Particulate Emissions From Residual Fuel Fired Boilers: Influence of Combustion Modification

1977 ◽  
Vol 99 (3) ◽  
pp. 371-377 ◽  
Author(s):  
H. L. Goldstein ◽  
C. W. Siegmund
Keyword(s):  
Size Distribution ◽  
Flue Gas ◽  
Fuel Oil ◽  
Particulate Emissions ◽  
Preheat Temperature ◽  
Flue Gas Recirculation ◽  
Residual Fuel Oil ◽  
Excess Air ◽  
Stage Combustion ◽  
Gas Recirculation

Studies were carried out in a residual fuel fired package boiler to assess the effect of various combustion modification procedures on the amount and size distribution of particulate emissions. It was found that application of moderate levels of either two stage combustion or flue gas recirculation did not have much effect on particulate loading. Severe staging as well as use of interstage heat transfer to cool the gases between stages produced significantly more particulate. Likewise, higher levels of flue gas recirculation produced substantially more particulate. In both techniques the change in size distribution was mainly in the >10- and 1–10-μm ranges. Emulsified oil containing up to 30 percent water reduced particulate loading primarily in the coarse size ranges. Satisfactory combustion could be obtained using a preheat temperature and excess air level below that required for the straight residual fuel oil.

Development of Low Excess Air Combustion with Flue Gas Recirculation

2003 ◽  
Vol 2003.13 (0) ◽  
pp. 158-160
Author(s):  
Tadayuki Ishimi ◽  
Hisao Yamaguchi ◽  
Mitsuhiko Kamada ◽  
Eiji Matsukawa
Keyword(s):  
Flue Gas ◽  
Flue Gas Recirculation ◽  
Excess Air ◽  
Gas Recirculation

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

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

Low NO x Combustion of DME by Means of Flue Gas Recirculation

2007 ◽  
pp. 1247-1251 ◽  
Author(s):  
Ryosuke Matsumoto ◽  
Mamoru Ozawa ◽  
Shinya Terada ◽  
Takenori Iio
Keyword(s):  
Flue Gas ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

Modelling the Effect of External Flue Gas Recirculation on NOx and CO Emissions in a Premixed Gas Turbine Combustor With Chemical Reactor Networks

2018 ◽  
Author(s):  
V. Prakash ◽  
J. Steimes ◽  
D. J. E. M. Roekaerts ◽  
S. A. Klein
Keyword(s):  
Gas Turbine ◽  
Flue Gas ◽  
Recirculation Zone ◽  
Chemical Reactor ◽  
Inlet Temperature ◽  
Part Load ◽  
Flue Gas Recirculation ◽  
Reactor Networks ◽  
Gas Recirculation ◽  
The Impact

The increasing amount of renewable energy and emission norms challenge gas turbine power plants to operate at part-load with high efficiency, while reducing NOx and CO emissions. A novel solution to this dilemma is external Flue Gas Recirculation (FGR), in which flue gases are recirculated to the gas turbine inlet, increasing compressor inlet temperature and enabling higher part load efficiencies. FGR also alters the oxidizer composition, potentially leading to reduced NOx levels. This paper presents a kinetic model using chemical reactor networks in a lean premixed combustor to study the impact of FGR on emissions. The flame zone is split in two perfectly stirred reactors modelling the flame front and the recirculation zone. The flame reactor is determined based on a chemical time scale approach, accounting for different reaction kinetics due to FGR oxidizers. The recirculation zone is determined through empirical correlations. It is followed by a plug flow reactor. This method requires less details of the flow field, has been validated with literature data and is generally applicable for modelling premixed flames. Results show that due to less O2 concentration, NOx formation is inhibited down to 10–40% and CO levels are escalated up to 50%, for identical flame temperatures. Increasing combustor pressure leads to a rise in NOx due to thermal effects beyond 1800 K, and a drop in CO levels, due to the reduced chemical dissociation of CO2. Wet FGR reduces NOx by 5–10% and increases CO by 10–20%.

Introduction of Burners with In-Furnace Flue Gas Recirculation at a Power Boiler

2021 ◽  
Vol 68 (11) ◽  
pp. 865-872
Author(s):  
N. A. Zroychikov ◽  
D. R. Grigoriev ◽  
M. Gamburg ◽  
A. V. Pay
Keyword(s):  
Flue Gas ◽  
Flue Gas Recirculation ◽  
Gas Recirculation ◽  
Power Boiler
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