Characteristics and flame appearance of oxy-fuel combustion using flue gas recirculation

Fuel ◽  
2021 ◽  
Vol 297 ◽  
pp. 120775
Author(s):  
Mohsen Abdelaal ◽  
Medhat El-Riedy ◽  
Ahmed M. El-Nahas ◽  
Fathy R. El-Wahsh
Keyword(s):  
Flue Gas ◽  
Fuel Combustion ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

scholarly journals Combustion Characteristics of 0.5 MW Class Oxy-Fuel FGR (Flue Gas Recirculation) Boiler for CO2 Capture

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4333
Author(s):  
Joon Ahn ◽  
Hyouck-Ju Kim
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Power Plants ◽  
Fuel Combustion ◽  
Upstream Region ◽  
Exhaust Gas ◽  
Flue Gas Recirculation ◽  
Partial Load ◽  
Industrial Boilers ◽  
Gas Recirculation

A 0.5 MW class oxy-fuel boiler was developed to capture CO2 from exhaust gas. We adopted natural gas as the fuel for industrial boilers and identified characteristics different from those of pulverized coal, which has been studied for power plants. We also examined oxy-fuel combustion without flue gas recirculation (FGR), which is not commonly adopted in power plant boilers. Oxy-fuel combustion involves a stretched flame that uniformly heats the combustion chamber. In oxy-natural-gas FGR combustion, water vapor was included in the recirculated gas and the flame was stabilized when the oxygen concentration of the oxidizer was 32% or more. While flame delay was observed at a partial load for oxy-natural-gas FGR combustion, it was not observed for other combustion modes. In oxy-fuel combustion, the flow rate and flame fullness decrease but, except for the upstream region, the temperature near the wall is distributed not lower than that for air combustion because of the effect of gas radiation. For this combustion, while the heat flux is lower than other modes in the upstream region, it is more than 60% larger in the downstream region. When oxy-fuel and FGR combustion were employed in industrial boilers, more than 90% of CO2 was obtained, enabling capture, sequestration, and boiler performance while satisfying exhaust gas regulations.

scholarly journals Control system for an oxy-fuel combustion fluidized bed with flue gas recirculation

2011 ◽  
Vol 4 ◽  
pp. 972-979 ◽  
Author(s):  
I. Guedea ◽  
I. Bolea ◽  
C. Lupiáñez ◽  
N. Cortés ◽  
E. Teruel ◽  
...  
Keyword(s):  
Control System ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Fuel Combustion ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

Effect of flue gas recirculation during oxy-fuel combustion in a rotary cement kiln

Energy ◽  
2014 ◽  
Vol 64 ◽  
pp. 615-625 ◽  
Author(s):  
David A. Granados ◽  
Farid Chejne ◽  
Juan M. Mejía ◽  
Carlos A. Gómez ◽  
Ariel Berrío ◽  
...  
Keyword(s):  
Flue Gas ◽  
Fuel Combustion ◽  
Cement Kiln ◽  
Flue Gas Recirculation ◽  
Rotary Cement Kiln ◽  
Gas Recirculation

scholarly journals Improvement of power efficiency and environmental safety of ship boilers

2020 ◽  
Vol 2020 (3) ◽  
pp. 40-46
Author(s):  
Valery Alexandrovich Stenin ◽  
Irina Valer’yevna Ershova
Keyword(s):  
Nitrogen Oxide ◽  
Flue Gas ◽  
Thermal Power ◽  
Fuel Combustion ◽  
Nitrogen Oxide Emissions ◽  
Fuel Conversion ◽  
Flue Gas Recirculation ◽  
Study Results ◽  
Heat Regeneration ◽  
Gas Recirculation

The article focuses on the methods of reducing nitrogen oxide emissions that are important to consider and apply in operation of ship boilers and thermal power plants, along with other activities aimed to protect the environment. Nitrogen oxide emissions can be restrained by using the technological (primary, in-process) operations. Flue gas recirculation is the most popular method of restraining nitrogen oxide emissions in oil-gas boilers, reducing the temperature and nitrogen oxide concentration in flue gases. Besides affecting the environment, the combustion products recirculation greatly lowers the technical and economic performance of the boiler by decreasing its performance that is why using the method remains limited. There has been described the scheme of flue gas recirculation in the ship auxiliary boilers that ensures reduction of nitrogen oxide emissions and increase in efficiency of boiler furnace. It has been proposed to combine steam and carbon dioxide fuel conversion with power combustion and thermochemical heat regeneration. Thermodynamic feasibility of combustion product recirculation in ship auxiliary boiler has been given. Using the power and stoichiometric analyses of reference liquid fuel combustion, the possibility of fuel conversion has been illustrated for the case when both fuel and recirculation gases are supplied into reburning zone of the furnace. The calculations determine air oxygen ratio for reburning and oxidative zones, flue gas recirculation factor and furnace efficiency change at thermochemical heat regeneration. The study results are proposed to use in non-stoichiometric and staged fuel combustion.

CHARACTERISTICS OF OXY-FUEL COMBUSTION USING FLUE GAS RECIRCULATION

2016 ◽  
Vol 11 (41) ◽  
pp. 1265-1274
Author(s):  
Mohsen Abdelaal ◽  
Medhat El-Riedy ◽  
Fathy El-Wahsh ◽  
Ahmed El-Nahas
Keyword(s):  
Flue Gas ◽  
Fuel Combustion ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

Lean Blowout Limit and NOx-Production of a Premixed Sub-ppm NOx Burner With Periodic Flue Gas Recirculation

2004 ◽  
Author(s):  
Jochen R. Kalb ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Gas Content ◽  
Stable Operation ◽  
Reacting Flow ◽  
Nox Emissions ◽  
Lean Blowout ◽  
Fresh Mixture ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

The technological objective of this work is the development of a lean-premixed burner for natural gas. Sub-ppm NOx emissions can be accomplished by shifting the lean blowout limit (LBO) to slightly lower adiabatic flame temperatures than the LBO of current standard burners. This can be achieved with a novel burner concept utilizing periodic flue gas recirculation: Hot flue gas is admixed to the injected premixed fresh mixture with a mass flow rate of comparable magnitude, in order to achieve self-ignition. The subsequent combustion of the diluted mixture again delivers flue gas. A fraction of the combustion products is then admixed to the next stream of fresh mixture. This process pattern is to be continued in a cyclically closed topology, in order to achieve stable combustion of e.g. natural gas in a temperature regime of very low NOx production. The principal ignition behavior and NOx production characteristics of one sequence of the periodic process was modeled by an idealized adiabatic system with instantaneous admixture of partially or completely burnt flue gas to one stream of fresh reactants. With the CHEMKIN-II package a reactor network consisting of one perfectly stirred reactor (PSR, providing ignition in the first place) and two plug flow reactors (PFR) has been used. The effect of varying burnout and the influence of the fraction of admixed flue gas have been evaluated. The simulations have been conducted with the reaction mechanism of Miller and Bowman and the GRI-Mech 3.0 mechanism. The results show that the high radical content of partially combusted products leads to a massive decrease of the time required for the formation of the radical pool. As a consequence, self-ignition times of 1 ms are achieved even at adiabatic flame temperatures of 1600 K and less, if the flue gas content is about 50%–60% of the reacting flow after mixing is complete. Interestingly, the effect of radicals on ignition is strong, outweighs the temperature deficiency and thus allows stable operation at very low NOx emissions.

scholarly journals 658 NO_x formations in coal combustion with flue gas recirculation

2011 ◽  
Vol 2011.60 (0) ◽  
pp. _658-1_-_658-2_
Author(s):  
Ryo YOSHIIE ◽  
Takuya KAWAMOTO ◽  
Yasuaki UEKI ◽  
Ichiro NARUSE
Keyword(s):  
Flue Gas ◽  
Coal Combustion ◽  
Flue Gas Recirculation ◽  
Gas Recirculation
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