Torrefaction Conditions Research Articles

Fuel properties evaluation and inherent correlation analysis of oxidatively torrefied corn stalk

Fuel properties evaluation and inherent correlation analysis of biochar are important in assessing the variation of fuel performance. This study investigates fuel performance changes under different oxidative torrefaction conditions of corn stalks. The obtained results imply that such a method is conducive to enhancing fuel properties, with the values of energy-mass co-benefit index (EMCI), upgrading energy index (UEI), Hardgrove grindability index (HGI), and equilibrium moisture content (EMC) range at 4-9, 500-3500, 60-120, and 9.5-12. This indicates that oxidative torrefaction is efficient for fuel performance improvement. For elemental transformation and carbonization degree, the oxidatively torrefied biochar possesses a higher proportion of elemental carbon content and better graphitization degree (GD), thus contributing to a more stable structure. Good linear relationships are exhibited from the analysis of comprehensive pyrolysis index (CPI) versus elemental carbon proportion (ECP), comprehensive combustion index (CCI) versus ECP, CPI versus GD, and CCI versus GD, with correlation coefficients of 0.9741, 0.9524, 0.9689, and 0.9166, respectively. This suggests that the carbonization extent is highly related to biochar pyrolysis and combustion characteristics. Overall, the obtained results are conducive to enhancing inherent correlation cognition of fuel property indicators. In doing so, the fuel property can be better adjusted for performance enhancement, thus facilitating efficient biochar production with better industrial application potential.

Evolution of solid residue composition during inert and oxidative biomass torrefaction

Biomass torrefaction is a thermochemical pretreatment that can be used to improve biomass properties, contributing to the energy densification of biomass or increasing its grindability, burning and gasification characteristics, porous structure, etc. While it is typically carried out under inert conditions, oxygen-lean torrefaction of biomass can reduce the process cost and complexity. This work proposes a novel extended 2-step kinetics mechanism capable of accurately predicting the evolution of the chemical composition of torrefied biomass. The model parameters are obtained from data collected from an extensive experimental campaign in which the chemical composition of torrefied biomass was measured at different temperatures, residence times, and oxygen fractions. The carbon mass fraction of the torrefied products was found to increase by up to 50 % under severe inert torrefaction conditions, i.e., high temperatures and long residence times, whereas the hydrogen fraction decreased. In the presence of oxygen during torrefaction, the carbon and hydrogen contents in the solid residue decrease compared with those produced under inert torrefaction. The extended 2-step model can also be used to determine the high heating value and energy densification of the torrefied biomass, with the latter ranging from 1 to 1.4 for the operating conditions tested.

Optimization of torrefaction conditions on antioxidant activity of prickly pear seeds extract using response surface methodology and chemometric analysis

The prickly pear (Opuntia ficus-indica L., Cactaceae) seeds can be used as an alternative food product by the torrefaction process. Torrefaction is a pre-treatment process of biomass into solid fuel within a temperature range of 60-200°C. This study aimed to investigate the effect of torrefaction parameters on the antioxidant potential of prickly pear seeds, which is considered a food by-product, by using the Central Composite Design approach (CCD).The best torrefaction parameters found to have the optimal phytochemical contents were: 200°C and 50 min with 104.86±1.94 GAE/g extract for Total Phenolic Content (TPC), 200°C and 50 min with 81.23±0.90mg QE/g extract for Total Flavonoid Content (TFC), 200°C and 50 min with IC50=90.66±2.09 μg/ml for free radical scavenging activity (DPPH assay), 200°C and 50 min with IC50=124.9±4 μg/ml for radical cation total antioxidant capacity (ABTS assay). Our results demonstrated an increase of antioxidant activities with the increase of torrefaction parameters. Therefore, torrefaction has proven to be a value-added process to exploit prickly pear seed biomass and use it as a source of antioxidant food additives.

Parametric study on mechanical-press torrefaction of palm oil empty fruit bunch for production of biochar

This study investigated the impact of varying temperatures and pressures during torrefaction under mechanical compression on the mass yield and chemical properties of torrefied empty fruit bunch (MTEFB). It also examined how these factors influenced the biochar derived from MTEFB. Experiments were conducted at temperatures ranging from 240 °C to 300 °C and mechanical pressures of 25, 50, and 75 MPa. The results indicated that at all temperatures above 280 °C, mass yields were significantly reduced, and higher mechanical pressures further accelerated thermal degradation. FTIR analysis revealed structural modifications, including dehydration, decarboxylation, and demethylation, particularly at elevated pressures. Elemental analysis showed an increase in carbon content to 55.68 % when MTEFB was prepared at 300 °C and 75 MPa. The HHV reached 23.11 MJ/kg, indicating improved energy yield. The proximate analysis demonstrated an increase in fixed carbon to 26.32 %, highlighting the influence of temperature and pressure on biochar characteristics. Further carbonization at 600 °C of MTEFB, which was prepared under mechanical-press torrefaction conditions at 300 °C with 75 MPa, produced biochar with enhanced yield and a more graphitic structure. The combination of mechanical-press torrefaction and subsequent carbonization presented a promising pathway for producing high-quality biochar and other solid carbon materials.

Structural and molecular modifications of woody biomass under minimal torrefaction conditions toward making durable pellets

Extensive research has been published on pelletizing severely torrefied biomass with the aid of binders, but limited studies have investigated the structural modifications of biomass during mild torrefaction. This study investigates the effects of several combinations of minimal torrefaction temperatures (230°C and 250°C) and relatively short durations (10, 15, and 30 minutes) on the thermophysical and molecular structure of the model woody biomass loblolly pine (Pinus Taeda) residues. The low severity treated biomass is compared with the untreated biomass and the biomass torrefied at 270°C for 30 minutes. Structural characterization methods include laser diffraction for particle size distribution and Brunauer-Emmett-Teller (BET) analysis to evaluate specific surface area. Additionally, FTIR, XRD, and TGA are used to assess changes in crystallinity and thermochemical composition. The woody residue torrefied at 250°C for 10 minutes exhibited a higher BET surface area (4.7 m²/g) than torrefied at 250°C for 15 minutes (3.5 m²/g). At a constant temperature of 250°C, the crystallinity index increases with the treatment duration, emphasizing the effect of time on retaining more hydroxyl groups that may act as binders for pelletization. This study demonstrates that minimizing the combination of torrefaction time and temperature can help control the degree of biomass molecular structure degradation thus minimizing overall mass loss, offering potential applications in the emerging biocarbon pellet industry.

Enhancing torrefaction process efficiency for biochar production from filter cake residue in the sugar industry

The torrefaction process is a promising technique for enhancing the quality of solid biomass fuels. This study investigates the effects of torrefaction on biochar produced from filter cake residue, a byproduct of the sugar industry. The primary objectives were to evaluate the impact of process parameters on biochar properties and identify optimal conditions for maximizing the higher heating value (HHV). Filter cake residue was subjected to torrefaction at temperatures ranging from 220-340°C under an inert atmosphere. The influence of particle size (20, 60, and 100 mesh), nitrogen flow rate (20-30 ml/min), temperature (220-340°C), and residence time (30-90 min) on biochar properties was examined using response surface methodology. Proximate analysis revealed that torrefaction significantly reduced moisture, volatile matter, and ash content while increasing fixed carbon content. The maximum HHV of 21.9571 MJ/kg was achieved at a particle size of 20 mesh, nitrogen flow rate of 25 ml/min, temperature of 340°C, and residence time of 60 min. The experimental results agreed with predicted values from the developed models, with an average error of 3.64%. Optimal torrefaction conditions were determined to be a particle size of 21.77 mesh, nitrogen flow rate of 22.50 ml/min, temperature of 311.13°C, and residence time of 42.58 min, yielding a maximum HHV of 18.4853 MJ/kg. These findings demonstrate the potential of torrefaction for upgrading filter cake residue into a high-quality solid biofuel, providing a sustainable solution for waste utilization in the sugar industry.

A review on hydrothermal treatments for solid, liquid and gaseous fuel production from biomass

The rise in the population and rapid industrialization has resulted in a rise in the global energy consumption. In order to minimize the load on the conventional energy sources, various studies are being conducted for the production of biofuels by hydrothermal operations. Unlike conventional processes of biofuel production, wet biomass can be directly utilised without drying in turn reducing the energy consumption. Feedstocks such as agricultural residue, forest residue, energy crops, algae, sludge, litter and food waste can be utilised for the production of biofuels. The operation intensities (temperature and pressure) can be varied from pressurized hot water to supercritical water. Hydrothermal operations depending on the operating parameters are further subcategorised into four types namely wet torrefaction (WT), hydrothermal carbonization (HTC), hydrothermal liquefaction (HTL) and hydrothermal gasification (HTG). Even though the operating conditions of wet torrefaction and hydrothermal carbonization lie in similar categories, the difference is clearly visible in the level of carbonization. Due to the wide range of operating temperature and pressure, mainly three different products are produced through hydrothermal operations. The temperature range for wet torrefaction can be limited between 150 and 220 °C, whereas the HTC process can be between 200 and 260 °C. At higher temperatures (260 – 370 °C) in hydrothermal liquefaction (HTL), increased isomerization, depolymerization and repolymerization of organic compounds within the biomass occurred, causing liquid product (bio-oil) to be formed as the major product. Hydrothermal gasification can be further subcategorised into three types: namely aqueous phase refining, near critical water gasification and supercritical water gasification (SCWG). This paper has reviewed different hydrothermal operations based on biofuel production from different biomass.

An Optimized Method for Evaluating the Preparation of High-Quality Fuel from Various Types of Biomass through Torrefaction.

The pretreatment for torrefaction impacts the performance of biomass fuels and operational costs. Given their diversity, it is crucial to determine the optimal torrefaction conditions for different types of biomass. In this study, three typical solid biofuels, corn stover (CS), agaric fungus bran (AFB), and spent coffee grounds (SCGs), were prepared using fluidized bed torrefaction. The thermal stability of different fuels was extensively discussed and a novel comprehensive fuel index, "displacement level", was analyzed. The functional groups, pore structures, and microstructural differences between the three raw materials and the optimally torrefied biochar were thoroughly characterized. Finally, the biomass fuel consumption for household heating and water supply was calculated. The results showed that the optimal torrefaction temperatures for CS, AFB, and SCGs were 240, 280, and 280 °C, respectively, with comprehensive quality rankings of the optimal torrefied biochar of AFB (260) > SCG (252) > CS (248). Additionally, the economic costs of the optimally torrefied biochar were reduced by 7.03-19.32%. The results indicated that the displacement level is an index universally applicable to the preparation of solid fuels through biomass torrefaction. AFB is the most suitable solid fuel to be upgraded through torrefaction and has the potential to replace coal.

Impact of high-temperature biomass pyrolysis on biochar formation and composition

The development and utilization of biomass play a vital role in reducing fossil fuel dependency and mitigating greenhouse gas emissions. High-temperature pyrolysis provides a promising route for converting biomass into valuable products without tar formation. Kinetic models are essential for understanding biomass pyrolysis processes, aiding reactor design and optimization. In this study, rice husk (RH) and corn straw (CS) are selected, which exhibit significant differences in ash content but are widely present. Pyrolysis is performed using a thermogravimetric analyzer coupled with a mass spectrometer (TGA-MS). The results show a rapid decrease in solid residue oxygen content at elevated temperatures, which stabilized after reaching 900°C, accounting for about 8–10%. MS quantification indicates increased release of H2O and CO during this stage. Fourier transform infrared spectroscopy (FTIR) analysis on the biochar unveils that this phenomenon is attributed to the stretching vibration of C-O bonds and the conversion of -OH groups. The remaining oxygen primarily exists as carbonyl and carboxyl groups. Subsequently, the CRECK-S-B biomass pyrolysis kinetic model is updated, specifically targeting the transformation mechanism of oxygen-containing solids at high temperatures to improve the prediction of biochar yield and elemental composition. The relative error of oxygen content prediction is less than 10%. The accuracy of the model is validated through experimental data and an extensive literature database, leading to the establishment of a comprehensive database. The updated model demonstrates significantly enhanced prediction accuracy for pyrolysis temperatures above 800°C, expanding its applicability range. Moreover, it achieves an accuracy rate exceeding 80% for char yield and elemental content in the temperature range of 200–1000°C, including torrefaction conditions. It provides a theoretical foundation for the effective utilization of high-temperature biochar, offers a novel insight into biomass thermochemical conversion, and contributes to the sustainable development of biomass energy.

Machine learning models for predicting biochar properties from lignocellulosic biomass torrefaction

This study developed six machine learning models to predict the biochar properties from the dry torrefaction of lignocellulosic biomass by using biomass characteristics and torrefaction conditions as input variables. After optimization, gradient boosting machines were the optimal model, with the highest coefficient of determination ranging from 0.89 to 0.94. Torrefaction conditions exhibited a higher relative contribution to the yield and higher heating value (HHV) of biochar than biomass characteristics. Temperature was the dominant contributor to the elemental and proximate composition and the yield and HHV of biochar. Feature importance and SHapley Additive exPlanations revealed the effect of each influential factor on the target variables and the interactions between these factors in torrefaction. Software that can accurately predict the element, yield, and HHV of biochar was developed. These findings provide a comprehensive understanding of the key factors and their interactions influencing the torrefaction process and biochar properties.

Torrefaction of Willow in Batch Reactor and Co-Firing of Torrefied Willow with Coal

The torrefaction process represents a thermal conversion technique conducted at relatively low temperatures ranging between 200 to 300 °C. Its objective is to produce fuel with a higher energy density by decomposing the reactive portion of hemicellulose. In this study, the kinetics of mass loss during torrefaction were investigated for willow. The experiments were carried out under isothermal conditions using thermogravimetric analysis. Batch torrefaction reactor designs were conducted and explained in detail. Co-combustion of willow with hard coal (origin: Katowice mine) in different mass ratios (25% biomass + 75% coal, 50% biomass + 50% coal, and 75% biomass + 25% coal) was conducted in addition to raw biomass torrefaction. TG/MS analysis (a combination of thermogravimetric analysis with mass spectrometry analysis) was performed in the research. The optimal torrefaction conditions for willow were identified as an average temperature of 245 °C and a residence time of 14 min, resulting in the lowest mass loss (30.15%). However, it was noted that the composition of torgas, a by-product of torrefaction, presents challenges in providing a combustible gas with sufficient heat flux to meet the energy needs of the process. Prolonged residence times over 15 min and higher average temperatures above 250 °C lead to excessive energy losses from volatile torrefaction products, making them suboptimal for willow. On the other hand, the co-combustion of torrefied biomass with hard coal offers advantages in reduced sulfur emissions but can lead to increased NOx emissions when biomass with a higher nitrogen content is co-combusted in proportions exceeding 50% biomass. This paper summarizes findings related to optimizing torrefaction conditions, challenges in torgas composition, and the emissions implications of co-combustion.

Improvement of fuel characteristics for forest by-products applied surface torrefaction process

Due to the continuous use of fossil fuels, global warming is accelerating; thus, the need for alternative energy sources has emerged. In this study, forest by-products (tree branches) were crushed into wood chips and pelletized to improve their fuel characteristics and energy yield through surface torrefaction; additionally, optimal process conditions for surface torrefaction were suggested. However, as determining optimal process conditions for surface torrefaction is laborious and time-consuming considering the energy yield, a mass reduction model was developed to effectively predict and ensure mass reduction applied as a variable in the energy yield. The rate constant was used to derive the mass reduction. The temperature, activation energy, and frequency factor applied as variables in the rate constant were derived through the finite element method and thermogravimetric analysis. The errors between the experimental and simulated energy yields of Populus euramericana and Pinus rigida wood chips were 0.04–0.85%p and 0.13–4.3%p, respectively, and of P. euramericana and P. rigida pellets were 0.18–1.15%p and 0.42–1.74%p, respectively. In this study, the improvement of fuel characteristics by species and type of forest by-products using the surface torrefaction process was confirmed, and the optimal process conditions were efficiently presented through a mass reduction model.

Valorization of Sewage Sludge with Pine Sawdust as Biochar: Optimization of the Torrefaction Conditions and Biochar Quality

Valorization of Sewage Sludge with Pine Sawdust as Biochar: Optimization of the Torrefaction Conditions and Biochar Quality

Enhancing fuel characteristics of jute sticks (Corchorus Sp.) using fixed bed torrefaction process

This is first article highlighting thermal degradation mapping of jute sticks in torrefaction regime. A critical investigation was done to torrefy the JS at four different temperatures (200 °C, 250 °C, 300 °C and 350 °C) and three different residence times (20 min, 40 min and 60 min) in fixed bed reactor. The effect of torrefaction on mass yield, energy yield, heating value, enhancement factor, degree of torrefaction, proximate analysis, ultimate analysis, grindability, and hydroscopicity was determined. Fourier transform infrared spectroscopy (FTIR) spectroscopy and Scanning electron microscopy (SEM) analyses were done to gain insights about chemical composition and morphological variations due to torrefaction process. The mass and energy yield of torrified jute sticks (TJS) were in the range of 68.45–85.31% and 85.87–99.99%, respectively. Results showed that, an increase in the carbon content was from 46.56 to 53.12% and HHV it was from 18.87 to 20.62 MJ/kg, respectively. The ratios of O/C and H/C decreased by 28.57% and 41.50%, respectively for highest torrefaction condition indicating that removal of hydrogen faster than oxygen. The energy-mass co-benefit index (EMCI) reaching the maximum of 17.63% at temperature of 350 °C and 20 min residence time. After torrefaction, grindability and hydrophobicity significantly improved. FTIR node at 1032.52, 1189.12, 1295.18 cm−1 showed stretch in cellulose, hemicellulose and lignin due to torrefaction. At higher temperature SEM structure of JS shows intergaps in structure due to release of volatile gases. Overall, torrefaction as a pre-treatment process showed the improvement in the characteristics of the JS.

Torrefaction under Different Reaction Atmospheres to Improve the Fuel Properties of Wheat Straw

This study aimed to produce biochar with an energy value in the range of sub-bituminous carbon by investigating the effect of oxidative and non-oxidative torrefaction on the torrefaction yield and fuel properties of wheat straw. Three independent variables were considered at different levels: temperature (230, 255, 280, 305 °C), residence time (20, 40, 60 min), and reaction atmosphere (0, 3, 6 vol% O2; N2 balance); and three dependent variables: mass yield, energy yield, and percentage increase in higher heating value (HHV). The results showed that it is possible to produce a sub-bituminous carbon type C biochar using oxidative torrefaction, significantly reducing time and temperature compared with non-oxidative torrefaction. The optimum torrefaction conditions were 287 °C–20 min–6.0% O2, which increased the HHV of wheat straw from 13.86 to 19.41 MJ kg−1. The mass and energy yields were 44.11 and 61.78%, respectively. The physicochemical and fuel properties of the obtained biochar were improved compared with the raw biomass. The atomic O/C ratio was reduced from 1.38 to 0.86. In addition, the hydroxyl groups in the lignocellulosic structure decreased and the hemicellulose content decreased from 26.08% to 1.61%. This improved grindability, thermal stability, porosity, and hydrophobicity.

Evaluation of the Optimal Conditions for Oxygen-Rich and Oxygen-Lean Torrefaction of Forestry Byproduct as a Fuel

Wood biomass is an alternative to fossil fuels. However, biomass use has several limitations. Torrefaction, in which reduction conditions prevail to overcome these limitations, has been suggested. Here, torrefaction using different wood chips (Liriodendron tulipifera, Populus canadensis, Pinus rigida, and Pinus koraiensis) was conducted under oxygen-rich and oxygen-lean conditions to determine the effects of oxygen. Torrefaction was conducted at 230–310 °C for 1 h. A mass yield difference of 3.53–20.02% p (percentage point) was observed between oxygen-lean and oxygen-rich conditions. The calorific value increased by a maximum of 50.95% and 48.48% under oxygen-rich and oxygen-lean conditions, respectively. Decarbonization (DC), dehydrogenation (DH), and deoxygenation (DO) occurred in the following order because of dehydration and devolatilization during biomass torrefaction: DO > DH > DC. The calorific value of the torrefied biomass increased linearly with the extent of all three processes. The combustibility index and volatile ignitability were calculated based on proximate composition to suggest the optimal conditions for replacing anthracite and bituminous coal. This study provides suggestions for stable operation in a standard boiler design.

Oxidative torrefaction of microalgae Chlorella sorokiniana: Process optimization by central composite design

Microalgae are currently not viable as solid biofuels owing to their poor raw fuel properties. Torrefaction under oxidative media offers a cost-effective and energy-efficient process to address these drawbacks. A design of experiment was conducted using central composite design with three factors: temperature (200, 250, and 300 °C), time (10, 35, and 60 min), and O2 concentration (3, 12, and 21 vol%). The responses were solid yield, energy yield, higher heating value, and onset temperatures at 50% and 90% carbon conversion determined from thermogravimetric analysis. Temperature and time significantly affected all responses, while O2 concentration only affected higher heating value, energy yield and thermodegradation temperature at 90% conversion. Oxidative torrefaction of microalgae is recommended to be conducted at 200 °C, 10.6 min, 12% O2 where the energy yield and enhancement factor are 98.73% and 1.08, respectively. It is also more reactive under an air environment compared to inert torrefaction conditions.

A hybrid optimization approach towards energy recovery from torrefied waste blends

The bottleneck of urban forest waste (UFW) as biofuel relies on surpassing its logistical management, feedstock quantity and supply, heterogeneity, and property drawbacks. This article proposes a hybrid approach based on multicriteria decision methods (MCDM) and response surface methodology (RSM) to optimize the definition of UFW blends and their torrefaction (temperature and process time). First, proximate, ultimate, and calorific analysis of UFWs (S1.Mangifera indica, S2.Ficus benjamina, S3.Pelthophorum dubium, S4.Persea americana, S5.Anadenanthera colubrina, and S6.Tapirira guianensis) were assessed. Then, understanding that UFW relies on species that do not always show promising characteristics as biofuels, the MCDM was applied to feedstock properties defining an optimum blend (OB) composed of 73%, 12.5%, and 14.5% of S1, S5, and S6, respectively. Next, the OB torrefaction was optimized using a central composite design (RSM-CCD), providing prediction models, the optimum torrefaction condition (273.3 °C and 40 min), and a torrefied optimum blend (TOB). Finally, the approach was validated by assessing TOB's properties, combustion behavior, and gaseous emissions. The methodology supplied a TOB with lower ash (2.67%), an HHV of 20.87 MJ kg−1, reduced nitrogen content (up to 39.65%), and more stable combustion resulting in a superior solid biofuel with a lower potential of NO-emissions in further applications.

Identification of Optimal Binders for Torrefied Biomass Pellets

The pretreatment of biomass through torrefaction is an effective means of improving the fuel quality of woody biomass and its suitability for use in existing facilities burning thermal coal. Densification of torrefied biomass produces a fuel of similar energy density, moisture content, and fixed carbon content to low-grade coals. Additionally, if the torrefaction conditions are optimized, the produced torrefied pellet will be resistant to weathering and biological degradation, allowing for outdoor storage and transport in a manner similar to coal. In untreated biomass, lignin is the primary binding agent for biomass pellets and is activated by the heat and pressures of the pellet extrusion process. The thermal degradation of lignin during torrefaction reduces its binding ability, resulting in pellets of low durability not suitable for transportation. The use of a binding agent can increase the durability of torrefied pellets/briquettes through a number of different binding mechanisms depending on the binder used. This study gives a review of granular binding mechanisms, as they apply to torrefied biomass and assesses a variety of organic and inorganic binding agents, ranking them on their applicability to torrefied pellets based on a number of criteria, including durability, hydrophobicity, and cost. The best binders were found to be solid lignin by-product derived from pulp and paper processing, biomass tar derived from biomass pyrolysis, tall oil pitch, and lime.

The influence of torrefaction on the biochar characteristics produced from sesame stalks and bean husk

Torrefaction encourages homogeneity and enhances the energy-producing capabilities of biomass. In the current study, bean husk (BH) and sesame stalks (SS) were torrefied for 30 and 60 min at operating temperatures of 200, 225, 250 and 275, and 300 °C with nitrogen purging. Mass yield (MY), higher heating value (HHV), energy yields (EY), and torrefaction severity index (TSI) were examined. The variations of the biochar characteristics, pyrolysis kinetics by applying two models (Coats and Redfern (CR) and Direct Arrhenius (DA)), and crystallinity index (CRI) were depicted. Depending on pyrolysis kinetics, thermodynamic activation parameters were derived to elucidate biomass pyrolysis. The alterations in the torrefied materials’ composition were also analyzed using Fourier transform infrared spectroscopy (FTIR). The calculations revealed that the torrefied SS and BH decreased MY by 32.74, 29.02% and decreased EY 26, 20.97%, increased high heating values by 14.1, 13.52%, increased fixed carbon by 55.1, 39.91% respectively, and had a slight reduction in bulk density (approximately 2%). Generally, 275 °C and 30 min were the optimal conditions for a balanced torrefaction of SS and BH based on the HHV that reached to 20.5, 16.2 MJ/kg and EY that reached to 86.16 and 85.56% respectively. The FTIR, XRD, and the thermogravimetric results showed that the torrefaction treatment altered samples owing to carbohydrate breakdown, a rise in lignin, and a reduction in hemicellulose as the temperature of the torrefaction process increased. The CR methodology yielded greater frequency factor (A) and activation energy (Ea) values than the DA method. The broadest peak width, lowest average Ea, and lnA were seen in sesame stalks that had been torrefied at 300 °C and 30 min that reached to 107.85 (kJ/mol) and 13.57 (min−1). Results indicated an excellent linear relationship with the index of comprehensive pyrolysis (CPI), CRI, atomic H/C ratio, severity index, and EY.