Characterization of Particulate Matter Emissions From a 4-Stroke, Lean-Burn, Natural Gas Engine

2007 ◽  
Author(s):  
Kris Quillen ◽  
Maren Bennett ◽  
John Volckens ◽  
Rudolf H. Stanglmaier
Keyword(s):  
Particulate Matter ◽  
Natural Gas ◽  
Internal Combustion Engines ◽  
Geometric Mean ◽  
Operating Conditions ◽  
Particulate Emissions ◽  
Scanning Mobility Particle Sizer ◽  
Health And Environmental Effects ◽  
Gas Engine ◽  
Natural Gas Engine

Regulatory agencies are becoming increasingly concerned with particulate emissions as the health and environmental effects are becoming better understood. While much research has been performed on diesel engines, little is known about particulate matter (PM) emissions from natural gas internal combustion engines. In this project, tests were conducted on a Waukesha VGF F18 natural gas engine running at full load. PM10 combustion emissions were collected on Teflon and quartz filters and a scanning mobility particle sizer (SMPS) was used to determine the particle size distribution. Tests were performed at 4, 5, 6, and 7% exhaust oxygen (O2) levels. Overall, it was found that a large number of small particles were emitted from this engine. The total mass based PM emissions were found to be 0.0148 gm/bkW-hr, which is slightly greater than the tier-4 nonroad diesel particulate emissions standard. Particle distributions revealed that the geometric mean diameter (GMD) of the natural gas particles was approximately 30 nm and did not change with air to fuel ratio. Particulate concentrations were found to decrease at leaner engine operating conditions. Results showed a strong correlation between the NOx and particle concentrations, while an inverse correlation between CO and particle concentrations was revealed.

Characterization of Particulate Matter Emissions From a Four-Stroke, Lean-Burn, Natural Gas Engine

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Kris Quillen ◽  
Maren Bennett ◽  
John Volckens ◽  
Rudolf H. Stanglmaier
Keyword(s):  
Particulate Matter ◽  
Natural Gas ◽  
Internal Combustion Engines ◽  
Geometric Mean ◽  
Operating Conditions ◽  
Particulate Emissions ◽  
Emission Standard ◽  
Particulate Emission ◽  
Gas Engine ◽  
Natural Gas Engine

Regulatory agencies are becoming increasingly concerned with particulate emissions as the health and environmental effects are becoming better understood. While much research has been performed on diesel engines, little is known about particulate matter (PM) emissions from natural gas internal combustion engines. In this project, tests were conducted on a Waukesha VGF F18 natural gas engine running at full load. PM10 combustion emissions were collected on teflon and quartz filters and a scanning mobility particle sizer was used to determine the particle size distribution. Tests were performed at 4–7% exhaust oxygen (O2) levels. Overall, it was found that a large number of small particles were emitted from this engine. The total mass based PM emissions were found to be 0.0148gm∕bkWh, which is slightly greater than the Tier-4 nonroad diesel particulate emission standard. Particle distributions revealed that the geometric mean diameter of the natural gas particles was approximately 30nm and did not change with air to fuel ratio. Particulate concentrations were found to decrease at leaner engine operating conditions. Results showed a strong correlation between the NOx and particle concentrations, while an inverse correlation between CO and particle concentrations was revealed.

scholarly journals Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

2017 ◽  
Vol 17 (14) ◽  
pp. 8739-8755 ◽  
Author(s):  
Jenni Alanen ◽  
Pauli Simonen ◽  
Sanna Saarikoski ◽  
Hilkka Timonen ◽  
Oskari Kangasniemi ◽  
...  
Keyword(s):  
Air Quality ◽  
Natural Gas ◽  
Particulate Emissions ◽  
Engine Exhaust ◽  
Gas Engine ◽  
Secondary Aerosol ◽  
Formation Potential ◽  
Natural Gas Engine ◽  
Evaporation Temperature ◽  
Catalyst Temperature

Abstract. Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6–268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9–20 mg kgfuel−1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize – more than half an hour – which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was measured to have the highest evaporation temperature, and nitrate had the lowest. The evaporation temperature of ammonium depended on the fractions of nitrate and sulfate in the particles. The average volatility of the total aged particles was measured to be lower than that of primary particles, indicating better stability of the aged natural gas engine-emitted aerosol in the atmosphere. According to the results of this study, the exhaust of a natural gas engine equipped with a catalyst forms secondary aerosol when the atmospheric ages in a PAM chamber are several days long. The secondary aerosol matter has different physical characteristics from those of primary particulate emissions.

The Effect of Parametric Variations on Formaldehyde Emissions From a Large Bore Natural Gas Engine

2002 ◽  
Author(s):  
Daniel B. Olsen ◽  
Bryan D. Willson
Keyword(s):  
Natural Gas ◽  
Environmental Protection Agency ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Air Pollutant ◽  
Formation Mechanisms ◽  
Combustion Engines ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Hazardous Air Pollutant

Formaldehyde is a hazardous air pollutant (HAP) that is typically emitted from natural gas-fired internal combustion engines as a product of incomplete combustion. The US Environmental Protection Agency (EPA) is currently developing national emission standards to regulate HAP emissions, including formaldehyde, from stationary reciprocating internal combustion engines under Title III of the 1990 Clean Air Act Amendments. This work investigates the effect that variations of engine operating parameters have on formaldehyde emissions from a large bore natural gas engine. The subject engine is a Cooper-Bessemer GMV-4TF two-stroke cycle engine with a 14″ (36 cm) bore and a 14″ (36 cm) stroke. Engine parameter variations investigated include load, boost, ignition timing, inlet air humidity ratio, air manifold temperature, jacket water temperature, prechamber fuel supply pressure, exhaust backpressure, and speed. The data analysis and interpretation is performed with reference to possible formaldehyde formation mechanisms and in-cylinder phenomena.

Particulate Matter Reduction From a Pilot-Ignited, Direct Injection of Natural Gas Engine

2012 ◽  
Author(s):  
G. P. McTaggart-Cowan ◽  
K. Mann ◽  
J. Huang ◽  
N. Wu ◽  
S. R. Munshi
Keyword(s):  
Particulate Matter ◽  
Natural Gas ◽  
Direct Injection ◽  
Pressure Rise ◽  
Gas Jet ◽  
Cfd Analysis ◽  
Heavy Duty ◽  
Effective Technique ◽  
Gas Engine ◽  
Natural Gas Engine

This paper reports an evaluation of various combustion strategies aiming to reduce engine-out particulate matter (PM) emissions from a natural-gas fuelled heavy-duty engine. The work is based on a Westport HPDI fuelling system, which provides direct injection of both natural gas and liquid diesel into the combustion chamber of an otherwise unmodified diesel engine. The diesel acts as a pilot to ignite the natural gas, which normally burns in a non-premixed fashion, leading to significant PM formation. The concepts to reduce PM evaluated in this work are: 1) adjusting the relative phasing of the natural gas and diesel injections to allow more premixing of the natural gas prior to ignition; 2) reducing the pilot quantity to increase the ignition delay of the gas jet; and 3) reducing the level of EGR at select modes to reduce PM formation. These strategies are evaluated at steady state using single- and multi-cylinder research engines, supported by CFD analysis. The results demonstrate that allowing limited premixing of the gas jet prior to ignition can significantly reduce PM emissions. Excessive premixing can lead to high rates of pressure rise; EGR can be used to moderate the combustion under these conditions, without causing increased PM emissions. Reducing pilot quantity is another effective technique to reduce PM, primarily by allowing more air to mix with the gas jet before ignition. These various techniques can be combined to form a new operating strategy that significantly reduces engine-out PM and NOx emissions compared to the baseline strategy without significantly impacting fuel consumption.

Response surface method optimization of a natural gas engine with dedicated exhaust gas recirculation

2021 ◽  
pp. 146808742199652
Author(s):  
Chris A Van Roekel ◽  
David T Montgomery ◽  
Jaswinder Singh ◽  
Daniel B Olsen
Keyword(s):  
Natural Gas ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Effective Pressure ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Indicated Mean Effective Pressure ◽  
Surface Method ◽  
Rsm Optimization ◽  
Gas Recirculation

Stoichiometric industrial natural gas engines rely on robust design to achieve consumer driven up-time requirements. Key to this design are exhaust components that are able to withstand high combustion temperatures found in this type of natural gas engine. The issue of exhaust component durability can be addressed by making improvements to materials and coatings or decreasing combustion temperatures. Among natural gas engine technologies shown to reduce combustion temperature, dedicated exhaust gas recirculation (EGR) has limited published research. However, due to the high nominal EGR rate it may be a technology useful for decreasing combustion temperature. In previous work by the author, dedicated EGR was implemented on a Caterpillar G3304 stoichiometric natural gas engine. Examination of combustion statistics showed that, in comparison to a conventional stoichiometric natural gas engine, operating with dedicated EGR requires adjustments to the combustion recipe to achieve acceptable engine operation. This work focuses on modifications to the combustion recipe necessary to improve combustion statistics such as coefficient of variance of indicated mean effective pressure (COV of IMEP), cylinder-cylinder indicated mean effective pressure (IMEP), location of 50% mass fraction burned, and 10%–90% mass fraction burn duration. Several engine operating variables were identified to affect these combustion statistics. A response surface method (RSM) optimization was chosen to find engine operating conditions that would result in improved combustion statistics. A third order factorial RSM optimization was sufficient for finding optimized operating conditions at 3.4 bar brake mean effective pressure (BMEP). The results showed that in an engine with a low turbulence combustion chamber, such as a G3304, optimized combustion statistics resulted from a dedicated cylinder lambda of 0.936, spark timing of 45° before top dead center (°bTDC), spark duration of 365 µs, and intake manifold temperature of 62°C. These operating conditions reduced dedicated cylinder COV of IMEP by 10% (absolute) and the difference between average stoichiometric cylinder and dedicated cylinder IMEP to 0.19 bar.

Combustion Analysis of a Natural Gas Engine

2003 ◽  
Author(s):  
Seref Soylu
Keyword(s):  
Natural Gas ◽  
Burning Rate ◽  
Equivalence Ratio ◽  
Operating Conditions ◽  
Engine Fuel ◽  
Ignition Timing ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Rate Analysis ◽  
Propagation Period

A two-zone thermodynamic model was developed for a spark ignition natural gas engine. The model was used to calculate instantaneous mass burning rate and thermodynamic state of burned and unburned zones of the combustion chamber content. Cylinder pressure data was collected at various engine operating conditions. Natural gas and natural gas–propane mixtures were used as engine fuel. From the burning rate analysis various combustion characteristics, such as flame initiation period (FIP) and flame propagation period (FPP) were calculated at various engine operating conditions. It was observed that both the FIP and FPP decrease with increasing equivalence ratio for lean mixtures. While the retarded timing decreases the FIP, the FPP has a tendency to increase. Addition of propane to natural gas reduces the FPP although the FIP is not affected. Unburned and burned gas temperatures are significantly raised with increase in equivalence ratio. However, ignition timing and propane fraction do not influence the temperatures as much as equivalence ratio does.

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