NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines: Approaches Toward NOx Free Automobiles

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NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines: Approaches Toward NOx Free Aut ...
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Contents
Contributors
Preface
About the editor
Chapter 1: Emission formation in IC engines
1.1. Introduction
1.2. Emission standards
1.3. Exhaust pollutants from spark ignition engines
1.3.1. Regulated emissions
1.3.1.1. Hydrocarbon emissions
1.3.1.2. Carbon monoxide emissions
1.3.1.3. Oxides of nitrogen emissions
1.3.1.4. Sulfur and lead emissions
1.3.2. Unregulated emissions
1.3.2.1. Aldehydes and ketones
1.4. Exhaust pollutants from compression ignition engines
1.4.1. Regulated emissions
1.4.1.1. Hydrocarbons emissions
1.4.1.2. Particulate matter
1.4.1.3. Nitrogen oxides emissions
1.4.1.4. Carbon monoxide emissions
1.5. Environmental and health effects of engine emissions
1.5.1. Primary pollutants
1.5.2. Secondary pollutants
1.6. SI engine emission formation and its root cause
1.7. CI engine emission formation and its root cause
1.8. Concept of emission mitigation technologies for NOx emissions
1.8.1. Engine design and operation parameter-based NOx emission control
1.8.1.1. Alteration of injection timing
1.8.1.2. Technique of exhaust gas recirculation
1.8.1.3. Usage of alcohols
1.8.1.4. Alteration of injection pressure
1.8.2. After treatment-based NOx emission control
1.8.2.1. Three-way catalytic converter
1.8.2.2. Selective catalytic reduction
1.8.3. Other emission control techniques
1.8.3.1. Diesel particulate filter
Active regeneration system
Passive regeneration systems
Continuously regenerating trap
1.9. Conclusions
References
Chapter 2: NOx formation chemical kinetics in IC engines
2.1. Introduction
2.2. Chemical kinetic model of NO formation
2.3. Thermodynamic properties
2.4. Reaction mechanism
2.5. NOx formation in IC engines
2.6. Thermal NO formation
2.7. Prompt NO formation
2.8. NO production from fuel nitrogen
2.9. Mechanisms for the formation of NO
2.9.1. Zeldovich mechanism
2.9.2. Nitrous oxide mechanism
2.9.3. Fenimore mechanism
2.9.4. NNH mechanism
2.10. Uncontrolled NOx emission levels in IC engines
2.11. Factors influencing NOX emissions from IC engines
2.11.1. Engine design and operating parameters
2.11.2. Air-to-fuel ratio (A/F) and charging method
2.11.3. Ignition timing
2.11.4. Combustion chamber and valve design
2.11.5. Engine combustion cycle
2.11.6. Engine load and speed
2.12. Effects of alternative fuel (biodiesel)
2.12.1. Speed of sound
2.12.2. Isentropic bulk modulus
2.12.3. Radiative heat transfer
2.12.4. Adiabatic flame temperature
2.12.5. Combustion phasing
2.12.6. Engine control strategy
2.13. Ambient conditions
2.14. Concluding remarks
References
Chapter 3: NOx and PM trade-off in IC engines
3.1. Introduction
3.2. Legislative norms aimed at controlling vehicular emissions
3.3. NOx reduction techniques in IC engines
3.3.1. Role of precombustion engine parameters and oxygenated fuels on NOx control
3.3.2. Postcombustion NOx emission control techniques in IC engines
3.4. Differences in PM emissions based on their nature and size
3.5. PM control techniques in IC engines
3.5.1. Precombustion factors influencing PM emission while operating on alternative fuels
3.5.2. Influence of postcombustion PM emission control techniques in IC engines
3.6. Trade-off relationship between NOx and PM emissions in IC engines
3.6.1. Improving NOx-PM trade-off in IC engines
3.6.2. Role of oxygenated additives and alternative fuels in NOx-PM trade-off
3.7. Simultaneous reduction of NOx and PM emissions
3.7.1. Combined influence of alternative fuels and NOx-PM control techniques
3.7.2. Limitations and challenges in simultaneous control of NOx-PM emissions
3.8. Conclusion
References
Chapter 4: Effect of engine design parameters in NOx reduction
4.1. Introduction
4.2. Role of engine design parameters on NOx emission
4.3. Effect of intake system design on NOx emissions
4.4. Effect of injection system design on NOx emissions
4.5. Design of combustion chamber
4.6. Effects of chamber geometry on NOx emission
4.7. Effects of chamber design parameters on NOx emissions
4.8. Effect of compression ratio on NOx emissions
4.9. Role of compression ratio in NOx mitigation for CI engines
4.10. Role of compression ratio in NOx mitigation for SI engines
4.11. Effect of valve timing and design on NOx emissions
4.12. Effect of thermal barrier coating on NOx emissions
4.13. Low-temperature combustion for NOx reduction
4.14. Overall engine design requirements and considerations for NOx mitigation
4.15. Conclusion
References
Chapter 5: Effect of engine operating parameters in NOx reduction
5.1. Introduction
5.2. Engine operating factors influencing NOx emissions in CI and SI engines
5.3. Effect of fuel injection parameters on NOx emissions in CI engines
5.3.1. Injection pressure
5.3.2. Injection timing
5.3.3. Injection duration
5.4. Effect of fuel ignition parameters on NOx emissions in SI engines
5.4.1. Spark timing
5.4.2. Spark intensity
5.4.3. Flame travel distance
5.5. Effect of air-fuel/equivalence ratio on NOx emissions
5.6. Effect of inlet conditions on NOx emissions
5.6.1. Variable valve actuation
5.6.2. Turbocharger
5.6.3. Inlet air temperature
5.7. Effect of inlet condition of fuel on engine NOx emissions
5.7.1. Dual fuel operation
5.7.2. Fumigation
5.8. Effect of coolant temperature on NOx emissions in CI and SI engines
5.9. Effect of engine speed on NOx emissions
5.10. Effect of engine load on NOx emissions
5.11. Comparison of different operating parameters
5.12. Conclusion
References
Chapter 6: Application of exhaust gas recirculation of NOx reduction in SI engines
6.1. Introduction
6.2. Different types of EGR set-up
6.3. Stratified form of EGR
6.4. Hot and cooled EGR
6.5. Correlation between knock and NOx emissions
6.6. EGR vs. NOx and soot emissions
6.6.1. Fuel/air ratio on NOx emissions
6.6.2. Effect of ignition timing on NOx emission
6.7. EGR in advanced SI engines
6.7.1. EGR in MPFI engines
6.7.2. EGR in GDI engines
6.7.3. EGR in lean-burn engines
6.8. EGR implementation in advanced SI engines
6.8.1. Turbocharged SI engine with EGR
6.8.2. Natural gas-powered SI engine with dedicated EGR
6.8.3. Hydrogen powered SI engine with dedicated EGR
6.9. Conclusion
Acknowledgment
References
Chapter 7: Application of exhaust gas recirculation for NOx reduction in CI engines
7.1. Introduction
7.2. Exhaust gas recirculation
7.3. Design configurations
7.4. EGR operating window and significance
7.5. EGR control strategies
7.5.1. Mechanical control
7.5.2. Electrical control
7.5.3. Electronic/microcomputer control
7.6. EGR implementation in conventional CI engines
7.6.1. Under steady state
7.6.2. Under transient state
7.7. EGR implementation in advanced combustion CI engines
7.7.1. HCCI
7.7.2. PPCCI and PCCI
7.7.3. RCCI
7.8. EGR implementation for alternate fueled engines
7.9. Effect of EGR on oil contamination, engine wear, and soot
7.10. EGR in conventional/advanced SI and CI engines-A comparison
7.11. Conclusion
References
Chapter 8: NOx reduction in IC engines through after treatment catalytic converter
8.1. Introduction
8.2. Evolution of catalytic converter
8.2.1. First-generation catalytic converter
8.2.2. Second-generation catalytic converter
8.2.3. Modern catalytic converter
8.2.3.1. Three-way catalytic converter for SI engines
8.2.3.2. Three-way catalytic converter for CI engines
Challenges in implementing three-way catalytic converters in CI engines
8.3. Design and fabrication of three-way catalytic converters
8.3.1. Heat capacity-catalytic surface area, cell density, wall thickness
8.3.1.1. Significance
8.3.2. Catalyst diameter
8.3.2.1. Significance
8.3.3. Flow distribution
8.3.3.1. Significance
8.3.4. Coating
8.3.4.1. Significance
8.3.5. Catalyst length
8.3.5.1. Significance
8.3.6. Fabrication of the three-way catalytic converter
8.4. Catalysts for NOx control
8.5. NOx reaction mechanism and chemical kinetics in three-way catalytic converter
8.6. Factors affecting performance of three-way catalytic converters
8.6.1. Thermal stability
8.6.2. Backpressure
8.6.3. Flow distribution
8.6.4. Conversion efficiency
8.6.5. Catalyst light-off temperature
8.6.6. Cold start emission
8.6.7. Lean burn emission
8.6.8. Durability analysis of catalytic converters
8.6.9. Control of engine air-fuel ratio with ECU
8.7. Recent developments in catalytic converters
8.8. Conclusion
References
Chapter 9: NOx reduction in IC engines through adsorbing technique
9.1. Introduction
9.2. Active NOx adsorption or lean NOx trap (LNT)
9.2.1. LNT working characteristics
9.3. Influences of exhaust gas species, temperature, and hydrogen in LNT
9.3.1. Influences of CO2 and H2O on NOx adsorption
9.3.2. Influence of temperature on NOx reduction
9.3.3. Influence of hydrogen on NOx reduction
9.4. Selective NOx recirculation (SNR)
9.4.1. NOx adsorbing catalyst materials
9.5. Passive NOx adsorber or low-temperature NOx adsorber (LTNA)
9.5.1. Metal oxides and zeolite for passive NOx adsorption
9.6. Operating conditions for NOx adsorption
9.6.1. Influence of adsorption temperature
9.6.2. Influence of space velocity
9.6.3. Influence of exhaust gas species
9.6.3.1. Influence of NO and NO2 concentration
9.6.3.2. Influence of H2O and CO2 on oxide-based catalyst
9.6.3.3. Influence of H2O and CO2 on zeolite-based catalyst
9.6.4. Influence of ethene (C2H4)on NOx adsorption
9.6.5. Sulfur poisoning of passive NOx adsorber
9.7. NOx desorption characteristics
9.7.1. Influence of desorption temperature and exhaust gas species
9.7.2. Influence of ramp rate
9.8. Conclusions
References
Chapter 10: Selective catalytic reduction for NOx reduction
10.1. Introduction
10.2. Overview of SCR system and its components
10.2.1. Reductant system
10.2.2. SCR catalyst
10.2.3. Sensing system
10.2.4. SCR controller
10.2.5. Dosing system
10.2.6. Emplacement of SCR system
10.3. De-NOx chemistry in SCR
10.4. An assortment of reductants used in SCR
10.4.1. Ammonia reductant
10.4.2. HC reductant
10.4.3. Other reductants
10.5. An assortment of catalysts for various SCR
10.5.1. Catalyst for NH3 SCR system
10.5.1.1. Vanadium-based catalysts
10.5.1.2. Zeolite-based catalysts
10.5.1.3. Various composite metal oxide catalysts
10.5.2. Catalyst for HC-SCR system
10.5.3. Catalyst for H2-SCR system
10.5.4. Catalyst for CO-SCR system
10.6. SCR controller
10.7. Conclusion
References
Chapter 11: Effects of fuel reformulation techniques in NOx reduction
11.1. Introduction
11.2. Common factors that are crucial for fuel reformulations
11.2.1. General compositions of fuels
11.2.2. Fuel properties
11.3. Methods of fuel refining and its role in tailoring fuel composition
11.4. Formulation of fuels by blending to reduce NOx emissions in IC engines
11.5. Importance of additives on fuel reformulations for NOx reduction in SI engines
11.5.1. Role of fuel additive combinations to reformulate gasoline for NOx control
11.5.2. Notable fuel additives with interrelated functionalities in SI engine outputs
11.6. Importance of additives on fuel reformulations for NOx reduction in CI engines
11.6.1. Role of nanoadditives in conventional diesel fuel composition for NOx reduction
11.6.2. Reformulations of biodiesel with nanoadditives for NOx reduction
11.6.3. Tailoring of diesel fuel with tertiary additives and alcohols for NOx reduction
11.7. Distinctions in fuel reformulation techniques to mitigate NOx emissions
11.8. Conclusion
References
Chapter 12: Influence of alcohol and gaseous fuels on NOx reduction in IC engines
12.1. Introduction
12.2. Suitability of alcohol fuels for the engine application
12.2.1. Methanol
12.2.2. Ethanol
12.2.3. Propanol
12.2.4. Butanol
12.2.5. Pentanol
12.3. Influence of alcohol fuels on NOx reduction in CI engines
12.3.1. Lower alcohol fuels
12.3.2. Higher alcohol fuels
12.4. Influence of alcohol fuels on NOx reduction in SI engines
12.4.1. Lower alcohol fuels
12.4.2. Higher alcohol fuels
12.5. Suitability of gaseous fuels for engine applications
12.5.1. Hydrogen
12.5.2. Compressed natural gas
12.5.3. Biogas
12.6. Influence of gaseous fuels on NOx reduction in CI engines
12.6.1. Hydrogen
12.6.2. Compressed natural gas
12.6.3. Biogas
12.7. Influence of gaseous fuels on NOx reduction in SI engines
12.7.1. Hydrogen
12.7.2. Compressed natural gas
12.7.3. Biogas
12.8. Conclusion
References
Chapter 13: Impact of NOx control measures on engine life
13.1. Introduction
13.2. Various methods for the determination of engine life
13.2.1. Long-term endurance study
13.2.1.1. Long-term endurance test for constant speed internal combustion engines
13.2.1.2. Long-term endurance test for variable speed internal combustion engines
13.2.2. Material compatibility study
13.2.3. Impact of endurance study on lube oil degradation
13.3. Correlation of smoke and NOx emissions on engine life
13.3.1. Impact of smoke emission on engine durability
13.3.2. Impact of NOx emissions on engine life
13.3.3. Effect of oil degradation on NOx emissions
13.4. Effect of NOx reduction devices on SI engine life
13.4.1. Engine performance behavior
13.4.2. Tribological behavior
13.4.3. Wear on engine components
13.5. Impact of NOx reduction devices on CI engine life
13.5.1. Engine performance behavior
13.5.2. Tribological behavior
13.5.3. Wear on engine components
13.6. Effect of advanced technologies on engine durability
13.7. Effect of fuels on engine durability
13.7.1. Desirable fuel properties for longer engine life
13.7.2. Influence of conventional fuels on engine life
13.7.3. Effect of alternate fuels on engine life
13.7.4. Effect of various additives on engine durability
13.8. Reformulation of fuels on engine life
13.9. Conclusions
References
Chapter 14: NOX reduction through various low temperature combustion technologies
14.1. Introduction
14.2. Homogeneous charge compression ignition engine
14.2.1. Significance of external homogeneous charge preparation (EHCP) techniques in NOX reduction
14.2.1.1. Influence of port fuel injection (PFI) strategy on NOx emission
14.2.1.2. Influence of port fuel injection with vaporizer (PFIV) on NOx emissions
14.2.2. Significance of internal homogeneous charge preparation techniques in NOX reduction
14.2.2.1. Influence of early direct injection (EDI) strategy on NOx emissions
14.2.2.2. Influence of late direct injection strategy on NOx emissions
14.2.2.3. Influence of premixed/direct injection homogeneous charge technique on NOx
14.2.3. Influence of fuel properties and blends on HCCI engine NOX emissions
14.3. Premixed charge compression ignition engine
14.3.1. Significance of premixed charge preparation technique in NOx reduction
14.3.2. Role of distinct premixed conventional and alternative fuels on PCCI engine NOx emissions
14.3.2.1. Influence of diesel fuel on PCCI NOx emissions
14.3.2.2. Influence of biodiesel on PCCI NOx emissions
14.3.2.3. Influence of gaseous fuels on PCCI NOx emissions
14.3.3. Role of blend/dual fuels on PCCI NOx emissions
14.3.3.1. Influence of gasoline and diesel blends on PCCI NOx emissions
14.3.3.2. Influence of alcohol and diesel blends on PCCI NOx emissions
14.3.3.3. Influence of biogas and diesel blends on PCCI NOx emissions
14.3.3.4. Influence of DME and diesel blends on PCCI NOx emissions
14.4. Reactivity controlled compression ignition engine
14.4.1. Influence of low and high reactive fuel combustion in RCCI engine exhaust NOx emissions
14.4.1.1. Influence of low reactive gasoline fuel on RCCI engine exhaust NOx emissions
14.4.1.2. Influence of low-reactive alcoholic fuels on RCCI exhaust NOx emissions
14.4.1.3. Influence of low-reactive gaseous fuels on RCCI NOx emissions
14.5. Comparative study on LTC mode advanced combustion engines
14.6. Conclusion
References
Index
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