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Particle size distribution, number, and mass emissions from the exhaust of a 92 kW 1999 Isuzu 6BG1 nonroad naturally aspirated diesel engine were measured. The engine exhaust was equipped with a Dry System Technologies® (DST) auxiliary emission control device that included an oxidation catalyst, a heat exchanger, and a disposable paper particulate filter. Particle measurement was taken during the ISO 8178 8-mode test for engine out and engine with the DST using a scanning mobility particle sizer (SMPS) in parallel to the standard filter method (SFM), specified in 40 CFR, Part 89. The DST efficiency of removing particles was about 99.9 percent based on particle number, 99.99 percent based on particle mass derived from number and size. However, the efficiency based on mass derived from the SFM was much lower on the order of 90 to 93 percent.

This paper describes an on-vehicle demonstration of a hydrogen-heated catalyst (HHC) system for reducing the level of cold-start hydrocarbon emissions from a gasoline-fueled light-duty vehicle. The HHC system incorporated an onboard electrolyzer that generates and stores hydrogen (H2) during routine vehicle operation. Stored hydrogen and supplemental air are injected upstream of a platinum-containing automotive catalyst when the engine is started. Rapid heating of the catalytic converter occurs immediately as a result of catalytic oxidation of hydrogen (H2) with oxygen (O2) on the catalyst surface. Federal Test Procedure (FTP) emission results of the hydrogen-heated catalyst-equipped vehicle demonstrated reductions of hydrocarbons (HC) and carbon monoxide (CO) up to 68 and 62 percent, respectively. This study includes a brief analysis of the emissions and fuel economy effects of a 10-minute period of hydrogen generation during the FTP.

Bearing capability of one million miles has been demonstrated in line-haul truck operations with Cummins, Detroit Diesel, Caterpillar and Mack Truck engines. Bearing failure analysis helped to define the requirements for long service bearings, in terms of the appropriate oil and bearing quality, and proper maintenance practice. Surface science instrumentation was used for failure analysis, since visual observations alone cannot provide a definitive answer. This paper should help prevent bearing failures in the future and enable others to identify the failure mode correctly and quickly.

The Coordinating Research Council (CRC), California Air Resources Board (ARB), and Texas Commission on Environmental Quality sponsored a program to evaluate the effects of air conditioning (AC) operation on vehicle emissions and fuel economy. Phase 1 of this work measured the effect of AC use with vehicles operated over several standard driving cycles and verified results previously obtained by other investigators. Phase 2 provided a better understanding of the effects of the interactions between ambient conditions (solar load, temperature, and humidity) and AC operation on emissions and fuel economy. The Phase 2 program also verified results of Phase 1 by using a different population of vehicles. The program results demonstrated that AC operation had a substantial impact on emissions and fuel consumption. Operation of the vehicle AC system over a range of environmental conditions resulted in consistent increases in vehicle emissions of nitrogen oxides (NOx) and carbon monoxide (CO).

Proposed emissions standards will require that emissions control systems function at extremely high efficiency. Recently, studies have shown that elevated gasoline fuel sulfur levels (GFSL) can impair catalytic converter efficiency. In this study, a variety of tri-metal catalysts were evaluated to determine if formulation changes could reduce emissions sensitivity to GFSL. Catalysts with elemental composition similar to an OEM, but with double the precious metal (PM) loading, were evaluated using 38 and 620 ppm GFSL. Doubling the PM loading significantly reduced catalyst sensitivity to sulfur. Doubling the rhodium loading, at the expense of the platinum loading, significantly improved NOx emission sulfur sensitivity.