Charles T. Hare

CHARACTERIZATION OF PARTICULATE AND GASEOUS EMISSIONS FROM TWO DIESEL AUTOMOBILES AS FUNCTIONS OF FUEL AND DRIVING CYCLE

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, 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.

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

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 alter analysis on groups of organics present.

EMISSION FACTORS FOR SMALL UTILITY ENGINES

A major gap exists in available baseline emissions data on the small utility engine population between the mid-1970s 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. (A) For the covering abstract of the conference see IRRD 852385.

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

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. /GMRL/

Emissions from two methanol-powered buses

Emissions from the two methanol-powered buses used in the California Methanol Bus Demonstration have been characterized. The M.A.N. SU 240 bus is powered by M.A.N.s D2566 FMUH methanol engine, and utilizes catalytic exhaust aftertreatment. The GMC RTS II 04 bus is powered by a first-generation DDAD 6V-92TA methanol engine without exhaust aftertreatment. Emissions of HC, CO, NO/subX/, unburned methanol, aldehydes, total particulates, and the soluble fraction of particulate were determined for both buses over steady-state and transient chassis dynamometer test cycles. Emission levels from the M.A.N. bus were considerably lower than those from the GMC bus, with the exception of NO/subX/. Comparison of emission levels from methanol-and diesel-powered buses indicates that substantial reductions in emissions are possible with careful implementation of methanol fueling.

Public Opinion of Diesel Odor

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. It was found that a relationship existed between perceived diesel exhaust odor intensity and the objectionability of these odors. The nature of this relationship was that increasingly intense diesel exhaust odors were considered increasingly objectionable.

HEAVY-DUTY DIESEL EMISSIONS AS A FUNCTION OF ALTERNATE FUELS

Exhaust emissions from a Mack EM6-300 heavy-duty diesel 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 a 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 degrees. Emission measurements included HC, CO, CO2, NOx, visible smoke, particulate, IHC, aldehydes, odor (DOAS), phenols, sulfate, elemental composition, particle sizing, SOF, SOF boiling point distribution, BaP, Ames bioassay and HPLC fractionation. HC, CO, NOx and particulate emissions were similar for this engine on all fuels tested with exception of higher particulates for the soybean oil and higher NOx for the SRC-II blend. Ames response was highest for the EDS and SRC-II blends. The BaP level was highest for the soybean oil.

Heavy-duty diesel emissions from operation on crude and minimally-processed shale oils

Three crude shale oils were chosen from six candidates to investigate their possible use as substitutes for No. 2 diesel fuel. Satisfactory hot engine operation was achieved on the crudes using a fuel heating system, allowing emissions characterization during transient and steady-state operation. Regulated gaseous emissions changed little with the crudes compared to diesel fuel; but total particulate and soluble organics increased, and larger injector tip deposits and piston crown erosion were observed. After engine rebuild, two minimally-processed shale oils were run without the fuel heating system, causing no engine problems. Most emissions were higher than for No. 2 fuel using and 80 percent distillate of crude shale oil, but lower using a hydrotreated form of the distillate.

COMPARISON OF PETROLEUM AND ALTERNATE-SOURCE DIESEL FUEL EFFECTS ON LIGHT-DUTY DIESEL EMISSIONS

Exhaust emission data from several fuel effects studies were normalized and subjected to statistical analyses. The goal of this work was to determine whether emission effects of property variation in alternate-source fuels were similar, less pronounced, or more pronounced than the effects of property variation in petroleum fuels. A literature search was conducted, reviewing hundreds of studies and finally selecting nine which dealt with fuel property effects on emissions. From these studies, 15 test cases were reported. Due to the wide variety of vehicles, fuels, test cycles, and measurement techniques used in the studies, a method to relate them all in terms of general trends was developed. Statistics and methods used included bivariate correlation coefficients, regression analysis, scattergrams and goodness-of-fit determinations. Insertion of alternate-source fuel properties into exhaust emissions prediction equations based on petroleum fuel results indicated that the effects of alternate-source fuel property changes on exhaust emissions were statistically indistinguishable from those associated with petroleum fuels.

Light-Duty Diesel Emission Correction Factors for Ambient Conditions

To determine the effects of ambient conditions on emissions from light-duty diesels, 174 emission tests were conducted on four vehicles. The major program objective was estimation of a factor to correct NOx emissions to a standard humidity. Humidity effects on NOx emissions were found to be substantial and quite predictable. Relationships observed between other emissions and ambient conditions were relatively weak and unpredictable. /SASI/