Simplified Kinetic Model of the Chemistry in the Reburning Zone Using Natural Gas

Bilbao, Rafael; Alzueta, María U.; Millera, Ángela; Duarte-García, Mario Alberto

doi:10.1021/ie00039a048

Cited by 27 publications

(18 citation statements)

References 12 publications

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“…Other commonly used reburning fuels are gaseous fuels [18,[22][23][24][25][27][28][29]. Studies have shown that by using such reburning fuel, with a suitably selected residence time of the reactants in the combustion chamber in the installation of 350 MW power, it can be achieved the degree of NO conversion of more than 60% [18].…”

Section: Reburning Methodsmentioning

confidence: 99%

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

Baron¹,

Kowarska²,

Żukowski³

2013

Advances in Internal Combustion Engines and Fuel Technologies

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Section: Reburning Methodsmentioning

confidence: 99%

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

Baron¹,

Kowarska²,

Żukowski³

2013

Advances in Internal Combustion Engines and Fuel Technologies

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“…The reason for the discussion of the detection of volatile compounds just after char addition is because they can have an influence in the evaluation of the rate of NO reduction on the char surface. Under rich conditions, the reduction of NO by natural gas is a well-known technique to reduce nitrogen oxide emissions in different combustion systems (Bilbao et al, 1995, Xu et al, 1999. Thus, it can be expected that at the temperatures in which the production of volatiles was higher (1273 K) the reduction of nitrogen oxide due to gas phase reaction is important and can affect the evaluation of the rate of nitric oxide reaction with the char surface.…”

Section: Influence Of Char In Situ Preparation On the Rate Of Nitric mentioning

confidence: 99%

Minimization of No Emissions From Multi-Burner Coal-Fired Boilers

Eddings¹,

Molina²,

Pershing³

et al. 2002

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The focus of this program is to provide insight into the formation and minimization of NOx in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NOx emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames-particularly under low NOx conditions. A CO/H 2 /O 2 /N 2 flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined.. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state 13 C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that aims to predict the conversion of char-nitrogen to nitric oxide should allow for the conversion of char-nitrogen to HCN. The extent of the HCN conversion to NO or N 2 will depend on the composition of the atmosphere surrounding IV the particle. A pilot-scale testing campaign was carried out to evaluate the impact of multiburner firing on NOx emissions using a three-burner vertical array. In general, the results indicated that multiburner firing yielded higher NOx emissions than single burner firing at the same fuel rate and excess air. Mismatched burner operation, due to increases in the firing rate of the middle burner, generally demonstrated an increase in NOx over uniform firing. Biased firing, operating the middle burner fuel rich with the upper and lower burners fuel lean, demonstrated an overall reduction in NOx emissions; particularly when the middle burner was operated highly fuel rich. Computational modeling indicated that operating the three burner array with the center burner swirl in a direction opposite to the other two resulted in a slight reduction in NOx. V

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“…Hence, many investigations have focused on gas-phase reburning chemistry to reveal the underlying mechanism. Extensive studies have been carried out on reburning mechanism in air combustion; − typically, Glarborg and Miller , updated and structured a detailed chemical kinetic modeling, which predicts the experimental very well in flow reactors, to reveal the reburning mechanism for C 1 and C 2 hydrocarbon. Dagaut et al further investigated the kinetics of C 1 –C 4 hydrocarbon/NO interactions in relation to reburning mechanism.…”

Section: Introductionmentioning

confidence: 99%

Comparison of the Reburning Chemistry in O₂/N₂, O₂/CO₂, and O₂/H₂O Atmospheres

Luo

et al. 2017

Energy Fuels

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The reburning chemistry in oxy-fuel and oxy-steam combustion of methane was investigated both experimentally and numerically. Comparison experiments in O2/N2, O2/CO2, and O2/H2O atmospheres were performed in a flow reactor at atmospheric pressure with equivalence ratio ranging from fuel-rich to fuel-lean and temperature from 973 to 1773 K. Experimental results showed that compared with N2 and CO2 atmospheres NO reduction observed in H2O atmosphere is the lowest under fuel-rich and stoichiometric conditions, while it is the highest under fuel-lean conditions. The NO reduction intensity in CO2 atmosphere lies between N2 and H2O atmosphere under fuel-rich and fuel-lean conditions; however, it is the highest under stoichiometric conditions. A chemical kinetic mechanism, which was hierarchically structured and updated in our previous work, captured the main characteristics and quantity of CO and NO formation satisfactorily even under fuel-lean conditions. According to the analysis from a chemical kinetic point of view, CO2 and H2O exert significant impacts on altering the radical pool structure to OH dominant, subsequently varying the availability of hydrocarbon radical as a reducing agent, which is the primary reason for the different degrees of NO reduction under fuel-rich, stoichiometric, and fuel-lean conditions. In addition, CO2 and H2O also impact the NO reduction by nitrogen-containing radicals. For CO2 atmosphere, NCO radical always occupies an overwhelmingly dominant position in NO reduction due to HCN → CH3CN → CH2CN → CN → NCO, and HNCO → NCO channel is amplified substantially. For H2O atmosphere, under fuel-rich and stoichiometric conditions, NH2 and NH radical are dominant due to the enhancement of NCO → HNCO → NH2 → NH channel. Under fuel-lean conditions, NCO radical is dominant due to the strength of HNCO → NCO channel.

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Simplified Kinetic Model of the Chemistry in the Reburning Zone Using Natural Gas

Cited by 27 publications

References 12 publications

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

Minimization of No Emissions From Multi-Burner Coal-Fired Boilers

Comparison of the Reburning Chemistry in O₂/N₂, O₂/CO₂, and O₂/H₂O Atmospheres

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Simplified Kinetic Model of the Chemistry in the Reburning Zone Using Natural Gas

Cited by 27 publications

References 12 publications

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

Low-Emission Combustion of Alternative Solid Fuel in Fluidized Bed Reactor

Minimization of No Emissions From Multi-Burner Coal-Fired Boilers

Comparison of the Reburning Chemistry in O2/N2, O2/CO2, and O2/H2O Atmospheres

Contact Info

Product

Resources

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Comparison of the Reburning Chemistry in O₂/N₂, O₂/CO₂, and O₂/H₂O Atmospheres