This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Lean Burn Natural Gas Fueled S.I.Engine and Exhaust Emissions
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 01, 1995 by SAE International in United States
Annotation ability available
An experimental study was undertaken to study exhaust emission from a lean-burn natural gas spark ignition engine. The possibility that such an engine may help to reduce exhaust emissions substantially by taking advantage of natural gas fuel properties, such as its antiknock properties and extended lean flammability limit compared to gasoline, was the main motivation behind the investigation. A four cylinder, automotive type spark ignition engine was used in the investigation. The engine was converted to operate on natural gas by replacing its fuel system with a gaseous carburetion system. A 3-way metal metrix catalytic converter was used in the engine exhaust system to reduce emission levels.
The engine operated satisfactorily at an equivalence ratio as lean as 0.6, at all speeds and loads. As a result NOx emissions were significantly reduced. However, hydrocarbon emissions were high, particularly at very lean conditions and light loads. Most of these hydrocarbons were made up of methane with small concentrations of ethane and propane. Coefficient of variations in hydrocarbons were generally high at very lean operating conditions and light loads, but decreased with increasing equivalence ratio and engine speed. Methane concentrations in the engine exhaust decreased with increasing load and equivalence ratio. At lean air-to-fuel ratios and light loads oxidation of methane in the catalyst was substantially limited and no NOx reduction was achieved. In addition, the proportion of nitric oxide in oxides of nitrogen increased with increasing amount of NOx in the engine exhaust. A major problem encountered in the study was the inability of the fuel system to maintain near constant air-to-fuel ratios at steady operating conditions.
CitationVarde, K., Patro, N., and Drouillard, K., "Lean Burn Natural Gas Fueled S.I.Engine and Exhaust Emissions," SAE Technical Paper 952499, 1995, https://doi.org/10.4271/952499.
- Bartholomew, E, “Four Decades of Engine Fuel Technology,” SAE Paper 660771, 1966.
- Kuivaneu, G. J., Westra, R. O., and Lien, D. G., “Engine Fuel Relationships with LPG and Natural Gas,” SAE Paper 670053, 1967.
- King, R. O., Wallace, W. A., and Mahapatra, B., “The Oxidation, Ignition, and Detonation of Fuel Vapors and Gases,” Can. J. Research(F), 26,264, 1948.
- Kamo, R. and Cooper, P., “Modern Ignition Systems for Gas Engines.” ASME Paper 64- OGP-15, 1964.
- Warner, R., New “Ignition Concepts and Their Application to Gas Engines,” ASME Paper 66-DGEP-11, 1966.
- Genslak, S. L., “Evaluation of Gaseous Fuels for Automobiles,” SAE Paper 720125, 1972.
- Karim, G. A. and Wierzba, I., “Comparative Studies of Methane and Propane as Fuels for Spark Ignition and Compression Ignition Engines,” SAE Paper 8311966, 1983.
- Weaver, C. S., “Natural Gas Vehicle--A Review of the State of the Art,” SAE Paper 892133, 1989.
- Nyland, N. and Riikonen, A., “Low Polluting Gas Fueled Heavy Duty Vehicles,” SAE Paper 912365, 1991.
- Yakabe, H., Tai, H., dan Matsura, M., “Air-to-Fuel Ratio Control of Gas Engines Using Response Characteristics of Three-Way Catalysts under Dynamic Operation,” SAE Paper 912362, 1991.
- Engman, T. J., “Stationary, Gaseous-Fueled, I.C. Engine Air-Fuel Ratio Control for Application of Three-Way Catalysts for Exhaust Emission Reduction,” ASME Paper 83-DPG-3, 1983.
- Varde, K. S., Cherng, J. C., Bailey, C. J., and Majewski, W. A., “Emissions and Their Control in Natural Gas Fueled Engines,” SAE Paper 922250, 1992.
- Hundleby, G. E., “Low Emissions Approaches for Heavy-Duty Gas-Powered Urban Vehicles,” SAE Paper 892134, 1989.
- Varde, K. S. and Bohr, T., “MHC and Other Conversions in a Natural Gas-Fueled Engine,” SAE Paper 931632, 1993.
- Obert, E. F., Internal Combustion Engines and Air Pollution, Intext Educational Publishers, Third Ed., New York, 1973.
- Heywood, J. B., Internal Combustion Engine Fundamentals, McGraw-Hill, Inc., NY, 1988.
- Daniel, W. A., “Flame Quenching at the Walls of an Internal Combustion Engine,” Proc. of Sixth Int. Symposium on Combustion, 886, 1957.
- Peters, B. D., “Mass Burning Rates in a SI Engine Operating in the Partial-Burn Regime,” Proc. Fuel Economy and Emissions of Lean Burn Engines, Paper C92/79, Inst. Mech Engr, London, 1979.
- Rudy, W. M., “Catalytic Control of Exhaust Emissions from CNG Fueled Engines,” technical presentation at the SAE Optimize Methanol and Natural Gas Fueled Vehicles Workshop, Knoxville, Tennessee, September 1990.