Thermodynamic Analysis Research Articles

Adsorption Properties of Fishbone and Fishbone-Derived Biochar for Cadmium in Aqueous Solution

Cadmium (Cd) contamination in aquatic ecosystems is a serious global environmental issue. Biochar derived from agricultural wastes has recently attracted remarkable attention as it is used as an absorbent in combating heavy metal contamination of water bodies. In the present study, the absorption efficacy of fish bone (FBM) and fishbone-derived biochar prepared at 200 °C, 400 °C, 600 °C, and 800 °C (referred to as B200, B400, B600, and B800, respectively) for the Cd ion (Cd2+) in aqueous solution was investigated. The results showed that high-temperature pyrolysis could optimize the pore structure and specific surface area of FBM, and Cd2+ successfully adsorbed onto FBM and fishbone-derived biochar. High-temperature pyrolysis significantly increased the FBM adsorption capacity for Cd2+ by 49.5–135.1%, with the optimal pyrolysis temperature being 600 °C. Furthermore, the kinetic data of FBM and fishbone-derived biochar for Cd2+ were in better alignment with the pseudo-second-order model, their adsorption isotherms were better in accordance with the Langmuir models, and the thermodynamic analysis showed that the adsorption process was monolayer and favorable adsorption. Moreover, the potential adsorption mechanisms of Cd2+ on FBM and fishbone-derived biochar might be related to pore filling, ion exchange, complexation with oxygen functional groups, and precipitation with the minerals on the biochar surface. Fishbone-derived biochar has significant potential for wastewater treatment and agricultural waste applications.

Efficient CO2 adsorption by deoiled flaxseed hydrochar.

This study optimizes CO2 adsorption using hydrochar from de-oiled flaxseed (FDOP), a waste byproduct of the oil extraction industry, through hydrothermal carbonization (HTC). The aim is to enhance CO2 capture sustainably and cost-effectively. Using Response Surface Methodology (RSM), in optimal conditions achieved 1153.26mg/g CO2 adsorption capacity under 215.15°C synthesis temperature, 3.05h synthesis time, 0.99M acid concentration, 8.997bar pressure, and 25.07°C adsorption temperature. Statistical analysis (F-value: 44.48, R²: 0.9705) confirmed strong model reliability. Kinetic analysis showed both physical and chemical adsorption, while thermodynamic analysis revealed exothermic behavior (ΔH° values: -46.697kJ/mol for M-225, -40.230kJ/mol for MA-203). After 10 regeneration cycles, the adsorption capacity was reduced by only 2.8% and 3.1%, indicating excellent recyclability. This study highlights FDOP-derived hydrochar as a highly efficient, low-cost adsorbent, offering industrial applications for carbon capture and waste management.

Kinetic modeling of the removal of phenolic compounds from olive mill wastewater by hierarchical zeolite/carbon nanotubes: Isotherm, kinetics, and thermodynamic

ABSTRACT In this study, plain zeolite (ZSM5) and hierarchical zeolite (H-ZSM5) were synthesized as efficient adsorbents for the removal of polyphenolic/antioxidant compounds from olive mill wastewater (OMW). The XRD and FTIR results confirmed the successful synthesis of ZSM5 zeolites. SEM images and BET demonstrated that H-ZSM5 possessed a markedly greater surface area of 337.99 m2/g in contrast to ZSM5 (162.84 m2/g). For H-ZSM5, the values determined for pore volume, total volume, and pore diameters are 77.655 cm3 g−1, 0.1844 cm3 g−1, and 2.1826 nm. The absolute zeta potential values varied between 5.36 ± 1.21 and − 46.41 ± 1.32 mV, with the peak absolute value of − 46.41 ± 1.32 mV occurring at pH 4. The optimal conditions for the removal of phenolic compounds, achieving an efficiency exceeding 90%, were identified as a pH of 4, an adsorbent dosage of 50 mg, and a contact duration of 90 minutes. The adsorption isotherm was found to align with the Langmuir model rather than the Freundlich model, indicating a monolayer adsorption capacity of 48.7 mg/g. Kinetic studies were consistent with a pseudo-first-order model (R2 >0.99). Ultimately, the thermodynamic analysis suggested that the adsorption of OMW onto ZSM5 is both spontaneous and governed by a physisorption mechanism.

The novel mechanism on the inhibition of superoxide anion generating from xanthine oxidase in the presence of myricetin.

To gain an in-depth understanding of the process of myricetin (MY) inhibiting the generation of •O2- from Xanthine Oxidase (XOD) at a novel perspective, the inhibiting pathway is necessary to be re-elaborated through inhibitory type, thermodynamic analysis and molecular simulation. The results demonstrated that MY is indeed a potent inhibiting agent for •O2- producing from XOD, with the maximum value of 33.78 % in the inhibition of •O2-. Furthermore, the deprotonated form (De-MY) of MY was examined to be an effective agent for interacting with XOD, with the measurement of •O2- in productions from MY, XOD@MY and XAN-XOD@MY, as comparing to the XAN-XOD@ALL. On the inhibition kinetics, De-MY was witnessed to be on a mixed-type inhibition, with more competitive inhibition. In the thermodynamic analysis, the Stern-Volmer plots for De-MY obtained at 298 K, 303 K and 308 K, were polynomial-fitted to form curves approaching the X axis via the fluorescence quenching of XOD, which was against the reported with good linearity. It indicated that the interaction between De-MY and XOD occurred at the range of MY concentrations from 0 to 0.025 (×10-5 mol L-1), is dominated by a static quenching procedure, ascribing to the appearance of accessible interaction with corresponding f values less than 1. As well, via combining the synchronous fluorescence data, Molecular dynamics simulations showed that MY binding to the Trp 283, ARG-60 and Tyr 58 with H-binding interactions is an available access to block the transfer of free electrons from FADH2 to O2. Therefore, in this work, successfully re-elaborating the inhibition mechanism of •O2- generating from XOD by MY is benefited for MY in the future applications.

Carbon dioxide capture in large-scale CCGT power plant from flue gases obtained from various fuel mixtures

In this study, the thermodynamic analysis of a combined cycle gas turbine integrated with post-combustion carbon capture and storage using the solvent method is performed. The syngas obtained from the gasification of sewage sludge is mixed with methane and nitrogen-rich natural gas fuels at different proportions, used in the gas turbine, and the properties of fuel and flue gases are analyzed. The flue gas obtained from the fuel mixture is passed through the post-combustion carbon capture and storage at various load conditions to assess the heat and electricity required for the carbon capture process. The solvent used for the carbon capture from flue gases enables CO2 capture with the high efficiency of 90%. With the calculated results, the load conditions of flue gas using fuel mixtures are identified, which reduces the heat and power demand of post-combustion carbon capture and storage and provides the possibility to achieve neutral emission. The impact of selected operating conditions of post-combustion carbon capture and storage on the CO2 emission reduction process and on the power plant performances is investigated. Considering the factors of electricity generation, energy efficiency, heat supply to the consumers, operating load of post-combustion carbon cap-ture and storage and CO2 emission, the 50% mixture of syngas with both fuels performs better. Also, the use of a mixture of 2-amino-2methyl-1-propanol and piperazine with reboiler duty 3.7 MJ/kgCO2 in post-combustion carbon capture and storage slightly enhanced the performance of the power plant compared to the use of monoethanolamine with reboiler duty 3.8 MJ/kgCO2.

Sustainable Removal of Chloroquine from Aqueous Solutions Using Microwave-Activated Cassava Biochar Derived from Agricultural Waste

This study presents a sustainable solution for the removal of the emerging contaminant chloroquine from aqueous solutions, utilizing biochar synthesized from cassava waste through a rapid, single-step microwave activation process. By repurposing cassava waste, a prevalent agricultural by-product, this method aligns with circular economy principles, promoting the sustainable reuse of waste materials. Characterization of the biochar demonstrated a highly porous, crystalline structure optimized for adsorption applications. Adsorption studies demonstrated optimal performance at 45 °C, with a maximum adsorption capacity of 39 mg g−1 in the Langmuir model. Thermodynamic analysis confirmed that the process was spontaneous, endothermic, and consistent with physisorption. Kinetic experiments revealed that 200 rpm agitation provided the most favorable conditions. Notably, the biochar demonstrated substantial reusability, maintaining up to 70% of its adsorption capacity over five desorption cycles. This sustainable adsorbent stands out as a practical, eco-friendly option for removing pharmaceutical contaminants while also corroborating with the beneficial reuse of agricultural by-products.

Theoretical analysis and application of immobilized methanotrophs as typical adsorbent materials for adsorption/degradation of trichloroethylene

ABSTRACT Trichloroethylene (TCE) contamination presents a significant environmental challenge, necessitating efficient treatment solutions. This study aimed to develop an optimized immobilized bioreactor using methanotrophs for TCE degradation. Activated carbon fibres were identified as the optimal immobilization material, with an adsorption rate of 6–23 h – significantly faster than over 50 h for other materials – and the highest methane oxidation capacity of 0.970 mL·g−1·h−1. Adsorption kinetics indicated that activated carbon fibres followed a second-order kinetic model with a constant of 0.598 g·mg−1·h−1, suitable for low-concentration bacterial solutions. Thermodynamic analysis confirmed an exothermic process, favouring lower temperatures (288.15 K). The negative interaction energies, as per DLVO theory, suggested electrostatic attraction as a key mechanism. The bioreactor achieved 99% TCE removal within 1 h at an initial concentration of 10 mg·L−1, with visible microbial immobilization within 5 days. This research provides a novel and effective approach for using immobilized methane-oxidizing bacteria in TCE treatment, offering both theoretical and practical advancements for chlorinated hydrocarbon wastewater management.

Thermodynamic evaluation of contrail formation from a conventional jet fuel and an ammonia-based aviation propulsion system.

Condensation trail (contrail) formation in an airplane's wake requires thermodynamics supersaturation and ice nucleation to form visible ice crystals. Here, using a thermodynamic analysis, we evaluate the potential for forming contrails in a carbon-free, ammonia-powered propulsion system compared to conventional planes powered by jet fuel. The analysis calculates the moisture released by fuel into the atmosphere for each one-degree increase in air temperature due to exhaust gas. It then determines if this moisture can saturate the initially undersaturated atmosphere, maintain saturation as temperature rises, and result in supersaturation with respect to ice while leaving enough moisture for a visible cloud to form. With ammonia increases the critical temperature required for supersaturation. Although ammonia does not generate soot particles in the exhaust gas, various aerosols exist in the atmosphere through other sources that can facilitate heterogeneous ice nucleation. Hence, while ammonia's contrails might not be as dense, they can form at lower altitudes where the air is warmer and endure longer due to the increased water content, which preserves supersaturation for longer as fresh air dilutes the contrail.

Preparation and characterisation of chitosan/bacterial Escherichia coli biocomposite for malachite green dye removal: modeling and optimisation of the adsorption process

ABSTRACT Herein, a new biocomposite was obtained by loading a bacterial suspension of Escherichia coli onto a chitosan matrix to produce a unique biocomposite (chitosan – E. coli) with effective properties for biosorption of malachite green dye from water. The physicochemical characteristics of the chitosan – E. coli biocomposite were studied by employing XRD, FTIR, FESEM-EDX and pHpzc. The optimisation of biosorption conditions was achieved using a Box-Behnken Design (RSM-BBD) to assess the effect of variables on the dye removal: biocomposite dose (0.02–0.1 g/100 mL), pH (4–8) and contact time (10–300 min). The optimal conditions for dye removal (84.3%) were achieved with a chitosan – E. coli dose of 0.1 g/100 mL, and a contact time of 160 minutes with a pH of 8. The equilibrium and kinetic experimental findings show the biosorption of malachite green dye by chitosan – E. coli follows the Langmuir and pseudo-second-order models, respectively. The maximum dye adsorption capacity (q max ) of malachite green for the chitosan – E. coli biocomposite was 164.7 mg/g, where the dye adsorption mechanism was attributed to several effects such as hydrogen bonding, n-π interactions, and electrostatic attraction. Thermodynamic analysis indicated that the biosorption process was spontaneous and endothermic, with a positive enthalpy change (ΔH° = 40.9 kJ/mol) and a negative Gibbs free energy (ΔG°) at all tested temperatures. The biocomposite chitosan – E. coli adsorbent exhibits favourable cationic dye adsorption that is anticipated to have utility for remediation of dye effluent in industrial wastewater.

Optimizing Co-generation performance of reactivity controlled compression ignition engines with solar steam reforming of methanol; a thermoeconomic, economic and exergoenvironmental analysis

Reactivity-controlled compression ignition engines have garnered significant interest for their potential to deliver enhanced performance, particularly in environmental aspects. This study investigates the performance of such engines within a co-generation framework for simultaneous power and cooling production. Low reactivity fuel for the engine is derived from solar steam reforming of methanol, with waste heat recovered through a supercritical CO2 cycle and an absorption refrigeration cycle. The designed configuration undergoes comprehensive analysis encompassing thermodynamic, economic, and exergoenvironmental assessments, including parametric analysis. Optimal engine performance is evaluated through computational fluid dynamics, thermodynamic, and exergoenvironmental analyses across various syngas compositions and reforming conditions. Results indicate that a syngas portion of 60% at a reforming temperature and CH3OH to H2O ratio of 200 °C and 1.2 yields optimal engine performance. Besides, the inlet temperature of the CO2 turbine exhibits the greatest impact on co-generation performance. At the optimal state, co-generation's power and cooling load generation reach 467.8 kW and 225 kW, with a unit cost of 53.89 $/GJ, an exergy efficiency of 38.14%, a sustainability index of 1.622, and an exergoenvironmental impact index of 1.607.

Interplay of c- and a-domains on the anomalous electrocaloric effect in BaTiO3 (001) single crystals

Electrocaloric effects of adiabatic temperature change via the application of external electric fields are explored for energy-efficient solid-state refrigeration. These effects are typically estimated from the thermodynamic analyses of polarization and field in electrocaloric materials, which implies that higher field application gives larger temperature changes. However, this may not be always true. Here, using both indirect and direct methods, we report an anomalous effect where larger thermal changes occur by applications of lower fields in a multi-domain BaTiO3 (001) single crystal. A large temperature change of 1.9 K under a low field change of 8 kV/cm at 404 K is observed in a multi-domain BaTiO3 (001) single crystal in comparison to that of 1.4 K at a high field change of 30 kV/cm. We attribute this counterintuitive effect to the interplay of the c- and a-domains in the BaTiO3 (001) single crystal under the influence of temperature and field changes. This work provides a fundamental understanding of the complex role of domains in governing the electrocaloric response of ferroelectric materials which is often overlooked but critical for their practical applications.

Facile Synthesis of Polypyrrole-Decorated RGO-CuS Nanocomposite for Efficient Nickel Removal from Wastewater

Efficient wastewater treatment, particularly the removal of heavy metal ions, remains a challenging priority in environmental remediation. This study introduces a novel sandwich-structured nanocomposite, RGO-CuS-PPy, composed of reduced graphene oxide (RGO), copper sulfide (CuS), and polypyrrole (PPy), synthesized via a straightforward hydrothermal method. The unique combination of RGO, CuS, and PPy offers enhanced adsorption capacity for Ni(II) ions due to RGO’s high surface area and CuS’s active binding sites, supported by PPy’s structural stability contributions. This study is among the first to explore this specific nanocomposite architecture for Ni(II) removal, achieving an adsorption capacity of 166.67 mg/g and a high removal efficiency of 94.9% within 210 min for 55 mg/L of Ni(II) concentration at pH 6 and adsorbent dose of 3 mg/15 mL. The kinetic analysis shows the best fitted time-dependent experimental data with the pseudo-second-order model, indicating chemisorption. Isotherm studies confirmed the Langmuir model as the best fit, yielding a high monolayer adsorption capacity of 166.67 mg/g. Thermodynamic analysis shows the adsorption process was endothermic (ΔH° = 80.23 kJ/mol) and spontaneous (ΔG° ranging from −6.985 to −14.399 kJ/mol). Additionally, reusability tests using 0.1 M HCl for desorption demonstrated good reusability, emphasizing the RGO-CuS-PPy nanocomposite’s potential as a sustainable adsorbent for Ni(II) removal in wastewater treatment applications.

Application of a magnetic graphene nanocomposite modified with 5-aminoisophthalic acid amine group for chromium (VI) adsorption from aqueous solutions: kinetic and thermodynamic studies

ABSTRACT Polymer nanocomposites are composite materials that incorporate nanomaterials, such as magnetic graphene oxide (mGO), into a polymer matrix. To enhance its adsorption capacity, the surface of mGO nanoparticles was polymerised by a 5-aminoisophthalic acid amine group (mGO-AIPA) through a simplified co-precipitation method. The structural and morphological characteristics of the synthesised nanoparticles were evaluated through techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Thermogravimetric analysis (TGA), and Vibrating sample magnetometer (VSM). Response surface method (RSM) was used to evaluate the effectiveness of mGO-AIPA nanocomposite in removing chromium (VI) ions by examining variables such as solution of pH, contact time, adsorbent dose and initial concentration. Also, the study of kinetic models, adsorption isotherms and thermodynamic modelling of the process were evaluated. The results found that the mGO-AIPA nanocomposite has the maximum removal of chromium (VI) ions from the aqueous solution by 83.11% in optimal conditions including pH 3.5, contact time of 35 min, an adsorbent dosage of 25 mg g−1 and an initial concentration of 55 mg L−1. The pseudo-second-order kinetic and Langmuir isotherm models had a better fit with the experimental data of adsorption and the maximum adsorption capacity of chromium (VI) the base of the Langmuir model was 90.91 mg g−1. Moreover, the thermodynamic analysis indicated that the process was exothermic and nonspontaneous process, implying that it was energetically unfavourable. These findings suggest that the mGO-AIPA nanocomposite has a high performance as an effectual adsorbent to eliminate chromium heavy metal from an aqueous medium.

Removal of hexavalent chromium and pentavalent arsenic from aqueous solutions by adsorption on polyethylenimine-modified silica nanoparticles.

Chromium and arsenic are commonly found in water and wastewater as hexavalent chromium, Cr(VI), and inorganic arsenic species, such as pentavalent arsenic, As(V). In aqueous media, both Cr(VI) and As(V) exist predominantly in the form of oxy-anions. In our study, we prepared a polyethylenimine-silica composite material (SiO₂-PEI) as an adsorbent to study the adsorption capacity for chromate and arsenate ions. Polyethylenimine (PEI) can effectively bind negatively charged species through electrostatic interactions. The parameters that were evaluated, regarding the adsorption capacity were the effect of pH, the effect of the initial concentration of Cr(VI) and As(V), and the presence of other anions. Also, we examined the effect of Cr(VI) and As(V) on each other by studying the simultaneous removal of chromate and arsenate ions. Isotherm, kinetic, and thermodynamic analyses on the experimental data obtained were conducted. The results showed that the pH of the solution is affecting the charge density of PEI, and at pH 4, the lower value that was examined, the SiO₂-PEI exhibited higher adsorption capacity. The presence of other anions, such as phosphate, nitrate, and sulfate ions, had an adverse effect on the adsorption capacity of the SiO₂-PEI material for both chromate and arsenate ions. The adsorption capacity of arsenate was more affected by the presence of other anions compared to the chromate, and the higher impact was observed by the sulfate ions at pH 4, on the contrary for the chromate ions the higher impact was observed by the sulfate ions at pH 7 and by the phosphate ions at pH 4. Concerning the effect of temperature, the adsorption is an exothermic process and it was more favorable at lower environmental temperature. The study of simultaneous removal of Cr(VI) and As(V) declares the material's ability to accommodate both types of ions without requiring separate treatment steps. Addressing the simultaneous removal is essential for reducing the complexity of water treatment systems, lowering operational costs, and improving the safety of treated water.

Driving Forces in the Formation of Biocondensates of Highly Charged Proteins: A Thermodynamic Analysis of the Binary Complex Formation

A thermodynamic analysis of the binary complex formation of the highly positively charged linker histone H1 and the highly negatively charged chaperone prothymosin α (ProTα) is detailed. ProTα and H1 have large opposite net charges (−44 and +53, respectively) and form complexes at physiological salt concentrations with high affinities. The data obtained for the binary complex formation are analyzed by a thermodynamic model that is based on counterion condensation modulated by hydration effects. The analysis demonstrates that the release of the counterions mainly bound to ProTα is the main driving force, and effects related to water release play no role within the limits of error. A strongly negative Δcp (=−0.87 kJ/(K mol)) is found, which is due to the loss of conformational degrees of freedom.

Thermodynamic Analysis of the Fe-B-C Ternary System and an Evaluation of the Grain Boundary Segregation Behavior of B and C

Thermodynamic Analysis of the Fe-B-C Ternary System and an Evaluation of the Grain Boundary Segregation Behavior of B and C

Thermodynamic and Kinetic Analysis of TiN Precipitation in Nickel-Based Superalloys During Solidification

Large TiN inclusions in nickel-based superalloys promote micropore formation, compromising the mechanical properties of the alloys. However, current research lacks a comprehensive coupled model that considers both solute element microsegregation and TiN precipitation specifically in nickel-based superalloys. This study investigated TiN precipitation during the solidification of IN718 alloys through a combined thermodynamic and kinetic approach. A modified Clyne–Kurz model was applied to account for multi-element microsegregation, enabling an integrated analysis of both microsegregation and precipitation processes. The results indicated that solute elements in the molten alloy segregated to varying degrees during solidification. At an initial nitrogen concentration of 25 ppm, TiN inclusions precipitated when the solid fraction reached 0.256, eventually resulting in a total TiN precipitation of 64 ppm by the end of solidification, while residual nitrogen in the liquid phase decreased to 1.3 ppm. Increasing the initial nitrogen concentration from 10 ppm to 40 ppm advanced the onset of TiN precipitation and raised the total amount from 16 ppm to 126 ppm. Further analysis indicated that cooling rates of 0.03 °C/s, 0.06 °C/s, and 0.18 °C/s did not significantly affect the final TiN accumulation.

Energy, exergy, and economic analysis of a novel solar-assisted ejector subcooling CO2 transcritical refrigeration systemt

To further enhance the performance of transcritical CO2 refrigeration cycle (base cycle), a solar-assisted ejector subcooling transcritical CO2 refrigeration cycle (SESRS) is proposed. The base cycle is subcooled utilizing a solar-assisted ejector refrigeration cycle. This research performed energy, exergy, and economic evaluations of SESRS utilizing the eco-friendly refrigerant R152a in the ejector cycle based on the established model. The thermodynamic analysis results demonstrate that SESRS outperform the base cycle. At typical working conditions, the COPm of the SESRS demonstrates a 22.96 % increase compared to that of the base cycle. Although the total cost of the SESRS is 7.98 %–17.9 % higher than that of the base cycle when subcooling degree is 5 °C, the enhancement of COPm is larger and is increased by approximately 18.34 %–26.22 %. The impact of subcooling degree and other parameters on system performance are also investigated. Overall, this study confirms the potential of the SESRS system for utilization in the refrigeration and air-conditioning fields. Considering both the system’s performance and economy, further optimized analysis should be done on key operational parameters, such as subcooling degree and discharge pressure.

Co-pyrolysis of rubber seed oil and industrial hemp stem: Asym2sig deconvolution, thermal behavior, synergistic reaction and kinetic

Evaluation of Kinetic triplets and thermodynamics of the co-pyrolysis of industrial hemp stem (IHS) and rubber seed oil (RSO) contributes to the efficient utilization of agricultural waste. The thermodynamics and kinetics of four pseudo components from mixture (RSO: IHS=1: 1) are investigated using Asym2sig deconvolution. The results show that the Eα of pseudo hemicellulose, pseudo cellulose, pseudo triglyceride and pseudo lignin are 76.019, 193.587, 231.764 and 408.552 kJ/mol. The average differences in Eα and ΔH for the four pseudo-fractions also are 4.439, 4.929, 5.576 and 6.018 kJ/mol. Lower energy barrier favors the reaction. The frequency factor values for four pseudo-components pyrolysis are 1.07 × 108 s−1 for pseudo hemicellulose, 1.78 × 1019 s−1 for pseudo cellulose, 6.04 × 1018 s−1 for pseudo triglyceride, and 6.96 × 1031 s−1 for pseudo lignin. The four pseudo-components have different pyrolysis reaction mechanisms. The synergistic effect calculations show a significant interaction between RSO and IHS. According to thermodynamic analysis, the pyrolysis of the four pseudo components requires the provision of external energy. FT-IR results indicate that RSO can significantly increase the release of C2H2, C2H4, C2H6 and CH4 during the co-pyrolysis of RSO and IHS. The co-pyrolysis of IHS and RSO can increase the content of alkene, alkane and MAHs, which improve the quality of bio-oil significantly. Besides, it can reduce the content of PAHs, which reduces the viscosity of the bio-oil. The results can provide new insights into the synergistic and efficient disposal of triglycerides and lignocellulosic biomass.

Pyrolysis features of Dracaena draco lignocellulosic fibers: Kinetic and thermodynamic analysis at various heating rates through coats-redfern method

This study evaluated the thermokinetic and thermodynamic properties of Dracaena draco fibers (DDFs) through thermogravimetric analysis (TGA). The DDFs underwent non-isothermal heating in a nitrogen atmosphere, with 5, 10, and 20 °C/min heating rates starting at 20 °C and reaching 800 °C. TGA analysis demonstrated that the pyrolysis of DDFs took place in three clearly defined phases: dehydration, devolatilization, and solid biochar. The thermokinetic and thermodynamic properties were computed for the devolatilization phase of mass reduction. The Coats-Redfern technique employed twenty-one separate kinetic equations derived from four fundamental solid-state reaction processes. Out of all the diffusivity models (DMs), the Ginstlinge-Brounshtein (DM5), Jander (3D diffusion) (DM7), and Ginstling models (DM8) had the best fit, as indicated by their highest coefficient of regression values (R2 > 0.990) across all the three heating rates. The activation energy values found by the DM5, DM7, and DM8 models are 76.5, 82.32, and 76.47 kJ/mol, respectively, for the 5 °C/min heating rate. The thermodynamic variables, including the entropy, free energy, and enthalpy change, were calculated based on the kinetic data. The study’s findings are significant for evaluating the DDFs' potential as an energy source, constructing reactors, producing chemicals, and understanding the DDFs’s features for composite synthesis.