Sample Heating Rate Research Articles

COMSOL-Based Simulation of Microwave Heating of Al2O3/SiC Composites with Parameter Variations

The process of microwave heating involves the coupling of multiple physical phenomena, specifically including the distribution of the electromagnetic field in the resonant cavity. The electromagnetic effect generates heat and encourages the transfer of heat inside the material. In this numerical study, a 3D computer model of microwave heating of Al2O3/SiC composites using a multimode microwave heating chamber was established based on the simulation software COMSOL Multiphysics 5.6, and the symmetry treatment of the model was carried out, which effectively reduced the amount of model calculations and accurately analyzed the microwave heating characteristics of the samples. The analysis of the microwave heating characteristics of the sample was mainly preformed from the perspective of the electric field distribution in the resonant cavity, the sample heating rate and the sample heating uniformity, and then it was determined how the microwave source power and sample mold selection affect the temperature and electric field parameters of the sample. After experimental verification, the error between the simulation results and the temperature parameters obtained from the actual experiments is less than 2%. This study contributes to further understanding the heating behavior of Al2O3/SiC composites in complex multimode microwave heating environments and can be used to control the dynamic parameters during microwave heating in order to improve the heating rate and heating uniformity of samples.

An Experimental Study of Zinc Evaporation from Bottom Zinc Dross at Atmospheric Pressure and in Inert Atmosphere with Integrated CFD Modelling.

In the present study, the recycling process of bottom zinc dross was performed by evaporation and subsequent condensation at 800 °C for 30 min with an observed argon flow rate of 100-400 mL/min to ensure an inert atmosphere, to observe the evaporation rate and final form of the product. Under the set conditions of over 98% zinc purity, products in the form of nanofibres (thickness 500 nm), powder (size of spherical particles 2-5 μm), dendrites, and metallic forms were obtained. The employed mathematical modelling (via Ansys 2023R1 software) predicted the behaviour of the argon flow current in the quartz tube, as well as the temperature gradient in the quartz tube and in the close vicinity of the zinc sample. Via Inventor 2014 software, the rate of zinc sample heating was calculated. All the simulations were compared with the physical measurements and correlation was proven.

Heat transfer deformation test and model of coal during LN2 cyclic freezing and thawing process

Exploring the temperature response and deformation characteristics of coal during the freeze–thaw process is crucial for maintaining coal seam stability under liquid nitrogen (LN2) treatment and enhancing gas extraction efficiency. This study investigates the temperature diffusion and deformation characteristics of coal during LN2 cyclic freeze–thaw processes, using saturated and dry anthracite samples. Real-time monitoring of the freeze–thaw characteristics of the anthracite samples was conducted using temperature and strain detectors to quantitatively analyze the evolution of coal temperature and strain. Additionally, a nuclear magnetic resonance (NMR) testing system was used to monitor the pore evolution characteristics of the coal before and after LN2 treatment. The results indicate: After LN2 cyclic freeze–thaw, the internal pores of the saturated samples were highly developed, and fracture connectivity was enhanced, whereas the pores in the dry samples significantly decreased, leading to a sharp reduction in overall connectivity. The cooling and heating rates of the saturated samples were higher than those of the dry samples, both exhibiting exponential trends. This variation is primarily due to the phase change of pore water and the formation and expansion of the internal fracture network within the coal. The deformation magnitude of both sample types showed an overall exponential decline, with the saturated samples exhibiting higher deformation magnitudes than the dry samples. The presence of fracture water not only accelerates coal deterioration during the freeze–thaw process but also enhances coal cementation, maintaining deformation stability. Furthermore, this paper derives a temperature-strain coupling model for coal subjected to LN2 F-T cycles, aiming to provide a reference for understanding the freeze–thaw damage mechanism of coal and the practical application of LN2 fracturing.

INVESTIGATION OF THE KINETICS OF THE COAL PYROLYSIS PROCESS

The study of the processes occurring in the temperature range of the main decomposition of the organic mass of coal (OMC) makes it possible to understand both the general patterns and the specifics of the decomposition of solid fuels. This temperature interval is used to calculate the kinetic parameters of the process, which carry important information both about the nature of the structural-chemical transformations and about the structure and direction of thermal destruction of OMC. In this article, to study the kinetics of pyrolysis of coal, the method of thermogravimetric analysis was used, in which heating of coal samples was carried out in ceramic crucibles in the temperature range of 25-900 °C at different heating rates (5-25 deg/min) in nitrogen and oxygen media. Coal from the Kenderlyk deposit was chosen as the object of study. Based on the constructed differential DTG curves (dependence of the sample mass change rate on time) at different heating rates, the kinetic parameters of pyrolysis of coal were calculated using the equations of non-isothermal formal kinetics. The effect of the rate and temperature of coal heating on the kinetic parameters of pyrolysis of coal has been studied. The main stages of OMC decomposition are revealed. It has been found that the heating rate of coal samples significantly affects the temperature and process rate corresponding to the main decomposition maxima on the differential DTG curves. The dependence between the kinetic parameters of pyrolysis of coal in the temperature range of the main decomposition of OMC on the rate and temperature of heating, as well as between the kinetic parameters at different stages of the main decomposition of coal, is analyzed.

Thermal stability and decomposition kinetics of polybenzoxazine and oligomeric polyhedral octaphenyl silsesquioxane nanocomposites

AbstractIn this study, the impact of octaphenyl polyhedral oligomeric silsesquioxane (POSS) on the thermal stability of polybenzoxazine resin at 1, 3, and 5 wt% POSS loading through dynamic thermogravimetric analysis (TGA) at heating rates of 10, 20, 30 and 40°C min−1 was investigated. Besides, the decomposition kinetics of polybenzoxazine resin (PBZ) and various nanocomposites were studied using Kissinger, Friedman, Flynn‐Wall‐Ozawa (FWO) and Coats‐Redfern (CR) models and also, the activation energies of samples were calculated. At first, benzoxazine monomer was synthesized and then nanocomposites were prepared via solution mixing method. The qualitative dispersion of nanoparticles in benzoxazine resin was examined through the utilization of scanning electron microscopy and x‐ray diffraction experiments. The results showed that the addition of nanoparticles improved the thermal stability of PBZ resin specially at 1 wt% POSS loading and at higher POSS content the thermal stability of the resin decreased. As determined by TGA, the char yield of resin was enhanced by 2.6% upon the addition of 1 wt% nanoparticles. In addition, in 1 weight percent of nanoparticles, as the heating rate rose from 10 to 40°C min−1, the Integral Program Decomposition Temperature (IPDT) has increased by about 260°C, and this increase is about 183°C compared to the resin, and also elevating the heating rate, Td (5%) and Td (10%) weight loss of samples shifted to higher temperatures. The degradation mechanism of the resin and nanocomposites was evaluated through Kissinger, Friedman, FWO and CR models. The results displayed that the addition of 1 wt% nanoparticles increased the activation energy (Ea) values of the nanocomposites compared to that of neat resin and above this filler content, the Ea values decreased. The findings derived from the FWO model indicated that the inclusion of a 1 wt% filler raised the Ea values of the first and second stages of PBZ resin decomposition from 136–200 and 151–214 kJ mol−1 to 148–210 and 180–228 kJ mol−1, respectively.

The Influence of Selected Process Parameters on the Efficiency of the Process of Gas Nitriding of AISI 1085 Steel.

The main aim of the manuscript was to investigate the impact of modifying the parameters of the gas nitriding process of samples made from AISI 1085 steel on the course and results of the process carried out in a chemical reactor allowing for thermogravimetric measurements. The tested steel was subjected in a chemical reactor to the process of gas nitriding in the temperature range of 490-580 °C, using different sample heating rates (in the range of 1-25 °C/min) and various mixtures of nitriding gases (pure NH3, or NH3 with the addition of H2 or N2). To assess the impact of the tested process parameters on its efficiency, the thickness of the nitrided layers produced, the change in sample mass, the structure of the phases produced, the phase composition and the microhardness were examined. For the research methodology used, it was found that reducing the amount of NH3 and/or using H2 or N2 admixtures adversely affects the thickness of the nitride layers produced. At the same time, the use of a lower maximum process temperature with the same gas mixture resulted in a significant difference in the thickness of the layers. It was also found that the use of pure NH3 or a gas mixture (NH3 + H2) with higher NH3 contents resulted in higher surface microhardnesses of the samples and that for these samples, the hardness increased to a greater depth.

Effect of outdoor ageing on pyrolytic characteristics and kinetics of different organic components in waste photovoltaic panels

Pyrolysis is a potential approach for volume reduction and utilization of organic components in waste photovoltaic panels. During a usage period of 20–25 years, the physical and chemical properties of photovoltaic panels might undergo ageing and deterioration, thereby affecting their thermal decomposition characteristics. The characteristics of samples before and after ageing were studied using Fourier transform infrared spectroscopy, scanning electron microscopy, elemental analyzer, and thermogravimetry-Fourier transform infrared spectroscopy-mass spectrometry. There were certain differences in the weight loss temperature, time, residual mass, and activation energy of the samples in the pyrolysis reaction. After ageing, the production of acetic acid and methane in ethylene vinyl acetate pyrolysis products increased, while the production of CO2 decreased. After ageing, Tedlar-Polyethylene Terephalate-Tedlar mainly produced water, carbon dioxide, and fluorocarbon compounds, and the percentage of harmful fluorocarbon compounds in the human body increased. Cyclosiloxane, CO2, and hydrocarbons containing C-H bond were detected in each weight-loss stage of aged silica gel. As the heating rate changed, the amount of pyrolysis products also changed. Controlling the sample's heating rate would help to lessen the quantity of hazardous pollutants that were produced. The influence of ageing on the weight loss of mixed samples was discussed. This study seeks to give a fundamental understanding of the physicochemical properties, pyrolysis behaviour, and volatiles of samples before and after ageing, thus providing helpful insights for the final disposal or recovery of waste photovoltaic panels through pyrolysis.

The experimental study of the kinetics and modes of polymethyl methacrylate thermal degradation in argon flows

The experimental study of the kinetics and modes of the thermal degradation of polymethyl methacrylate (PMMA) in an argon flow was carried out. During thermogravimetric analysis the sample heating rates were 2, 5, 8, 20 and 35 K/min. Based on the integral isoconversional method the values of the kinetic rate constants of the PMMA thermal degradation were determined. When modeling the decomposition process of PMMA for low conversion degrees, it is advisable to use the reaction rate constant obtained for the conversion degree equal to 20 %, and for modeling the whole process – 50 %. Therefore, for evaluation calculations, it is possible to describe the process of PMMA decomposition with one gross reaction. Also, the investigation of the thermal degradation of PMMA particles under conductive heating conditions (680, 700, 720 K) in an argon and air was carried out. Based on the analysis of the data obtained, a scheme for the decomposition of PMMA, consisting of four stages, was established.

CHAMBER FURNACE FOR SIMULATION OF CARBON MATERIALS HEAT TREATMENT IN ELECTROTHERMAL FLUIDIZED BED

Existing laboratory furnaces for high-temperature heat treatment of materials at around 3000°C, which have graphite heaters, allow samples to be heated at a rate two orders of magnitude lower than in electrothermal fluidized bed furnaces. This makes it impossible to use them in the research into the heat treatment of carbon materials because they do not meet the conditions of shock heating and do not allow to keep accurate residence time. The paper presents the research into the use of low-density composite carbon materials as heaters. Based on the results obtained, a high-temperature chamber furnace was designed, studied, and the temperature field in the heater was simulated. As a result, a high-temperature laboratory furnace was created with a sample heating rate of 20 °C/s - 100 °C/s, which made it possible to use it to simulate the heating process in the electrothermal fluidized bed furnace. Comparison of energy consumption in the furnace with a traditional graphite heater and a low-density carbon composite heater showed that heat loss in the furnace is reduced by 1.7 to 1.8 times.

Laser temperature programmed desorption: A flexible technique to study ion-surface interaction.

Understanding the physical-chemical processes ruling the interaction of particles (atoms, molecules, and ions) with surfaces is fundamental in several research fields, such as heterogeneous catalysis, astrochemistry, and nuclear fusion. In particular, the interaction of hydrogen isotopes with plasma facing materials represents a high-priority research task in the fusion community. Such studies are essential to ensure the successful operation of experimental fusion reactors, such as the tokamak ITER. In this work, we present a surface science apparatus developed to study ion-surface interaction in fusion relevant systems. It combines laser-based techniques with contaminant-free ion/molecular beams, mass spectrometry, and surface science tools such as low-energy electron diffraction and Auger electron spectroscopy. It allows to cover a wide range of sample temperatures, from 130 to 2300K, by changing the heating rate of samples from 0.1 to 135 K/s and maintaining the linearity of the heating ramps, a powerful feature to gain insight on adsorption, absorption, and desorption mechanisms. Experimental calibration and performance are presented in detail. Moreover, to provide a factual overview of the experimental capabilities, we focus on two different applications: the protocol used to clean a W(110) single crystal sample and the development of laser temperature programmed desorption to study helium retention in tungsten.

Effect of Mass and Temperature Rate on the Thermal Properties of High-Density Polyethylene Using Differential Scanning Calorimetry

Mass and heating rates alter the thermal properties, molecular structure, and phase changes of the materials. This study aimed to investigate the influence of sample mass (10-30 mg) and heating rate (4-15 °C/min) on the thermal characteristics of high-density polyethylene (HDPE) using differential scanning calorimetry (DSC). The experiments were conducted in two cycles. In the first cycle, samples of different masses (10-30 mg) were heated to 180 °C followed by cooling at a constant heating rate of 10 °C/min with a mass flow rate of 20 ml/min of purging gas (nitrogen). In the second cycle, a sample mass of 15 mg was used to investigate the thermal characteristics while varying the temperature rates (4, 6, 8, 10, and 15 °C/min). It was concluded that the variation in sample mass significantly affected the thermal properties of HDPE, leading to a slight increase in the melting temperature and latent heat, which shifted towards higher temperatures. In contrast, the temperature rate caused a reduction in the latent heat and crystallization temperatures. The thermograms obtained from the experiments provided insight into the thermal behavior of HDPE under different conditions, and the findings emphasized the importance of carefully considering the effects of mass and temperature rate when measuring the thermal properties of HDPE.

Continuum modeling predictions of nonlinear specific heat in phase transition of energetic materials

We propose a chemo-thermal-mechanical model that considers phase transition phenomena, heat generation due to chemical reactions and mechanical deformations, and finite strain elasto-plastic behavior. We implement this highly nonlinear model in a state-of-the-art finite element solver. We study the chemical, thermal, and mechanical processes in the phase change of heterogeneous reactive materials at the microstructural level. The model is calibrated and applied to the HMX β→δ phase transition within plastic-bonded explosives. We present computational results such as chemical heating extrema, highly nonlinear and non-equilibrium specific heat, and accumulated plastic strain in representative unit cells for several volume fractions and heating histories. We show that particle volume fraction and sample heating rate are highly relevant for the pre-ignition response of plastic-bonded explosives to thermo-mechanical loads. We predict highly nonlinear specific heats for a finite system at the continuum level. Moreover, we utilize an analytic expression that estimates with a high degree of accuracy the critical temperature at which the maximum chemical heat release occurs.

Thermogravimetric kinetic analysis of catalytic and non-catalytic pyrolysis of simulated municipal solid waste

Municipal solid waste (MSW) disposal through landfill and incineration represents a costly and hazardous challenge to global health, and loss of underutilised resource for the circular economy. Thermal pyrolysis of the organic components of MSW offers a scalable route to liquid fuels, but process optimisation requires deep insight into the associated thermochemistry and kinetics. Here we apply thermogravimetric analysis (TGA) and kinetic modelling to the (catalytic) pyrolysis of a model MSW feedstock comprising cellulose, sucrose, sugarcane bagasse and low-density polyethylene (LDPE). Co-pyrolysis of biomass and plastic waste, with or without Al-SBA-15, MM-Al-SBA-15 or HZSM-5 catalysts, occurs in three main stages, namely the melting and concomitant evaporation of volatiles, and subsequent decomposition of carbohydrate, then LDPE and finally lignin components. The rate of non-catalytic MSW pyrolysis increased with sample heating rates (from 20 to 120 °C /min) but had little impact on the temperature or mass loss during each stage. Catalytic pyrolysis is sensitive to the catalyst:feedstock mass ratio; increasing this ratio from 1 to 5 increased mass losses during the removal of volatiles and three subsequent decomposition stages, while lowering the temperature of LDPE decomposition. Kinetic analysis by Friedman’s isoconversional method reveals a monotonic increase in activation energy for each stage of (non-catalytic and catalytic) MSW pyrolysis. However, energy barriers for individual stages decreased with increasing catalyst:feedstock ratio and were sensitive to the catalyst type: Al-SBA-15 offers the largest decrease in barriers for carbohydrate (−86 kJ/mol) and LDPE decomposition (−92 kJ/mol), and similar promotion to HZSM-5 for lignin decomposition (∼100 kJ/mol), at the highest catalyst content. TGA is an effective tool for catalyst selection and process optimisation provided heating rates < 60 °C /min are employed, above which pyrolysis appears heat transfer limited.

Design and properties of polyurethane solid–solid phase-change granular temperature regulation asphalt mixtures

The application of phase change materials (PCMs) in asphalt pavement is one of the effective methods to adjust the pavement temperature. In this study, polyurethane-based solid–solid PCMs (PUSSPCMs) was synthesized by two-step solution polymerization, the asphalt mixtures using PUSSPCMs as fine aggregate were formed. The suitable particle size of PUSSPCMs was determined by the viscoelastic properties of asphalt mortars, the maximum content of PUSSPCMs was determined by the engineering performance of asphalt mixtures, and temperature regulation properties of asphalt mixtures was tested by self-designed experiment. It is demonstrates that the viscoelastic properties of PUSSPCMs-asphalt mortars was related to curing temperature, loading frequency, PUSSPCMs content and particle sizes. The elastic modulus of PUSSPCMs-asphalt mortars plays a leading role at low temperature, as the temperature increases, the viscosity modulus is dominant. The sample 2 # can absorb more light components in the asphalt and have greater interference on the viscoelasticity of the asphalt mortar, PUSSPCMs with 0.6–2.36 mm particle size is recommended. The high-temperature performance and low-temperature performance of 1–20 % asphalt mixtures increased by 26.2 % and 14.2 %, respectively. However, PUSSPCMs-asphalt mixtures show a worse water stability, and the residual stability of 1–30 % sample failed to meet the requirements. The heating rate of PUSSPCMs sample is always lower than that of the control samples during heating process, and the temperature difference between control sample and 1–20 %, 1–10 % samples is 4.6 ℃ and 3.3 ℃. In conclusion, the PUSSPCMs with 0.6–2.36 mm particle size, and volume replacement level with 20 % (1–20 % sample) is recommended to prepare temperature regulation asphalt pavement.

Exploring pyrolysis characteristics of bituminous coal: a combined modelling and experimental investigation with TG-IR

This research investigates the pyrolysis characteristics of Barapukurian bituminous coal from Bangladesh. The aim is to address the escalating energy demand and mitigate reliance on rapidly depleting natural gas reserves. A thermogravimetry analyser (TGA) combined with infrared spectroscopy (IR) was employed to carry out the study. Kinetic parameters are derived from a two-stage kinetic model, followed by the validation against experimental data. The release of functional groups and the evolution of gas species were identified from IR. Results demonstrate the sensitivity of coal devolatilisation to operating conditions such as sample mass, particle size, and heating rate. The weight loss profile and its first-order derivatives reveal the multi-stage nature of the pyrolysis process, with most of the mass loss occurring during the rapid pyrolysis stage. The average activation energy determined from the kinetic model is 145.7 kJ/mol. The IR spectrum obtained from the study can be categorised into five main groups: OH, group stretching, CH group stretching, oxygen-containing stretching, C=C stretching, and absorption of inorganic metals.

Mixed MFI-MORD Zeolite Reactivation Study in Micro Structured Reactor in Methanol to Hydrocarbons Transformation Reaction

Restoring the activity of catalytic systems is an important scientific and technical problem. To date, a large number of catalyst regeneration methods have been developed, including: treatment with ultrasound, acids, alkalis, hydrogen, air, etc. However, to determine the necessary technological parameters, it is necessary to conduct experiments. Catalysts for the transformation of methanol into hydrocarbons are characterized by a significant tendency to lose their activity during operation. The main method for restoring their activity is oxidation in an air stream, however, it is possible to restore a different number of acid sites, both as a result of the retention of a certain amount of residual carbon, and as a result of thermal destruction of acid sites. In this connection, the determination of the optimal modes of zeolite thermal oxidation makes it possible to ensure the maximum residual activity of the regenerated catalyst. The article presents the results of studying the activity recovery of the MFI-MORD zeolite by the method of temperature-programmed oxidation at a sample heating rate of 5℃/min, 10℃/min, 20℃/min. Heating at 5℃/min leads to the recovery of the minimum number of acid sites, as well as the minimum value of the residual activity of the transformation of methanol into hydrocarbons of 0.121 kg(Hc)/(kg(Cat)×h). Increasing the heating rate to 10℃/min leads to the restoration of the maximum number of active centers and the achievement of a maximum residual activity of 0.21 kg(Hc)/(kg(Cat)×h). And an increase in the heating rate to 20℃/min leads to a decrease in the number of acid sites and a decrease in the residual catalytic activity of 0.142 kg(Hc)/(kg(Cat)×h). The decrease in the number of acid sites and residual activity at the highest heating rate of the sample may be due to the thermal destruction of active sites during rapid heating.

Advanced Fitting Method for the Kinetic Analysis of Thermogravimetric Data.

The article considered the solution of the inverse problem of chemical kinetics of the analysis of experimental data of a thermogravimetric experiment at a constant sample heating rate. The fitting method for identifying the parameters of a kinetic triplet using the integral method for a model of a solid-state reaction based on the modified Arrhenius equation is described. The effectiveness of the proposed approach was confirmed by solving test cases for low, medium, and high rates of material conversion. Unlike other methods, setting the parameters of the reaction mechanism is not required, as they are determined by the solution. Solutions for real data of TGA studies with high and low sample heating rates were compared with the results obtained by other authors and experimental data. A description of the full cycle of calculations used to identify kinetic parameters from thermogravimetric experimental data is given, from the derivation of calculated relationships to the implementation of a short (three to five formulas) program code for MS Excel spreadsheets. The presented code is easy to verify and reproduce and can be modified to solve various problems.

Influence of the conditions of internal heat exchange on the process of thermal decomposition of carbonates in iron ore raw materials

This work considers influence of heating rate of iron ore raw materials on chemical and metallurgical processes of thermal dissociation of carbonates, which occur during its high-temperature roasting. The research was conducted for the temperature ranges of the existing roasting and sintering machines, taking into account macro-kinetics of calcination processes. Substantial influence of heating rate of iron ore samples on kinetics of thermal decomposition of carbonates was revealed. The cause of the effect of internal heat exchange conditions in reacting iron ore sample on macro-kinetics of dissociation reaction for carbonates was substantiated scientifically. Influence of nonisothermal properties on precision of thermal analytical investigations, which were conducted using the methods of non-isothermal kinetics with different heating rates of iron ore samples, was studied. The authors suggested the mathematical model, which allows to take into account wide range of variations of the parameters in kinetic equations and volumetric thermal and chemical-metallurgical dissociation processes for carbonates. A series of calculating experiments, aimed on reveal of the relationship between heating rate of iron ore samples and evolution of concentration fields, transformation rates and temperature gradients, was carried out using the suggested model. The obtained results can be used for development of the optimal operating conditions for sintering and roasting machines, which propose optimization of heat treatment processes for iron ore preparation, owing to intensification of heat and mass exchange processes during high-temperature roasting. These conditions are considered as optimal from the point of view of power- and resource efficiency. Forming of the above-mentioned conditions allows to decrease fuel and power expenses for thermal preparation of raw materials at metallurgical production facilities, as well as to lower total economical production charges due to use of thermal decomposition of carbonates. The reported study was funded by RSF according to the&nbsp;research project № 22-11-00335.

Sterilizing Ready-to-Eat Poached Spicy Pork Slices Using a New Device: Combined Radio Frequency Energy and Superheated Water.

In this study, a new device was used to inactivate G. stearothermophilus spores in ready-to-eat (RTE) poached spicy pork slices (PSPS) applying radio frequency (RF) energy (27.12 MHz, 6 kW) and superheated water (SW) simultaneously. The cold spot in the PSPS sample was determined. The effects of electrode gap and SW temperature on heating rate, spore inactivation, physiochemical properties (water loss, texture, and oxidation), sensory properties, and SEM of samples were investigated. The cold spot lies in the geometric center of the soup. The heating rate increased with increasing electrode gap and hit a peak under 190 mm. Radio frequency combined superheated water (RFSW) sterilization greatly decreased the come-up time (CUT) compared with SW sterilization, and a 5 log reduction in G. stearothermophilus spores was achieved. RFSW sterilization under 170 mm electrode gap reduced the water loss, thermal damage of texture, oxidation, and tissues and cells of the sample, and kept a better sensory evaluation. RFSW sterilization has great potential in solid or semisolid food processing engineering.

Slow thermal decomposition of lignocelluloses compared to numerical model: Fine particle emission, gaseous products analysis

This paper is focused on aerosol fine particle release during the thermal decomposition of beech wood samples with identical mass under an oxidizing and inert atmosphere. This thermal degradation of wood is a significant part of the biomass combustion and pyrolytic process. This contribution focuses on nanoparticles emission with specifying sizes and concentrations in the range of 18–545 nm during thermal degradation processes and determining correlations between individual thermal degradation processes of a wood sample with the same weights but with different heating rates. The flue gases' chemical composition was simultaneously analyzed using a quadrupole mass spectrometer during the thermal degradation process. The weight loss of the sample and its derivation were monitored using a thermogravimeter. This combination made it possible to identify the ranges with the highest particle emission concerning the wood sample and the sample's heating rate. The fine particle identification apparatus uses a Scanning Mobility Particle Sizer and a condensation particle counter. This experimentally obtained data were then compared with the numerical model CPD-Bio. In this case, the comparison was focused on the prediction of the temperatures of the individual pyrolysis stages, at which gaseous products and especially tars are formed.