Reduction of Pollutant Emissions From Industrial Boilers by Combustion Modification

1977 ◽  
Vol 99 (3) ◽  
pp. 320-328 ◽  
Author(s):  
G. A. Cato ◽  
R. E. Hall ◽  
L. J. Muzio
Keyword(s):  
Flue Gas ◽  
Pollutant Emissions ◽  
Particulate Emissions ◽  
Test Program ◽  
Utility Boilers ◽  
Boiler Efficiency ◽  
Before And After ◽  
Particulate Size ◽  
Oil And Natural Gas ◽  
Industrial Boilers

The use of combustion modification has enabled many utility boilers to meet the emission standards for NOx. Its usefulness in reducing NOx emissions from industrial boilers (ranging from 11 GJ/hr to 528 GJ/hr) has been investigated during a recently completed field test program. The gaseous and particulate emissions from coal, oil, and natural-gas fuels were measured both before and after the combustion modification. Data were taken on particulate size as well as concentration. The principal combustion modification methods that were investigated included reduced excess combustion air, staged combustion air, recirculated flue gas, tuned burners, and reset burner registers. Staging was implemented by the use of overfire air ports or by turning off the fuel to some burners and increasing the fuel to others, thus creating zones of fuel-rich combustion. All of the combustion modification methods were effective to varying degrees in reducing the nitrogen oxides emissions, and reductions of as much as 50 percent were obtained with several of the modifications. In most instances the boiler efficiency was not degraded, although the particulate emissions increased by up to 50 percent in some cases. There was no substantive effect on the other pollutant emissions that were measured.

NOx Emissions From Industrial Boilers: Potential Control Methods

1974 ◽  
Vol 96 (1) ◽  
pp. 1-6 ◽  
Author(s):  
C. W. Siegmund ◽  
D. W. Turner
Keyword(s):  
Flue Gas ◽  
Two Stage ◽  
Potential Control ◽  
Excess Air ◽  
Stage Combustion ◽  
Utility Boilers ◽  
Industrial Boilers ◽  
Potential Methods ◽  
Further Development ◽  
Methods Of Control

Future regulations may limit emissions of NOx from industrial/commercial boilers as well as utility boilers. The potential methods of control for these boilers are the same as those for utility boilers—low excess air, flue gas recycle, and two stage combustion. Low excess air and flue gas recycle can control NOx from thermal fixation. Two stage combustion controls both thermal and fuel NOx. Further development work is needed to apply these combustion modification procedures to industrial/commercial boilers in which volumetric heat release rate is normally quite high.

Dew Point of the Flue Gas of Boilers Co-Firing Biomass with Coal

2013 ◽  
Vol 34 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Szymon Ciukaj ◽  
Marek Pronobis
Keyword(s):  
Regression Analysis ◽  
Moisture Content ◽  
Flue Gas ◽  
Large Scale ◽  
Fuel Mixture ◽  
Dew Point ◽  
Outlet Temperature ◽  
Utility Boilers ◽  
Boiler Efficiency ◽  
The Impact

Abstract The paper deals with the impact of co-firing biomass with coal in boilers on the dew point of the flue gas. Co-firing of biomass may have twofold implications on corrosion and fouling, which are the processes that determine the lowest acceptable flue gas outlet temperature and as a result, boiler efficiency. Both phenomena may be reduced by co-firing of usually low sulphur biomasses or enhanced due to increased moisture content of biomass leading to increased water dew point. The present study concerns the problem of low-temperature corrosion in utility boilers. The paper gives (in the form of diagrams and equations) a relationship between water dew point and moisture content of fuel mixture when co-firing coal and various biomasses. The regression analysis shows that despite significant differences in the characteristics of coals and these of additional fuels, which are planned for co-firing in large-scale power boilers, the water dew point can be described by a function given with the accuracy, which shall be satisfactory for engineering purposes. The discussion of the properties of biofuels indicates that the acid dew point surplus over the water dew point (Δtr = tr - twr) is not likely to exceed 10 K when co-firing biomass. The concluding remarks give recommendations for the appropriate operation of boilers in order to reduce risks associated with biomass co-combustion.

Improving the Boiler Efficiency by Optimizing the Combustion Air

2015 ◽  
Vol 787 ◽  
pp. 238-242 ◽  
Author(s):  
R. Pachaiyappan ◽  
J. Dasa Prakash
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Steam Generator ◽  
Air Temperature ◽  
Flue Gas ◽  
Maximum Heat ◽  
Air Preheater ◽  
Hot Air ◽  
Boiler Efficiency ◽  
Efficient Combustion

Air pre-heater and economizer are heat transfer surfaces in which air temperature and water temperature are raised by transferring heat from other media such as flue gas. Hot air is necessary for rapid combustion in the furnace and also for drying coal in milling plants. So an essential boiler accessory which serves this purpose is air pre-heater. The air pre-heater is not essential for operation of steam generator, but they are used where a study of cost indicates that money can be saved or efficient combustion can be obtained by their use. The decision for its adoption can be made when the financial advantages is weighed against the capital cost of heater. The efficiency of the boiler increases with the increase in the temperature of the combustion air used in the furnace. This is achieved by the increased temperature of the flue gas in the air preheater and economizer zone. This paper deals with the different ways to obtain the maximum heat from the flue gas travelling through the air preheater and the economizer zone to improve the boiler efficiency.

scholarly journals Modified High Back-Pressure Heating System Integrated with Raw Coal Pre-Drying in Combined Heat and Power Unit

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2487 ◽  
Author(s):  
Heng Chen ◽  
Zhen Qi ◽  
Qiao Chen ◽  
Yunyun Wu ◽  
Gang Xu ◽  
...  
Keyword(s):  
Power Generation ◽  
Flue Gas ◽  
Waste Heat ◽  
Heating System ◽  
Combined Heat And Power ◽  
Back Pressure ◽  
Coal Consumption ◽  
Heating Capacity ◽  
Boiler Efficiency ◽  
Saving Effect

A conceptual high-back pressure (HBP) heating system cooperating raw coal pre-drying for combined heat and power (CHP) was proposed to improve the performance of the HBP-CHP unit. In the new design, besides of heating the supply-water of the heating network, a portion of the exhaust steam from the turbine is employed to desiccate the raw coal prior to the coal pulverizer, which further recovers the waste heat of the exhaust steam and contributes to raising the overall efficiency of the unit. Thermodynamic and economic analyzes were conducted based on a typical 300 MW coal-fired HBP-CHP unit with the application of the modified configuration. The results showed that the power generation thermal efficiency promotion of the unit reaches 1.7% (absolute value) owing to suggested retrofitting, and meanwhile, the power generation standard coal consumption rate is diminished by 5.8 g/kWh. Due to the raw coal pre-drying, the energy loss of the exhaust flue gas of the boiler is reduced by 19.1% and the boiler efficiency increases from 92.7% to 95.4%. The impacts of the water content of the dried coal and the unit heating capacity on the energy-saving effect of the new concept were also examined.

Intake-Air Oxygen-Enrichment of Diesel Engines as a Power Enhancement Method and Implications on Pollutant Emissions

2009 ◽  
Author(s):  
Theodoros C. Zannis ◽  
Dimitrios T. Hountalas ◽  
Elias A. Yfantis ◽  
Roussos G. Papagiannakis ◽  
Yiannis A. Levendis
Keyword(s):  
Theoretical Investigation ◽  
Diesel Engines ◽  
Equivalence Ratio ◽  
Combustion Efficiency ◽  
Oxygen Enrichment ◽  
Pollutant Emissions ◽  
Particulate Emissions ◽  
Engine Simulation ◽  
Hc Emissions ◽  
Experimental Findings

Increasing the in-cylinder oxygen availability of diesel engines is an effective method to improve combustion efficiency and to reduce particulate emissions. Past work on oxygen-enrichment of the intake air, revealed a large decrease of ignition delay, a remarkable decrease of soot emissions as well as reduction of CO and unburned hydrocarbon (HC) emissions while, brake specific fuel consumption (bsfc) remained unaffected or even improved. Moreover, experiments conducted in the past by authors revealed that oxygen-enrichment of the intake air (from 21% to 25% oxygen mole fraction) under high fuelling rates resulted to an increase of brake power output by 10%. However, a considerable increase of NOx emissions was recorded. This manuscript, presents the results of a theoretical investigation that examines the effect of oxygen enrichment of intake air, up to 30%v/v, on the local combustion characteristics, soot and NO concentrations under the following two in-cylinder mixing conditions: (1) lean in-cylinder average fuel/oxygen equivalence ratio (constant fuelling rate) and (2) constant in-cylinder average fuel/oxygen equivalence ratio (increased fuelling rate). A phenomenological engine simulation model is used to shed light into the influence of the oxygen content of combustion air on the distribution of combustion parameters, soot and nitric oxide inside the fuel jet, in all cases considered. Simulations were made for a naturally aspirated single-cylinder DI diesel engine “Lister LV1” at 2500 rpm and at various engine loads. The outcome of this theoretical investigation was contrasted with published experimental findings.

Experiment on fine particle purification by flue gas condensation for industrial boilers

Fuel ◽  
2017 ◽  
Vol 199 ◽  
pp. 684-696 ◽  
Author(s):  
Jing Liu ◽  
Donglin Chen ◽  
Jidong Lu
Keyword(s):  
Flue Gas ◽  
Fine Particle ◽  
Gas Condensation ◽  
Industrial Boilers

scholarly journals VALUASI PENGENDALIAN EMISI BOILER BATU BARA PADA INDUSTRI KERTAS DAN ESTIMASI EMISI MERKURI (Hg) (VALUATION ON EMISSION CONTROL OF COAL-FIRED BOILER OF PAPER INDUSTRY AND ESTIMATION OF MERCURY (Hg) EMISSION)

2017 ◽  
Vol 7 (01) ◽  
pp. 39 ◽  
Author(s):  
Yusup Setiawan
Keyword(s):  
Flue Gas ◽  
Paper Industry ◽  
Emission Control ◽  
Air Emissions ◽  
Particulate Emissions ◽  
Emissions Control ◽  
Gas Emissions ◽  
Coal Combustion Products ◽  
Control Devices

Steam and electricity needs in the paper industry have been provided itself through coal-fired boiler equipped with emission control devices. Boiler flue gas emissions of coal combustion products contain contaminants such as particulate emissions , NO2 and SO2 , and a small amount of emissions of mercury (Hg). Valuation on boiler emissions quality associated with air emissions control systems and emissions standard has been carried out. Estimation of mercury concentration in air emissions of boiler flue gas in the paper industry has also been conducted. The valuation on the air emissions quality of non-mercury parameters of paper industry boilers has also been done based on national emissions standards. The results of the valuation indicated that the current applied of flue gas emissions control devices in the paper industry has been optimally operated so that the emission quality of boiler for both non-mercury parameters and mercury parameters has been complied with the emission quality standards. Prediction of mercury content in air emissions of a coal boiler stack of paper industry that is discharged into environment based on the content of mercury in coal is 0.0205 mg/Nm3 (20.5 µg/Nm3 ) maximum. Paper industry needs to consider the application of co-benefit technology when mercury is used as a quality standard emissions parameter. ABSTRAKKebutuhan uap dan atau listrik pada industri kertas disediakan melalui unit boiler berbahan bakar batu bara yang dilengkapi alat pengendali emisi. Emisi gas boiler mengandung pencemar berupa partikulat, NO2 dan SO2 , dan merkuri (Hg). Valuasi kualitas emisi boiler berkaitan dengan sistem pengendalian emisi udara dan baku mutu emisi telah dilakukan, Estimasi kadar merkuri di udara emisi cerobong boiler pada industri kertas juga telah dilakukan. Valuasi kualitas emisi udara non-merkuri emisi boiler industri kertas juga telah dilakukan berdasarkan baku mutu emisi nasional. Hasil valuasi menunjukkan bahwa alat pengendali emisi gas buang boiler yang telah diterapkan saat ini pada industri kertas telah dioperasikan secara optimal sehingga kualitas emisi boiler baik untuk parameter non-merkuri maupun untuk parameter merkuri telah memenuhi baku mutu emisi. Prediksi kadar merkuri dalam udara emisi cerobong boiler batu bara industri kertas yang dibuang ke lingkungan dihitung berdasarkan kadar merkuri dalam batu bara adalah maksimum sebesar 0,0205 mg/Nm3 (20,5 µg/Nm3 ). Industri kertas perlu mempertimbangkan penerapan teknologi co-benefit bilamana suatu saat parameter merkuri ditetapkan sebagai parameter baku mutu emisi.

Research on Energy-Saving Control Technology of Boiler

2011 ◽  
Vol 383-390 ◽  
pp. 2603-2607
Author(s):  
Yao Yi ◽  
Guang Jian Chen ◽  
Jin Ling Jia
Keyword(s):  
Energy Saving ◽  
Intelligent Control ◽  
Flue Gas ◽  
Combustion Efficiency ◽  
Wind Pressure ◽  
Boiler Furnace ◽  
Door Opening ◽  
Boiler Efficiency ◽  
Secondary Air ◽  
Energy Saving Control

Focusing on energy-saving issues of boiler, this paper finds out the combustion conditions inside boiler furnace by monitoring and analysis on oxygen content of flue gas, carbon content of fly ash, CO and CO2 contents. The intelligent control of boiler combustion was achieved and combustion efficiency was rosen. Using neural network controlling model, automatic optimization of oxygen delivery volume,coal delivery volume, the total wind pressure of primary air, the secondary air-door opening degree and furnace negative pressure were achieved, and the boiler efficiency increasing by 5 ~ 7%.

Effects of Flue Gas Recirculation on NOx Emissions from Gas-Fired Utility Boilers

2021 ◽  
pp. 319-337
Author(s):  
Nikola Tanasić ◽  
Mirjana Stamenić ◽  
Vladimir Tanasić
Keyword(s):  
Flue Gas ◽  
Nox Emissions ◽  
Flue Gas Recirculation ◽  
Utility Boilers ◽  
Gas Recirculation
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