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 Automobiles presents the fundamental theory of emission formation, particularly the oxides of nitrogen (NOx) and its chemical reactions and control techniques. The book provides a simplified framework for technical literature on NOx reduction strategies in IC engines, highlighting thermodynamics, combustion science, automotive emissions and environmental pollution control. Sections cover the toxicity and roots of emissions for both SI and CI engines and the formation of various emissions such as CO, SO2, HC, NOx, soot, and PM from internal combustion engines, along with various methods of NOx formation. Topics cover the combustion process, engine design parameters, and the application of exhaust gas recirculation for NOx reduction, making this book ideal for researchers and students in automotive, mechanical, mechatronics and chemical engineering students working in the field of emission control techniques. Front Cover NOx Emission Control Technologies in Stationary and Automotive Internal Combustion Engines: Approaches Toward NOx Free Aut ... Copyright 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 Back Cover