Nitrogen-doped carbon-13 materials as models for the release of NOx and N2O during coal char combustion

Thomas, K. Mark; Grant, Ken; Tate, Kirsty

doi:10.1016/0016-2361(93)90291-9

Cited by 29 publications

(9 citation statements)

References 15 publications

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“…The nitrogen remaining in the coal char was considered to be first released in the form of −CN or HCN and then converted to NO by the homogeneous reaction. The mechanism of the nitrogen-containing funtional groups oxidized to NO proposed by Thomas et al was …”

Section: Resultsmentioning

confidence: 99%

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

et al. 2019

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As a novel technology, coal preheating technology has been proved to be effective on NO x reduction by previous experiments. However, the role of some components of the fuel is still not clear in the preheating process and combustion process. To clarify the effects of volatile and carbon on NO x formation and reduction, three fuels with different volatile contents were used, and the experiments were launched in a bench-scale coal preheating combustion test apparatus. Results showed that the self-preheating burner was widely adaptable to the fuels and the fuels could be stably preheated to be above 860 °C. The coal gas mainly containing the combustible components of CO, H2, and CH4 was generated in the self-preheating burner, accompanying with the high-temperature coal char. Due to the high contents of carbon and volatiles, more combustible components in coal gas could be yielded by the bituminous coal after being preheated. Most of the volatile matters and carbon were released into the coal gas, and the volatile-N was mainly converted into N2. Because of the reduction of CO and carbon in char, the NO x conversion rates were low enough of the bituminous coal and the semicoke, while the NO x conversion rate of the coal gasification fly ash was a little high for its low carbon content.

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Section: Resultsmentioning

confidence: 99%

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

et al. 2019

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“…In the presence of O 2 , the MS detected a peak concentration value of NO of about 1100 ppm during the first 4 s of the reaction, whereas there was no corresponding peak value of NO in the absence of O 2 . This is because at the initial stage of the reaction, the coal particles just entered the fluidized bed and the high temperature made the volatiles release rapidly in a short time, including nitrogen containing substances such as HCN and NH 3 . ,, When the volatiles first came into contact with the reaction atmosphere (O 2 existed and was relatively abundant), some of those nitrogenous substances were first oxidized with O 2 to form NO and a small amount of N 2 O and NO 2 . , Then, as O 2 was consumed rapidly, the O 2 concentration in the fluidized bed dropped sharply and the NO x formed by these oxidation reactions would be reduced by subsequently released volatiles and char particles in homogeneous reacting way and heterogeneous reacting way, respectively, resulting in a sharp reduction of the NO concentration from the highest peak value and much lower than the initial concentration (<200 ppm). In addition, it can be seen from Figure that at the same temperature, the effect of the presence of a small amount (e.g., from 2 to 6%) of O 2 on the NO peak concentration value in the first 5 s is not obvious.…”

Section: Resultsmentioning

confidence: 99%

NO Reduction and Emission Characteristics of Coal/Char Mixtures in a Microfluidized Bed Reaction Analyzer

et al. 2018

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The reaction characteristics of different mixing ratios of coal/char to NO reduction were investigated under the conditions of relatively low O 2 concentration at 1073−1203 K. The inlet NO concentration ranges used in this study were 270− 600 ppm. The results showed that even a small increase in O 2 concentration can significantly accelerate the reaction process, but the increase in O 2 concentration also made the total efficiency of NO reduction gradually decline. Besides, under the presence of O 2 , with the increase of temperature, the reduction efficiency of char was gradually reduced, whereas the reduction efficiency of coal was gradually increased. Under the condition of the 25%/75% coal/char mixing ratio, the NO reduction in the earlier stage and the NO release in the later stage seemed to reach a balance; thus, the total reduction efficiency did not change significantly with the change of temperatures. Meanwhile, in the subsequent combustion and emission, characteristics of residues after NO reduction were also investigated under the O 2 -free condition and it can be concluded that the combustion reactivity of the residues of different samples was the best for coal samples and the worst for char samples.

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“…12 (Heikkilä et al, 2021;HermannHüttinger, 1986;MoulijnKapteijn, 1995); it also matters whether CO can convert NO to N 2 , whose reaction mechanism is shown in Eq. 13, 14 (Chan et al, 1983;Thomas et al, 1993;AarnaSuuberg, 1997;Dong et al, 2007;Gong et al, 2021).…”

Section: The Effects Of Additives On the Generation Of Char-no Xmentioning

confidence: 99%

Effects of Temperature and Additives on NOx Emission From Combustion of Fast-Growing Grass

et al. 2021

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Fast-growing grass, as a popular renewable energy, is low in sulfur content, so NOx is the major pollutant during its combustion. To study the emission characteristics of NOx and obtain the data of controlling NOx emission, the effects of combustion temperature as well as the additive type and mass fraction were investigated on the emission characteristics of NOx from the combustion of fast-growing grass. Results revealed that the first peak for NOx emission from this combustion gradually increases with an increase in temperature. Moreover, the additives were found to dramatically impact the amount of NOx emission and its representative peak. The optimal additives and their optimal mass fractions were determined at various specific temperatures to reduce NOx emission. At combustion temperatures of 600, 700, 750, 800, and 850°C, the optimal conditions to limit NOx emissions were 5% SiO2, 3% Al2O3, 3% Ca(OH)2, 15% Al2O3, and 3% SiO2 (or 3% Al2O3), respectively; the corresponding emission peaks decreased by 43.59, 44.21, 47.99, 24.18, and 30.60% (or 31.51%), with denitration rates of 63.28, 50.34, 57.44, 27.05, and 27.34% (or 27.28%), respectively.

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Nitrogen-doped carbon-13 materials as models for the release of NOx and N2O during coal char combustion

Cited by 29 publications

References 15 publications

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

NO Reduction and Emission Characteristics of Coal/Char Mixtures in a Microfluidized Bed Reaction Analyzer

Effects of Temperature and Additives on NOx Emission From Combustion of Fast-Growing Grass

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Nitrogen-doped carbon-13 materials as models for the release of NOx and N2O during coal char combustion

Cited by 29 publications

References 15 publications

Experimental Research on Combustion Characteristics and NOx Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

Experimental Research on Combustion Characteristics and NOx Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

NO Reduction and Emission Characteristics of Coal/Char Mixtures in a Microfluidized Bed Reaction Analyzer

Effects of Temperature and Additives on NOx Emission From Combustion of Fast-Growing Grass

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Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner

Experimental Research on Combustion Characteristics and NO_x Emission of Three Kinds of Solid Fuels Preheated by a Self-Preheating Burner