Sulphur Neutralization by Lignite Ash: Pilot-Scale Combustion Experiments

1979 ◽  
Vol 101 (4) ◽  
pp. 615-619 ◽  
Author(s):  
T. D. Brown ◽  
G. K. Lee ◽  
H. A. Bambrough
Keyword(s):  
Nitric Oxide ◽  
Flue Gas ◽  
Solid Phase ◽  
Coal Ash ◽  
Pilot Scale ◽  
Controlled Experiments ◽  
Excess Air ◽  
Nitric Oxide Emissions ◽  
Carry Over ◽  
Lime Addition

A pilot-scale research boiler (750 kg steam/hr) has been used to study the degree of sulphur neutralization during combustion experiments with three lignites. A series of four closely controlled experiments showed that sulphur balances close to 100 percent could be achieved in the pilot-scale system burning Gascoyne lignite; in these experiments the sulphur retained in solid phase residues varied between 21 and 24 percent of the input sulphur. It was also demonstrated with Utility lignite that external recirculation of flue-gas was moderately effective in reducing nitric oxide emissions at the expense of major increased in the carry-over of unburnt carbon. However, sulphur dioxide neutralization by the coal-ash cations remained essentially unchanged as the recirculation ratio increased. Enhancement of sulphur neutralization by dry lime addition to Poplar River lignite was only found to be effective at addition rates above 1/2 percent lime by weight. The effectiveness of the lime was found to increase as the excess-air level increased.

On the Influence of Fuel Mixing and Flue Gas Recirculation on the Emissions of a Fuel Flexible Gas Turbine Combustor

2015 ◽  
Author(s):  
Stefan Fischer ◽  
David Kluß ◽  
Franz Joos
Keyword(s):  
Nitric Oxide ◽  
Flue Gas ◽  
Nox Emissions ◽  
Combined Effects ◽  
Fuel Gas ◽  
Flue Gas Recirculation ◽  
Mixing Behavior ◽  
Nitric Oxide Emissions ◽  
Fuel Mixing ◽  
Gas Recirculation

The main benefits of operating a combustor under flue gas recirculation conditions are the increase in efficiency of the post combustion carbon capture and storage process and the potential to reduce NOX emissions while keeping the thermal load of the gas turbine constant. The latter is primarily caused by the change in thermodynamic properties of the combustive mixture with increasing vitiation. As a result, the dominant NOX formation pathways change with increasing FGR ratio. In a partially premixed combustor, the formation of NOX emissions can also be influenced by the fuel mixing behavior. Different setups lead to combustive mixtures with different degrees of homogeneity as well as influencing the distribution of the mixture within the combustion chamber. In this paper the combined effects of the variation of mixture homogeneity and the flue gas recirculation ratio on the NOX emissions and the stability range is experimentally investigated for different fuel gases. The experiments are performed on the atmospheric laboratory test rig, which is equipped with a partially premixed combustor. The burner is equipped with modular fuel gas nozzles allowing for the variation of the fuel mixing behavior. Exhaust gas measurements are performed to evaluate the influence of the parameters on the emissions profile of the combustor and to compare the results to a theoretical study. The results of this study show that the level of nitric oxide emissions as well as the potential to decrease said emissions with FGR operation is dependent on the mixing behavior of the combustor. Furthermore, the combined effects of fuel gas nozzle and FGR operation lead to a proposal of an operational strategy for the combustor which combines the advantages of low nitric oxide emissions and a broad range of stability.

Greater nitrous and nitric oxide emissions from the soil between rows than under the canopy in subtropical tea plantations

Geoderma ◽  
2021 ◽  
Vol 398 ◽  
pp. 115105
Author(s):  
Zhaoqiang Han ◽  
Jinyang Wang ◽  
Pinshang Xu ◽  
Zhirong Sun ◽  
Cheng Ji ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Tea Plantations ◽  
Nitric Oxide Emissions

NOx process inhibition and energy efficiency improvement in new swirl modification device for steel slag based on coal combustion

2018 ◽  
Vol 16 (7) ◽  
Author(s):  
Junxiang Guo ◽  
Lingling Zhang ◽  
Daqiang Cang ◽  
Liying Qi ◽  
Wenbin Dai ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Flue Gas ◽  
Coal Combustion ◽  
Steel Slag ◽  
Coal Ash ◽  
Combustion Efficiency ◽  
Gas Temperature ◽  
Staged Combustion ◽  
Energy Efficiency Improvement ◽  
Swirl Combustion

Abstract In this study, a novel swirl combustion modified device for steel slag was designed and enhanced with the objective of achieving highly efficient and clean coal combustion and also for achieving the whole elements utilization of coal. Coal ash and steel slag were melted in the combustion chamber and subsequently entered the slag chamber. The detrimental substances solidified and formed crystals, which allowed for the comprehensive utilization of the ash and slag. Our experiments mainly aimed to mitigate the formation of NOx, while using the heat and slag simultaneously during the coal combustion without a combustion efficiency penalty. The increase in the device’s energy efficiency and reduction in the NOx emissions are important requirements for industrialization. The experiments were carried out in an optimized swirling combustion device, which had a different structure and various coal feeding conditions in comparison to previously reported devices. The fuel-staged and non-staged combustion experiments were compared under different coal ratios (bitumite:anthracite). For the fuel-staged combustion experiments, the NOx concentration in the flue gas was observed to decrease significantly when the coal ratio of 1:1, an excess air coefficient of 1.2, and a fuel-staged ratio of 15:85 were used. Under these conditions, the flue gas temperature was as high as 1,620°C, while the NOx concentration was as low as 320 mg/m3 at 6 % O2. The air-surrounding-fuel structure that formed in the furnace was very beneficial in reducing the formation of NOx. In comparison to other types of coal burners, the experimental combustion device designed in this study achieved a significant reduction of NOx emissions (approximately 80 %).

Biological elimination of nitric oxide and carbon dioxide from flue gas by marine microalga NOA-113 cultivated in a long tubular photobioreactor

1996 ◽  
Vol 82 (4) ◽  
pp. 351-354 ◽  
Author(s):  
Ken-Ichi Yoshihara ◽  
Hiroyasu Nagase ◽  
Kaoru Eguchi ◽  
Kazumasa Hirata ◽  
Kazuhisa Miyamoto
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Flue Gas ◽  
Tubular Photobioreactor ◽  
Marine Microalga

Study on Oil-Ash Corrosion and Coal-Ash Corrosion Occurred in the Flue-Gas Side of Fossil Power Plant

2011 ◽  
Vol 418-420 ◽  
pp. 918-921
Author(s):  
Yong Yan Zhou ◽  
Yu Zhou ◽  
Guo Hua Lu ◽  
Tian Sheng Chen
Keyword(s):  
Flue Gas ◽  
High Speed ◽  
Fossil Fuels ◽  
Influence Factors ◽  
Heating Surface ◽  
Coal Ash ◽  
Chemical Corrosion ◽  
Boiler Tubes ◽  
Prevention Methods ◽  
Fossil Power Plant

A large number of high-speed soot particles would be produced after fossil fuels' (oil or coal) combustion in the boiler. These high-speed particles not only directly attack the heating surface of boiler tubes (damaging the tubes mechanically), but also condensate on the wall, causing even more serious chemical corrosion. The discussion has deeply studied the occurrence sites, reaction mechanism, influence factors as well as identification and prevention methods of oil-ash corrosion, coal-ash corrosion, so it would have a positive guiding significance for reducing (or preventing) the flue-gas side corrosion.

Numerical Simulation on Moisture Influence to MSW Combustion

2014 ◽  
Vol 1006-1007 ◽  
pp. 181-184
Author(s):  
Zhu Sen Yang ◽  
Xing Hua Liu ◽  
Shu Chen
Keyword(s):  
Numerical Simulation ◽  
Moisture Content ◽  
Flue Gas ◽  
Combustion Process ◽  
Average Temperature ◽  
Excess Air ◽  
Heat Value ◽  
Moisture Influence ◽  
Excess Air Coefficient ◽  
Combustible Gases

The combustion process of municipal solid waste (MSW) in a operating 750t/d grate furnace in Guangzhou was researched by means of numerical simulation. The influence of MSW moisture content on burning effect was discussed. The results show that: with the moisture content dropped from 50% to 30%, the heat value could be evaluated from 13.72% to 54.91% and the average temperature in the furnace could be promoted 90-248°C. However, the combustible gases and particle in the flue gas of outlet would take up a high proportion since lacking of oxygen would lead to an incomplete combustion. The excess air coefficient should be increased to 2.043~2.593 in order to ensure the flue gas residence time more than 2s and temperature in the furnace higher to 800°C.

Trajectory and Characteristics of Buoyancy and Momentum Dominated Horizontal Jet Flames From Circular and Elliptic Burners

2005 ◽  
Vol 128 (4) ◽  
pp. 300-310 ◽  
Author(s):  
Tracy Smith ◽  
Chendhil Periasamy ◽  
Benjamin Baird ◽  
S. R. Gollahalli
Keyword(s):  
Nitric Oxide ◽  
Reynolds Number ◽  
Flame Temperature ◽  
Major Axis ◽  
Equivalent Diameter ◽  
Flame Stability ◽  
Temperature Profiles ◽  
Burner Exit ◽  
Wide Range ◽  
Nitric Oxide Emissions

Relative effects of buoyancy and momentum on the characteristics of horizontally oriented circular (Circ) and elliptic (E) burner flames in a quiescent environment over a wide range of jet exit velocities are presented. The major axis of the elliptic burner was oriented horizontally and vertically (referred to as Emaj and Emin flames, respectively). Propane was used as fuel and a small amount of hydrogen was piloted to attach flames to the burner. Global flame characteristics such as flame dimensions, centerline trajectory, emission indices (EI) and radiative fraction, and in-flame transverse concentration and temperature profiles were measured. At a jet exit Reynolds number (Rej) of 2000, based on the area-equivalent diameter of the burner, the flame characteristics were affected by the burner geometry and its orientation. Also, the vertical dimension of the burner exit dictated buoyancy effects. At Rej=12,500, the influence of burner geometry or its orientation was negligible. Elliptic burner flames exhibited lower liftoff and blowout velocities than circular burner flames. Furthermore, the flame stability and nitric oxide emissions were not much affected by the orientation of elliptic burner. Although the elliptic burners produced higher EINO at lower jet exit velocities, the variation in EINO among three burners (Circ, Emaj, and Emin) was insignificant at higher velocities. Some effects of buoyancy on EICO were observed at lower jet exit velocities and the EICO was the lowest for the burners with largest buoyancy flux. Elliptic burner flames produced greater peak flame temperature than the corresponding circular burner flames under most conditions.

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