Kissinger Akahira Sunose Research Articles

Pyrolysis kinetics and conversion of pomegranate peels into porous carbon

AbstractPyrolysis is one of the most common, sustainable, and excellent environmental‐friendly method to evaluate the bio‐energy potential of different types of biomass wastes. Pomegranate peel is a well‐known low‐cost industrial waste. Thus, pomegranate peel's physicochemical properties were explored in detail, and a pyrolysis kinetic study and thermal behavior analysis were performed. Thermal degradation of biomass was investigated on different heating rates (5, 10, 15, and 20°C/min) by using TG‐DSC. To calculate the kinetic parameters (Ea, A), three different kinetic models were used, including the Flynn‐Wall‐Ozawa (FWO), Kissinger‐Akahira‐Sunose (KAS), and Starink methods. The average Ea values for FWO, KAS, and Starink methods are 85.2141, 80.37217, and 80.74315 kJ mol−1, respectively. Furthermore, the reaction mechanism and thermodynamic parameters (ΔH, ΔG, and ΔS) were simulated and calculated to further comprehend the pyrolysis process. The residual carbon (char) obtained after the pyrolysis process was further characterized by SEM‐EDX and BET to quantify the morphology, surface area, and porosity. SEM results revealed that the residual carbon has a honey‐comb like porous structure, whereas BET analysis reflects that PP800 possesses the highest specific surface area (SSA) ~ 1288.97 m2 g−1 with an average pore diameter of 8.85 nm. Thus, it has enormous potential to be used as adsorbent and active electrode material in energy storage devices.

Mechanistic investigation of pyrolysis kinetics of water hyacinth for biofuel employing isoconversional method

The current study employs non-isothermal thermogravimetric analysis to analyze the thermal degradation behavior of water hyacinth (WH), with the primary goal of determining the kinetic triplet. The pyrolysis of water hyacinth achieved approximately 80% thermal degradation during three phases of breakdown at temperatures ranging from 30 to 900 °C. The activation energy of feedstock breakdown was calculated using four different model-free approaches i.e., Flynn-Wall- Ozawa (FWO), Starink, Friedman, and Kissinger- Akahira-Sunose (KAS), with mean values ranging from 251.33 to 298.48 kJ/mol inside the conversion band of 0.15–0.75. The Master plot results depicted that for conversion (α) ≤ 0.5, the biomass degradation followed a two-dimensional process of diffusion. For α ≥ 0.5, the response, however, is adequately described by growth processes and nucleation. The values of excitation energy estimated using isoconversional techniques were also utilized to determine various thermodynamic parameters. From the thermodynamic study, the mean value of ΔH was 293.66 kJ/mol, suggesting that the generation of activated complex is simpler since the potential energy barrier is lower. A high ΔS value indicates increased reactivity and less time required to synthesize the activated compound. In conclusion, the characterization and kinetic analyses of biomass reveal their potential as pyrolysis feedstock.

Kinetic analysis and modeling of paper-laminated phenolic printed circuit board (PLP-PCB) pyrolysis using distributed activation energy models (DAEMs)

This work explores the pyrolysis characteristics and kinetic behavior of paper-laminated phenolic printed circuit boards (PLP-PCBs) using thermogravimetric analysis under non-isothermal linear heating programs. The initial estimation of the kinetic parameters during the pyrolysis was obtained from the analysis of the experimental data by three isoconversional kinetic models, i.e. Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) integral methods, as well as the Friedman differential method. For all three methods, the apparent activation energy exhibited a strong dependence on the degree of the reaction conversion. To allow for the complexity of the reactions involved in the PLP-PCB pyrolysis, two distributed activation energy models (DAEMs) with a first-order reaction function were derived by assuming the discrete and multi-Gaussian distributions for the activation energies. A six pseudo-component Gaussian DAEM was able to accurately describe the PLP-PCB pyrolysis. By applying the discrete DAEM algorithm, the pyrolysis of PLP-PCB could be precisely characterized by 37 dominating reactions.

In-depth study of kinetics, thermodynamics, and reaction mechanism of catalytic pyrolysis of disposable face mask using spent adsorbent based catalysts

Millions of face mask has been converted to waste since the onset of COVID-19 virus. Hence, present study explores the feasibility of converting disposable face masks to energy through catalytic pyrolysis process using a low-cost waste (spent aluminum hydroxide/oxide nanoparticle adsorbent) derived catalyst. Thermogravimetric analysis of the non-catalytic and catalytic pyrolysis of disposable face mask was conducted at varied heating rates of 10 °C/min, 20 °C/min, 30 °C/min, 40 °C/min, and 50 °C/min, respectively. Iso-conversional methods, Kissinger Akahira Sunose (KAS) and Ozawa Flynn Wall (OFW) were used for the kinetic study. The reaction mechanism was analyzed using Criado's z-master plot (CZMP) method along with the determination of thermodynamic parameters of the process. Results found that the addition of a catalyst to the process benefits the overall efficacy of the process by reducing the activation energy (Ea) (without catalyst; OFW-Ea: 188.7 kJ/mol, KAS-Ea: 186.2 kJ/mol) as well as lowering the disordered state of the process. Metal doped catalyst (Ni/ γ-Al2O3) (OFW-Ea: 168.4 kJ/mol, KAS-Ea: 167.8 kJ/mol) shows a larger reduction in activation energy in comparison to bare alumina (γ-Al2O3) (OFW-Ea: 183.2 kJ/mol, KAS-Ea: 180.4 kJ/mol). The current study presented disposable face masks as reclaimable in terms of energy and waste-derived catalyst as a potent solution to be explored in place of high-cost commercial catalysts.

Assessing the potential of the invasive grass Cenchrus echinatus for bioenergy production: A study of its physicochemical properties, pyrolysis kinetics and thermodynamics

The current study aims to investigate the physicochemical properties and pyrolysis characteristics (kinetic triplet and thermodynamic parameters) of the invasive grass Cenchrus echinatus to assess its bioenergy potential. A thermogravimetric analyzer was employed to obtain the pyrolysis behavior of the grass under slow non-isothermal conditions. First, a multi-component deconvolution analysis of differential thermogravimetry (DTG) curves using the Fraser–Suzuki function was performed, aiming to quantify the individual devolatilization reactions of hemicellulose (P–HC), cellulose (P–CL), and lignin (P–LG). The survey of the activation energy employing four isoconversional methods (Friedman, Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Starink) indicated the following devolatilization order: P–LG (329.9 − 376.7 kJ mol−1) > P–CL (178.4 − 188.2 kJ mol−1) > P–HC (157.8 − 161.2 kJ mol−1). With values of pre-exponential factors from 1.1 × 1015 to 1.4 × 1031 min−1, as estimated from the kinetic compensation effect, it was deduced that the chemical reactions with simpler nature are predominant. With the method of integral master plot, a geometrical contraction mechanism matched the devolatilization of P–CL, and an nth-order-based reaction model matched the devolatilizations of P–HC and P–LG. Besides, the thermodynamic study suggested that the conversion process is endothermic (ΔH≠ = 153.4 to 245.2 kJ mol−1) and nonspontaneous (ΔG≠ = 146.8 to 174.4 kJ mol−1). With the three kinetic triplets, one overall rate expression for the pyrolysis of invasive grass C. echinatus was established. The simulation results were then compared to experimental kinetic curves, and the agreement was deemed satisfactory. The outcomes from this research recommend the C. echinatus as a promising feedstock for bioenergy production and are decisive for scheming large-scale pyrolysis reactors for this invasive grass.

Mechanical and Thermal Properties of Extrudates Produced from Discarded Coal Fines and Recycled Plastics as Binders

This study focuses on the extrusion of discarded coal fines from the Highveld coalfield together with recycled low-density polyethylene (LDPE) and polypropylene (PP) which are used as binders to produce agglomerates with better handling properties than the coal fines for industrial use. The binder content varied between 5 and 100 wt %. The barrels of the twin screw extruder were kept at a temperature of 220 °C to melt the binders while forcing the mixture through a 10 mm die. The extrudates containing 10% or more binder were strong and homogeneous, while a 5% binder addition proved to be too low to produce homogeneous extrudates. The extrudates containing 10% LDPE and 10% PP showed compressive strengths of 17.5 and 7.9 MPa before breaking, respectively. The rest of the extrudates (>10% plastic addition) did not break but merely flattened as the plastic load increased. The compressive strength of all the extrudates showed no significant difference after being exposed to water. Furthermore, the extrudates absorbed less than 5% water after being submerged for 24 h. Thermogravimetric analysis of the extrudates was conducted under a nitrogen atmosphere up to 900 °C. Three iso-conversional methods, Kissinger–Akahira–Sunose, Starink, and Flynn–Wall–Ozawa, were used to determine the activation energy of the extrudates and raw materials. The lower activation energy and conversion temperatures found for the extrudates indicate a synergy between plastic and coal fines when the extrudates are pyrolyzed. Results from this study suggest that the co-extrusion of recycled plastic with coal fines will produce solid carbonaceous fuels with high hydrophobicity, heating value, and high mechanical strength compared to coal fines.

Fuel oil production from thermal decomposition of the model and waste polystyrene: Comparative kinetics and product distribution

The thermal degradation of model polystyrene (MPS) and waste polystyrene (WPS) was performed in a thermobalance system at four heating rates (β) i.e., 5, 10, 15 and 20 °C/min in an inert atmosphere. The apparent activation energy (Ea) and frequency factor (A) for the MPS and the WPS were calculated using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), and Augis-Bennetis (AB) methods. It has been determined that Ea and A vary according to fraction conversion, heating rates, and applied models. The activation energy determined for MPS was found to be in the range of 91-106, 90-105, and 114-133 kJ/mol, while, for WPS, Ea was determined in the range of 82-160, 79-159 and 102-202 kJ/mol by applying OFW, KAS, and AB models, respectively. From the results obtained, it was concluded that the Ea determined by all of these methods increases with fraction conversion, indicating that the decomposition of polystyrene follows a complex mechanism of the solid-state reaction. Hence, the kinetic parameters, i.e., Ea and A, seem to play a key role in investigating the mechanism of solid-state reactions and will provide an opportunity to develop the mechanism of the industrial decomposition reactions. The results show that the MPS has a lower activation energy compared to WPS. This high Ea of WPS may be due to the additives used in the manufacturing of different polystyrene products. Pyrolysis GC/MS of WPS indicates that the main components of pyrolysis oil are 1-hydroxy-2-propanone, styrene, α-methyl styrene, toluene, and 1,2-dimethyl benzene. The presence of some oxygenated compounds in the fuel oil of WPS may be due to contamination or additives used during polystyrene processing, as the WPS samples were collected from a garbage dump near a local market. WPS can be utilized as fuel if the fuel oil collected from the pyrolysis of WPS is properly upgraded to make it equivalent to commercial fuel oil.

Crystallization kinetics of Hf28Be18Ti17Zr17Cu7.5Ni12.5 high-entropy bulk metallic glass

Crystallization kinetics of Hf28Be18Ti17Zr17Cu7.5Ni12.5 high-entropy bulk metallic glass (HE-BMG) in the non-isothermal and isothermal conditions were investigated by differential scanning calorimetry (DSC). In non-isothermal crystallization condition, DSC traces exhibited three crystallization processes. The apparent activation energies of peak crystallization temperatures were calculated by Kissinger methods and found to be Ep1 > Ep2 > Ep3. The dependence of local activation energy on crystallized volume fraction was summarized by the Kissinger-Akahira-Sunose (KAS) method. The non-isothermal crystallization reaction was described mathematically using the Šesták-Berggren model. In the isothermal crystallization condition, with the increase of annealing temperature, the incubation time and crystallization time become shorter and the crystallization peak becomes higher. All Avrami indices were less than 2.5, indicating that crystallization of glassy alloy is dominated by a diffusion-controlled three-dimensional growth with a decreasing nucleation rate.

Co-combustion of pulverized coal and walnut shells in air and oxy-fuel atmospheres: Thermal behavior, synergistic effect and kinetics

In this work, the combustion characteristics of pulverized coal, walnut shells, and their blends in the oxy-fuel atmosphere (21% O2/79% CO2) and air atmosphere (21% O2/79% N2) were investigated by the thermogravimetric analyzer (TGA). The interaction between the blends was quantified by the overlap ratio (OR) and the difference between theoretical and experimental weight loss (ΔW). The results showed that the combustion characteristics of walnut shells were better than coal attributed to its higher volatile components, whereas co-combustion of walnut shells with coal could improve the reactivity of coal. The replacement of the air atmosphere with the oxy-fuel atmosphere had a negligible effect on the ignition temperature of the selected materials but generated an increase in the burnout temperature to some extent. The activation energy was calculated by using Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods, and the order of reaction and pre-exponential factor of the selected samples was determined by the master plots method. The results of this study confirmed the feasibility of the co-combustion of walnut shells with coal under the oxy-fuel atmosphere and provided certain theoretical guidance to realize the operation of existing boilers in the oxy-fuel atmosphere.

Effect of LNR-g-MMA on the Mechanical Properties and Lifetime Estimation of PLA/PP Blends.

Polylactide (PLA) polymer, polypropylene (PP) polymer, and a PLA/PP (70:30 wt%) blend, with liquid natural rubber-graft-methy methacrylate (LNR-g-MMA) of 0.0, 2.5, 5.0, and 10.0 phr as compatibilizers, were prepared by internal mixing and compression molding. The effect of LNR-g-MMA content on the morphology, mechanical properties, water absorption, thermal degradation, and a lifetime of blends based on PLA and PP was investigated. Scanning electron microscopy (SEM) revealed that the PLA/PP blend underwent phase separation, and the presence of LNR-g-MMA in the PLA/PP blend showed a more homogenized and refined blend morphology. Hence, the addition of LNR-g-MMA was used as a compatibilizer to induce miscibility in the PLA/PP blend. The values of tensile strength, elongation at break, and impact strength of the polymer blends increased, whereas water absorption values decreased with increased LNR-g-MMA content. Thermal degradation kinetics was studied over a temperature range of 50-800 °C with multiple heating rates. The results demonstrated that the thermal stability of blends without LNR-g-MMA was greater than that of blends with LNR-g-MMA and that the thermal stability decreased with increasing LNR-g-MMA content. The activation energy (Ea) was calculated by using the Kissinger-Akahira-Sunose method. The Ea value of PLA was much lower than that of PP, and incorporating PP in the PLA matrix increased the Ea. The addition of LNR-g-MMA to the PLA/PP blend decreased the Ea. The lifetime of PLA/PP blends was reduced with the addition of LNR-g-MMA.

Investigation of optimum H2 production from date palm waste leaves using different modeling tools

Globally, the productive utilization of biomass has paid serious attention to fulfilling the energy requirements laid out by the international standards, as to reduce related carbon footprints. Therefore, this study investigates date palm waste leaves which aims to produce environment friendly H2 gas using gasification technology. The results of 25 experimental runs exhibited that the higher H2 produced at higher temperature which was mainly supported by water-gas-shift and steam-methane reforming reactions. H2 prediction was modeled using response surface methodology (RSM) and artificial neural network (ANN). The RSM model exhibited a strong interaction with the regression coefficient (R2) and p-value of 0.89 and 0.000000, respectively. ANN data was disseminated thru K-fold contrivance with back-propagation algorithm. Hence, the training (80% data) and validation (20% data) datasets were found with R2 and root mean squared error (RSME) of 0.90 and 0.28, and 0.86 and 0.39, respectively. Kinetics of the process estimated the activation energies (Ea) using Ozawa-Flynn-Wall (OFW), Starink (STK), and Kissinger-Akahira-Sunose (KAS) models. Hence, the values of Ea and R2 at conversion degrees (α) 0.1 to 0.8 were ranged between 129.40 and 326.64 kJ/mol and 0.92 to 0.97, respectively. Optimum H2 production of 49.03 vol% (with LHV of 11.10 MJ/Nm3) was produced. This finding is thought to be a better source of energy which can be an appropriate fuel for Fischer Tropsch process for manufacturing of transportation fuels.

Thermal decomposition characteristics and study of the reaction kinetics of tea-waste

This study aimed to investigate waste-tea’s pyrolysis kinetics and thermodynamics to assess its potential for thermochemical processes. In this study, three primary samples of tea-waste are prepared for investigation: raw, torrefied at 200 °C, and torrefied at 600 °C. Under a nitrogen environment, thermogravimetric analyses (TGA) were conducted at seven heating rates (10, 15, 20, 25, 30, 35, and 40 °C/min) to investigate the effect of heating rates on the kinetic parameters at temperatures ranging from 27 to 1000 °C. Using seven heating rates was beneficial to take advantage of multiple heating rates techniques alongside single heating rate techniques. These heating rates were combined, forming four heating rate groups (HRG). The pyrolysis kinetic parameters are determined using two model-fit-methods, direct Arrhenius and Coats-Redfern methods, and two model-free methods, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods. Thermodynamic data comprising ΔH, ΔG, and ΔS are addressed. The X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectrum are used to assess the presence of natural minerals in tea-waste. The results indicated that the tea-waste material has the potential to produce syngas. The torrefaction process at 600 °C shows a 53% increase in the energy content compared to the raw biomass. The Coats-Redfern is shown to be more reliable than the direct Arrhenius method. The activation energy (Ea) witnesses rising with the heating rate (β) from Ea = 55.27 kJ mol−1 at β = 10 °C min−1 to 60.04 kJ mol−1 at β = 40 °C min−1 for raw tea-waste using Coats-Redfern method. For model-free approaches, the minimum activation energy values of the raw tea-waste samples are 82 kJ/mol for FWO and 78 kJ/mol for KAS, whereas the peak values are 420 kJ/mol for KAS and 411 kJ/mol for FWO. A comparison of the effect of heating rate groups for FWO method in raw material case indicated that HRG1 has the maximum activation energy average value. The resulting values of HRG1, HRG2, HRG3, and HRG4 were 269 kJ/mol, 145 kJ/mol, 174 kJ/mol, and 202 kJ/mol, respectively.

Effect of the Curative on the Thermal Decomposition Behavior and Kinetics of Polyester-Based Polyurethanes

In this work, three different types of polyester-based polyurethanes (PUs) were synthesized from a hydroxyl-terminated polyester and three different curatives, namely methylenediphenyl diisocyanate (MDI), isophorone diisocyanate (IPDI), and 2,2,4-trimethyl hexamethylene diisocyanate (TMDI) as curing agents, by a polymerization reaction and these PUs are designated by PU/MDI, PU/IPDI, and PU/TMDI, respectively. The formation of urethane linkages in the PUs was confirmed by our Fourier Transform Infrared (FTIR) study. Chemical stability and thermal stability based on gas evolved and thermal decomposition by heat flow were studied by means of a vacuum stability tester (VST) and thermogravimetric analysis (TGA) techniques, respectively. The VST measurements were carried out at 100 °C for 40 h. The results revealed that the volume of gases evolved by these PUs was less than 2.0 mL/g according to Standardization Agreement (STANAG) 4147, indicating that they are chemically stable. The TGA method results indicated that the thermal stability of the polyester-based PU followed the order PU/TMDI > PU/IPDI ≃ PU/MDI. The thermal decomposition kinetics was studied through the TGA method at various heating rates, 2, 5, 10, and 20 °C/min, under nitrogen atmosphere by using the Kissinger–Akahira–Sunose (KAS) and Starink methods. The activation energy values calculated by the isoconversional KAS method for the thermal degradation of PU/MDI, PU/IPDI, and PU/TMDI were 226.5, 206.8, and 183.6 kJ/mol, respectively, with extents of conversion being 0.55–0.95. The activation energies obtained from the KAS method were similar to those obtained from the Starink method. The results indicated that there was significant variation in the thermal stability and activation energy with varying the above-mentioned three curing agents in the polyester-based PUs.

A non-isothermal thermokinetic degradation study of the mesoporous Ni–Co layered double hydroxide using isoconversional approaches

The present study describes the phenomenological thermokinetic behavior of the mesoporous Ni–Co layered double hydroxide (LDH) and determines three basic parameters called ‘kinetic triplets’. The non-isothermal kinetic heating program was carried out at four different heating rates, viz. 5,10,15, and 20oC.min−1, respectively, in the temperature range of 50−800oC. Various isoconversional or model-free kinetics involving integral and differentials like Kissinger–Akahira–Sunose, Flynn-Wall-Ozawa, Friedman, and non-linear Vyazovkin methods were utilized. Due to the presence of physisorbed gas or moisture phases, the temperature integral from 50−198oC was excluded from the present study. The experimental and simulation results described the consistency in depicting the effective activation energies by either Friedman or non-linear Vyazovkin isoconversional methods. Also, it was observed that the variation in activation energies was found to differ by 9–10%, which confirms the Ni–Co LDH degradation undergoes a kinetically complex process. The evaluation of the preexponential factor and master plot determination of reaction models f(α) showed that the mesoporous Ni–Co LDH degradation pathway strongly depends on kinetic compensation effect and undergoes a reaction process governed by nucleation models. Furthermore, the kinetics of pseudo-components of Ni–Co LDH (mathematical deconvolution analysis) showed that the second (three subtransitions) and third stage (two subtransitions) degradation process are controlled by a number of individual peak components in the thermodynamic temperature range 536–727 K (second) and 727–803 K (third).

Evaluation of oil palm waste mild pyrolysis kinetic parameters

With the goal of contrasting model-fitting and model-free methods for the kinetics of mild pyrolysis for empty fruit bunches (EFB), EFB were thermal decomposed and the profile was analysed using thermalgravimetric analysis (TGA). Coats-Redfern (CR) and Kissinger-Akahira-Sunose (KAS) methods were selected to represent model-fitting and model-free methods respectively. The activation energies (Ea) calculated for CR ranged between 22.45 and 26.31 kJ mol−1 (regression coefficient, R2 of 0.93 to 0.95) while the average Ea for KAS was 3.98 kJ mol−1. Compared with other typical model fuels, the mild pyrolysis of EFB from this work shows higher thermal instability, hence more reactive compared to previous works. Furthermore, the KAS method is more reliable in representing the mild pyrolysis process due to its higher overall regression coefficients showing that the assumptions of the KAS method are more accurate.

Co-pyrolysis of petroleum coke and wood pellet blend: Kinetic and Thermodynamic Evaluation using Thermogravimetric Analysis

The increasing demand for sustainable energy attracted researchers to explore the co-pyrolysis of several wastes. The present study evaluated the kinetic and thermodynamic parameters for the co-pyrolysis of wood pellets and petroleum coke (1:1 by mass) blends using thermogravimetric analysis. The TGA data were analyzed through iso-conversional Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) models, along with the Coats-Redfern method. The results reflect that the order of reaction increases with an increased heating rate. An average value of activation energy calculated was 119.6 kJ mol−1 (OFW) and 126.2 kJ mol−1 (KAS). The values calculated for ΔH, ΔG and ΔS were in line with the past relevant studies on blends. The value ΔG was observed to fall around 182 kJ mol−1. The Coats-Redfern reaction mechanism indicates that D5 (based on diffusion) and F3 (based on chemical reaction) are best apt to the thermal process of degradation. DTA data specifies that degradation involves exothermic and endothermic reactions for the temperature range under study. The study not only provide the basic characteristics of one of the most dominant waste from refinery, but provides a platform for its futuristic potential usage with reliable kinetic and thermodynamic parameters for scale up, optimization, utilization and limitation for efficient system design.

Pyrolysis of low-value waste Trapa natans peels: An exploration of thermal decomposition characteristics, kinetic behaviour, and pyrolytic liquid product

The current work seeks to maximise the bio-oil yield by optimizing the experimental conditions and process parameters for the pyrolysis of water chestnut peels (WCP). The pyrolysis process was carried out in a stainless steel reactor to produce the pyrolysis product. The kinetic analysis was carried out using the model-free techniques such as Ozawa-Flynn-Wall (OFW), Vyazovkin (VZK), and Kissinger-Akahira-Sunose (KAS), while the thermal degradation profile was measured using a thermogravimetric analyzer (TGA) at dynamic heating rates (10, 15, and 20 °C min−1). Additionally, Gas Chromatography (GC) was used to study the non-condensable gases, whereas biochar was characterized according to its physicochemical properties. The results of the kinetic analysis exhibited that utilising the KAS, OFW, and VZK, the average apparent activation energies of WCP were obtained to be 344.37, 337.10, and 325.10 kJ mol−1, respectively. The thermal pyrolysis results revealed that the highest bio-oil yield (42.20 wt%) was achieved at 600 °C temperature, 25 °C min−1 heating rate, and 6 cm bed height. According to GC results, the hydrocarbon levels increased as the temperature increased. Biochar's suitability for usage in various industrial applications was validated by the findings of its characterization.

A Review of Degradation and Life Prediction of Polyethylene

After around 50 years of development, the key substance known as polyethylene has been extremely influential in a variety of industries. This paper investigates how polyethylene materials have been used in the domains of water, packaging, and medicine to advance contemporary society in order to comprehend the physical and chemical alterations that polyethylene undergoes after being subjected to long-term environmental variables (e.g., temperature, light, pressure, microbiological factors, etc.). For the safe operation of polyethylene materials, it has always been of the utmost importance to evaluate polyethylene’s service life effectively. This paper reviews some of the most common literature journals on the influence of environmental factors on the degradation process of polyethylene materials and describes methods for predicting the lifetime of degradable polyethylene materials using accelerated aging tests. The Arrhenius equation, the Ozawa–Flynn–Wall (OFW) method, the Friedman method, the Coats–Redfern method, the Kissinger method and Kissinger–Akahira–Sunose (KAS) method, Augis and Bennett’s method, and Advanced Isoconversional methods are all discussed, as well as the future development of polyethylene.

Study on the pyrolysis characteristics and reaction mechanisms of WLED packaging materials

The waste light-emitting diode (WLED) is a new type waste electrical and electronic equipment (WEEE). The volume of waste WLEDs is huge and effective recycling and treatment have attracted widespread attention. However, it’s difficult to handle the WLED packaging materials in the recycling process because of the complex structure. Few studies have been conducted to analyze the efficient recycling of WLED packaging materials. In this study, the pyrolysis characteristics, pyrolysis kinetics and product composition of light-emitting diode (LED) packaging materials methyl phenyl silicon (MPS) were investigated using TG analysis, kinetic analysis, TG-FTIR analysis and Py-GC/MS analysis. Density functional theory (DFT) calculation was further combined to study the pyrolysis process of MPS. The TG analysis showed that the MPS pyrolysis was divided into two stages: 310–561 °C and 499–980 °C. The apparent activation energies of MPS pyrolysis were calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods to be 144.68–149.76 kJ·mol−1 (Stage I) and 95.99–105.47 kJ·mol−1 (Stage II), respectively. The pyrolysis kinetic reaction model of MPS was determined by the Coats-Redfern (CR) method: D1 for Stage I, C2 for Stage II. According to the TG-FTIR and Py-GC/MS analysis results, 8 major gaseous products in the MPS pyrolysis process were identified, including CO2, benzene, HCl, biphenyl, chlorobenzene, styrene, ethylbenzene and chlorodimethylphenylsilane. Finally, the formation mechanism of different pyrolysis products was determined by DFT calculation. The pyrolysis characteristics and pyrolysis mechanism of WLED packaging materials may be helpful for the optimization of WLEDs pyrolysis recycling process and the regulation of pyrolysis products.

Thermal degradation behaviour and chemical kinetic characteristics of biomass pyrolysis using TG/DTG/DTA techniques

The goal of the current study is to investigate the thermal degradation of palm fronds (PF), olive leaves (OL), and wheat straw (WS) through pyrolysis and calculate their kinetic data using TG-DTG and DTA approaches. The kinetic parameters were assessed using isoconversional techniques like the Ozawa-Flynn-Wall (OFW) and Kissinger–Akahira–Sunose (KAS) methods, as well as model-fitting techniques like the integral method, which employs various diffusion and reaction order models. Using kinetics data models, typical parameters for pyrolysis and thermodynamics were estimated. For PF, OL, and WS, the values of activation energy (E) from the integral method ranged between 8.82 and 167.13, 23.06 and 149.20, and 11.01 and 156.27, respectively, for diffusion models. On the other hand, the values of (E) ranged between 22.3 and 117.49, 51.69 and 92.88, and 23.48 and 125.97, respectively, for reaction-order models. The average activation energies (E) calculated by using PF, OL, and WS samples are 91.9, 69.1, and 65.2, respectively, for the OFW method and 87.5, 101.8, and 63.4, respectively, for the KAS method. The results demonstrated that the integral method provided values of (E) that were almost identical to those produced by the KAS and OFW methods. In the same range of (α), results showed that reaction order models yielded greater frequency factor values than diffusion models, demonstrating how simpler and quicker pyrolysis is. The values of (ΔGav\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\Delta \\mathrm{G}}_{av}$$\\end{document}) demonstrated the acceptability of these materials for pyrolysis, and for the OFW and KAS techniques, the sequence of the degradation process was OL > WS > PF. The calculated (ΔGav\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\Delta \\mathrm{G}}_{av}$$\\end{document}) showed that more heat energies are required for OL, PF, and WS to dissociate the reagent bonds, which agrees with the (E) values derived from the OFW model.Graphical