Effect of Heating Rate on Chemical Kinetics of Chicken Manure With Different Gas Agents

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Osama M. Selim ◽  
Mohamed S. Hussein ◽  
Ryoichi S. Amano
Keyword(s):  
Carbon Dioxide ◽  
Heating Rate ◽  
Measurement Errors ◽  
Chemical Kinetic ◽  
Chicken Manure ◽  
Slow Heating ◽  
Quasi Equilibrium ◽  
Heating Rates ◽  
Gasification Process ◽  
Kinetics Of

Abstract This paper presents the study on the effect of different heating rates on the pyrolysis and gasification process of the chicken manure. The obtained results are shown by the extent of reaction, the kinetics of the reaction, and differential thermal analysis. In total, 24 cases were carried out; eight heating rates with three different gas agents each. The results show that when using nitrogen or carbon dioxide as gas agents, the reactions were endothermic. Consequently, the energy must be supplied in terms of heating to sustain the reaction. Furthermore, the air gasification was exothermic, which means that the reaction can be sustained without external heating, where the self-ignition was observed between 450 °C–600 °C. The thermal degradation of the three main components of the chicken manure was obtained. The pyrolysis process was divided into two regions at 360 °C and the order of reaction of five for both regions. For the gasification process, it was observed that carbon dioxide had the most complicated mechanism with four stages. Finally, it is recommended to use the lowest heating rate to allow a quasi-equilibrium state through slow heating. Consequently, the delay in response or any transient error can be avoided as they are the main reason for measurement errors. These chemical kinetic parameters can be used in the future for the chicken manure simulation using the order of reaction mechanism for solid-state gasification.

Co-Pyrolysis of Chicken and Cow Manure

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Osama M. Selim ◽  
Ryoichi S. Amano
Keyword(s):  
Measurement Errors ◽  
Exothermic Reaction ◽  
Heat Rate ◽  
Chicken Manure ◽  
Slow Heating ◽  
Quasi Equilibrium ◽  
Cow Manure ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Cellulose Decomposition

Abstract Conventional pyrolysis is a relatively simple way for biochar production; however, a single biomass feedstock approach is not promising for the development of multiple properties of biochar used in various applications. This study provides a detailed comparison in terms of pyrolysis kinetics between the cow manure and chicken manure, in addition to the co-pyrolysis by mixing the two livestock at different ratios. Eight different heating rates were tested, 5–40 °C/min with 5 °C/min step, on both livestock using the nitrogen as a gas agent with a flowrate of 50 ml/min. The initial results show that for the slow heating rates, 5 °C/min, the thermal degradation of the cow manure is different compared to that obtained from chicken manure. For the cow manure, the first peak, associated with hemicellulose decomposition, is higher than the second peak, associated with cellulose decomposition, which is the other way around for chicken manure. At 5 °C /min, the hemicellulose decomposition took place at 250 °C and 300 °C for the chicken manure and cow manure, respectively. The cellulose decomposition was started at 300 °C for chicken manure and 470 °C for cow manure. The lowest heat rate was selected for the co-pyrolysis case study to allow a quasi-equilibrium state to avoid measurement errors and heat transfer limitation in terms of thermal lag. Co-pyrolysis is studied with different blend ratios between the chicken and cow manure, where the 40% cow manure shows a positive result in terms of keeping an exothermic reaction over the co-pyrolysis process.

scholarly journals Melting Kinetics of Nascent Poly(tetrafluoroethylene) Powder

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 791
Author(s):  
Fotis Christakopoulos ◽  
Enrico Troisi ◽  
Theo A. Tervoort
Keyword(s):  
Kinetic Model ◽  
Heating Rate ◽  
Melting Temperature ◽  
Melting Behavior ◽  
Slow Heating ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Exponential Factor ◽  
Melting Kinetics ◽  
Kinetics Of

The melting behavior of nascent poly(tetrafluoroethylene) (PTFE) was investigated by way of differential scanning calorimetry (DSC). It is well known that the melting temperature of nascent PTFE is about 344 ∘ C, but reduces to 327 ∘ C for once molten material. In this study, the melting temperature of nascent PTFE crystals was found to strongly depend on heating rate, decreasing considerably for slow heating rates. In addition, during isothermal experiments in the temperature range of 327 ∘ C < T < 344 ∘ C, delayed melting of PTFE was observed, with complete melting only occurring after up to several hours. The melting kinetics of nascent PTFE were analyzed by means of the isoconversional methodology, and an apparent activation energy of melting, dependent on the conversion, was determined. The compensation effect was utilized in order to derive the pre-exponential factor of the kinetic model. The numerical reconstruction of the kinetic model was compared with literature models and an Avrami-Erofeev model was identified as best fit of the experimental data. The predictions of the kinetic model were in good agreement with the observed time-dependent melting of nascent PTFE during isothermal and constant heating-rate experiments.

scholarly journals Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

2020 ◽  
Vol 39 (2) ◽  
pp. 227
Author(s):  
Adnan Kurt ◽  
Hacer Andan ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Heating Rate ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Heating Rates ◽  
Diffusion Type ◽  
Optimum Heating ◽  
Rate Loss ◽  
Kinetics Of

A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.

Influence of Rate of Heating to Aging Temperature on Precipitation Hardening in a Metastable β Titanium Alloy

2014 ◽  
Vol 1025-1026 ◽  
pp. 445-450 ◽  
Author(s):  
Ashwary Pande ◽  
Salil Sainis ◽  
Santhosh Rajaraman ◽  
Geetha Manivasagam ◽  
M. Nageswara Rao
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Heating Rate ◽  
Aging Temperature ◽  
Alpha Phase ◽  
Slow Heating ◽  
Precipitation Reaction ◽  
Heating Rates ◽  
Rate Of Heating ◽  
Reduction In Area

A comparison between slow heating to aging temperature and direct charging at aging temperature on the microstructure and mechanical properties obtained after the aging was established for the metastable beta (β) titanium alloy Ti-15V-3Cr-3Al-3Sn. The alloy was subjected to two single aging (SA) and two duplex aging (DA) conditions, with two heating rates to aging temperature: (i) low heating rate of 5 oC/min (ii) direct charging into a furnace heated to aging temperature. The microstructure analysis was carried out using Field Emission Scanning Electron Microscopy. Mechanical Testing was carried to evaluate Ultimate Tensile Strength (UTS), 0.2% Yield Strength (YS), % Elongation (%El.), % Reduction in area (%RA) and hardness. In the case of SA samples aged at 500 °C for 8 h and 500 °C for 10 h, heating rate of 5 °C/min to aging temperature resulted in a finer microstructure but did not help in achieving better strength-ductility combination compared to direct charging. Lower rate of heating allows enough dwell time in the temperature range 250-300 oC for pre-precipitation reaction to occur which aids in fine scale precipitation of alpha phase during aging. In the case of DA samples aged at 250 oC for 24 h followed by 500 oC for 8 h and 300 oC for 10 h followed by 500 oC for 10 h, no tangible difference between lower rate of heating and direct charging was observed in mechanical properties or microstructure. This is believed to be due to the pre-aging steps 250 oC/24 h or 300 oC/10h in the two DA treatments, which create finely distributed precursors thereby leaving no scope for the heating rate to play a role.

scholarly journals The Formation of the Oxides of Carbon by the Pyrolysis of Tobacco

1975 ◽  
Vol 8 (1) ◽  
Author(s):  
R. R. Baker
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
High Temperature ◽  
Low Temperature ◽  
Heating Rate ◽  
Temperature Region ◽  
High Temperature Region ◽  
Heating Rates ◽  
Carbon Oxides ◽  
Decomposition Reactions

AbstractFlue-cured Virginia tobacco has been heated in nitrogen and nitrogen/oxygen mixtures under flow conditions, and the rate of formation of carbon monoxide and carbon dioxide has been determined as a function of temperature, heating rate, and proportion of oxygen in the gas. When the tobacco is heated in nitrogen at heating rates comparable to those in a smouldering cigarette, 27 % of the carbon content of the tobacco is converted to carbon oxides. Both carbon oxides show two distinct formation regions: a low-temperature region (about 100°-450°C), and a high-temperature region (about 550°-900°C). These temperature limits are almost identical to those predicted from studies on the combustion coal of a cigarette burning in air. When tobacco, or the carbonaceous residue remaining after the pyrolysis experiments, is heated in nitrogen / oxygen mixtures, the total amount of carbon converted to carbon monoxide and carbon dioxide is independent of heating rate, but the relative proportions of the two oxides are strongly dependent on heating rate. At the lower heating rate, proportionally less carbon monoxide, and more carbon dioxide, is produced. Under oxidation conditions, about 70 % of both carbon oxides formed in the low-temperature region (100°-450°C) are produced by tobacco decomposition reactions, whereas in the high-temperature region about 10-20 % of the carbon monoxide, and 2-9 % of the carbon dioxide, are produced by tobacco decomposition.

Study on the Pyrolysis Kinetics of HCl-Pretreated Soybean Stalk

2014 ◽  
Vol 953-954 ◽  
pp. 261-266
Author(s):  
Dong Yu Chen ◽  
Yan Qing Hu ◽  
Qing Yu Liu
Keyword(s):  
Heating Rate ◽  
Temperature Increase ◽  
Loss Rate ◽  
High Efficiency ◽  
Three Dimensional ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Acid Washing ◽  
Shoulder Peak ◽  
Kinetics Of

To study the influences of the acid-washing on the characteristics of soybean stalk pyrolysis , and search the high-efficiency catalyst for biomass pyrolysis, pyrolysis experiments of soybean stalk pretreated by 0.1mol/L HCl acid solution were performed by nonisothermal thermogravimetric analysis (TGA) at five different heating rates. The results showed the pyrolysis process of HCl-washed soybean stalk can be separated into four stages (water loss, depolymeri-zation and vitrification, thermal decomposition, and carbonization). At the same heating rate, the maximum pyrolysis rate of HCl-washed is larger than untreated soybean stalk, but the corresponding temperature is higher. All the DTG (differential thermogravimetric) curveas appear a smaller shoulder peak respectively. With the heating rate increasing, the main pyrolysis zone of the TG (thermogravimetric) and DTG curves move to the high-temperature direction, and the maximum pyrolysis rate and its corresponding temperature increase too. HCl-wahsed makes the weight loss rate of the final temperature increase 5% approximately. The value area of activation energy of the main pyrolysis area is 140.19~174.59 kJ/mol calculated by the method of Ozawa. The Šatava method inferred the most possible mechanism function of HCl-wahsed soybean stalk is Zhuralev-Lesakin-Tempelman equation, which is three-dimensional diffusion.

scholarly journals Flash Pyrolysis Kinetics of Extracted Lignocellulosic Biomass Components

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefan Pielsticker ◽  
Benjamin Gövert ◽  
Kentaro Umeki ◽  
Reinhold Kneer
Keyword(s):  
Heating Rate ◽  
Molecular Structures ◽  
Small Scale ◽  
Drop Tube ◽  
Pyrolysis Kinetics ◽  
Heating Rates ◽  
Flash Pyrolysis ◽  
Step Model ◽  
The Individual ◽  
Kinetics Of

Biomass is a complex material mainly composed of the three lignocellulosic components: cellulose, hemicellulose and lignin. The different molecular structures of the individual components result in various decomposition mechanisms during the pyrolysis process. To understand the underlying reactions in more detail, the individual components can be extracted from the biomass and can then be investigated separately. In this work, the pyrolysis kinetics of extracted and purified cellulose, hemicellulose and lignin are examined experimentally in a small-scale fluidized bed reactor (FBR) under N2 pyrolysis conditions. The FBR provides high particle heating rates (approx. 104 K/s) at medium temperatures (573–973 K) with unlimited reaction time and thus complements typically used thermogravimetric analyzers (TGA, low heating rate) and drop tube reactors (high temperature and heating rate). Based on the time-dependent gas concentrations of 22 species, the release rates of these species as well as the overall rate of volatiles released are calculated. A single first-order (SFOR) reaction model and a 2-step model combined with Arrhenius kinetics are calibrated for all three components individually. Considering FBR and additional TGA experiments, different reaction regimes with different activation energies could be identified. By using dimensionless pyrolysis numbers, limits due to reaction kinetics and heat transfer could be determined. The evaluation of the overall model performance revealed model predictions within the ±2σ standard deviation band for cellulose and hemicellulose. For lignin, only the 2-step model gave satisfying results. Modifications to the SFOR model (yield restriction to primary pyrolysis peak or the assumption of distributed reactivity) were found to be promising approaches for the description of flash pyrolysis behavior, which will be further investigated in the future.

Investigation of defect levels in Bi12SiO20 single crystals by thermally stimulated current measurements

2021 ◽  
Author(s):  
Mehmet Isik ◽  
Serdar Delice ◽  
Nizami M Gasanly
Keyword(s):  
Heating Rate ◽  
Czochralski Method ◽  
Intrinsic Defect ◽  
Heating Rates ◽  
Thermally Stimulated Current ◽  
Rate Dependent ◽  
Defect Centers ◽  
Curve Fit ◽  
Maximum Temperatures ◽  
Kinetics Of

Abstract Bi12SiO20 (BSO) single crystal belongs to the sillenite semiconducting family known as defective compounds. The present paper investigates the defect centers in BSO grown by Czochralski method by means of thermally stimulated current (TSC) measurements performed in the 10-260 K range. The TSC glow curve obtained at heating rate of β = 0.1 K/s presented several peaks associated with intrinsic defect centers. The activation energies of defect centers were revealed as 0.09, 0.15, 0.18, 0.22, 0.34, 0.70 and 0.82 eV accomplishing the curve fit analyses method. The peak maximum temperatures and orders of kinetics of each deconvoluted peak were also determined as an outcome of fitting process. TSC experiments were expanded by making the measurements at various heating rates between 0.1 and 0.3 K/s to get information about the heating rate dependent peak parameters.

Significance of the heating rate on the physical properties of carbonized maple wood

Holzforschung ◽  
2008 ◽  
Vol 62 (5) ◽  
Author(s):  
Xinfeng Xie ◽  
Barry Goodell ◽  
Yuhui Qian ◽  
Michael Peterson ◽  
Jody Jellison
Keyword(s):  
Electrical Resistivity ◽  
Physical Properties ◽  
Young’S Modulus ◽  
Heating Rate ◽  
Young's Modulus ◽  
Slow Heating ◽  
Graphene Sheets ◽  
Heating Rates ◽  
Cross Sectional ◽  
Carbonized Wood

Abstract Effects of the heating rate on the physical properties of carbonized wood were investigated by comparing the dimensional shrinkage, electrical resistivity, Young's modulus, and the evolution of turbostratic crystallites in maple hardwood samples carbonized at 600°C, 800°C, and 1000°C under heating regimes of 3°C h-1 and 60°C h-1. Important carbonized wood properties that developed at high temperature and high heating rates could also be produced at slow heating rates and lower temperatures. Furthermore, slow heating rates promoted the formation and growth of graphene sheets in turbostratic crystallites, which had a significant influence on the electrical resistivity and Young's modulus of the carbonized wood. The results indicate that the graphene sheets of turbostratic crystallites formed during wood carbonization were arranged parallel to the axial direction of wood cells and at an angle to the circumference of wood cells in the cross-sectional plane. With regard to the production of carbon products, a decrease in the heating rate may be beneficial for char properties and the prevention of crack production during manufacture of large monolithic carbon specimens from wood and wood-based materials.

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