Effect of N2 dilution on combustion instabilities and emissions in biogas flame

Yılmaz, İlker; Cam, Yakup; Alabaş, Buğrahan

doi:10.1016/j.fuel.2021.121943

Cited by 12 publications

(4 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the CO2 content of the biogas increased, the NOx generation rate monotonically decreased. Ilker et al [13] conducted experiments to explore flame stability with a nitrogen dilution ratio ranging from 0% to 60%. The combustion stability reached the best state when N2 content reached 30%, and the stability decreased when it exceeded 30%.…”

Section: Introductionmentioning

confidence: 99%

Effects of Hydrogen Addition on the Thermal Performance and Emissions of Biomass Syngas Combustion in a Horizontal Boiler

Suxing,

Yu,

et al. 2024

Energies

View full text Add to dashboard Cite

Due to its low calorific value, abnormal phenomena such as incomplete combustion and flameout may occur during the combustion process of biomass syngas. The applicability of adding hydrogen can assist in the combustion of biomass syngas in boilers to overcome the above defects, and the effects need to be investigated. In this study, a multi-mechanism model is employed to numerically simulate the flow and combustion of a horizontal boiler burning biomass syngas. The reliability verification of the model is conducted by comparing it with the experimental results of combustion in a domestic boiler with biomass syngas. From the views of multi-fields and synergy, the effects of hydrogen addition on the thermal performance and emissions of biomass syngas are further expounded. Two scenarios are taken into consideration: hydrogen addition at a constant fuel volume flow rate and constant heat input. The result indicates that hydrogen addition significantly affects the multi-field synergy, which is advantageous for improving the heat transfer performance and combustion efficiency of biomass syngas. However, when the hydrogen addition ratio exceeds 20% at a constant fuel volume flow rate and 25% at constant heat input, its impact may be reduced. When the hydrogen content increases, the outlet temperature of the combustion chamber decreases, and pollutant emissions are effectively controlled. The turbulent kinetic energy at the reversal section decreases, and the uniformity of the flow field improves. These results provide certain guidance for the efficient utilization of biomass syngas and the operation of boilers burning biomass syngas.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of Hydrogen Addition on the Thermal Performance and Emissions of Biomass Syngas Combustion in a Horizontal Boiler

Suxing,

Yu,

et al. 2024

Energies

View full text Add to dashboard Cite

show abstract

“…The mole fraction of intermediate radicals and NOx decreased with the increase of the N 2 doping ratio under the same equivalence ratio. Yilmaz et al 36 studied the effect of N 2 dilution on the instability and emission of a biogas flame. They found the dilution range of 20%–30% N 2 was the critical value of a biogas mixture containing 60% CH 4 –40% CO 2 .…”

Section: Introductionmentioning

confidence: 99%

Suppression of thermoacoustic instability and NOx emissions of unsteady swirl premixed flame with upstream microjets

Zhou

2022

Asia-Pacific J Chem Eng

View full text Add to dashboard Cite

Passive control methods are widely used in unsteady combustion systems due to their robustness and convenience. This paper used the upstream microjets method for the first time to control thermoacoustic instability and pollutant NOx emissions in unsteady swirl premixed flame. Three variables of CO 2 microjets flow rate, upstream microjets distance, and microjets number are investigated. Results demonstrate the upstream microjets distance plays a significant role in restraining the thermoacoustic instability and NOx emissions. The smaller the upstream microjets distance, the more completely the thermoacoustic instability is suppressed while the NOx emissions are the opposite, which means a compromise choice needs to be made between them. The damping ratio of pressure amplitude in the chamber can reach the maximum of 81.3%, and the damping ratio of CH* intensity can reach the maximum of 80.2%. Besides, the frequency of pressure and CH* will transit to a lower mode. NOx emissions can realize a maximum reduction of 12.2 ppm. Meanwhile, the flame mode switches from an enlarged Mode-A flame to a shrunk Mode-B flame, and the flame length shows a maximum reduction of 14 mm at the largest upstream distance. However, the specific control mechanism under upstream microjets still needs further study to clarify. This research proved the feasibility of suppressing combustion instability and NOx emissions with upstream microjets in unsteady swirl premixed flame, promoting its practical application in gas turbine systems.flame mode, NO x emissions, thermoacoustic instability, unsteady swirl premixed flame, upstream microjets | INTRODUCTIONAs a complex multidisciplinary problem, combustion instability was first proposed by scholar Rayleigh. 1 When combustion instability occurs, it is often accompanied by periodic large pressure oscillations. 2,3 The power engines in gas turbines, industrial furnaces, and rockets will face the threat of damage or even failure.To prevent the occurrence of combustion instability, researchers often implement control strategies from the two necessary factors of combustion instability, namely, acoustic oscillations and heat release oscillations. For

show abstract

“…The problem of emissions into the environment has been studied by many authors. When burning biogas or other carbon fuels, there are several types of emissions: CO, CO2 and NOX [13]. Even with mixtures containing more CO2, CO2 emissions can be lower due to the fact that the kinetics of CO oxidation are favorable at higher temperatures [14].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Biogas Composition on the Characteristics of the Combustion Process

Leonov

Trubaev

2022

DJES

View full text Add to dashboard Cite

Biogas can serve as a substitute for natural fuel, but its use is associated with a number of features associated with the difference in its composition from natural gas. Landfill gas generated in the body of MSW landfills is characterized by a significant change in composition. The purpose of the work was a theoretical study of the effect of changing the composition of biogas and the coefficient of excess air on the parameters of the combustion process - gas and air consumption, combustion temperature and on the volume of combustion products. The influence of the ratio of CO2 and N2 contained in biogas on the main combustion characteristics was also evaluated. It is concluded that the combustion of biogas of variable composition, subject to ensuring the specified heat output of the furnace or boiler, does not require a change in air flow, but only a change in the flow of biogas depending on the content of methane in it. Reducing the content of methane leads to an increase in the volume of exhaust gases and a decrease in their temperature. Therefore, a decrease in the methane content in biogas can lead to a decrease in the intensity of heat exchange and a decrease in the efficiency of the unit. The ratio of CO2 and N2 practically does not affect the thermal parameters of combustion. The results of the study are necessary when designing equipment and determining the operating mode of equipment that burns biogas that is formed in natural conditions, for example, landfill gas generated at HSW landfill.

show abstract

Effect of N2 dilution on combustion instabilities and emissions in biogas flame

Cited by 12 publications

References 31 publications

Effects of Hydrogen Addition on the Thermal Performance and Emissions of Biomass Syngas Combustion in a Horizontal Boiler

Effects of Hydrogen Addition on the Thermal Performance and Emissions of Biomass Syngas Combustion in a Horizontal Boiler

Suppression of thermoacoustic instability and NOx emissions of unsteady swirl premixed flame with upstream microjets

The Effect of Biogas Composition on the Characteristics of the Combustion Process

Contact Info

Product

Resources

About