Thermokinetic Analysis Research Articles

In-Depth Study on Synergic Interactions and Thermo-Kinetic Analysis of (Wheat Straw and Woody Sawdust) Biomass Co-Pyrolysis over Mussel Shell-Derived CaO Catalyst Using Coats–Redfern Method

The behavior of wheat straw biomass (WS), woody sawdust biomass (WB), and their blends during catalytic co-pyrolysis are analyzed in the presence of CaO catalyst, which is obtained from the calcination of mussel shells. Synergy analysis of blends and pure materials is measured by studying the difference between theoretical and experimental values of wt.%/min, (RL%), and (WL%), which correspond to maximum weight loss rate, residue left, and weight loss, respectively. The Coats–Redfern method is utilized for evaluating the thermo-kinetic properties. The chemical reaction order model F1 is the best model that describes the Ea of 60.05 kJ/mol and ∆H, ∆G, and ∆S values of 55.03 kJ/mol, 162.26 kJ/mol, and −0.18 kJ/mol.K, respectively, for the optimum blend 80WS−20WB, reducing the thermo-kinetic properties. Model D3 showed better results for the Ea, ∆H, ∆G, and ∆S for the 5% CaO blend, which certified the viability of co-pyrolysis of WS and WB, while DTG indicated that exothermic and endothermic reactions occur together.

Transition mechanism and thermokinetic analysis of Sr0.5Zr2(PO4)3–Ce0.5Sm0.5PO4 composite ceramics for nuclear waste forms based on in-situ synthesis

In this study, the novelly designed Sr0.5Zr2(PO4)3–Ce0.5Sm0.5PO4 composite ceramics were utilized as nuclear waste form to simultaneously immobilize simulated fission products Sr and actinide nuclides. The phase transition mechanism, thermokinetics and densification behavior of Sr0.5Zr2(PO4)3–Ce0.5Sm0.5PO4 composite ceramics based on in-situ synthesis were systemically analyzed by XRD, in-situ XPS, TG-DSC, SEM and density measurements. The results demonstrate that the formation of Ce0.5Sm0.5PO4 solid solution phase preceded that of Sr0.5Zr2(PO4)3 phase, of which there is a valence change of Ce from Ce4+ to Ce3+ before 1023 K. Additionally, as for the exothermic crystallization enthalpy, change of exothermic crystallization enthalpy and activation energy, the values of Sr0.5Zr2(PO4)3 and Ce0.5Sm0.5PO4 phases in composite ceramics are 286.17 – 515.61 mJ, 19.11 – 35.38 J/g, 702.45 kJ/mol and 145.21 – 232.44 mJ, 9.26 – 15.44 J/g, 450.04 kJ/mol, respectively. It is then indicated that the formation of Ce0.5Sm0.5PO4 phase is definitely more favorable than that of Sr0.5Zr2(PO4)3 phase. Simultaneously, the relative densities of Sr0.5Zr2(PO4)3–Ce0.5Sm0.5PO4 composite ceramics are more than 95 % when the sintering temperature exceeds 1273 K.

Novel composite electrolyte additive for enhancing the thermal and cycling stability of SiO/C anode Li-ion battery

SiO/C anode materials have gained significant attention due to their high specific capacity and environmental friendliness in high-energy-density lithium-ion batteries (LIBs). However, due to the volume effect generated during the long-term cycle, the battery capacity will decay rapidly and cause thermal safety problems. PFPN/TTFEB is employed as a compound electrolyte additive in this study to enhance the electrochemical performance and safety of Li/SiO@C batteries. The blank control electrolyte (BE) is the commercial electrolyte, which is 1.0 M LiPF6 dissolved in ethylene carbonate (EC) and ethyl methyl carbonate (EMC) at a 3:7 vol/vol ratio. The battery with the PFPN/TTFEB addition demonstrated a substantially higher capacity retention rate than the battery with BE, increasing from 45.23 % to 74.34 %, as indicated by the electrochemical and characterization test results. This suggests that the cycling stability of the battery was improved by the synergistic influence of ethoxy(pentafluoro)cyclotriphosphazene (PFPN) and tris(2,2,2-trifluoroethyl) borate (TTFEB). In addition, a LiF-rich solid electrolyte interphase layer was observed on the surface of the anode, increasing interface stability by reducing the direct contact between the electrolyte and electrode. Differential scanning calorimetry, thermogravimetric analysis, and thermokinetic analysis revealed that the addition of PFPN/TTFEB increased apparent activation energy from 439.56 to 1090.01 kJ/mol and increased initial exothermic reaction temperature from 233.67 to 292.83 °C. The thermal stability of the battery also considerably increased, and the exothermic reaction was substantially delayed. Overall, the multifunctional electrolyte additive developed in this study offers a feasible pathway for developing LIBs with excellent cycling performance and safety.

Thermal Hazard Analysis of Two Non-Ideal Explosives Based on Ammonium Perchlorate/Ammonium Nitrate and Aluminium Powder.

In recent years, various kinds of civil explosive detonation accidents have occurred frequently around the world, resulting in substantial human casualties and significant property losses. It is generally believed that thermal stimulation plays a critical role in triggering the detonation of explosives; consequently, the study of the thermal hazards of explosives is of great significance to many aspects of safety emergency management practices in the production, transportation, storage, and use of explosives. It is known that the thermal stability of the ammonium perchlorate-aluminium system and the ammonium nitrate-aluminium system has been extensively investigated previously in the literature. However, there is a paucity of research on the thermal hazard characteristics of non-ideal explosives under varying oxygen balance conditions within the academic sphere. Therefore, this research focused on the study of the thermal hazards of non-ideal explosives based on thermokinetic analysis. The thermal hazards of non-ideal explosive mixtures of ammonium perchlorate and aluminium and of ammonium nitrate and aluminium were studied by thermal analysis kinetics. The thermokinetic parameters were meticulously studied through differential scanning calorimetry (DSC) analysis. The results showed that the peak reaction temperature and activation energy of the ammonium perchlorate-aluminium system were significantly higher than those of the ammonium nitrate-aluminium system. Under the condition of zero oxygen balance, the peak reaction temperature of the ammonium nitrate-aluminium system was 259 °C (heating rate 5 °C/min), and the activation energy was 84.7 kJ/mol. Under the same conditions, the peak reaction temperature and activation energy of the ammonium perchlorate-aluminium system were 292 °C (heating rate 5 °C/min) and 94.9 kJ/mol, respectively. These results indicate that the ammonium perchlorate-aluminium system has higher safety under the same thermal stimulation conditions. Furthermore, research on both non-ideal explosive systems reveals that the activation energy is at its peak under negative oxygen balance conditions, recorded at 104.2 kJ/mol (ammonium perchlorate-aluminium) and 86.2 kJ/mol (ammonium nitrate-aluminium), which indicates a higher degree of safety. Therefore, the investigation into the thermal hazards of non-ideal explosive systems under different oxygen balance conditions is of utmost importance for the enhancement and improvement of safety emergency management practices.

Pyrolysis of Euphorbia Rigida: A study on thermal characterizations, kinetics, thermodynamics via TG-FTIR analysis

Euphorbia Rigida (E. Rigida), a lignocellulosic biomass with low ash content, is a suitable feedstock for pyrolysis. This work investigated the physicochemical characteristics and thermokinetic analysis of E. Rigida pyrolysis by using isoconversional and master plots methods. Ultimate and proximate analyses and oxygen bomb calorimeter were used to determine the physicochemical parameters. The activation energies were calculated using model-free methods (KAS, Friedman and Starink) and were found as 184, 178 and 185 kJ/mol, respectively. Using Fraser-Suzuki deconvolution, pseudo-components were also calculated and the active pyrolysis region was divided into three zones. The master plots showed that reaction order mechanisms (Fn) were effective in Zone I, and diffusion mechanisms (Dn) were well matched in Zone II and Zone III. The thermodynamic parameters (ΔH, ΔG and ΔS) were calculated and according to these results, E. Rigida pyrolysis was an endothermic and non-spontaneous process.

Pyrolysis of municipal solid waste: Kinetics and thermodynamic parameters via Coats-Redfern method

Renewable and sustainable energy resources are the dire need of time for environmental sustainability and to minimize the effects of global warming and climate change. The objective of this study was to investigate the thermos-kinetic parameters of municipal solid waste through pyrolysis. The sample was collected and prepared according to the American standards for test materials. Thermogravimetric analysis showed the three distinct regions, while the maximum degradation occurs in the second region within the temperature range of 230–400 ℃. A model-fitting approach using the Coats Redfern model was applied in this region to perform thermo-kinetic analysis. Based on the kinetic analysis, the D3 diffusion model showed the highest regression coefficient with an activation energy of 16–18 kJ/mole among all three diffusion models. Thermodynamic analysis showed that the pyrolysis process is endothermic, the product has more energy and a well-ordered arrangement of molecules confirmed by the positive change in enthalpy values and negative entropy values. The results demonstrate the usefulness of municipal solid waste in the creation of productive methods for converting to energy.

Using thermokinetic methods to enhance properties of epoxy resins with amino acids as biobased curing agents by achieving full crosslinking

Fibre-reinforced polymers (FRPs) are used in numerous industrial sectors and contribute to reducing CO2 emissions due to their outstanding properties in lightweight design. However, sustainable alternatives must be developed since the matrix polymers utilised contain substances hazardous to health and the environment. In widely used epoxy resins, the curing agents are mainly critical. Using biomolecules instead of synthetic curing agents can significantly reduce composites' toxicity and petrol-based carbon content. This study considerably exceeds the thermo-mechanical properties of epoxies cured with amino acids described in the literature until now. It demonstrates competitive or even better properties than state-of-the-art epoxies cured with petrol-based amine curing agents. For instance, the tensile strength of arginine-cured epoxy is more than twice as high as reported before and 13.5% higher compared to the petrol-based reference. At the same time, a high elongation at break of over 6% was accomplished, making these polymers suitable as matrix materials in FRPs. Furthermore, the glass transition onset of up to 130 °C is sufficiently high for many applications. The key to success is the development of individual curing profiles based on thermokinetic analysis. The work provides the development and analysis of several biomolecule-cured epoxies with promising property spectra.

Nano-clay treatment of jute fiber for reinforcement in polymer composites: Mechanical, morphological, and thermo-kinetic analysis

Natural fibers have demonstrated exceptional properties that can be utilized as a viable and environmentally reliable material for reinforcement in polymer composites replacing their synthetic counterparts creating numerous environmental problems. Jute fiber is a prominent natural fiber that has been successfully applied for manufacturing noble natural fiber-based composites. This article describes the advantages and comparison between two surface treatment techniques that is alkali treatment and nano-clay treatment of jute fiber to enhance the properties for producing improved composite material. FTIR, SEM, AFM, and TGA have been utilized to compare and study how different surface treatment methods affect jute fiber. Isoconversional methods FWO and KAS are applied for the thermos-kinetic analysis and evaluation of activation energy of thermal decomposition. More than 30% increase in peak activation energy has been observed (120 KJ/mole to 160 KJ/mol). Alkali–nano-clay treated jute fiber exhibits nearly 32% improvement (405 MPa to 535 MPa) in tensile strength, 24% increment (11.85 GPa to 14.69 GPa) in tensile modulus, and 15% improvement (1.4 gm/cm3 to 1.61 gm/cm3) in fiber density as compared to that of untreated jute fiber. This study validates that nano-clay treatment has shown promising results and can improve the overall properties of natural fibers significantly.

4,5-Difluoro-1,3-dioxolan-2-one as a film-forming additive improves the cycling and thermal stability of SiO/C anode Li-ion batteries

SiO/C is currently considered the most favorable anode material for high-energy-density lithium-ion batteries (LIBs). Nevertheless, its potential applications are constrained because of its inherent capacity decay and thermal safety concerns engendered by its volumetric expansion during extended cycling periods. The present study investigated the effectiveness of 4,5-difluoro-1,3-dioxolane-2-one (DFEC) as a film-forming additive to augment the safety and electrochemical efficacy of LIBs. A blank electrolyte (BE) was used as a control. Electrochemical test and characterization results revealed that the capacity retention rate of a battery containing the DFEC additive improved significantly; specifically, it increased from 45.23% (for a battery with the BE) to 73.14%. DFEC also increased the quantity of LiF components on the anode surface, resulting in the formation of a robust and stable solid electrolyte interphase film, which enhanced the battery’s cycling stability. Differential scanning calorimetry, thermogravimetric analysis, and thermokinetic analysis revealed that DFEC inhibited exothermic reactions between the electrolyte and the lithiated anode. Notably, the initial reaction temperature for the electrolyte slowly transitioned from 232.17 to 238.67 °C. The apparent activation energy increased from 439.56 to 506.995 kJ/mol. This study presents a practical approach for the development of safe, high-energy-density batteries by incorporating DFEC as a film-forming additive.

Corrosion Behavior of Binary Ni-Cr Alloys in Molten FLiNaK Salts at Different Electrochemical Potentials

The development of molten salt reactors (MSRs) is a collaborative effort among academia, government laboratories, and industry, with the aim of realizing the potential of clean nuclear energy. However, the corrosion of structural alloys presents a significant engineering challenge in this application. Addressing this issue requires investment not only in testing and characterizing candidate alloys, but also in developing a scientific framework to understand the fundamental mechanisms governing the corrosion of metallic materials in molten fluorides which can then guide alloy design [1].In this work, the corrosion behavior of binary Ni-Cr alloys (5-20 wt.% Cr) in molten LiF-NaF-KF (or FLiNaK) salts between 550oC and 750oC was interrogated using electrochemical methods coupled with thermo-kinetic analysis. Electrochemical techniques, including linear sweep voltammetry, electrochemical impedance spectroscopy (EIS) and chronoamperometry, were utilized to elucidate the rate-limiting kinetic factors and to identify the dependence of corrosion morphology on applied potential. Additionally, Ni-Cr alloys were also immersed 99.9% pure FLiNaK salts with a known oxidizer concentration (e.g., 0.1-5 wt.% EuF3) coupled with open-circuit potential measurement to provide a time-based description of morphological evolution in the case of a dynamically changing electrode potential. These results are corroborated by examination of the post-corrosion morphology using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron backscatter diffraction (EBSD) techniques as well as salt composition analysis using inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD) and in situ cyclic voltammetry.The systematic choice of potential revealed multiple potential regimes in which Ni-Cr alloys exhibit distinctly different corrosion morphologies. At intermediate potentials, a porous bicontinuous structure is formed by dealloying of the less noble element (Cr) and percolation into the Ni-rich alloy within grains and along grain boundaries. At other potentials, charge transfer control dissolution of both Cr and Ni leads to the formation of a crystallographic faceted structure. The morphological differences suggest the presence of multiple corrosion processes in Ni-Cr in FLiNaK controlled by either transport or interfacial reaction. These findings can be explained through electrochemical processes at the alloy-salt interface, as well as the roles of surface, grain boundary and bulk diffusion kinetics involving the alloying constituents. Furthermore, the effect of radiation damage on Ni20Cr alloys on these rate-limiting corrosion regimes will be investigated. Acknowledgment Research is primarily supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center (EFRC) funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES).[1] Chan, H.L., et al. Npj Materials Degradation 6(1), 46 (2022).

Comparative thermokinetic study of vegetable oils and deoxygenated derivatives

This study shows the usefulness of thermokinetic analysis in the characterization of vegetable oils and their deoxygenated derivatives (bioparaffin mixtures). The approach allows obtaining information about the complexity and nature of the process rate-controlling steps (inter- or intra-molecular), to establish quality criteria and to estimate the cohesive forces in liquids and fuels in general. The study also reveals the influence of the gaseous products, Ps, on the limit temperature, Tl, at which the liquid–vapor interface coexists or vanishes. The presence of multiple steps and stages, and the energy barrier variability between ∼ 120 and > 250 kJ mol−1 in the starting vegetable oils, demonstrates the importance of the origin and composition of triglyceride and the effect of unsaturation degree (C = C)n in the fatty acid degradation pathway. Besides, the isoconversional analysis of the deoxygenated products (bioparaffins) describes a kinetics controlled by a single-step, with almost constant activation energy barriers ∼ 70 kJ mol−1, related to the inter-molecular cohesive forces, usually E(α) < 100 kJ mol−1, equivalent to the vaporization enthalpy, ΔvH. The results are validated by a complementary thermokinetic analysis of pure solvents (n-decane and n-hexadecane). Finally, the study describes several experimental observations of great relevance and interest to understand and control the nature of thermally activated processes in vegetable oils and biofuels.

Sustainable valorization of Cascabela thevetia fruit peel and seed waste biomass: characterization and thermo-kinetic analysis

Sustainable valorization of Cascabela thevetia fruit peel and seed waste biomass: characterization and thermo-kinetic analysis

Taguchi method-based evaluation of thermal hazard of lift-off pyrotechnics under various storage conditions

This study employed the Taguchi method and analysis of variance to investigate the factors that influence the deterioration of the lift-off pyrotechnics when they are stored under various relative humidity (RH) and temperature conditions. A field emission scanning electron microscope and an energy-dispersive X-ray spectroscope were used to observe the microstructures and elements of pyrotechnic samples. Differential scanning calorimetry (DSC) and Vent Sizing Package 2 (VSP2) were applied to measure the relationship between the trace heat flow of the samples and temperature as well as the thermal runaway reactions in a pseudo-adiabatic environment. A DSC analysis and a thermodynamic ASTM E698 analysis were combined to explore the safety of lift-off pyrotechnics and the related thermal hazards.The energy-dispersive X-ray spectroscopy and DSC experimental results revealed that KNO3 is highly soluble. However, when RH and exposure time increased, the surface dissolution of oxidants decreased the height of the second exothermic peak, resulting in incomplete combustion and ignition failure. The ASTM E698 thermokinetic analysis results indicated that the apparent activation energy (Ea) of the samples increased substantially after being immersed in deionized water. Notably, the Ea of colored smoke increased from 46.88 to 155.91 kJ/mol, indicating that the examined pyrotechnics were more sensitive to a decrease in temperature than to an increase in humidity. A large amount of water can be used to alleviate the reactivity of pyrotechnics and thus reduce pyrotechnic hazards. The VSP2 analysis results indicated that the self-boosting rate of the samples was greater under 40% RH than under pristine conditions; however, this rate decreased substantially under 80% RH and after immersion in deionized water. The results of the Taguchi experiment and analysis of variance revealed that humidity contributed 63.60% and 50.86% to Ea and maximum pressure, respectively. Accordingly, controlling humidity should be prioritized to diminish the hazard of storing pyrotechnics.

Thermal hazard assessment of tert-butyl perbenzoate using advanced calorimetric techniques and thermokinetic methods

Tert-butyl perbenzoate (TBPB) is a common organic peroxide initiator in the polymer sector, and its thermal behavior and potential dangers are explored in this quantitative study. Advanced calorimetric techniques and thermokinetic models were used to examine the thermal stability and breakdown features of TBPB. During the first stage of the TBPB synthesis, the process safety analysis revealed a very exothermic reaction. Peak temperatures for TBPB thermal decomposition ranged from 133.37 to 156.64 °C, with heat release values of roughly 1279 ± 135 J/g, as determined by differential scanning calorimetry and thermogravimetric analysis. Apparent activation energies ranged from 78.78 to 133.92 kJ/mol in a thermokinetic analysis employing the Kissinger, Starink, ASTM E698, Friedman, Kissinger-Akahira-Sunose, and Flynn-Wall-Ozawa models. Based on multiple nonlinear regression analysis, a two-step reaction mechanism was postulated, one involving an autocatalytic reaction and the other involving a reaction of the nth order. In order to evaluate the thermal dangers related with TBPB, the self-accelerating decomposition temperature (SADT) and thermal risk index (TRI) were calculated. Based on TRI calculations, TBPB was assessed as having low thermal risk, with SADT values ranging from 40 to 60 °C depending on package size. These numerical findings add to our knowledge of the thermal risks posed by TBPB and shed light on how best to handle, store, and transport the compound for use in industrial settings.

Thermokinetic analysis of coconut husk conversion by pyrolysis process

The energy produced from agricultural wastes by pyrolysis can replace fossil fuels in many applications. Therefore, to make the process more efficient and optimal, an understanding of the kinetic and thermodynamic behaviour is required before progressing to pyrolytic applications. Thus, this study investigates the pyrolysis thermokinetic of coconut husk under varied heating conditions in nitrogen environment. Three model-free approaches, which are; Kissinger-Akahira-Sunose (KAS), Distributed Activation Energy Model (DAEM), Ozawa-Flynn-Wall (FWO) were deployed to analyse the kinetic parameters. The temperature range for the maximum devolatilization was found to be between 200 and 380 °C. Average activation energy was obtained based on various model free approaches with KAS, DEAM and FWO having a value of 99.15 kJmol−1, 99.15 kJmol−1 and 103 kJmol−1 respectively. The comparison between activation energy, Ea and change in enthalpy ΔH showed that average energy barrier is low with a value of 4.85 kJmol−1 for all methods. Further, maximum values of thermodynamic parameters, such as change in enthalpy, and Gibbs free energy were estimated at 98.49 kJmol−1, 158.50 kJmol−1 respectively. Overall, kinetic, and thermodynamic analysis shows that coconut husk has potential for bioenergy production through pyrolysis.

Pyrolysis of brown macroalgae Dictyota dichotoma and its thermokinetic analysis

Pyrolysis of brown macroalgae Dictyota dichotoma and its thermokinetic analysis

An integrated approach for the extraction of lipids from marine macroalgae consortium using RSM optimization and thermo-kinetic analysis

This work presents an integrated approach for the extraction of lipids from marine macroalgae using RSM optimization and thermo-kinetic analysis. The lipids were extracted from marine macroalgal biomass using a Soxhlet extractor. The Soxhlet extraction parameters, including temperature (60–80 °C), solvent-to-algae ratio (3:1–7:1), algal particle size (0.05–0.25 mm), and extraction time (60–180 min), were optimized using RSM to achieve the maximum possible lipid extraction yield from marine macroalgae. The highest lipid extraction yield of 12.76% was obtained using the optimized conditions, which included an extraction temperature of 72 °C, a solvent-to-algae ratio of 5:1, an algal particle size of 0.16 mm, and an extraction time of 134 min. The kinetic analysis revealed an activation energy of 52.79 kJ mol−1 for the Soxhlet extraction process. The thermodynamic analysis of the Soxhlet extraction process demonstrated the following results: ΔH = 49.98 kJ mol−1, ΔS = −128.24 J K−1 mol−1, and ΔG = 93.98 kJ mol−1. The GC-MS analysis confirmed that the extracted algal lipids exhibited a composition of 14.20% palmitic acid, 4.89% stearic acid, and 76.97% oleic acid. The physiochemical analysis ensured that the extracted algal lipids possess excellent qualities, making them desirable for sustainable biofuel production.

Simultaneous adsorption of methylene blue and amoxicillin by starch-impregnated MgAl layered double hydroxide: Parametric optimization, isothermal studies and thermo-kinetic analysis

Textile and pharmaceutical effluents contain significant amounts of dyes and antibiotics, which pose a serious threat to the ecosystem when discharged directly. Therefore, they should be treated by facile treatment techniques using low-cost materials. Layered double hydroxide (LDH) and its hybrids have emerged as robust and economic adsorbents for water treatment. Herein, magnesium/aluminum LDH and its starch-based composite were synthesized by a co-precipitation technique. The physicochemical features of the developed adsorbents were thoroughly characterized using various analytical tools. The developed materials were tested for the eradication of methylene blue (MB) and amoxicillin (AMX) in batch mode adsorption by varying operating conditions. Adsorption performance depends on the solution's pH. Under optimum adsorption conditions of pH 11, adsorbent dosage of 50 mg/L, and treatment time of 120 min, starch-impregnated MgAl-LDH exhibited maximum MB and AMX adsorption capacities of 114.94 and 48.08 mg/g, respectively. The adsorption mechanism states that hydrogen bonds and weak van der Waals forces are responsible for the removal of pollutants by the developed materials. Moreover, equilibrium and kinetic studies revealed that the removal of dye and antibiotic followed the Freundlich and Langmuir models with the pseudo-second-order reaction kinetics, respectively. The spent adsorbents were regenerated using 0.1 M HCl (for MB) and methanol (for AMX) eluent, and reusability studies ensured that the developed adsorbents retained their performance for up to four consecutive adsorption/desorption cycles. MgAl-LDH and its starch-based hybrid could thus be used to effectively remove organic contaminants from wastewater streams on a commercial scale.

Activated waste cotton cellulose as renewable fuel and value-added chemicals: Thermokinetic analysis, coupled pyrolysis with gas chromatography and mass spectrometry

The bioenergy potential of waste textile cotton cellulose (BOC) and the activated waste textile cotton cellulose by H3PO4 (BOP) were assessed in this study. BOC and BOP were pyrolyzed in TG at four heating rates. The thermal weight-loss process of BOC and BOP can be separated into drying stage, rapid pyrolysis stage and carbonization stage. The kinetic and thermodynamic parameters of the pyrolysis reaction were evaluated using an isoconversion model. The Ea, ΔH and ΔG values of BOC are 84.79–206.79 kJ mol−1, 159.85–318.88 kJ mol−1 and 357.72–359.16 kJ mol−1, respectively. The Ea, ΔH and ΔG values of BOP are 101.81–453.85 kJ mol−1, 169.11–389.47 kJ mol−1 and 257∼335.78 kJ mol−1, respectively. Py-GC/MS analysis illustrated that the peak area percentages of the products of BOC/BOP, including Glucopyranose, Ketones, Cycloalkane, Aromatic, Furan, Aliphatic, CO2, and others, were 47.7%/5%, 4.66%/30.41%, 0%/27.12%, 16.64%/3.22%, 8.55%/12.44%, 12.75%/13.29%, 4.19%/3.91% and 5.51%/4.61%, respectively. Compared with BOC, the low-quality products of BOP, Glucopyranose and Aromatic, decreased from 47.7% to 16.64%–5% and 3.22%, respectively, and the high-quality products, Ketone and Cycloalkane, increased from 4.66% to 0%–30.41% and 27.12%, respectively. The complexity of bio-oil of BOP is reduced, which gives a positive prospect for the purification of backward position.

Synthesis, characterization and thermo-kinetic analysis of sawdust biochar for adsorbent and combustion drives

Biochar is synthesized using two wood species as Dalbergia sissoo wood (DSW) and Mangifera indica wood (MIW), employing pyrolysis of sawdust on a lab-scale. Chemical analysis of these biochars is carried out using elemental analyzer, BET, FTIR, FE-SEM-EDX, and TGA-DTG-DTA analyses. Results showed that high surface area (87.12 and 88.04 m2/g), pore volume (0.0439 and 0.0443 cm3/g), and gross calorific value (28.19 and 28.00 MJ/kg) of DSW and MIW biochar indicate their suitability as sorbent and energy source. Thermogravimetric modeling, based on Coats-Redfern method, is applied on combustion data of biochar samples obtained at 10 and 20 °C/min. Activation energy of DSW- and MIW-biochar are estimated as 2.61–80.49 kJ/mol and 2.58–77.90 kJ/mol, respectively. Statistical analysis of results (R2 > 0.90) indicated the adequacy of proposed kinetic modeling in reproducing the experimental combustion behavior. The propitious outcome of this study account for favoring sawdust-biochar as a good adsorbent and combustion feedstock.