The Interrelationship between Soot and Fuel NOx Control in Gas Turbine Combustors

1981 ◽  
Vol 103 (1) ◽  
pp. 43-48 ◽  
Author(s):  
W. S. Blazowski ◽  
A. F. Sarofim ◽  
J. C. Keck
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Soot Formation ◽  
Emission Control ◽  
Nox Emission ◽  
Current Understanding ◽  
Conflict Prevention ◽  
Primary Zone ◽  
Nitrogen Conversion ◽  
Nox Control

The decreased hydrogen content of future fuels will lead to increased formation of soot, while increased organically bound nitrogen in the fuel can result in excessive NOx emission. Control concepts for these two problems are in conflict: prevention of soot requires leaner operation while control of emissions from fuel nitrogen requires fuel-rich operation. However, recent results of two DOE research programs point to both processes having a major dependence on “hydrocarbon breakthrough.” Control of both fuel nitrogen conversion and soot formation can be achieved by primary zone operation at equivalence ratios just below that for hydrocarbon breakthrough. This paper reviews the evidence for the importance of hydrocarbon breakthrough, explains our current understanding of why hydrocarbon breakthrough is important, and offers suggestions of how these results might be applied.

Dependence of Soot Production on Fuel Blend Characteristics and Combustion Conditions

1980 ◽  
Vol 102 (2) ◽  
pp. 403-408 ◽  
Author(s):  
W. S. Blazowski
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Soot Formation ◽  
Combustion Products ◽  
Small Scale ◽  
Inlet Temperature ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Energy Demands ◽  
Primary Zone

Liquid synthetic fuels derived from nonpetroleum resources will play a major role in meeting future national energy demands. In the case of gas turbine applications, it is known that the different properties of these fuels can result in substantially altered combustion performance. Most importantly, decreased fuel hydrogen content resulting from an increased aromatic content has been observed to result in increased exhaust smoke and particulates as well as greater flame luminosity. This paper contributes empirical information and insight which allows the greater soot formation tendencies of low hydrogen content fuels to be better understood. A small scale laboratory device which simulates the strongly backmixed conditions present in the primary zone of a gas turbine combustor is utilized. The Jet Stirred Combustor provides for very rapid mixing between a premixture of vaporized fuel and air and the combustion products within a 5.08 cm dia hemispherical reactor. Results to be presented are gaseous combustion product distributions, incipient soot limits, and soot production (mg/l) for a variety of fuels. The influences of combustor inlet temperature and reactor mass loading have been evaluated and the sooting characteristics of fuel blends have been studied. These results have been analyzed to develop useful correlations which are in general agreement with existing mechanistic concepts of the soot formation process.

Application of Reburning for NOx Control to a Firetube Package Boiler

1985 ◽  
Vol 107 (3) ◽  
pp. 739-743 ◽  
Author(s):  
J. A. Mulholland ◽  
W. S. Lanier
Keyword(s):  
Natural Gas ◽  
Reaction Order ◽  
Nox Reduction ◽  
Process Variable ◽  
Nox Emission ◽  
Boiler Load ◽  
Second Stage ◽  
Primary Zone ◽  
Dominant Process ◽  
Nox Control

A 730 kW (2.5 × 106 Btu/hr) firetube package boiler was used to demonstrate the application of reburning for NOx emission control. An overall reduction of 50 percent from an uncontrolled NOx emission of 200 ppm was realized by diverting 15 percent of the total boiler load to a natural-gas-fired second stage burner. Tests indicate that the overall reaction order of destruction with respect to initial NOx is greater than one; thus, larger reductions can be expected from reburning applications to systems with higher initial NOx. Rich zone stoichiometry has been identified as the dominant process variable. Primary zone stoichiometry and rich zone residence time are parameters that can be adjusted to maximize NOx reduction. Reburning applied to firetube package boilers requires minimal facility modification. Natural gas would appear to be an ideal reburning fuel as nitrogen in the reburning fuel has been shown to inhibit NOx reduction.

scholarly journals Nonlinear response of ozone to precursor emission changes in China: a modeling study using response surface methodology

2011 ◽  
Vol 11 (10) ◽  
pp. 5027-5044 ◽  
Author(s):  
J. Xing ◽  
S. X. Wang ◽  
C. Jang ◽  
Y. Zhu ◽  
J. M. Hao
Keyword(s):  
Response Surface Methodology ◽  
Air Quality ◽  
Response Surface ◽  
Surface Ozone ◽  
Emission Control ◽  
Nox Emission ◽  
Ozone Sensitivity ◽  
Nox Control ◽  
Ozone Levels ◽  
Modeling Study

Abstract. Statistical response surface methodology (RSM) is successfully applied for a Community Multi-scale Air Quality model (CMAQ) analysis of ozone sensitivity studies. Prediction performance has been demonstrated through cross validation, out-of-sample validation and isopleth validation. Sample methods and key parameters, including the maximum numbers of variables involved in statistical interpolation and training samples have been tested and selected through computational experiments. Overall impacts from individual source categories which include local/regional NOx and VOC emission sources and NOx emissions from power plants for three megacities – Beijing, Shanghai and Guangzhou – were evaluated using an RSM analysis of a July 2005 modeling study. NOx control appears to be beneficial for ozone reduction in the downwind areas which usually experience high ozone levels, and NOx control is likely to be more effective than anthropogenic VOC control during periods of heavy photochemical pollution. Regional NOx source categories are strong contributors to surface ozone mixing ratios in three megacities. Local NOx emission control without regional involvement may raise the risk of increasing urban ozone levels due to the VOC-limited conditions. However, local NOx control provides considerable reduction of ozone in upper layers (up to 1 km where the ozone chemistry is NOx-limited) and helps improve regional air quality in downwind areas. Stricter NOx emission control has a substantial effect on ozone reduction because of the shift from VOC-limited to NOx-limited chemistry. Therefore, NOx emission control should be significantly enhanced to reduce ozone pollution in China.

scholarly journals Dependence of Soot Production on Fuel Blend Characteristics and Combustion Conditions

1979 ◽  
Author(s):  
W. S. Blazowski
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Soot Formation ◽  
Combustion Products ◽  
Small Scale ◽  
Inlet Temperature ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Energy Demands ◽  
Petroleum Resources

Liquid synthetic fuels derived from non-petroleum resources will play a major role in meeting future national energy demands. In the case of gas turbine applications, it is known that the different properties of these fuels can rusult in substantially altered combustion performance. Most importantly, decreased fuel hydrogen content resulting from an increased aromatic content has been observed to result in increased exhaust smoke and particulates as well as greater flame luminosity. This paper contributes empirical information and insight which allows the greater soot formation tendencies of low hydrogen content fuels to be better understood. A small scale laboratory device which simulates the strongly backmixed conditions present in the primary zone of a gas turbine combustor is utilized. The Jet Stirred Combustor provides for very rapid mixing between a premixture of vaporized fuel and air and the combustion products within a 5.08-cm-dia hemispherical reactor. Results to be presented are gaseous combustion product distributions, incipient soot limits, and soot production (mg) for a variety of fuels. The influences of combustor inlet temperature and reactor mass loading have been evaluated and the sooting characteristics of fuel blends have been studied. These results have been analyzed to develop useful correlation which are in general agreement with existing mechanistic concepts of the soot formation process.

Environmental Aspects of a 10 MW Heavy Duty Gas Turbine Burning Coke Oven Gas With a Hydrogen Content of 60%

1993 ◽  
Author(s):  
T. Becker ◽  
M. Perkavec
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Hydrogen Content ◽  
Waste Product ◽  
Flame Temperature ◽  
Coke Oven ◽  
Steam Injection ◽  
Nox Emission ◽  
Coke Oven Gas ◽  
Coking Plant

In a coking plant in which coal tar is processed coke oven gas occurs as a waste product. Coke oven gas can be used as an alternative fuel for a gas turbine, instead of natural gas, if it meets the local environmental regulations. As a result of higher flame temperature of coke oven gas caused by the hydrogen content, the NOx emission of a gas turbine burning coke oven gas is higher than in case of natural gas. In Germany a 10 MW gas fired gas turbine has to meet a NOx emission limit of 150 mg/Nm3 @ 15% O2 dry. To reach this goal in case of MS 3002, which is installed in the coking plant as reported in previous ASME paper, steam injection is necessary. NOx- and CO-emissions of a gas turbine are difficult to be predicted by calculation, therefore measurements had to be done to see how good the predictions were, that were made in face of the local regulations. This paper deals with the NOx- and CO-emissions of a coke oven gas fired gas turbine with and without steam injection in difference to natural gas fired gas turbine. It shows also significantly lower CO2-emissions, because coke oven gas contains less hydrocarbon which is a great benefit for the greenhouse problem. It illustrates the effect of power augmentation and discusses the different thermal efficiency with steam injection. This paper gives a short glance to the effects which influence the emissions, so that the specific problems caused by burning coke oven gas can be understood.

Emission Control Technology for Stationary Natural Gas Engines

1989 ◽  
Vol 111 (3) ◽  
pp. 369-374 ◽  
Author(s):  
C. M. Urban ◽  
H. E. Dietzmann ◽  
E. R. Fanick
Keyword(s):  
Natural Gas ◽  
Emission Control ◽  
Nox Emission ◽  
Control Technology ◽  
Natural Gas Engines ◽  
The Status ◽  
Nox Control

This paper summarizes the status of NOx emission control technology for stationary reciprocating natural gas engines. It provides information on most of the known methods of NOx control for natural gas engines that are in use, are being considered for use, or may be considered for use.

The Influence of Fuel Hydrogen Content Upon Soot Formation in a Model Gas Turbine Combustor

1984 ◽  
Vol 106 (4) ◽  
pp. 789-794 ◽  
Author(s):  
T. T. Bowden ◽  
J. H. Pearson ◽  
R. J. Wetton
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Soot Formation ◽  
Polycyclic Aromatics ◽  
Low Oxygen ◽  
Gas Turbine Combustor ◽  
Fuel Blends ◽  
High Concentrations ◽  
Model Gas Turbine Combustor ◽  
Absorption Measurements

The sooting tendencies of various fuel blends containing either single-ring or polycyclic aromatics have been studied in a model gas turbine combustor at a pressure of 1.0 MPa and varying values of air/fuel ratio. Sooting tendencies were determined by flame radiation, exhaust soot, and infra-red absorption measurements. The results of this study have indicated that, even for fuels containing high concentrations of naphthalenes or tetralins (> 10 percent v), fuel total hydrogen content correlates well with fuel sooting tendency. The present results are explained by a hypothesis that assumes that the majority of soot is formed in regions of high temperature, low oxygen content, and low fuel concentration, e.g., the recirculation zone.

Soot Formation and Its Effect in an Aero Gas Turbine Combustor

2019 ◽  
Vol 36 (1) ◽  
pp. 61-73 ◽  
Author(s):  
R. K. Mishra ◽  
Sunil Chandel
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Soot Formation ◽  
Cone Angle ◽  
Peak Temperature ◽  
Soot Concentration ◽  
Gas Turbine Combustor ◽  
Spray Cone ◽  
Primary Zone ◽  
Soot Deposit

Abstract Soot formation and the effect of soot deposit on the performance and integrity on an aero gas turbine combustor has been studied. Defective atomizer or blockage of air passages creates a fuel rich mixture which promotes soot formation in combustor primary zone. The temperature field and soot concentration inside the liner has been analyzed at high equivalence ratio using computational model in CFX. The peak temperature in primary zone increases till equivalence ratio reaches ϕ=1.1. But at high equivalence ratio, i. e., ϕ≥1.2, the peak temperature in primary zone decreases and that in dilution zone increases. Soot concentration increases at liner front end as well as in dilution zone when equivalence ratio increases from 1.25 to 3.0. Erosion and distortion of atomizer flow passages cause higher spray cone angle which again increases the soot concentration. Soot deposit inside liner has detrimental effect on the life and performance of the combustor as well as of the aero engine.

NOx Reduction in Gas Turbine Combustors With Compact Non-Premixed Flame Front

2014 ◽  
Author(s):  
V. V. Tsatiashvili ◽  
V. G. Avgustinovich
Keyword(s):  
Flame Front ◽  
Gas Turbine ◽  
Nox Reduction ◽  
Premixed Flame ◽  
Nox Emission ◽  
Nox Formation ◽  
New Approach ◽  
Index Reduction ◽  
Primary Zone ◽  
Low Emission

This paper represents results of R&D efforts towards reducing a bypass turbofan engine NOx emission by 45 % compared with CAEP/6 to meet the ICAO NOx emission goal of 2020. To achieve ICAO NOx technology goal, a new approach is used based on the NOx emission reduction in combustors with non-premixed combustion well proved in operation. The new approach is represented by structured system of low emission combustion principles — a concept of combustor featuring compact non-premixed flame (CNPF). The essence of CNPF concept is in suppression of volume and surface NOx formation sources by flame front blocking in liner primary zone and by increasing of fuel effective burning rate. The paper represents the development of concept up to and including the 4th technology maturity level. It demonstrates CNPF concept independence and interaction with other up-to-date gas turbine low emission concepts. The paper indicates comparison of rig test results between in-service combustor and CNPF adopted combustors carried out on a single liner. A CNPF adopted combustor shows NOx emission index reduction by 35 …47 % at take-off engine conditions. Preliminary estimation shows that it is possible to reach the ICAO goal for NOx emission level of 2020.

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