scholarly journals Nonoxidizing heating of chip‑powder dispersions of ferrous metals in hydrocarbon atmosphere

2021 ◽  
pp. 79-89
Author(s):  
O. M. Dyakonov ◽  
V. Yu. Sereda
Keyword(s):  
Thermal Destruction ◽  
Gaseous Products ◽  
Carbon Particles ◽  
Ferrous Metals ◽  
Air Suspension ◽  
Consecutive Reactions ◽  
Hydrocarbon Gas ◽  
Temperature Transformation ◽  
Pyrocarbon Coating ◽  
Phase Proceeds

The process of inorganic and organic components temperature transformation of metal waste into solid and gaseous products in a continuous hot briquetting muffle furnace has been studied. The composition of the hydrocarbon atmosphere formed in the muffle under conditions of limited access to the oxidizer has been determined. It is shown that the thermal destruction of the coolant oil phase proceeds according to a complex mechanism of consecutive reactions, including polycondensation, polymerization, and deep compaction with a constant decrease in the hydrogen content and ends with the formation of a coke‑like carbon residue on the surface of metal particles and an air suspension of finely dispersed carbon particles (smoke). When it is heated to hot briquetting temperatures of 750–850 °C, chemically active dispersions of ferrous metals are protected from oxidation first by a hydrocarbon gas with a density of 9.0–13.5 kg/m3, then by a pyrocarbon coating with a thickness of 0.1–0.3 mm up to the completion of the processes of pressing and cooling the briquette.

scholarly journals Study of Ignition and Combustion of Two-Fraction Coal-Air Suspension

2018 ◽  
Vol 63 (4) ◽  
pp. 370
Author(s):  
S. G. Orlovskaya ◽  
V. V. Kalinchak ◽  
O. N. Zuj ◽  
M. V. Liseanskaia
Keyword(s):  
Fine Particles ◽  
Equal Mass ◽  
Critical Parameters ◽  
Gas Temperature ◽  
Carbon Particles ◽  
Air Suspension ◽  
Temperature Heat ◽  
Mass Fractions ◽  
Different Temperatures ◽  
Ignition And Combustion

A two-fraction dust-air mixture is the simplest example of polydisperse suspensions. We aim to study the characteristics of ignition and combustion of a two-fraction suspension of carbon particles in air at different temperatures. The main characteristics of the dispersed fuel combustion are the ignition delay, burning temperature and time, and critical parameters (temperature, diameters of particles, and mass concentrations) corresponding to the fuel ignition and extinction. The high-temperature heat and mass transfer and chemical kinetics are modeled for a two-fraction particles-gas suspension (diameter of fine particles 60 мm and for that with coarse particles 120 мm) with equal mass fractions. The gas temperature is varied in the interval between 1100 K and 1500 K.

Influence of Carbon Source for Carbon Nanotubes Synthesis from Controllable Flame

2014 ◽  
Vol 1048 ◽  
pp. 410-413
Author(s):  
Yuan Chao Liu ◽  
Jun Tie Che ◽  
Jing Hao Ren
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Monoxide ◽  
Carbon Source ◽  
Iron Catalyst ◽  
Structural Defects ◽  
Catalyst Precursor ◽  
Hydrocarbon Gases ◽  
Carbon Particles ◽  
Hydrocarbon Gas ◽  
Flame Method

The flame method is a kind of new method for preparation of carbon nanotubes. The hydrocarbon gas (acetylene, ethylene, methane) or carbon monoxide is often selected as carbon source gas in this method. Carbon monoxide is a kind of effective carbon source gas in preparation of carbon nanotubes from the high temperature flame compared with hydrocarbon gases. The pentacarbonyl iron is served as catalyst precursor in the experiment. Austenitic stainless steel type316 is selected as sampling substrate in the flame experiment. The carbon nanotubes from the controllable flame have graphite well-crystallized and less structural defects relatively. The nanotube diameter consistency is also relatively good. Carbon monoxide began to decompose at higher temperature than that of hydrocarbon gas and its decomposition rate is suitable for the synthesis of carbon nanotubes in the flame. In addition, the carbon monoxide has the ability to split large iron catalyst particles and prefers to react with iron catalyst. But only a few carbon nanotubes mixed with lots of iron catalyst particles, soot and amorphous carbon particles come into being when low mass flow of carbon monoxide is provided.

scholarly journals Thermo-chemical analysis and modeling of combustion of waste pyrolysis gaseous products

2021 ◽  
Vol 247 ◽  
pp. 01056
Author(s):  
Alexey Demin ◽  
Grigorii Pavlov ◽  
Mansur Khasiyatullov
Keyword(s):  
Thermal Destruction ◽  
Raw Materials ◽  
Solid Carbon ◽  
Mass Ratio ◽  
Temperature Level ◽  
Pyrolysis Products ◽  
Gaseous Products ◽  
Liquid Products ◽  
Joint Pyrolysis ◽  
Pyrolysis Gases

The results of the study of joint pyrolysis of various types of waste (municipal solid waste, plastic waste, etc.) are presented. Preliminarily crushed and dried wastes were fed into the pyrolysis chamber of the model experimental setup. Thermal energy required for heating raw materials and carrying out their thermal destruction was obtained by burning a part of the pyrolysis gases. The rest of these gases were removed from the pyrolysis chamber and cooled. The temperature in the pyrolysis zone was about 650 °C. Plant productivity was up to 500 kg/h. The target product was the liquid phase, which is a mixture of hydrocarbon compounds. When organizing the processes, the yield of solid carbon residue was minimized. The obtained mass ratio of the final gas/liquid products was approximately equal to 1/6. Experimental results of the analysis of the chemical composition of the gas and liquid fractions are presented. The results of modeling the combustion of pyrolysis products at different amounts of supplied air are also shown. The operating parameters at which the optimum temperature level in the pyrolysis zone is maintained are numerically determined and recommended.

A mechanism for two-step thermal decomposition of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105)

2020 ◽  
Vol 22 (24) ◽  
pp. 13729-13736
Author(s):  
Qian Yu ◽  
Chuande Zhao ◽  
Longyu Liao ◽  
Hongzhen Li ◽  
Heliang Sui ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Decomposition Mechanism ◽  
Thermal Decomposition Mechanism ◽  
Gaseous Products ◽  
Consecutive Reactions

The thermal decomposition mechanism of the consecutive reactions of LLM-105 was investigated based on the gaseous products and solid reactants.

scholarly journals Thermo-chemical equilibrium modeling and simulation of biomass gasification

2020 ◽  
Vol 161 ◽  
pp. 01081
Author(s):  
Alexey Demin ◽  
Roza Dyganova ◽  
Nail Fakhreev
Keyword(s):  
Chemical Equilibrium ◽  
Fine Particles ◽  
Biomass Conversion ◽  
Calorific Value ◽  
Biomass Gasification ◽  
Solid Carbon ◽  
Gaseous Products ◽  
Carbon Particles ◽  
Chemical Equilibrium Modeling ◽  
Gasification Products

Here, we present the results of numerical studies of biomass gasification using poultry litter, sewage sludge and wood waste (pine shavings) as examples of starting materials. The aim of the study was to find ways to increase the degree of biomass conversion to combustible gaseous products (CO, H2, CnHm) and to achieve high calorific value of the generated synthesis gas. Modeling biomass gasification was performed for a multicomponent reacting system in a state of thermodynamic and chemical equilibrium. The mathematical model and the calculation program created by the authors were used. The presence of a condensed phase in the form of fine particles of solid carbon and ash in biomass gasification products was taken into account. The optimal levels of gasification temperatures and conditions that help minimizing the concentration of solid carbon particles in gasification products were determined. For optimal biomass gasification, we recommend using the thermal energy obtained from burning part of the generated syngas.

scholarly journals Thermal analysis of building materials for decoration and INFRARED spectroscopy of gaseous products of their thermal destruction

2021 ◽  
pp. 119-123
Author(s):  
Е.В. Чернушевич ◽  
М.Ю. Принцева ◽  
П.В. Ширинкин ◽  
Ю.Н. Безбородов
Keyword(s):  
Thermal Analysis ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Heat Flow ◽  
Building Materials ◽  
Thermal Destruction ◽  
Chemical Compounds ◽  
Gas Cell ◽  
Gaseous Products ◽  
Analysis Instrument

В настоящей статье представлены результаты экспериментального исследования термической деструкции отделочных строительных материалов и идентификации продуктов их термического разложения. Исследование термической деструкции отделочных строительных материалов осуществлялось методом динамического термогравиметрического анализа, а идентификация продуктов термического разложения отделочных строительных материалов – методом инфракрасной спектроскопии. Термический анализ проводился на приборе синхронного термического анализа NETZSCH STA 449 F3 Jupiter, позволяющем фиксировать изменение массы и величин теплового потока от температуры. Нагрев образцов осуществлялся со скоростью 10℃/мин в атмосфере воздуха с расходом 100 мл/мин в интервале температур 25℃-650℃. Образующиеся при термической деструкции газообразные продукты анализировались на ИК-Фурье спектрометре «ФСМ 1201» с газовой кюветой ТГА 100 при длинах волн 600-4500 см-1. По результатам исследования получены ТГ, ДТГ и ДСК-кривые, характеризующие соответственно потерю массы образца, скорость потери массы и изменение величины теплового потока от температуры, а также ИК-спектры продуктов термической деструкции отделочных строительных материалов при различных температурах. Установлено, что отделочные строительные материалы при их термической деструкции образуют различные химические соединения, отдельные из которых представляют опасность для организма человека. This article presents the results of experimental research on thermal destruction of finishing building materials and a hazard assessment of the process. Thermal destruction of finishing materials was investigated by thermal analysis and the risk of the process was assessed by infrared spectroscopy of gaseous products resulting from thermal destruction. The thermal analysis was carried out by dynamic thermogravimetric analysis on the synchronous thermal analysis instrument NETZSCH STA 449 F3 Jupiter, which makes it possible to detect changes in mass and heat flow from temperature. The heating of the samples was carried out at a rate of 10 ℃/min in the atmosphere with a consumption of 100 ml/min. The gaseous products formed during thermal destruction were analyzed by infrared spectroscopy on IR-Fourier spectrometer «FSM 1201» with gas cell TGA 100 at wavelengths of 600-4500 cm-1. The results of the study led to the production of TG, TFG and DSK curves, describing respectively the loss of sample mass, the rate of mass loss and the change of heat flow from temperature as well as infrared spectra of products of thermal destruction of finishing building materials at various temperatures. It has been found that the finishing building materials, when thermally disrupted, form various chemical compounds, some of which are dangerous to the human body.

Non-hydrocarbons of significance in petroleum exploration: volatile fatty acids and non-hydrocarbon gases

1987 ◽  
Vol 51 (362) ◽  
pp. 483-493 ◽  
Author(s):  
G. P. Cooles ◽  
A. S. Mackenzie ◽  
R. J. Parkes
Keyword(s):  
Volatile Fatty Acids ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Gas Generation ◽  
Hydrocarbon Gases ◽  
Natural Systems ◽  
Gaseous Products ◽  
Hydrous Pyrolysis ◽  
Hydrocarbon Gas ◽  
Thermodynamic Effects

AbstractNon-hydrocarbon gas species (CO2, N2, H2) are locally important in exploration for gas, and there is a growing body of evidence that acid water originating in shales materially affects the diagenesis of nearby sandstones. These gases have been studied by analysing the products of closed-vessel hydrous pyrolysis of known petroleum source rocks, and comparing the results with field observations. Alteration of petroleum source rocks at temperatures >250°C yields a significant amount of non-hydrocarbon components. Ethanoate and higher acid anions are liberated in substantial quantities; the yield appears to be related to the oxygen content of the sedimentary organic matter present.The non-hydrocarbon gases CO2, H2and N2are frequently the dominant gaseous products from hydrous pyrolysis: in the natural environment the same rock sequences at a higher maturity preferentially generate hydrocarbon gases—mainly methane. This discrepancy may be attributed to reaction and phase thermodynamic effects between laboratory and natural systems, behaviour that has important implications in the prediction of gas generation and composition in nature by source rock pyrolysis in the laboratory.

scholarly journals Thermal destruction of polymers: analysis of the process physicochemical parameters

2021 ◽  
Vol 4 (10(112)) ◽  
pp. 31-37
Author(s):  
Oleksii Sezonenko ◽  
Oleksii Vasechko ◽  
Viktor Aleksyeyenko
Keyword(s):  
Experimental Study ◽  
Low Temperature ◽  
Synthesis Gas ◽  
Thermal Destruction ◽  
Caloric Content ◽  
Industrial Installation ◽  
Polymer Waste ◽  
Gaseous Products ◽  
Low Temperature Pyrolysis ◽  
Polymeric Waste

This experimental study has confirmed that during thermal decomposition of polymeric waste samples at a temperature of 850 °C, without oxygen access, there is a 90 % drop in the mass of this waste with the release of a large volume of gaseous products. This feature should be taken into consideration in the engineering calculations of reaction chambers, reactors, and connecting gas pipelines. The analytical study was carried out by a method of thermodynamic analysis using the universal estimation system Astra (TERRA). It has been shown that with an increase in reaction temperature there is a change in the composition of the products of thermal destruction of polymeric waste by reducing the mole fraction of СН4 and increasing the proportion of Н2. The calorific value was calculated according to Mendeleev’s empirical formula. The experimental study (a pyrolysis-gas chromatography method) has confirmed the calculation results regarding an increase in the proportion of hydrogen in the gaseous products of destruction with an increase in process temperature. As a result, due to the lower volumetric heat of hydrogen combustion, the total caloric content of the synthesis gas obtained is significantly reduced. For the experiments, a laboratory installation of low-temperature pyrolysis of polymers with external supply of thermal energy was built, and synthesis gas was used as an energy carrier. At the experimental-industrial installation, by a low-temperature pyrolysis method, the synthesis gas of a stable composition with a lower heat of combustion of 24.8 kJ/m3 was obtained. The reliability of the results of the proposed estimation method to the results of instrumental measurements has been shown. Promising areas of further studies have been determined, including the optimization of processes of thermal destruction of chlorine-containing polymer waste; the effective use of hydrogen from the composition of the synthesis gas obtained.

New replica method with plasma polymerized film by glow discharge

1988 ◽  
Vol 46 ◽  
pp. 414-415
Author(s):  
A. Tanaka ◽  
M. Yamaguchi ◽  
T. Hirano
Keyword(s):  
Power Supply ◽  
Plasma Polymerization ◽  
Vacuum Chamber ◽  
Complex Surface ◽  
Replica Method ◽  
Metal Extraction ◽  
High Voltage Power Supply ◽  
Negative Glow ◽  
Hydrocarbon Gas ◽  
Hydrocarbon Molecules

The plasma polymerization replica method and its apparatus have been devised by Tanaka (1-3). We have published several reports on its application: surface replicas of biological and inorganic specimens, replicas of freeze-fractured tissues and metal-extraction replicas with immunocytochemical markers.The apparatus for plasma polymerization consists of a high voltage power supply, a vacuum chamber containing a hydrocarbon gas (naphthalene, methane, ethylene), and electrodes of an anode disk and a cathode of the specimen base. The surface replication by plasma polymerization in negative glow phase on the cathode was carried out by gassing at 0.05-0.1 Torr and glow discharging at 1.5-3 kV D.C. Ionized hydrocarbon molecules diffused into complex surface configurations and deposited as a three-dimensionally polymerized film of 1050 nm in thickness.The resulting film on the complex surface had uniform thickness and showed no granular texture. Since the film was chemically inert, resistant to heat and mecanically strong, it could be treated with almost any organic or inorganic solvents.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

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