Oxygen-Enriched Combustion Characteristics of Solid Fuel - The Lignite

2016 ◽  
Vol 693 ◽  
pp. 594-596
Author(s):  
X.Y. Chen ◽  
Yong Feng Zhang ◽  
Q.C. Zhang ◽  
Q. Zhou

Oxygen-enriched Combustion behavior of indigenous lignite was investigated by using thermo gravimetric analyzer (TG). Combustion tests were carried out in six different atmospheres. The experiment results showed the oxygen–enriched atmosphere can improve the combustion rate of the lignite and expand the application scope of the lignite. Determine the Combustibility index to reveal the oxygen-enriched combustion process in detail.

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 682
Author(s):  
Lei Shao ◽  
Guoliang Xie ◽  
Hongying Li ◽  
Wanran Lu ◽  
Xiao Liu ◽  
...  

The combustion behavior and mechanism of Ti14 titanium alloy are studied by promoted ignition combustion tests at different oxygen pressures in this paper. The burning velocity increases at higher oxygen pressures and also increases with longer burning times instead of a constant at the same pressure. The Cu atoms are found enriched in two zones—i.e., the heat affected zone and melting zone during the combustion process—which can prevent the diffusion process of oxygen atoms. The different combustion behavior of Ti14 and Ti-Cr-V alloys is basically controlled by the characteristics of phase structures and chemical reactions.


Author(s):  
Pengqian Wang ◽  
Chang'an Wang ◽  
Zichen Tao ◽  
Maobo Yuan ◽  
Yongbo Du ◽  
...  

In this work, the combustion characteristics of semi-coke, coal, and their blends under air conditions were studied. The influence of blending ratio on the combustion characteristics of blended fuels were investigated by thermogravimetric analysis. It was found that the co-combustion of semi-coke and bituminous coal was a complicated process rather than a simple linear superposition, with interaction effect occurring in the co-combustion process. The synergy occurred in the whole combustion process and it was analyzed quantitatively by comparing the interaction coefficient f and the relative root mean square error RMS. The combustion of semi-coke and the blends can be divided to three stages, as well as two stages of coal. In addition, the blends show better combustion behavior with enhancing bituminous coal proportion, and bituminous coal can improve the combustion behavior of semi-coke.


2022 ◽  
pp. 1-22
Author(s):  
Pritam Kumar ◽  
Barun Kumar Nandi

Abstract This present work reports the combustion studies of coal, petroleum coke (PC) and biomass blends to assess the effects of the mustard husk (MH), wheat straw (WS) and flaxseed residue (FR) blending towards improvement of coal combustion characteristics. Ignition temperature (TS), maximum temperature (TP), burnout temperature (TC), activation energy (AE) and thermodynamic parameters (ΔH, ΔG and ΔS) were analyzed to evaluate the impact of biomass and PC blending on coal combustion. Experimental results indicate that coal and PC have inferior combustion characteristics compared to MH, WS and FR. With the increase in WS content in blends from 10 to 30%, TS reduced from 371 to 258OC, TP decreased from 487 to 481OC, inferring substantial enhancements in combustion properties. Kinetic analysis inferred that blended fuel combustion could be explained mostly using reaction models, followed by diffusion-controlled and contracting sphere models. Overall, with the increase in FR mass in blends from 10 to 30%, AE decreased from 108.97 kJ/mol to 70.15 kJ/mol signifying ease of combustion. Analysis of synergistic effects infers that higher biomass addition improves coal and PC blends' combustion behavior through catalytic effects of alkali mineral matters present in biomass. Calculation of thermodynamic parameters signified that combustion of coal and PC is challenging than biomasses, however, blending of biomass makes the combustion process easier.


2020 ◽  
Vol 11 (3) ◽  
pp. 521-529
Author(s):  
Lilis Yuliati ◽  
◽  
David Simanungkalit

This research was conducted to investigate the effect of inlet airflow direction on the combustion characteristics of a wood pellet stove. The direction of the airflow into the wood pellet stove is varied for four methods, namely inlet I, inlet II, inlet III, and inlet IV. At inlets, I, II, and III air is injected into the plenum in the radial direction with the injection points at r = -8, 0, and 8 cm respectively, whereas at inlet IV the direction of airflow into the plenum is in the axial direction with the injection point at r = 0. The combustion characteristics were observed in the wood pellet stove with a continuous fuel feeding system. The combustion characteristics investigated in this research consist of flame visualization, flame temperature, combustion rate, and the efficiency of the wood pellet stove. The results showed that wood pellet stoves with inlet IV had a lower combustion rate and flame height, however, this stove indicates a higher flame temperature and stove efficiency. Air entrance through the inlet IV induces most of the airflow to enter the combustion chamber through the primary channel, compared to that through the secondary and tertiary channels. The primary airflow through the wood pellet encourages a better devolatilization and combustion process. These conditions conduce the flame dimension which is a zone where the combustion reaction occurs is smaller with a higher flame temperature, due to higher volumetric heat release rate. This matter results in better heat transfer from the flame to the test fluid and higher stove efficiency.


Author(s):  
V. A. Poryazov ◽  
◽  
O. G. Glotov ◽  
V. A. Arkhipov ◽  
G. S. Surodin ◽  
...  

The goal of this research is to obtain experimental information about combustion characteristics of the composite propellant containing various metallic fuels. The propellant formulations contained two fractions of ammonium perchlorate (64.6%), inert binder (19.7%) - butadiene rubber SKD plastized with transformer oil, and metal fuel (15.7% of aluminum ASD-4, ASD-6, Alex; boron; aluminum diboride; aluminum dodecaboride; some mixtures of above listed ingredients). Experimental information will be used further as a background to develop the physical and mathematical model of combustion process.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2784
Author(s):  
Jerzy Cisek ◽  
Szymon Lesniak ◽  
Winicjusz Stanik ◽  
Włodzimierz Przybylski

The article presents the results of research on the influence of two fuel additives that selectively affect the combustion process in a diesel engine cylinder. The addition of NitrON® reduces the concentration of nitrogen oxides (NOx), due to a reduction in the kinetic combustion rate, at the cost of a slight increase in the concentration of particulate matter (PM) in the engine exhaust gas. The Reduxco® additive reduces PM emissions by increasing the diffusion combustion rate, while slightly increasing the NOx concentration in the engine exhaust gas. Research conducted by the authors confirmed that the simultaneous use of both of these additives in the fuel not only reduced both NOx and PM emissions in the exhaust gas but additionally the reduction of NOx and PM emissions was greater than the sum of the effects of these additives—the synergy effect. Findings indicated that the waveforms of the heat release rate (dQ/dα) responsible for the emission of NOx and PM in the exhaust gas differed for the four tested fuels in relation to the maximum value (selectively and independently in the kinetic and diffusion stage), and they were also phase shifted. Due to this, the heat release process Q(α) was characterized by a lower amount of heat released in the kinetic phase compared to fuel with NitrON® only and a greater amount of heat released in the diffusion phase compared to fuel with Reduxco® alone, which explained the lowest NOx and PM emissions in the exhaust gas at that time. For example for the NOx concentration in the engine exhaust: the Nitrocet® fuel additive (in the used amount of 1500 ppm) reduces the NOx concentration in the exhaust gas by 18% compared to the base fuel. The addition of a Reduxco® catalyst to the fuel (1500 ppm) unfortunately increases the NOx concentration by up to 20%. On the other hand, the combustion of the complete tested fuel, containing both additives simultaneously, is characterized, thanks to the synergy effect, by the lowest NOx concentration (reduction by 22% in relation to the base). For example for PM emissions: the Nitrocet® fuel additive does not significantly affect the PM emissions in the engine exhaust (up to a few per cent compared to the base fuel). The addition of a Reduxco® catalyst to the fuel greatly reduces PM emissions in the engine exhaust, up to 35% compared to the base fuel. On the other hand, the combustion of the complete tested fuel containing both additives simultaneously is characterized by the synergy effect with the lowest PM emission (reduction of 39% compared to the base fuel).


2011 ◽  
Vol 135-136 ◽  
pp. 1057-1059
Author(s):  
Heng Tao Zhou ◽  
Yong Wei

With a thermo gravimetric analysis apparatus combustion characteristics experiments of coal residue cornstalk and mixtures of them were done at 20 C/min heating rate. Then the combustion characteristic Parameters were obtained by above experiments. The c combustion activation energies were acquired by kinetics analysis. The results show those: the ignition characteristic and synthesis combustion characteristic of coal residue are bad. The ignition characteristic and synthesis combustion characteristic of cornstalk are better. The combustion characteristics of the mixture of coal residue and cornstalk are determined by mixing ratio. The ratio of cornstalk is more and the synthesis combustion characteristic is better.


Author(s):  
How Wei Benjamin Teo ◽  
Anutosh Chakraborty ◽  
Kim Tiow Ooi

As promising material for gas storage applications, MIL-101(Cr) can further be modified by doping with alkali metal (Li+, Na+, K+) ions. However, the doping concentration should be optimized below 10% to improve the methane adsorption. This article presents (i) the synthesis of MIL-101 (Cr) Metal Organic Frameworks, (ii) the characterization of the proposed doped adsorbent materials by X-ray Diffraction, Scanning Electron Microscopy, N2 Adsorption, Thermo-Gravimetric Analyzer, and (iii) the measurements of methane uptakes for the temperatures ranging from 125 K to 303 K and pressures up to 10 bar. It is found that the Na+ doped MIL-101(Cr) exhibits CH4 uptake capacity of (i) 295 cm3/cm3 at 10 bar and 160 K and (ii) 95 cm3/cm3 at 10 bar at 298 K. This information is important to design adsorbed natural gas (ANG) storage tank under ANG-LNG (liquefied natural gas) coupling conditions.


2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.


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