Independent Parallel Reactions Research Articles

APPLICATIO STUDY ON KINETICS OF BIOMASS PYROLYSIS IN THE FIXED BED. 1. SIMULATION AND NUMERICAL ANALYSIS OF LIGNIN THERMAL DECOMPOSITION

A non-stationary model of the biomass thermolysis process was built based on three primary independent parallel reactions of the biomass active part conversion into gas, liquid phase and char, taking into account the secondary reactions of tar decomposition into char and light gas. It is shown that the main role in the production of mixed pyrolysis gas (primary gas and light gas) is played by the light gas generation rate due to the secondary reaction of tar decomposition into light gas. This reaction rate significantly exceeds the primary gas production rate due to the fact that the activation energy of the primary gas formation reaction lignin → gas is higher than the activation energy of the lignin → tar reactions. It was found that the rate of generation of the primary reaction lignin → char significantly outweighs the rate of tar → char production, so the latter reaction can be neglected. It is shown that as the temperature of lignin pellets increases, CO and light hydrocarbon C1.16H4 increase and carbon dioxide CO2 and H2О decrease. The consumption of volatile components in the pyrolyzer depends on the temperature distribution of biomass pellets across the pyrolyzer cross-section, which decreases towards the center of the retort, following the consumption of gaseous components decreases as they approach the axis of the pyrolyzer. The amount of mixed pyrolysis gas released and char depends on the radial coordinate r. At r = 0.047 m and time τ = 380 s, the amount of mixed pyrolysis gas is 90 % and char is 10 %, at r = 0.016 m and τ = 380 s = 83 % and = 17 %. Bibl. 13, Fig. 7.

Thermal conversion potential of tea stems: Experimental investigation, reaction mechanism, and kinetic modeling

Recent studies on tea waste pyrolysis have revealed significant gaps, including a lack of experimental data regarding the types of tea waste and a scarcity of comprehensive studies devoted to kinetic models and well-established reaction pathways tailored to this process. This study systematically investigates tea stem pyrolysis, employing comprehensive physicochemical, thermogravimetric, and kinetic analyses. By Identifying the promising characteristics of tea stem, such as its low ash content, high volatile matter, substantial phenolic compounds, and impressive calorific value, this study underscores its potential and delves deep into the complex stages of tea stem pyrolysis. The decomposition process of pseudo-components related to cellulose, hemicellulose, and lignin is an integral part of the comprehensive description of the thermal degradation of tea stems. This description includes the analysis of the contribution factors of its components and their interactions, which significantly influence the reaction rates. These aspects constitute key focal points of our investigation. Furthermore, a comprehensive comparative analysis, incorporating four semi-global reaction mechanisms, was conducted to identify the most optimal reaction mechanism for the thermal decomposition of tea stems. The present study employed a multivariate optimization technique to intricately characterize the kinetics of the process, with a final objective of determining the most appropriate reaction mechanism. Additionally, during the optimization process, it was found that incorporating nucleation-growth reaction model into the reaction mechanism substantially enhances the accuracy. Based on the analysis of kinetic triplets and a comparison of the reaction mechanisms, the mechanism with two independent parallel reactions containing an intermediate consecutive step demonstrates the best agreement with experimental results, with a fit quality of 4.396% and an R-squared (R2) value of 0.997. The findings of this study contribute to a better understanding of the thermal conversion potential of tea stems and provide a deeper understanding of their pyrolysis behavior and kinetic characteristics.

Pyrolysis of municipal solid waste: A kinetic study through multi-step reaction models

The present study endeavors to establish a comprehensive kinetic analysis of Municipal Solid Waste residue pyrolysis. As the sample exhibits four distinct degradation stages, it has been carried out by adopting a multi-step process behavior. Different approaches have been compared, including five isoconversional methods (Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall, Starink, Friedman and Advanced integral Vyazovkin), Mathematical Deconvolution Analysis, and Independent Parallel Reaction Model. The study focuses on the two active pyrolysis steps, the first one corresponds to the biomass components between 150 and 400 °C, with the decomposition peak between 300 and 350 °C, whereas the second corresponds to the plastic fraction with temperature ranging between 400 and 520 °C. The activation energy values obtained from the different kinetic methods for both steps are estimated at 240 and 250 kJ/mol, respectively. It was observed that the biomass components degradation obeys a third-order kinetic model, while the plastic fraction follows a first-order kinetic model. The analytical pyrolysis of the two main stages allows for the identification and semi-quantification of the compounds produced during municipal solid waste pyrolysis. Through analytical pyrolysis, it has been determined that up to 64 % of hydrocarbons are produced, of which 24 % correspond to aromatic compounds. Meanwhile, 20 % of oxygenated compounds were obtained, with ketones, furans, and acids being the most predominant families.

Pyrolysis and Combustion Characteristics of Two Russian Facemasks: Kinetic Analysis, Gaseous Emissions, and Pyrolysis By-Products

Pyrolysis and combustion experiments were performed on two facemasks (hereafter named Tissue and Surgical) commonly used in the Russian Federation, first in a thermobalance and under four low-temperature ramps (5, 10, 15, and 20 °C/min). The pyrolysis mass rate curves present a unique devolatilization peak. The combustion mass rate curves present a unique devolatilization peak followed by a shoulder or a small further peak on its right-hand side. Both processes mainly occur between 200 and 500 °C. Simulations of these pyrolysis and combustion processes are performed with good agreement using the extended independent parallel reaction (EIPR) model. The gas chromatography technique was used to analyze the by-products of pyrolysis experiments performed under isothermal temperatures of 300, 400, and 500 °C. Combustion experiments were finally performed in a horizontal oven under a temperature ramp approximately equal to 5 °C/min to measure the main gaseous emissions: CO2 emissions are the main emissions of the Tissue mask, while total hydrocarbons are the main emissions of the Surgical mask. Significant differences are observed between the results obtained for the two masks because of the fibers they are built with (natural or synthetic).

Co-processing of Lignite with Corn Residues for Energy or Syngas Production Thermochemical Behavior and Kinetic Modeling

The combustion and carbon dioxide gasification behavior of lignite/corn cobs mixtures through thermal analysis experiments was investigated. A simple and accurate model was developed to provide and compare the kinetics of these processes. The characteristic parameters of combustion and gasification, such as decomposition temperature, reaction rate and reactivity, were correlated to the pore structure of the fuels, the composition of ash and mutual interactions between blend components. Combustion of fuels studied occurred in two distinct stages. The reactivity of corn cobs was much higher. When this material was blended with the lignite it improved its combustion efficiency and the mixture presented an additive behavior. The gasification process of chars took place between 750 °C and 950 °C. Corn cobs char exhibited a higher rate. The percentage of this material in the blend was quite low to influence the reactivity of the lignite. The independent parallel reactions model fitted the experimental results with a good accuracy. Activation energy values of combustion varied between 65 kJ/mol and 261 kJ/mol, while those of gasification were enhanced 136-395 kJ/mol, due to the higher thermal stability of chars. The similar thermochemical behavior of the fuels could be advantageous for their co-processing in existing lignite plants, offering economic and environmental benefits.

A comparison between two kinetic models for the pyrolysis and gasification of woody wastes under a carbon dioxide atmosphere

A pine forest residue, a pine wood industrial waste and their mixture were pyrolyzed and subsequently gasified under a carbon dioxide atmosphere up to 1000 °C in a thermal analysis system. Thermal decomposition parameters, such as reactivity, reaction rate and syngas yield, were determined and the influence of CaO catalyst was examined. Two kinetic models, independent parallel reactions model (IPR) and distributed activation energy model (DAEM), were developed in Matlab® code for the kinetic analysis of the processes. Three first order reactions were found to accurately describe the pyrolysis process by both models, with deviation values between 1.3 % and 2.9 %. Activation energy values varied between 26 kJ/mol and 201 kJ/mol. One pseudo-component was necessary to describe successfully the gasification process by application of both models, with deviation values 2.4–6.5 %. Activation energy values ranged between 192 kJ/mol and 345 kJ.mol. The IPR model was found to be more practical to employ.

Physicochemical properties, pyrolysis kinetics, thermodynamic parameters of activation, and evolved volatiles of mango seed waste as a bioenergy feedstock: A potential exploration

An investigation was conducted to elucidate the bioenergy potential of mango seed waste through pyrolysis kinetics, thermodynamics parameters of activation, and analysis of evolved volatiles. Experiments were performed in a thermogravimetric analyzer (TGA) coupled with a Fourier transform infrared (FTIR) spectrometer. The pyrolysis behavior was assumed to be the sum of four independent parallel reactions corresponding to the devolatilization of extractives, hemicellulose, cellulose, and lignin. The four applied isoconversional methods could determine the average activation energies in the ranges of 113.7 − 120.3, 150.0 − 159.9, 190.0 − 201.1, and 172.6 − 184.8 kJ mol−1 for the decomposition of these components, respectively. The pre-exponential factors obtained by Kissinger's method fell between 3.7 × 1011 and 2.6 × 1015 min−1, with A > 109 min−1, indicating that only simple chemistry reactions occurred. The master plot method assigned F-type reaction models to the devolatilization of pseudo-extractives, pseudo-hemicellulose, and pseudo-lignin. Yet, an A-type model matched well with the devolatilization of pseudo-cellulose. From the verification step of the overall kinetic expression, it was found that the simulated pyrolysis progress profiles match with an excellent agreement with the experimental data with a minimum quality of fit of 92.9%. Thermodynamic parameters of activation were determined within the range of 109.3 − 183.3 kJ mol−1 for ΔH≠, 141.7 − 191.2 kJ mol−1 for ΔG≠, and (−71.3)−3.1 J mol−1K − 1 for ΔS≠. TGA–FTIR analysis indicated that most volatile species, comprising propanoic acid, methanol, acetaldehyde, dimethyl ether, and ethanol, are released below 650 K. The results of this study are important for using mango seed waste as a low-priced material for pyrolysis, with the potential of producing bioenergy and bio-based chemicals. This approach aligns with the valorization principle of utilizing lignocellulosic residues.

A Monte Carlo-Based Strategy to Assess Complex Kinetics: Application of the Null-Reaction Method to DAEM.

The distributed activation energy model (DAEM) is widely used in chemical kinetics to statistically describe the occurrence of numerous independent parallel reactions. In this article, we suggest a rethink in the context of a Monte Carlo integral formulation to compute the conversion rate at any time without approximation. After the basics of the DAEM are introduced, the considered equations (under isothermal and dynamic conditions) are respectively expressed into expected values, which in turn are transcribed into Monte Carlo algorithms. To describe the temperature dependence of reactions under dynamic conditions, a new concept of null reaction, inspired from null-event Monte Carlo algorithms, has been introduced. However, only the first-order case is addressed for the dynamic mode due to strong nonlinearities. This strategy is then applied to both analytical and experimental density distribution functions of the activation energy. We show that the Monte Carlo integral formulation is efficient in solving the DAEM without approximation and that it is well-adapted due to the possibility of using any experimental distribution function and any temperature profile. Furthermore, this work is motivated by the need for coupling chemical kinetics and heat transfer in a single Monte Carlo algorithm.

Thermodegradation characterization of microplastics: Dispersion effect and pyrolysis kinetics by artificial intelligence

The research of pyrolytic thermodegradation of plastic wastes has received much attention. However, detailed combustion behavior and pyrolysis kinetics of microplastics are still absent in the current research. Understanding the characteristics and kinetics of microplastic pyrolysis is vital for designing and optimizing operational conditions. Adding silica to high-density polyethylene (HDPE) microplastics can effectively avoid the agglomeration of microplastics during pyrolysis, thereby better elucidating their thermodegradation. In the experiment, HDPE microplastics are mixed with SiO2 at different weight ratios (10 %, 20 %, 50 %, 70 %, and 100 %) to observe the dispersion effect on the microplastic thermodegradation. The results suggest that less than 20 % of PE in the mixture can retain microplastic pyrolysis characteristics. In combustion analysis, 10 % PE undergoes a faster thermo-oxidation reaction than pure HDPE. This study applies the independent parallel reaction (IPR) model and particle swarm optimization (PSO) algorithm to investigate microplastic pyrolysis kinetics. The pyrolysis activation energy is between 273.89 and 292.90 kJ‧mol−1, with fit quality high than 95 %, and rises with decreasing dispersion degree and increasing heating rate. This indicates that microplastic thermodegradation has low activation energy and is affected by heat transfer rate. The Py-GC/MS analysis indicates that up to 83.6 % of alkene and 52.3 % of products comprise high carbon numbers (17-Pentatriacontene and 1-Octatriacontene), respectively, suggesting the suppression of the secondary reaction of microplastics in the pyrolysis reaction. The calculated kinetic parameters are beneficial for understanding microplastic thermodegradation characteristics and can provide useful information for reactor design in industrial pyrolyzers or gasifiers.

Predicting Pyrolysis of a Wide Variety of Petroleum Coke Using an Independent Parallel Reaction Model and a Backpropagation Neural Network

In this work, the pyrolysis behavior and gaseous products of petroleum coke were investigated by nonisothermal thermogravimetric analysis (TGA) and thermogravimetry-mass spectrometry (TG-MS). Then, the pyrolysis kinetics of six kinds of petroleum coke (Fushun (FS), Fuyu (FY), Wuhan (WH), Zhenhai (ZH), Qilu (QL), and Shijiazhuang (SJZ)) were determined by an independent parallel reaction (IPR) model, and the kinetic parameters (activation energy and preexponential factor) were obtained. In addition, an efficient backpropagation neural network (BPNN) was developed to predict the thermal data of six kinds of petroleum coke. The BPNN-predicted thermal data were used to calculate the kinetic parameters based on the IPR model, and the results were compared with the ones calculated using experimental data. The results showed that the pyrolysis process of six kinds of petroleum coke was divided into three stages, of which stage II (250-900 °C) had the significant mass loss, corresponding to the devolatilization of petroleum coke. MS fragmented ion intensity analysis indicated that the main pyrolysis products were methane CH x (m/z = 13, 14, 15, and 16), aliphatic hydrocarbon C3H5, H2, CO, CO2, and H2O. The thermal data predicted by the IPR, BPNN, and BPNN-IPR (BPNN combined with IPR) models were in good agreement with the experimental data. Most importantly, it was concluded that the BPNN-predicted data can be further applied to calculate the kinetic parameters using the IPR kinetic model.

Proteomics and liquid biopsy characterization of human EMT-related metastasis in colorectal cancer.

Tumor cells undergo epithelial-mesenchymal transition (EMT), however, there is a room of disagreement in role of EMT heterogeneity to colorectal cancer metastasis (mCRC) evolution. To uncover new EMT-related metastasis proteins and pathways, we addressed the EMT status in colorectal cancer liver metastasis patient-derived CTCs to identify proteins that promote their distant metastasis. And then, we performed a comparative proteomic analysis in matched pairs of primary tumor tissues, adjacent mucosa tissues and liver metastatic tissues. By integrative analysis we show that, unstable Epithelial/Mesenchymal (E/M)-type CTCs had the strongest liver metastases formation ability and the proportion of E/M-type CTCs correlated with distant metastases. Using an optimized proteomic workflow including data independent acquisition (DIA) and parallel reaction monitoring (PRM), we identified novel EMT-related protein cluster (GNG2, COL6A1, COL6A2, DCN, COL6A3, LAMB2, TNXB, CAVIN1) and well-described (ERBB2) core protein level changes in EMT-related metastasis progression, and the proteomic data indicate ERBB2, COL6A1 and CAVIN1 are promising EMT-related metastatic biomarker candidates. This study contributes to our understanding of the role that EMT plays in CRC metastasis and identifies heterogeneous EMT phenotypes as a key piece for tumor progression and prognosis. We further propose that therapies targeting this aggressive subset (E/M-type) of CTCs and related protein may be worthy of exploration as potential suppressors of metastatic evolution.

Thermal behavior and kinetic analysis of torrefied coconut fiber pyrolysis

The present work discusses the effect of mild torrefaction on coconut fiber pyrolysis kinetics. Firstly, it was evaluated by statistical experimental design (473–523 K, 15–45 min) in the fixed bed reactor. The results showed a reduction of volatile matter content and atomic ratios of hydrogen-to-carbon (H/C) and oxygen-to-carbon (O/C), and an increase in heating values. Secondly, the thermal decomposition was quantified by thermogravimetric analysis, in which the hemicellulose fraction was partially removed after torrefaction. Thirdly, the activation energy was determined by two isoconversional methods (single-step reaction) obtaining a variation from 184 to 238 kJ/mol. Fourthly, the kinetics of thermal decomposition of the torrefied sample was well-described (average deviation <3%) by three independent parallel reactions scheme assuming first-order reactions with activation energies of 99.5, 203.2 and 45.4 kJ/mol for hemicellulose, cellulose, and lignin, respectively. Finally, these kinetic parameters remained constant at different heating rates, providing more reliable information, which can be used to model the pyrolysis of coconut fiber in future works.

Pyrolysis of micro- and macroalgae in thermobalance coupled with mass spectrometer

Due to the constant increase of energy demand, new ecological sources of energy are being sought. One of the promising directions is the use of algae biomass from special cultivation or biomass floating on the sea. In order to determine the potential of algae for thermal decomposition, the pyrolysis study in thermobalance coupled with mass spectrometer was carried out at heating rates of 5, 10, 20 °C/min, in the temperature range of 30–900 °C Three types of algae: macroalgae Cladophora glomerata and Fucus vesiculosus, and microalgae Chlorella pyrenoidesa were used in this research. During the deconvolution of the derivative of the thermogravimetric curves, three peaks were assigned to the decomposition of carbohydrates, proteins and lipids. The isoconversional kinetic model used indicated that the pyrolysis process occurred in several reactions. The proposed kinetic model consists of three nth order independent parallel reactions of pseudo-components. The calculated activation energy ranged from 39 to 266 kJ/mol for carbohydrates, 177–181 kJ/mol for proteins, and 110–229 kJ/mol for lipids. The obtained results could be used in the design of 3rd generation biorefineries.

One-Week Dynamic Changes in Cardiac Proteomes After Cardiac Radioablation in Experimental Rat Model.

BackgroundRecently, stereotactic ablative radiotherapy (SABR) has been adopted to non-invasively treat catheter ablation-refractory ventricular tachycardia (VT). VT episodes have been dramatically reduced after SABR, within weeks; however the underlying mechanisms of these clinical effects and potential mediators of early anti-arrhythmic effect remain unclear.MethodsIn this study, cardiac tissue was harvested from non-irradiated control (0 Gy), conventional irradiated control (2 Gy), and radioablative test (25 Gy) rat groups after 3 and 7 days of irradiation. The samples were proteomically analyzed to identify the differentially expressed proteins (DEP) between different groups. Validation experiments were performed similar to validation in profiling where Data independent acquisition and parallel reaction monitoring methods were used. Data are available via ProteomeXchange with identifier PXD030878.ResultsFunctional enrichment analysis of 25 Gy sample showed that among the downregulated proteins, “intracellular signal transduction” and “cell to cell adhesion” proteins were significantly affected at day 3 while “Ras protein signal transduction,” “GTPase regulation,” and “actin filament-based process” proteins were majorly affected at day 7. GO analysis demonstrated that most of the upregulated proteins belonged to the classes “cellular stress response,” “endomembranal organization,” or “endoplasmic reticulum stress response” at day 3. At day 7, 42 proteins, mainly associated with response to drug, organic substance, or radiation, were specifically upregulated in 25 Gy. DEP analysis of cardiac conduction showed Ryr2 and Cav1 upregulation and Cacna2d2, Gja3, Scnb2, and Kcnn3 downregulation in the 25 Gy group compared to 0 Gy. In validation experiments, four proteins (Gsta1, Myot, Ephx1, and Capg) were repeatedly detected with 25 Gy-specific patterns at day 7.Conclusions25 Gy single fractional irradiation induces considerable cardiac proteome changes within the first 7 days, distinct from 2 Gy. Several candidate proteins displayed 25 Gy-specific changes and were related to oxidative stress-induced innate response or cardiac remodeling processes. Future studies should explore the specific role of these proteins upon cardiac radioablation.

Thermal Debinding Kinetics of Gelcast Ceramic Parts via a Modified Independent Parallel Reaction Model in Comparison with the Multiple Normally Distributed Activation Energy Model.

This work aims to provide useful insights into the thermal debinding kinetics of gelcast ceramic parts, especially for debinding kinetics prediction involving heat preservation. Debinding experiments were conducted in a differential thermogravimetric analyzer at five heating rates (5, 8, 10, 15, and 20 °C/min) in the temperature range of 35–900 °C under an air atmosphere. The conversion (α) and pyrolysis rate (dα/dT) data were simulated using a modified independent parallel reaction (IPR) model and a multiple normally distributed activation energy model (M-DAEM). Their validity was assessed and compared by checking the agreement between the experimental results and the prediction capability. The results showed that both the modified IPR model and M-DAEM had high predictability for thermal debinding kinetics under linear heating conditions. The fitting quality parameters (Fit) were less than 1.406 and 1.01%, respectively. The activation energies (Ei, i = 1, 2, 3, 4, and 5) calculated by the M-DAEM ranged from 153.312 to 217.171 kJ/mol. The relationships between Ei of pseudo components 1 to 5 calculated by the modified IPR model were a function of the conversion rate. The Ei values were E1(α) = 116.750 + 11.153α – 26.772α2 + 4.362α3 kJ/mol, E2(α) = 139.595 – 66.162α + 75.702α2 – 38.041α3 kJ/mol, E3(α) = 190.854 + 135.755α – 214.801α2 + 116.093α3 kJ/mol, E4(α) = 64.068 + 280.086α – 380.270α2 + 264.724α3 kJ/mol, and E5(α) = 188.257 – 77.086α + 74.129α2 – 48.669α3 kJ/mol, respectively. However, it is noteworthy that the α and dα/dT curves predicted by the modified IPR model with a deviation of less than 8% were better than those predicted by the M-DAEM for the linear thermal debinding process with the holding stage. Accordingly, it is believed that the proposed modified IPR model is suitable for describing the thermal debinding kinetics involving the heat preservation of gelcast green parts.

Tucumã endocarp pyrolysis kinetics: A comparative analysis between independent parallel and consecutive reactions schemes

This study investigates the thermal decomposition kinetics of tucumã endocarp pyrolysis by non-isothermal thermogravimetric analysis in a nitrogen atmosphere applying global (isoconversional methods) and multiple reactions model. The experiments were conducted using a particle diameter of 0.13 mm and three heating rates (2.5, 5.0 and 10 °C/min). Thermal decomposition stages were outlined according to each reaction model. The differential (Friedman), integral (Ozawa-Flynn-Wall/modified Coats Redfern) and advanced (Vyazovkin) methods were used for an initial guess of activation energies (190.83–272.07 kJ/mol, 0.05 < α < 0.85). The kinetic triplets of independent parallel and consecutive reactions schemes were obtained considering three first-order reactions, activation energies of 39.89–168.42 kJ/mol and 39.99–152.65 kJ/mol, and pre-exponential factor logarithms of −0.41–11.84 1/s and −0.41–10.46 1/s, respectively, as well as volatilization fractions of 0.22–0.43 for IPRS and stoichiometric constants of 0.01–1.00 for CRS. Finally, the theoretical conversions and conversion rates were akin to experimental data, providing average deviations <5.0% between 150 and 900 °C.

Devolatilization of Lippia origanoides bagasse. A kinetic study

Biomass is one of the most promising renewable energy sources; however, there is a lack of knowledge about the fuel properties of several biomasses. Lippia origanoides bagasse is a residue from the essential oil extraction process that could be used as fuel for the same process. With the aim of contributing to the knowledge of the fuel properties of that residual biomass, in this work, we carried out a kinetic study of its devolatilization using the Friedman method and the Independent Parallel Reactions Scheme. The results were verified by comparing the calculated and measured conversion curves. Although both methods show good agreement with the experimental results, the parallel reactions scheme provides a more detailed description of the process. The results are similar to those reported for other biomasses used as solid fuels, which indicates that the studied biomass could be a potential fuel for solid combustion systems.

A new strategy for butanol extraction from COVID-19 mask using catalytic pyrolysis process over ZSM-5 zeolite catalyst and its kinetic behavior

This research aims to develop a new thermochemical strategy to extract butane from the billions of wasted COVID-19 masks that are generated every month. The experiments were conducted with 3-ply face masks (3PFM) over ZSM-5 zeolite with different ratios of ZSM-5 to 3PFM (w/w: 6, 12, 25, and 50 wt.%) using thermogravimetry (TGA) at different heating conditions. Also, the effect of ZSM-5 concentration and heating rates was examined using TG-FTIR and GC–MS measurements. Besides, the kinetics behavior of the developed strategy was modelled using linear and nonlinear isoconversional modeling techniques, thus calculating the activation energy (Ea) for each conversion region. Finally, all required parameters to fit TGA and differential scanning calorimetry (DTG) experimental curves were estimated using the distributed activation energy (DAEM) and the independent parallel reactions (IPR) techniques, respectively. The results showed that the decomposed samples are very rich in aromatic and aliphatic (-C-H) compounds. Meanwhile, and based on GC–MS results, butanol compound was the basic component in the generated compounds with abundance of 31% at 25 wt.% of ZSM-5 at lowest heating rate (5 °C/min), whereas the average Ea at 25% of ZSM-5 (sample enriched with butanol) was estimated in the ranges 158–187 kJ mol−1 (linear methods with R2 > 0.96) and 167–169 kJ/mol (nonlinear methods with R2 > 0.98). Finally, DAEM and IPR succeeded to simulate TGA and DTG curves of ZSM-5/3PFM samples with very small deviation. Based on that, the catalytic pyrolysis strategy over ZSM-5 zeolite can be used effectively to dispose of COVID-19 masks and to convert them into butanol compound that can be used as a liquid fuel and lubricant.

Pyrolysis and combustion of Russian mixed sludge and subsequent gaseous emissions: Analysis and kinetic modeling

The Arkhangelsk Region, North-West of the Russian Federation, has an important pulp and paper production whose plants generate industrial sludge which is mixed with municipal sludge. Thermal degradations under nitrogen or synthetic air of this mixed sludge were performed under four low temperature ramps of 5, 10, 15 and 20 °C/min. Kinetic modeling of the pyrolysis and combustion experiments was performed applying the Extended Independent Parallel Reaction model with five constituents. Different error measurements were computed to validate the optimal values of the kinetic parameters. Complementary combustion experiments were performed in a horizontal oven to continuously measure the main gaseous emissions (CO, CO2, THC, NO and NO2). The NO and NO2 emissions were observed at very low amounts. The curves associated with the CO, CO2 and THC emissions were observed to well superimpose with the mass rate curve of the corresponding combustion experiment performed in the thermobalance, but with a small time delay.

Catalytic pyrolysis kinetic behaviour of glass fibre-reinforced epoxy resin composites over ZSM-5 zeolite catalyst

The catalytic pyrolysis process is an environmentally friendly technology used to decompose the organic waste into chemical and volatile compounds with high abundance and quality. In the present research, the catalytic pyrolysis treatment was used to decompose the organic fraction of end-of-life glass fibre-reinforced epoxy resin composites (GFRP) over ZSM-5 zeolite catalyst into energy products, thus liberating a fiberglass fraction. The pyrolysis process was performed using thermogravimetry (TGA) with different ZSM-5 to GFRP ratios (w/w; 0.5, 1, 2, 5 wt%) and the generated volatile compounds at ratio were observed using TG-FTIR and GC–MS system. Also, the effect of catalyst concentration on pyrolysis kinetics of GFRP and its activation energies (Ea) was studied using (KAS, FWO, and Friedman) linear isoconversional, (Vyazovkin and Cai) nonlinear isoconversional, the distributed activation energy (DAEM), and the independent parallel reactions (IPR) models. The characteristics of the TGA curves and FTIR spectra were not significantly changed by addition of the catalyst, where the average weight loss was in the ranges 60–64 wt% and aromatic benzene and CO2 the main functional groups in FTIR results. Meanwhile, GC–MS analysis showed that catalyst and heating rates play an important role in the yield of the recovered phenol compound and the highest yield (66%) was obtained at 5 °C/min and ZSM-5 to GFRP ratio = 2 (with increasing 43% compared with virgin GFRP). Based on that, the pyrolysis process supported by ZSM-5 zeolite can be used to recover phenol from GFRP.