spalling of particles’ outer shell caused by compressive stress. Based on the model, the impact of various process- and particle-related factors on the maximum thermal tensile stress and its appearance time are quantitatively evaluated, which significantly reduces the required time and effort in comparison to experimental analysis of the fragmentation. This study provides direct visual evidence and numerical validation of the fragmentation mechanism, which can be utilized to predict the coal particle behavior and the resulting particle size distribution.