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Technical Paper

Simultaneous Reduction of Diesel Particulate and NOx Using a Plasma

1994-10-01
942070
A non-thermal plasma treatment of diesel engine exhaust was effective in removing particulate (soot) and oxides of nitrogen (NOx) from two different light-duty diesel vehicles: an older-technology indirect-injection Toyota truck, and a newer-technology direct-injection Dodge truck. Particulate removal efficiencies and NOx conversion efficiencies were determined at space velocities up to 20,000/hr. Particulate removal efficiencies were above 60 percent for most conditions, but decreased with increasing space velocities. Conversion efficiencies for NOx and carbon monoxide (CO) were also dependent on the space velocity. The NOx conversion efficiencies were generally greater than 40 percent at space velocities less than 7000/hr. The CO concentration increased through the plasma reaction bed indicating that CO was produced by reactions in the plasma.
Technical Paper

Characterization of MOD I Multifuel Stirling Demonstration Vehicle Emissions

1989-02-01
890150
Emissions from a Stirling engine-powered 1986 model light-duty truck were measured using current EPA (chassis dynamometer) emissions certification procedures and certain specialized tests. Three fuels were used including unleaded gasoline, a blend of MTBE in unleaded gasoline, and JP-4. City (FTP) cycles and Highway (FET) cycles were run on all three fuels, and emissions measured during the cycles included hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). Fuel economy was also calculated for these tests. Additional pollutants measured during some of the tests included aldehydes, 1,3-butadiene, individual hydrocarbon species, and total particulate matter. In addition to the cyclic schedules, steady-state conditions were run on JP-4 and straight gasoline for regulated emissions and fuel economy. The conditions consisted of several simulated gradients at three vehicle speeds, plus idle.
Technical Paper

Emission Factors for Small Utility Engines

1991-02-01
910560
A major gap exists in available baseline emissions data on the small utility engine population between the mid-1970's and present day. As part of the input required for a standard-setting process, the California Air Resources Board has funded limited laboratory emission measurements on a number of modern small engines, both 2-stroke and 4-stroke designs. Exhaust constituents characterized in this study include total hydrocarbons, reactive hydrocarbons (RHC), methane, CO, NOx, CO2, O2, aldehydes, and particulate matter. A total of nine engines were evaluated, spanning the range from the smallest widely-used 2-strokes (about 20 cc displacement) to 4-strokes approaching 20 hp.
Technical Paper

A Next-Generation Emission Test Procedure for Small Utility Engines - Part 1, Background and Approach

1990-09-01
901595
Measurement of emissions from small utility engines has usually been accomplished using steady-state raw emissions procedures such as SAE Recommended Practice J1088. While raw exhaust measurements have the advantage of producing modal exhaust gas concentration data for design feedback; they are laborious, may influence both engine performance and the emissions themselves, and have no provision for concurrent particulate measurements. It is time to consider a full-dilution procedure similar in principle to automotive and heavy-duty on-highway emission measurement practice, leading to improvements in many of the areas noted above, and generally to much higher confidence in data obtained. When certification and audit of small engine emissions become a reality, a brief dilute exhaust procedure generating only the necessary data will be a tremendous advantage to both manufacturers and regulatory agencies.
Technical Paper

Toward the Environmentally-Friendly Small Engine: Fuel, Lubricant, and Emission Measurement Issues

1991-11-01
911222
Small engines which are friendly toward the environment are needed all over the world, whether the need is expressed in terms of energy efficiency, useful engine life, health benefits for the user, or emission regulations enacted to protect a population or an ecologically-sensitive area. Progress toward the widespread application of lower-impact small engines is being made through engine design, matching of engine to equipment and task, aftertreatment technology, alternative and reformulated fuels, and improved lubricants. This paper describes three research and development projects, focused on the interrelationships of fuels, lubricants, and emissions in Otto-cycle engines, which were conducted by Southwest Research Institute. All the work reported was funded internally as part of a commitment to advance the state of small engine technology and thus enhance human utility.
Technical Paper

Exhaust Emissions from Farm, Construction, and Industrial Engines and Their Impact

1975-02-01
750788
The research program on which this paper is based included both laboratory emission measurements and extrapolation of results to the national population of heavy-duty farm, construction, and industrial engines. Emission tests were made on four gasoline engines and eight diesel engines typical of those used in F, C, and I equipment. Gaseous and particulate emissions were measured during engine operation on well-accepted steady-state procedures, and diesel smoke was measured during both steady-state conditions and the Federal smoke test cycle. Emissions measured were hydrocarbons, CO, CO2, NO, NOx, O2, aliphatic aldehydes, light hydrocarbons, particulate, and smoke. Emission of sulfur oxides (SOx) was estimated on the basis of fuel consumed, and both evaporative and blowby hydrocarbons were also estimated where applicable (gasoline engines only). Data on emissions obtained from this study were compared with those available in the literature, where possible.
Technical Paper

Characterization of Particulate and Gaseous Emissions from Two Diesel Automobiles as Functions of Fuel and Driving Cycle

1979-02-01
790424
Particulate and gaseous emissions from two light-duty diesel vehicles were measured over eight operating schedules, using five different fuels. Characterization included regulated exhaust emissions and a number of unregulated constituents. Non-routine gas measurements included phenols, hydrocarbon boiling range, and aldehydes. Particulate characterization included mass rates and concentrations, visible smoke, aerodynamic sizing, total organics, BaP, sulfate, phenols, trace elements, and major elements. Statistical analysis of emissions data was undertaken using fuel properties and operating schedule statistics as independent variables. Regressions were computed for a few variables, and analysis of variance and multiple comparisons were used where the data were not suitable for regression analysis.
Technical Paper

Characterization of Heavy - Duty Diesel Gaseous and Particulate Emissions, and Effects of Fuel Composition

1979-02-01
790490
Gaseous and particulate emissions from two heavy-duty diesel engines were characterized while the engines were operated on five different fuels. Characterization included mass rates of major exhaust products, plus analysis of particulate matter for sulfate, trace elements, major elements, total solubles, and other properties. Analysis of rate and composition data was conducted with regard to fuel and engine effects on particulate. Two large particulate samples were also collected for later analysis on groups of organics present.
Technical Paper

Design and Development of Catalytic Converters for Diesels

1992-09-01
921677
Improvements in diesel engine design to reduce particulate emissions levels, and a recent Environmental Protection Agency (EPA) ruling limiting the maximum sulfur content in diesel fuel, enhanced the viability of catalytic aftertreatment for this market. The Department of Emissions Research, Southwest Research Institute (SwRI), under contract from the Engine Manufacturers Association, (EMA), conducted a search to identify flow-through catalyst technologies available to reduce particulate emissions without trapping. The search revealed a variety of catalyst formulations, washcoats, and substrate designs which were screened on a light-duty diesel. Based on the performance of eighteen converters evaluated, several designs were selected to continue experimentation on a modern technology heavy-duty diesel engine.
Technical Paper

Motorcycle Emissions, Their Impact, and Possible Control Techniques

1974-02-01
740627
Seven motorcycles, ranging in size from 100 to 1200 cm3, were tested for emissions characterization purposes. They were operated on the federal seven-mode test procedure (for 1971 and older light-duty vehicles), the federal LA-4 test procedure (for 1972 and later LDVs), and under a variety of steady-state conditions. Four of the machines tested had 4-stroke engines, and the other three had 2-stroke engines. Emissions which were measured included hydrocarbons, CO, CO2, NO, NOx, O2, aldehydes, light hydrocarbons, particulates, and smoke. Emissions of SOx were estimated on the basis of fuel consumed, and evaporative hydrocarbon losses were also estimated. Crankcase “blowby” emissions from one 4-stroke machine were measured. The impact of motorcycles on national pollutant totals was estimated, based on the test results and information from a variety of sources on national population and usage of motorcycles.
Technical Paper

Exhaust Emissions from 2-Stroke Outboard Motors and Their Impact

1974-02-01
740737
To characterize exhaust emissions from water-cooled 2-stroke outboard motors (the predominant type), four new motors were tested on dynamometer stands. The engines ranged from 4-65 hp in size, and operating conditions were chosen along lines of simulated boat loading. All the measurements were taken at steady-state conditions. Emission concentrations were measured in raw exhaust gas and after the gases had been bubbled through water in a specially constructed tank. Constituents measured included hydrocarbons, CO, CO2, NO, NOx, O2, light hydrocarbons, and aldehydes. Emissions of sulfur oxides (SOx) were estimated on the basis of fuel consumed, and all the exhaust emissions data were used with available information on population and usage of motors to estimate exhaust emission factors and national exhaust emissions impact.
Technical Paper

Snowmobile Engine Emissions and Their Impact

1974-02-01
740735
This paper describes a research program on exhaust emissions from snowmobile engines, including both emissions characterization and estimation of national emissions impact. Tests were conducted on three popular 2-stroke twins and on one rotary (Wankel) engine. Emissions that were measured included total hydrocarbons, (paraffinic) hydrocarbons by NDIR, CO, CO2, NO (by two methods), NOx, O2, aldehydes, light hydrocarbons, particulate, and smoke. Emissions of SOx were estimated on the basis of fuel consumed, and evaporative hydrocarbons were projected to be negligible for actual snowmobile operation. During emissions tests, intake air temperature was controlled to approximately -7°C (20°F), and room air at approximately 24°C (75°F) was used for engine cooling. Based on test results and the best snowmobile population and usage data available, impact of snowmobile emissions on a national scale was computed to be minimal.
Technical Paper

Small Engine Emissions and Their Impact

1973-02-01
730859
In an attempt to characterize emissions from small air-cooled utility engines, five gasoline-fueled models were operated over a variety of speeds and loads, and important exhaust constituents were measured. These emissions included hydrocarbons, CO, CO2, NO, O2, aldehydes, light hydrocarbons, particulates, and smoke. Emissions of SOx were estimated on the basis of the fuel consumed; evaporative losses of hydrocarbons were also estimated. The impact of small engine emissions was calculated on the basis of the test results and information on national engine populations and usage. From these data, it appears that the 50 million or more small engines currently being used account for only a small part of pollutants from all sources.
Technical Paper

Public Opinion of Diesel Odor

1974-02-01
740214
This paper describes the results of a public opinion survey on testing of diesel exhaust odors conducted during 1969 and 1970. Major goals of the research were to relate public opinion of the odors and the objectionability associated with them to odor intensity, and to obtain a dose-response curve as the primary result. The dose-response curve was needed to assess odor-control technology by providing a criterion for deciding whether or not the effect of a given control item would be noticed by the general public, reduce complaints, or be worth the cost and effort required for its implementation. The engine used as the live odor source for the subject research was a two-stroke cycle type similar to those used in many buses. This engine type was chosen because its exposure to the public in urban bus applications is very widespread, and because a large portion of the Environmental Protection Agency's odor research had been performed with similar engines.
Technical Paper

Fuel and Additive Effects on Diesel Particulate-Development and Demonstration of Methodology

1976-02-01
760130
To develop a methodology for characterizing particulate emissions from diesel engines, one 2-stroke cycle engine and one 4-stroke cycle engine were operated in both individual steady-state modes and according to a variation of the 13-mode diesel emissions measurement procedure. Both engines were operated on three fuels, each used with one of two available diesel fuel additives as well as by itself. The primary particulate sampling technique employed was a dilution tunnel, and secondary evaluation techniques included a diluter-sampler developed under contract to EPA by another organization, a light extinction smokemeter, and a filter-type sampling smokemeter. Gaseous emissions were also measured, providing a running check on engine condition. Particulate mass rates were calculated from gravimetric data; and analysis of particulate included determination of sulfur, carbon, hydrogen, nitrogen, phenols, nitrosamines, trace metals, and organic solubles.
Technical Paper

Characterization of Diesel Crankcase Emissions

1977-02-01
770719
Methods for measurement and expression of crankcase or “blowby” emissions from diesels were developed and demonstrated on a test engine. These methods were subsequently used to characterize gas and particulate emissions from two in-service engines. Crankcase emissions were evaluated under engine operating conditions corresponding to the EPA 13-mode certification test. Substances for which analyses were conducted included regulated pollutants, sulfate, trace elements, nitrosamines, individual hydrocarbons, and aldehydes. Emissions from the diesel crankcases were compared to exhaust emissions (where possible) to assess their importance. Analysis for nitrosamines was continued beyond the original effort, utilizing another test engine.
Technical Paper

Heavy-Duty Diesel Emissions as a Function of Alternate Fuels

1983-02-01
830377
Emissions from a modern heavy-duty Diesel truck engine were characterized with five different fuels during transient and steady-state operation. A control fuel (Phillips D-2) was used for baseline emissions, and as base stock in three alternate fuel blends containing EDS or SRC-II middle distillates, or used lubricating oil. The fifth fuel tested was neat soybean oil, heated to 145°C. HC, CO, NOX, and particulate emissions were similar for this engine on all fuels tested, with the exception of higher particulates for the soybean oil and higher NOX for the SRC-II blend.
Technical Paper

Emissions from Direct-Injected Heavy-Duty Methanol-Fueled Engines (One Dual-Injection and One Spark-Ignited) and a Comparable Diesel Engine

1982-02-01
820966
Emissions from two heavy-duty four stroke direct injection engines designed to use methanol fuel, one using Diesel pilot fuel injection and the other using spark ignition, were characterized in this program along with those from a comparably-sized Diesel engine. Emissions evaluated during both steady-state and transient FTP procedures included regulated gases (HC, CO, and NOx), unburned methanol, aldehydes, other gaseous organics, total particulate, sulfate, soluble organics in particulate and BaP. The engines adapted for methanol fuel and using catalysts emitted less HC, CO, particulate, soluble organics, and BaP than the Diesel fueled engine.
Technical Paper

Light-Duty Diesel FTP Emissions as Functions of Fuel Volatility and Aromatic Content

1986-08-01
861120
The influence of fuel composition on exhaust emissions from four 1982 model light-duty diesel vehicles was studied on the FTP cycle and at two steady-state conditions, but only the FTP results are presented and discussed in this paper. Nine test fuels were blended specifically for the program, with intentional variation in aromatic content, 90% boiling point, and 10% boiling point. Limited data were also acquired with injection timing at advanced and retarded settings, in addition to the main body of data taken with the engines adjusted to recommended timing. A comparatively small effort was also made to evaluate a tenth fuel consisting of a blend of two of the original nine fuels. Of the fuel characteristics varied intentionally, aromatic content generally had the greatest effect on most emissions of major interest (hydrocarbons, oxides of nitrogen, particulate, soluble organic fraction, polynuclear aromatic hydrocarbons, and mutagenicity of extract by Ames bioassay).
Technical Paper

Effects of a Narrow-Cut No, 1 Fuel, and Variation in Its Properties, on Light-Duty Diesel Emissions

1981-10-01
811193
Several properties of a refinery “straightrun kerosene“, which had a narrow boiling range approximating the middle of a No. 1 diesel fuel, were altered to study their effects on regulated and unregulated exhaust emissions. Eleven fuel blends, representing changes in nitrogen content, aromatic level, boiling point distribution, olefin content, and cetane number, were evaluated in a 1975 Mercedes-Benz 240D. Statistical analysis, including regression, was performed using selected fuel properties as independent variables. Higher aromatic levels were generally associated with increased emissions, while increased olefin levels were generally associated with decreased emissions.
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