•Co-pyrolysis of biomass-PVC was investigated for the first time by TGA/MS/FT-IR.•Different methods were applied to explore the kinetics of pyrolysis and co-pyrolysis.•Evolved species (methyl, water, ...methoxy, hydrogen chloride, carbon dioxide and benzene) were monitored.•Pyrolysis and co-pyrolysis zones at different temperature stages was established.
This study aims to investigate the thermal behaviours of a specific biomass and a polymer sample through co-pyrolytic degradation. Therefore, a non-edible food processing waste (cherry seed: CS) and a typical plastic waste (polyvinyl chloride (PVC)) were selected and their interaction was studied using a combined TGA/MS/FT-IR system. By the help of TGA data, the non-isothermal kinetic analysis was performed using four different kinetic methods Friedman, Flynn-Wall-Ozawa (FWO), Vyazovkin and distributed activation energy (DAEM). The kinetic results showed that the activation energy values were in agreement over the conversion degree values between 0.1 and 0.9. For determination of the synergistic or inhibitive interactions, theoretical and experimental thermogravimetry values were also compared. Moreover, in situ determination of the main pyrolytic and co-pyrolytic degradation compounds such as methyl, water, methoxy, hydrogen chloride, carbon dioxide and benzene with respect to temperature and time was studied for the first time. By this way, primary and secondary reactions related to methylation, dehydration, aromatization, fragmentation, dehydrochlorination were interpreted. Consequently, PVC was found to change pyrolytic degradation behaviour of lignocellulosic biomass by changing reactivity, activation energy and reaction mechanisms.
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•Alternative to common TGA–FTIR/MS techniques for analysing complex mixtures of thermal decomposition products of polymers.•Development of a new technique consisting of thermogravimetry ...(TGA)–solid-phase extraction (SPE)–thermal desorption (TDS)–gas chromatography mass spectrometry (GC–MS).•Ease of handling, unambiguous product identification, good repeatability.•Influence by specific binding of different products.
For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA–FTIR) and mass spectrometry (TGA–MS). These methods offer a simple approach to the decomposition mechanism, especially for small decomposition molecules. Complex spectra of gaseous mixtures are very often hard to identify because of overlapping signals. In this paper a new method is described to adsorb the decomposition products during controlled conditions in TGA on solid-phase extraction (SPE) material: twisters. Subsequently the twisters were analysed with thermal desorption gas chromatography mass spectrometry (TDS–GC–MS), which allows the decomposition products to be separated and identified using an MS library. The thermoplastics polyamide 66 (PA 66) and polybutylene terephthalate (PBT) were used as example polymers. The influence of the sample mass and of the purge gas flow during the decomposition process was investigated in TGA. The advantages and limitations of the method were presented in comparison to the common analysis techniques, TGA–FTIR and TGA–MS.
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•TGA/MS/FT-IR was used toexplore effect of polystyrene on pyrolytic decomposition of biomass.•The model-free iso-conversional methods were used for kinetic analysis.•Interactions ...occurred depending on the characteristics of the biomass.•TGA/MS and TGA/FT-IR coupling were used for gas analysis of co-pyrolysis for the first time.
The purpose of this study was to investigate the effect on polystyrene (PS) during co-pyrolysis with biomass through thermal decomposition. The model-free iso-conversional methods (Kissinger, Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Starink and Vyazovkin) were adopted to calculate activation energy of the pyrolysis and co-pyrolysis process of two biomass samples (walnut shell: WS and peach stones: PST) with PS. It is found that biomass blending to PS decreased activation energy values and resulted in multi-step reaction mechanisms. Furthermore, changes in the evolution profiles of methyl, water, methoxy, carbon dioxide, benzene and styrene was monitored through evolved gas analysis via TGA/FT-IR and TGA/MS. Detection of temperature dependent release of volatiles indicated the differences occur as a result of compositional differences of biomass.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK, ZRSKP
To evaluate the oxidation behavior of AlN ceramics prepared using a pressureless sintering method, aluminum nitride bulk samples were annealed at temperatures ranging from 900°C to 1300°C for 1–5h ...under an air atmosphere. The phase composition, microstructure and weight change of the oxidized samples were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis-mass spectrometry (TGA-MS), respectively. The results showed that certain of the gaseous oxidation products of AlN ceramics were nitrogen oxides (NOx). The oxidation reaction started at approximately 800°C to 900°C. The thermal conductivity and flexural strength of AlN ceramics were enhanced slightly after the heat treatment in the 900–1100°C temperature range. The entire surface of the AlN block was covered with a thin, compact alumina layer after oxidizing at 1100°C for 3h, which may enhance the metal adhesion to the AlN surface in a metallization process. At 1200°C and higher, the AlN ceramics oxide layer became rough, porous, and cracked, leading to a sharp drop in the flexural strength and thermal conductivity of the AlN ceramics.
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•Improved evolved gas analysis (EGA) for pyrolysis data of various biomass feedstocks.•Functional connection between heat of reaction and operating pressure was identified.•H2 ...evolution strongly interferes with C3H3+ fragment arising from ionic reactions.•Acetylene shares the series of re-combination reactions as secondary pyrolysis event.•Syngas low heating value was obtained in the range of 6.97–10.27 MJ m−3.
This paper provides in-depth knowledge about the evolved gas analysis interpretation via newly proposed semi-quantitative approach, arising from thermogravimetric analysis (TGA) – mass spectrometry (MS) coupled measurements, for studying pyrolysis behavior of three kinds of biomass waste materials (spent coffee grounds, beech sawdust and wheat straw). TGA – MS coupling allows accurate correlation between molecular ion peak and fragment peaks to the corresponding mass loss rates from derivative thermogravimetry curves. Within proposed semi-quantitative analysis, MS spectra were interpreted through the comparative analysis of compounds fragments and of the compound itself, where the single atomic mass unit was identified by multiple compounds exhibition. It was shown that by this procedure which involves overlapping multiple curves supervising, the identification of gases in volatiles complex scheme becomes more simplified. By setting up semi-quantitative formulas, easy and reliable calculations of gaseous products yield and syngas energy capacities are possible to achieve. The H2/CO ratio derived from the proposed method for wood waste product (sawdust) is in an excellent agreement with H2/CO ratio for sawdust syngas production, in fuel reactor for biomass gasification and H2 production.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•The study of the oxy-combustion of manure was carried out.•Two different atmospheres were evaluated in this work: Ar/O2 and CO2/O2.•The kinetics of the process were computed by the ...Kissinger-Akahira-Sunose method.•The gaseous products released during the process were evaluated by TGA-MS.
The oxy-fuel combustion of swine manure has been evaluated by thermogravimetric-mass spectrometric analysis. Manure samples showed a two-stage decomposition profile. The first stage is related to devolatilization of the sample and the second stage involved oxidation of the char formed in situ. Replacement of the inert carrier gas by CO2 did not seem to affect the first stage. However, this change in carrier gas delayed the oxidation of the samples during the second stage. This finding is mainly attributed to the slower transfer of thermal energy to the fuels in CO2/O2 atmospheres. The increase in the oxygen partial pressure in the reaction medium had a marked effect on the oxidation stage by shifting the process to lower temperatures (from 514 to 478°C and from 525 to 475°C for Ar/O2 and CO2/O2, respectively). The kinetics of the process were evaluated by the integral iso-conversional method of Kissinger–Akahira–Sunose (KAS). The two aforementioned stages were clearly identified as two regions of apparent activation energy were obtained. A similar profile was found for the gaseous products released in the process in both atmospheres, as evidenced by a distribution with two emission peaks, which is consistent with the two combustion regions. However, the formation of light products such as H2, CO and CH4 was favored on using high proportions of CO2 (∼80vol.%).
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•Pyrolytic decomposition behaviors of three different food processing wastes were studied.•Iso-conversional kinetic methods were applied to TGA data.•Activation energies of pyrolysis ...processes were elaborated with respect to conversion degree.•Complex reaction schemes during pyrolysis were noticed.•Evolved gases were explored by FT-IR and MS spectra.
The objective of this study was to identify the pyrolysis of different bio-waste produced by food processing industry in a comprehensible manner. For this purpose, pyrolysis behaviors of chestnut shells (CNS), cherry stones (CS) and grape seeds (GS) were investigated by thermogravimetric analysis (TGA) combined with a Fourier-transform infrared (FT-IR) spectrometer and a mass spectrometer (MS). In order to make available theoretical groundwork for biomass pyrolysis, activation energies were calculated with the help of four different model-free kinetic methods. The results are attributed to the complex reaction schemes which imply parallel, competitive and complex reactions during pyrolysis. During pyrolysis, the evolution of volatiles was also characterized by FT-IR and MS. The main evolved gases were determined as H2O, CO2 and hydrocarbons such as CH4 and temperature dependent profiles of the species were obtained.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The development and utilization of biomass play a vital role in reducing fossil fuel dependency and mitigating greenhouse gas emissions. High-temperature pyrolysis provides a promising route for ...converting biomass into valuable products without tar formation. Kinetic models are essential for understanding biomass pyrolysis processes, aiding reactor design and optimization. In this study, rice husk (RH) and corn straw (CS) are selected, which exhibit significant differences in ash content but are widely present. Pyrolysis is performed using a thermogravimetric analyzer coupled with a mass spectrometer (TGA-MS). The results show a rapid decrease in solid residue oxygen content at elevated temperatures, which stabilized after reaching 900°C, accounting for about 8–10%. MS quantification indicates increased release of H2O and CO during this stage. Fourier transform infrared spectroscopy (FTIR) analysis on the biochar unveils that this phenomenon is attributed to the stretching vibration of C-O bonds and the conversion of -OH groups. The remaining oxygen primarily exists as carbonyl and carboxyl groups. Subsequently, the CRECK-S-B biomass pyrolysis kinetic model is updated, specifically targeting the transformation mechanism of oxygen-containing solids at high temperatures to improve the prediction of biochar yield and elemental composition. The relative error of oxygen content prediction is less than 10%. The accuracy of the model is validated through experimental data and an extensive literature database, leading to the establishment of a comprehensive database. The updated model demonstrates significantly enhanced prediction accuracy for pyrolysis temperatures above 800°C, expanding its applicability range. Moreover, it achieves an accuracy rate exceeding 80% for char yield and elemental content in the temperature range of 200–1000°C, including torrefaction conditions. It provides a theoretical foundation for the effective utilization of high-temperature biochar, offers a novel insight into biomass thermochemical conversion, and contributes to the sustainable development of biomass energy.
•The distinct thermal behaviors at high temperatures are revealed.•The remaining oxygen exists as carbonyl and carboxyl groups in the solid residue.•The CRECK-S-B biomass pyrolysis kinetic model is updated.•A comprehensive database comprising pyrolysis experiments is established.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Pyrolysis of rice husk (RH) in the presence of three different types of catalysts (nickel, natural zeolite, and coal bottom ash) for syngas production were investigated by TGA-MS. The catalyst to RH ...ratio of 0.1 was pyrolyzed at different heating rates of 10, 20, 30, and 50 Kmin-1 in the temperature range of 323 K–1173 K. Furthermore, X-ray diffraction (XRD), Brunaur-Emmett-Teller (BET), field emission scanning electron microscope (FESEM) and X-ray fluorescence (XRF) were employed to understand the physiochemical properties and activities of the catalysts before and after pyrolysis of RH. Lastly, four different types of kinetic models such as first-order Coats-Redfern equation, Friedman, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) were employed to determine the activation energy (EA). The kinetic analysis revealed that the EA values reduced when catalysts were introduced into RH as compared to absence of catalysts in the pyrolysis process. The lowest EA value was attained in catalytic pyrolysis using natural zeolite (51.35–157.4 kJ/mol), followed by coal bottom ash (53.56–161.4 kJ/mol) and nickel (56.51–162.9 kJ/mol).
•Catalytic pyrolysis of rice husk was studied using TGA-MS equipment.•Thermal degradation behavior of rice husk was investigated.•Different kinetic models were employed to investigate the kinetic parameters.•Effects of different catalysts on product gaseous were studied.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Comparison between commercial catalyst and industrial waste catalyst were studied.•High quality syngas was attained in catalytic pyrolysis of rice husk using coal bottom ash catalyst.•Coal bottom ...ash catalyst has the potential to replace the commercial catalysts in industrial pyrolysis of biomass.
Comparison between industrial waste coal bottom ash catalyst and commercial catalysts (nickel and natural zeolite) in catalytic pyrolysis of rice husk were investigated in this study. Characterization through X-ray fluorescence (XRF), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy disperse X-ray analysis (EDX), and Brunauer–Emmett–Teller analysis (BET) were carried out to understand the physiochemical activity of the catalysts in pyrolysis of rice husk. The catalyst to rice husk ratio of 0.1 was pyrolyzed in the temperature range of 323–1173 K using thermogravimetric analyzer coupled with mass spectrometer (TGA-MS) equipment to investigate the effect of catalysts in thermal degradation behavior of biomass and syngas production. The study revealed that lowest coke formation (3.65 wt%) associated with high syngas (68.3 vol%) were attained in catalytic pyrolysis using coal bottom ash catalyst compared to nickel and natural zeolite catalysts. Moreover, the hydrogen concentration had increased 8.4 vol% in catalytic pyrolysis of rice husk using coal bottom ash catalyst compared to non-catalytic pyrolysis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK, ZRSKP
