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Technical Paper

Relationship among Various Particle Characterization Metrics Using GDI Engine Based Light-Duty Vehicles

In recent years, gasoline direct injection (GDI) engines have been widely used by manufacturers in light-duty to meet stringent fuel economy and emissions standards. This study focuses on the relationship between various particle metrics such as number, size, surface area and mass of dilute exhaust particles from 12 different light-duty vehicles equipped with GDI engines. The campaign included the measurement of total particulate matter (PM) using Title 40 CFR Part 1066 compliant filter measurement, soot mass using photo-acoustics based analyzer, organic carbon (OC) & elemental carbon (EC) mass using thermo-optical analysis of quartz filter samples, solid particle number using European Union Regulation No. 49 compliant number system and solid particle size/number using an electrical mobility based size spectrometer.
Technical Paper

Solid Particle Number and Ash Emissions from Heavy-Duty Natural Gas and Diesel w/SCRF Engines

Solid and metallic ash particle number (PN) and particulate matter (PM) mass emission measurements were performed on a heavy-duty (HD) on-highway diesel engine and a compressed natural gas (CNG) engine. Measurements were conducted under transient engine operation that included the FTP, WHTC and RMC. Both engines were calibrated to meet CARB ultra low NOX emission target of 0.02 g/hp-hr, a 90% reduction from current emissions limit. The HD diesel engine final exhaust configuration included a number of aftertreatement sub-systems in addition to a selective catalytic reduction filter (SCRF). The stoichiometric CNG engine final configuration included a closed coupled Three Way Catalyst (ccTWC) and an under floor TWC (ufTWC). The aftertreatment systems for both engines were aged for a full useful life (FUL) of 435,000 miles, prior to emissions testing. PM mass emissions from both engines were comparable and well below the US EPA emissions standard.
Technical Paper

Fuel Effects Study with Small (<19kW) Spark-Ignited Off-Road Equipment Engines

This paper covers work performed for the California Air Resources Board and the United States Environmental Protection Agency by Southwest Research Institute. Emission measurements were made on nine types of off-road equipment with small (<19kW) spark-ignited engines including handheld and non-handheld equipment utilizing oxygenated and non-oxygenated fuels. Emission data was produced to augment ARB and EPA's off-road emission inventory. It was intended that this program provide ARB and EPA with emission test results they require for atmospheric modeling. The paper describes the equipment and engines tested, test procedures, emissions sampling methodologies, and emissions analytical techniques. Fuels used in the study are described, along with the emissions characterization results. The fuel effects on exhaust emissions and operation due to ethanol content and fuel components is compared.
Technical Paper

Fuel Effects Study with In-Use Two-Stroke Motorcycles and All-Terrain-Vehicles

This paper covers work performed for the California Air Resources Board and US Environmental Protection Agency by Southwest Research Institute. Emission measurements were made on four in-use off-road two-stroke motorcycles and all-terrain vehicles utilizing oxygenated and non-oxygenated fuels. Emission data was produced to augment ARB and EPA's off-road emission inventory. It was intended that this program provide ARB and EPA with emission test results they require for atmospheric modeling. The paper describes the equipment and engines tested, test procedures, emissions sampling methodologies, and emissions analytical techniques. Fuels used in the study are described, along with the emissions characterization results. The fuel effects on exhaust emissions and operation due to ethanol content and fuel components is compared.
Technical Paper

Locomotive Emissions Measurements for Various Blends of Biodiesel Fuel

The objective of this project was to assess the effects of various blends of biodiesel on locomotive engine exhaust emissions. Systematic, credible, and carefully designed and executed locomotive fuel effect studies produce statistically significant conclusions are very scarce, and only cover a very limited number of locomotive models. Most locomotive biodiesel work has been limited to cursory demonstration programs. Of primary concern to railroads and regulators is understanding any exhaust emission associated with biodiesel use, especially NOX emissions. In this study, emissions tests were conducted on two locomotive models, a Tier 2 EMD SD70ACe and a Tier 1+ GE Dash9-44CW with two baseline fuels, conventional EPA ASTM No. 2-D S15 (commonly referred to as ultra-low sulfur diesel - ULSD) certification diesel fuel, and commercially available California Air Resource Board (CARB) ULSD fuel.
Journal Article

Determination of the PEMS Measurement Allowance for PM Emissions Regulated Under the Heavy-Duty Diesel Engine In-Use Testing Program

This paper summarizes the Heavy-Duty In-Use Testing (HDUIT) measurement allowance program for Particulate Matter Portable Emissions Measurement Systems (PM-PEMS). The measurement allowance program was designed to determine the incremental error between PM measurements using the laboratory constant volume sampler (CVS) filter method and in-use testing with a PEMS. Two independent PM-PEMS that included the Sensors Portable Particulate Measuring Device (PPMD) and the Horiba Transient Particulate Matter (TRPM) were used in this program. An additional instrument that included the AVL Micro Soot Sensor (MSS) was used in conjunction with the Sensors PPMD to be considered a PM-PEMS. A series of steady state and transient tests were performed in a 40 CFR Part 1065 compliant engine dynamometer test cell using a 2007 on-highway heavy-duty diesel engine to quantify the accuracy and precision of the PEMS in comparison with the CVS filter-based method.
Technical Paper

Countering the Effects of Media Interferences and Background Contamination in Collection of Low Concentration Aldehydes and Ketones in Engine Exhaust with Dinitrophenylhydrazine (DNPH) Derivatization

This paper discusses a method developed to counter the variability of media interferences for the measurement of aldehydes and ketones in automotive exhaust. Dinitrophenylhydrazine (DNPH) Derivatization Methodology for the collection of aldehyde and ketone compounds in vehicle exhaust has been in use for over thirty years. These carbonyl compounds are captured by passing diluted exhaust gas through a sample medium containing DNPH. The sampling medium can take the form of DNPH dispersed on a solid sorbent or as a DNPH solution in a solvent such as acetonitrile. Carbonyl compounds react readily to form DNPH derivatives which are stable and which absorb ultra-violet (UV) light, facilitating quantitative measurement. However, when the procedure was developed, emissions rates from vehicles were much higher than the current (2010) emissions levels.
Technical Paper

Verification of a Gaseous Portable Emissions Measurement System with a Laboratory System Using the Code of Federal Regulations Part 1065

This paper summarizes the validation testing of the Horiba Instruments OBS-2200 gaseous portable emissions measurement system (PEMS) for in-use compliance testing per Title 40 of the Code of Federal Regulations (CFR) Part 1065.920 (Section 1065.920). The qualification process included analyzer verifications as well as engine testing on a model-year 2007 heavy-duty diesel engine produced by Volvo Powertrain. The measurements of brake-specific emissions with the OBS-2200 were compared to those of a CFR Part 1065-compliant CVS test cell over a series of not-to-exceed (NTE) events. The OBS-2200 passed all linearity verifications and analyzer checks required of PEMS. Engine test validation was achieved for all three regulated gaseous emissions (CO, NMHC, and NOX) per 40 CFR Part 1065.920(b)(5)(i), which requires a minimum of 91 percent of the measurement allowance adjusted deltas to be less than or equal to zero.
Technical Paper

Portable Emissions Measurement for Retrofit Applications – The Beijing Bus Retrofit Experience

In 2005, the United States Environmental Protection Agency (EPA) and Southwest Research Institute (SwRI) embarked on a mission to help the city of Beijing, China, clean its air. Working with the Beijing Environmental Protection Bureau (BEPB), the effort was a pilot diesel retrofit demonstration program involving three basic retrofit technologies to reduce particulate matter (PM). The three basic technologies were the diesel oxidation catalyst (DOC), the flowthrough diesel particulate filter (FT-DPF), and the wallflow diesel particulate filter (WF-DPF). The specific retrofit systems selected for the project were verified through the California Air Resources Board (CARB) or the EPA verification protocol [1]. These technologies are generally verified for PM reductions of 20-40 percent for DOCs, 40-50 percent for the FT-DPF, and 85 percent or more for the high efficiency WF-DPF.
Technical Paper

Performance Test Results of a New On Board Emission Measurement System Conformed with CFR Part 1065

A new on-board portable emission measurement system (PEMS) for gaseous emissions has been designed and developed to meet CFR Part 1065 requirements. The new system consists of a heated flame ionization detector (HFID) for the measurement of total hydrocarbon, a heated chemiluminescence detector (HCLD) for the measurement of NOx, and a heated non-dispersive infra-red detector (HNDIR) for the measurement of CO and CO2. The oxygen interference and relative sensitivity of several hydrocarbon components have been optimized for the HFID. The CO2 and H2O quenching effect on the HCLD have been compensated using measured CO2 and H2O concentration. The spectral overlap and molecular interaction of H2O on the HNDIR measurement has also been compensated using an independent H2O concentration measurement. The basic performance of the new on-board emission measurement system has been verified accordingly with CFR part 1065 and all of the performances have met with CFR part 1065 requirement.

Diesel Emissions and Their Control

This book will assist readers in meeting today's tough challenges of improving diesel engine emissions, diesel efficiency, and public perception of the diesel engine. It can be used as an introductory text, while at the same time providing practical information that will be useful for experienced readers. This comprehensive book is well illustrated with more than 560 figures and 80 tables. Each main section is broken down into chapters that offer more specific and extensive information on current issues, as well as answers to technical questions.
Technical Paper

Marine Outboard and Personal Watercraft Engine Gaseous Emissions, and Particulate Emission Test Procedure Development

The U.S. EPA and the California Air Resources Board have adopted standards to reduce emissions from recreational marine vessels. Existing regulations focus on reducing hydrocarbons. There are no regulations on particulate emissions; particulate is expected to be reduced as a side benefit of hydrocarbon control. The goal of this study was to develop a sampling methodology to measure particulate emissions from marine outboard and personal watercraft engines. Eight marine engines of various engine technologies and power output were tested. Emissions measured in this program included hydrocarbons, carbon monoxide, oxides of nitrogen. Particulate emissions will be presented in a follow-up paper.
Technical Paper

Particle Size Distribution from a Heavy-Duty Diesel Engine: Steady-State and Transient Emission Measurement Using Two Dilution Systems and Two Fuels

Particle size distribution and number concentration were measured in the dilute exhaust of a heavy-duty diesel engine for steady-state and transient engine operation using two different dilution systems that included a full flow CVS that was coupled to an ejector pump (CVS-EP), and a double-ejector micro-dilution tunnel (DEMDT) that was connected to engine exhaust close to turbocharger outlet. Measurements were performed using a scanning mobility particle sizer (SMPS), an electrical low pressure impactor (ELPI), and a parallel flow diffusion battery (PFDB). Fuels with sulfur content of about 385 ppm and 1 ppm were used for this work. The PFDB performed well in measuring nanoparticles in the size range below 56 nm when compared with the SMPS. This was especially valid when a distinct log-normal size distribution in the size range below 56 nm in diameter, the upper size limit of the PFDB, was present.
Technical Paper

Effects of Water-Fuel Emulsions on Spray and Combustion Processes in a Heavy-Duty DI Diesel Engine

Significant reductions of particulate matter (PM) and nitrogen oxides (NOx) emissions from diesel engines have been realized through fueling with water-fuel emulsions. However, the physical and chemical in-cylinder mechanisms that affect these pollutant reductions are not well understood. To address this issue, laser-based and chemiluminescence imaging experiments were performed in an optically-accessible, heavy-duty diesel engine using both a standard diesel fuel (D2) and an emulsion of 20% water, by mass (W20). A laser-based Mie-scatter diagnostic was used to measure the liquid-phase fuel penetration and showed 40-70% greater maximum liquid lengths with W20 at the operating conditions tested. At some conditions with low charge temperature or density, the liquid phase fuel may impinge directly on in-cylinder surfaces, leading to increased PM, HC, and CO emissions because of poor mixing.
Technical Paper

Performance of Partial Flow Sampling Systems Relative to Full Flow CVS for Determination of Particulate Emissions under Steady-State and Transient Diesel Engine Operation

The use of a partial flow sampling system (PFSS) to measure nonroad steady-state diesel engine particulate matter (PM) emissions is a technique for certification approved by a number of regulatory agencies around the world including the US EPA. Recently, there have been proposals to change future nonroad tests to include testing over a nonroad transient cycle. PFSS units that can quantify PM over the transient cycle have also been discussed. The full flow constant volume sampling (CVS) technique has been the standard method for collecting PM under transient engine operation. It is expensive and requires large facilities as compared to a typical PFSS. Despite the need for a cheaper alternative to the CVS, there has been a concern regarding how well the PM measured using a PFSS compared to that measured by the CVS. In this study, three PFSS units, including AVL SPC, Horiba MDLT, and Sierra BG-2 were investigated in parallel with a full flow CVS.
Technical Paper


The first Clean Snowmobile Challenge (CSC) was held in Jackson Hole, Wyoming in late March of 2000.(1)* It drew public attention to environmental issues associated with recreational products such as snowmobiles, and encouraged development of novel solutions through this SAE-sponsored student competition. While much good information was obtained, one area needing improvement was emissions measurement. In 2000, snowmobile emissions were measured using a drive-by infrared-type device. While this provided a rough indication of emission levels, more accurate data was desired to better reflect progress in reducing emissions. For this year's competition, Southwest Research Institute (SwRI) assembled the equipment necessary to provide brake-specific emissions measurement on-site. A truck-mounted mobile unit was outfitted with laboratory-grade instrumentation for measurement of HC, CO, NOx, CO2, and O2. A snowmobile chassis dynamometer was used to load the engines.
Technical Paper

Catalytic Converter Thermal Environment Measurement Under Dynamometer Simulated Roadloads

An increasing number of passenger vehicle exhaust systems incorporate catalytic converters that are “close-coupled” to the exhaust manifold to further reduce the quantity of cold-start emissions and increase overall catalyst conversion efficiencies. In general, close-coupled catalytic converters are not necessarily subjected to higher inlet exhaust temperatures than conventional underbody catalytic converters. To establish a foundation of on-vehicle temperature data, several passenger vehicles with close-coupled catalytic converters were studied while operating on a chassis dynamometer. Converter temperatures were measured over a variety of vehicle test conditions, including accelerations and extended steady-state speeds for several throttle positions, at both zero- and four-percent simulated road grades.
Technical Paper

Development and Validation of a Snowmobile Engine Emission Test Procedure

An appropriate test procedure, based on a duty cycle representative of real in-use operation, is an essential tool for characterizing engine emissions. A study has been performed to develop and validate a snowmobile engine test procedure for measurement of exhaust emissions. Real-time operating data collected from four instrumented snowmobiles were combined into a composite database for analysis and formulation of a snowmobile engine duty cycle. One snowmobile from each of four manufacturers (Arctic Cat, Polaris, Ski-Doo, and Yamaha) was included in the data collection process. Snowmobiles were driven over various on- and off-trail segments representing five driving styles: aggressive (trail), moderate (trail), double (trail with operator and one passenger), freestyle (off trail), and lake driving. Statistical analysis of this database was performed, and a five-mode steady-state snowmobile engine duty cycle was developed.
Technical Paper

Emissions From Snowmobile Engines Using Bio-based Fuels and Lubricants

Snowmobile engine emissions are of concern in environmentally sensitive areas, such as Yellowstone National Park (YNP). A program was undertaken to determine potential emission benefits of use of bio-based fuels and lubricants in snowmobile engines. Candidate fuels and lubricants were evaluated using a fan-cooled 488-cc Polaris engine, and a liquid-cooled 440-cc Arctco engine. Fuels tested include a reference gasoline, gasohol (10% ethanol), and an aliphatic gasoline. Lubricants evaluated include a bio-based lubricant, a fully synthetic lubricant, a high polyisobutylene (PIB) lubricant, as well as a conventional, mineral-based lubricant. Emissions and fuel consumption were measured using a five-mode test cycle that was developed from analysis of snowmobile field operating data.
Technical Paper

Reduced Cold-Start Emissions Using Rapid Exhaust Port Oxidation (REPO) in a Spark-Ignition Engine

An emissions reduction strategy was developed and demonstrated to significantly reduce cold-start hydrocarbon (HC) and CO emissions from a spark ignition (SI), gasoline-fueled engine. This strategy involved cold-starting the engine with an ultra-fuel rich calibration, while metering near-stoichiometric fractions of air directly into the exhaust ports. Using this approach, exhaust constituents spontaneously ignited at the exhaust ports and burned into the exhaust manifold and exhaust pipe leading to the catalytic converter. The resulting exotherm accelerated catalyst heating and significantly decreased light-off time following a cold-start on the FTP-75 with a Ford Escort equipped with a 1.9L engine. Mass emissions measurements acquired during the first 70 seconds of the FTP-75 revealed total-HC and CO reductions of 68 and 50 percent, respectively, when compared to baseline measurements.