scholarly journals Properties and Developments of Combustion and Gasification of Coal and Char in a CO2-Rich and Recycled Flue Gases Atmosphere by Rapid Heating

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Zhigang Li ◽  
Xiaoming Zhang ◽  
Yuichi Sugai ◽  
Jiren Wang ◽  
Kyuro Sasaki
Keyword(s):  
Coal Gasification ◽  
Radiative Heat ◽  
Arrhenius Equation ◽  
Rapid Heating ◽  
Volatile Matter ◽  
Heating Process ◽  
Mass Ratio ◽  
Coal Oxidation ◽  
Transfer Condition ◽  
Coal Temperature

Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of high temperature gradient of order 200°C·s−1by a CO2gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser heating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize effects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experimental results indicated that coal weight reduction ratio to gases followed the Arrhenius equation with increasing coal temperature; further which were increased around 5% with adding H2O in CO2-rich atmosphere. In addition, coal-water mixtures with different water/coal mass ratio were used in order to investigate roles of water vapor in the process of coal gasification and combustion. Furthermore, char-water mixtures with different water/char mass ratio were also measured in order to discuss the generation ratio of CO/CO2, and specified that the source of Hydrocarbons is volatile matter from coal. Moreover, it was confirmed that generations of CO and Hydrocarbons gases are mainly dependent on coal temperature and O2concentration, and they are stimulated at temperature over 1000°C in the CO2-rich atmosphere.

Polyhedral Gold Nanoplate: High Fraction Synthesis of Two-Dimensional Nanoparticles through Rapid Heating Process

2008 ◽  
Vol 8 (8) ◽  
pp. 2638-2645 ◽  
Author(s):  
Jong-Hee Lee ◽  
Kai Kamada ◽  
Naoya Enomoto ◽  
Junichi Hojo
Keyword(s):  
Rapid Heating ◽  
Heating Process ◽  
Two Dimensional ◽  
High Fraction

scholarly journals Experimental Study on the Fractal Features and Permeability Characteristics of Low Metamorphic Coal Pore Structure under Thermal Damage

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhen Liu ◽  
Mingrui Zhang ◽  
Shijian Yu ◽  
Lin Xin ◽  
Gang Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Pore Structure ◽  
Coal Gasification ◽  
Thermal Damage ◽  
Fractal Model ◽  
Utilization Efficiency ◽  
Heating Process ◽  
Underground Coal Gasification ◽  
External Temperature ◽  
Permeability Characteristics

Underground coal gasification and exploitation of geothermal mine resources can effectively improve coal conversion and utilization efficiency, and the basic theory of the above technologies generally relies on the change law of the coal pore structure under thermal damage. Therefore, the influence mechanism of the development of the coal pore structure under thermal damage is analyzed by the nuclear magnetic resonance experiment, and the temperature-permeability fractal model is created. The results show that compared with microtransitional pores, the volume of meso-macropores in the coal body is more susceptible to an increase in temperature, which was most obvious at 200-300°C. During the heating process, the measured fractal dimension based on the T2 spectral distribution is between 2 and 3, indicating that the fractal characteristics did not disappear upon a change in external temperature. The temperature has a certain negative correlation with DmNMR, DMNMR, and DNMR, indicating that the complexity of the pore structure of the coal body decreased gradually with the increase of the temperature. Compared with the permeability calculated based on the theoretical permeability fractal model, the permeability obtained from the temperature-permeability fractal model has a similar increasing trend as the permeability measured by the NMR experiment when the temperature increases. The experimental study on pore structure and permeability characteristics of the low metamorphic coal under thermal damage provides a scientific theory for underground coal gasification and geothermal exploitation.

scholarly journals Effect of rapid heating process in hot stamping on compact strip production hot rolled plate

2018 ◽  
Vol 15 ◽  
pp. 1055-1061
Author(s):  
Bin Zhu ◽  
Jia Zhu ◽  
Zhoujie Zhu ◽  
Yilin Wang ◽  
Yisheng Zhang
Keyword(s):  
Rapid Heating ◽  
Hot Stamping ◽  
Rolled Plate ◽  
Heating Process ◽  
Compact Strip Production ◽  
Hot Rolled ◽  
Strip Production

Analisis Proximate Briket Tempurung Kelapa dan Ampas Tebu

2019 ◽  
Vol 16 (2) ◽  
pp. 91
Author(s):  
Vivin Setiani ◽  
Adhi Setiawan ◽  
Mey Rohma Dhani ◽  
Risya Dwi Maulidya
Keyword(s):  
Energy Source ◽  
Fossil Fuels ◽  
Quality Standards ◽  
Volatile Matter ◽  
Ash Content ◽  
Coconut Shell ◽  
Mass Ratio ◽  
Biomass Waste ◽  
Quality Value ◽  
Coconut Shells

Fossil fuels are a non-renewable energy source and their existence will be depleted. An alternative is needed that can reduce fossil fuels by using biomass. Biomass waste in the form of bagasse and coconut shell can be used as an alternative fuel in the form of biobriquette. This study aims to analyze the quality value of briquettes from the proximate test of the composition of bagasse and coconut shell produced with briquette quality standards that refer to SNI 01-6235-2000 about wood charcoal briquettes. The variables in this study consisted of five variables. The variables in this study were mass ratio coconut shells to bagasse were 90%: 10%, 80%: 20%, 70%; 30%, 60%: 40% and 50%: 50% respectively. The results of the test of water content, ash content, and volatile matter of the best quality briquettes of five variables were 90% coconut shell and 10% bagasse.

scholarly journals Gasification of Shenhua Bituminous Coal with CO2: Effect of Coal Particle Size on Kinetic Behavior and Ash Fusibility

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3313
Author(s):  
Jinzhi Zhang ◽  
Zhiqi Wang ◽  
Ruidong Zhao ◽  
Jinhu Wu
Keyword(s):  
Particle Size ◽  
Coal Gasification ◽  
Coal Ash ◽  
Heterogeneous Material ◽  
Volatile Matter ◽  
Slow Increase ◽  
Gaseous Mixtures ◽  
Char Gasification ◽  
Effect Of Particle Size ◽  
Ash Fusibility

Coal gasification is the process that produces valuable gaseous mixtures consisting primarily of H2 and CO, which can be used to produce liquid fuel and various kinds of chemicals. The literature shows that the effect of particle size on coal gasification and fusibility of coal ash is not clear. In this study, the gasification kinetics and ash fusibility of three coal samples with different particle size ranges were investigated. Thermogravimetric results of coal under a CO2 atmosphere showed that the whole weight loss process consisted of three stages: the loss of moisture, the release of volatile matter, and char gasification with CO2. Coal is a heterogeneous material containing impurities. Different grinding fineness leads to different liberation degrees for impurities. As for the effect of particle size on TG (thermogravimetry) curves, we found that the final solid residue amount was the largest for the coal sample with the smallest particle size. The Miura-Maki isoconversional model was proved to be appropriate to estimate the activation energy and its value experienced a slow increase when the particle size of raw coal increased. Further, we found that particle size had an important impact on ash fusion temperatures and small particle size resulted in higher ash fusion temperatures.

Refinement of Cementite in High Strength Steel Plates by Rapid Heating and Tempering

2007 ◽  
Vol 539-543 ◽  
pp. 4720-4725 ◽  
Author(s):  
A. Nagao ◽  
K. Hayashi ◽  
K. Oi ◽  
S. Mitao ◽  
N. Shikanai
Keyword(s):  
Rapid Heating ◽  
High Strength ◽  
Average Diameter ◽  
Carbon Steels ◽  
Steel Plates ◽  
Heating Process ◽  
Low Carbon ◽  
Precipitation Behavior ◽  
Heating Rates ◽  
Extraction Replica

The precipitation behavior of cementite in low carbon steels at various heating rates from 0.3 to 100 K/s has been studied using a high-frequency induction heating apparatus. The materials used in this study were steel platesfor welded structures: 610 and 780 MPa class steel plates with a mixed microstructure of bainite and martensite.Cementite was observed using a carbon extraction replica method and the hardness and toughness were also examined. When heated at the conventional slow rate of 0.3 K/s, relatively large cementite particles with an average diameter of 72 nm precipitated at the lath boundaries, whereas when heated at a rapid rate over 3.0 K/s, cementite precipitated both within the laths and at the lath boundaries, and the cementite was refined down to an average diameter of 54 nm. With such refinement of the cementite, the toughness was improved. On the other hand, the hardness was irrespective of the heating rate and was dependent on the tempering parameter. TEM observations of the cementite precipitation behavior during the rapid heating process revealed that cementite begins to precipitate at the lath boundaries at about 773 K and within the laths at about 873 K. It is concluded that rapid heating especially from 773 to 873 K contributes to the cementite refinement and consequently the improvement in toughness. The effect of alloying elements such as chromium, molybdenum or silicon on the cementite growth during the rapid heating and tempering treatment is also discussed.

Transient Thermal Analysis for Rapid Thermal Processing of GaAs

1988 ◽  
Vol 144 ◽  
Author(s):  
F. K. Yang ◽  
S. J. Pien ◽  
R. Kwor
Keyword(s):  
Thermal Analysis ◽  
Silicon Dioxide ◽  
Oxide Layer ◽  
Thermal Processing ◽  
Rapid Heating ◽  
Rapid Thermal Processing ◽  
Doping Effect ◽  
Heating Process ◽  
Light Sources ◽  
Transient Thermal

ABSTRACTA thermal analysis is performed to simulate the rapid heating process for ion implanted GaAs with consideration of the doping effect. The results are for cases with various concentrations and thicknesses of doping layer. Also studied are the heating processes for silicon dioxide capped GaAs. The effects of the thickness of the oxide layer are discussed. The magnitude of the temperature differences across the wafer is addressed. The present analysis considers xenon-arc lamps and tungsten-halogen lamps as the light sources.

A Simple Method for Fabrication of Mesoporous Films Using a Rapid Heating Process

2005 ◽  
Vol 34 (3) ◽  
pp. 328-329 ◽  
Author(s):  
Takeo Yamada ◽  
Haoshen Zhou ◽  
Itaru Honma ◽  
Yuko Ueno ◽  
Tsutomu Horiuchi ◽  
...  
Keyword(s):  
Rapid Heating ◽  
Heating Process ◽  
Mesoporous Films ◽  
Simple Method

scholarly journals Preparing High-Purity Anhydrous ScCl3 Molten Salt Using One-Step Rapid Heating Process

2020 ◽  
Vol 10 (15) ◽  
pp. 5174
Author(s):  
Junhui Xiao ◽  
Chao Chen ◽  
Wei Ding ◽  
Yang Peng ◽  
Kai Zou ◽  
...  
Keyword(s):  
Molten Salt ◽  
High Purity ◽  
Rapid Heating ◽  
Raw Material ◽  
Hydrolysis Rate ◽  
Heating Process ◽  
Crystal Water ◽  
Argon Flow ◽  
One Step ◽  
Scandium Chloride

In this study, a one-step rapid heating novel process was used to prepare high-purity anhydrous scandium chloride molten salt with low-purity scandium oxide. High-purity anhydrous ScCl3 molten salt was used as the Sc-bearing raw material for preparing the Sc-bearing master alloy. Inert gas was used to enhance the purity of anhydrous scandium chloride and reduce the hydrolysis rate of scandium. The results show that high-purity scandium chloride (purity, 99.69%) with the scandium content of 29.61%, was obtained, and the hydrolysis rate of scandium was 1.19% under the conditions used: removing ammonium chloride; residual crystal water temperature of 400 °C; m(Sc2O3):m(NH4Cl) = 1:2.5; holding-time of 90 min; heating-rate of 12 °C/min; and argon flow of 7.5 L/min. XRD, SEM, and EPMA analyses further verified that anhydrous scandium chloride crystallization condition was relatively good and the purity of high-purity anhydrous scandium chloride approached the theory purity of anhydrous scandium chloride.

scholarly journals Effect of Microstructure on Post-Rolling Induction Treatment in a Low C Ti-Mo Microalloyed Steel

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 694 ◽  
Author(s):  
Gorka Larzabal ◽  
Nerea Isasti ◽  
Jose Rodriguez-Ibabe ◽  
Pello Uranga
Keyword(s):  
Hot Rolling ◽  
Microalloyed Steel ◽  
Rapid Heating ◽  
Laboratory Simulation ◽  
Thin Strip ◽  
Induction Treatment ◽  
Heating Process ◽  
Low Carbon ◽  
Optimization Strategy ◽  
Hot Rolled

Cost-effective advanced design concepts are becoming more common in the production of thick plates in order to meet demanding market requirements. Accordingly, precipitation strengthening mechanisms are extensively employed in thin strip products, because they enhance the final properties by using a coiling optimization strategy. Nevertheless, and specifically for thick plate production, the formation of effective precipitation during continuous cooling after hot rolling is more challenging. With the aim of gaining further knowledge about this strengthening mechanism, plate hot rolling conditions were reproduced in low carbon Ti-Mo microalloyed steel through laboratory simulation tests to generate different hot-rolled microstructures. Subsequently, a rapid heating process was applied in order to simulate induction heat treatment conditions. The results indicated that the nature of the matrix microstructure (i.e., ferrite, bainite) affects the achieved precipitation hardening, while the balance between strength and toughness depends on the hot-rolled microstructure.

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