Acetone extracts of engine exhaust particulate matter (PM) and of vapor-phase semi-volatile organic compounds (SVOCs) collected from a set of 1998-2000 model year normal emitter diesel engine automobile or light trucks and from a set of 1982-1996 normal emitter gasoline engine automobiles or light trucks operated on the California Unified Driving Cycle at 22 [degree]C were assayed for in vitro genotoxic activities. Gasoline and diesel PM were comparably positive mutagens for Salmonella typhimurium strains YG1024 and YG1029 on a mass of PM extract basis with diesel higher on a mileage basis; gasoline SVOC was more active than diesel on an extracted-mass basis, with diesel SVOC more active on a mileage basis. For chromosomal damage indicated by micronucleus induction in Chinese hamster lung fibroblasts (V79 cells), diesel PM expressed about one-tenth that of gasoline PM on a mass of extract basis, but was comparably active on a mileage basis; diesel SVOC was inactive. For DNA damage in V79 cells indicated by the single cell gel electrophoresis (SCGE) assay, gasoline PM was positive while diesel PM was active at the higher doses; gasoline SVOC was active with toxicity preventing measurement at high doses, while diesel SVOC was inactive at all but the highest dose.

Limitations on the use of petroleum-based diesel fuel in California could occur pursuant to declaration by the California Air Resources Board (CARB) that the particulate matter component of diesel exhaust is a toxic air contaminant subject to the state’s Proposition 65. It is the declared intention of CARB not to ban diesel fuel, per se, at this time. Assuming no total ban, Argonne National Laboratory (ANL) explored two feasible “midcourse” strategies that result in some degree of (conventional) diesel displacement. In the first case, substantial displacement of compression-ignition (CI) by spark-ignition engines occurs and diesel fuel remains admissible for ignition assistance as a pilot fuel in natural gas–powered heavy-duty vehicles. Daily gasoline demand in California increases by 32.2 million L (8.5 million gal) overall, about 21 percent above the 2010 baseline demand projected by California’s energy and environmental agencies. Daily natural gas demand increases by 13.6 million diesel L (3.6 million gal) equivalents, about 7 percent above projected (total) consumption level. In the second case, CI engines utilize substitutes having similar ignition and performance properties for petroleum-based diesel. For each case, ANL estimated localized air emission plus generalized greenhouse gas and energy changes. Fuel replacement by dimethyl ether yields the greatest overall reduction in nitrogen oxide emissions. All scenarios bring about fine particulate matter (PM10) reductions relative to the 2010 baseline, with greatest reductions from the CI-displacement case and the least from fuel replacement by Fischer-Tropsch synthetic diesel. Institutional and cost implications of vehicle and engine replacement were not formally evaluated.

The effects of hybridization on heavy-duty vehicles are not well understood. Heavy vehicles represent a broader range of applications than light-duty vehicles, resulting in a wide variety of chassis and engine combinations, as well as diverse driving conditions. Thus, the strategies, incremental costs, and energy/emission benefits associated with hybridizing heavy vehicles could differ significantly from those for passenger cars. Using a modal energy and emissions model, they quantify the potential energy savings of hybridizing commercial Class 3-7 heavy vehicles, analyze hybrid configuration scenarios, and estimate the associated investment cost and payback time. From the analysis, they conclude that (1) hybridization can significantly reduce energy consumption of Class 3-7 heavy vehicles under urban driving conditions; (2) the grid-independent, conventional vehicle (CV)-like hybrid is more cost-effective than the grid-dependent, electric vehicle (EV)-like hybrid, and the parallel configuration is more cost-effective than the series configuration; (3) for CV-like hybridization, the on-board engine can be significantly downsized, with a gasoline or diesel engine used for SUVs perhaps being a good candidate for an on-board engine; (4) over the long term, the incremental cost of a CV-like, parallel-configured Class 3-4 hybrid heavy vehicle is about %5,800 in the year 2005 and $3,000 in 2020, while for a Class 6-7 truck, it is about $7,100 in 2005 and $3,300 in 2020; and (5) investment payback time, which depends on the specific type and application of the vehicle, averages about 6 years under urban driving conditions in 2005 and 2--3 years in 2020.

Synthetic diesel fuel can be made from a variety of feedstocks, including coal, natural gas and biomass. Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics. Moreover, synthetic diesel fuels may also economically competitive with California diesel fuel if .roduced in large volumes. Previous engine laboratory and field tests using a heavy-duty chassis dynamometer indicate that synthetic diesel fuel made using the Fischer-Tropsch (F-T) catalytic conversion process is a promising alternative fuel, because it can be used in unmodified diesel engines, and can reduce exhaust emissions substantially. The objective of this study was a preliminary assessment of the emissions from older model transit operated on Mossgas synthetic diesel fuel. The study compared emissions from transit buses operating on Federal no. 2 Diesel fuel, Mossgas synthetic diesel (MGSD), and a 50/50 blend of the two fuels. The buses were equipped with unmodified Detroit Diesel 6V92 2-stroke diesel engines. Six 40-foot buses were tested. Three of the buses had recently rebuilt engines and were equipped with an oxidation catalytic converter. Vehicle emissions measurements were performed using West Virginia University's unique transportable chassis dynamometer. The emissions were measured over the Central Business District (CBD) driving cycle. Themore » buses performed well on both neat and blended MGSD fuel. Three buses without catalytic converters were tested. Compared to their emissions when operating on Federal no. 2 diesel fuel, these buses emitted an average of 5% lower oxides of nitrogen (NOx) and 20% lower particulate matter (PM) when operating on neat MGSD fuel. Catalyst equipped buses emitted an average of 8% lower NOx and 31% lower PM when operating on MGSD than when operating on Federal no. 2 diesel fuel.« less

With the popularity of light trucks increasing in the United States, their share of the US light vehicle market had doubled between 1980 and 1996, climbing from 20 to 40%. By 1996, annual energy consumption for light trucks had risen to 5.97 x 10(15) Btu [5.97 quadrillion Btu, or "quad," or 6.30 x 10(18) joule (J)], compared to 7.94 quad (8.38 x 10(18) J) for cars. In recent years (since 1995), the fuel economy of US-manufactured light trucks (almost 99% of which use gasoline engines) has been below the Corporate Average Fuel Economy (CAFE) standards. This paper analyzes a strategy to reduce the CAFE shortfalls by adopting the new, highly energy-efficient clean diesel engine. Research on such engines has been funded by the US Department of Energy, Office of Heavy Vehicle Technologies, under its Light Truck Clean Diesel Engine Program. A clean diesel engine market penetration trajectory is developed, representing an industry response to meet the CAFE standards. Whether the engine will be produced inside the country or imported remains uncertain, so two cases are defined. Values of exports/imports of dean diesel engines/trucks under these cases are estimated. The macroeconomic benefits are estimated by using a model of the US economy developed by Standard & Poor's Data Resources, Inc. On the basis of gains in the gross domestic product projected under the alternative cases, domestic production of the clean diesel engine is favored over importing it. (C) 2000 Elsevier Science Ltd, All rights reserved.

The paper discusses alternatives to diesel displacement, describing several scenarios. It studies three basic cases: (1) cars and trucks; (2) urban buses; and (3) off-road vehicles. The discussion also includes changes in energy use and emissions expected from the production and combustion of alternative fuels.

Alternative compression ignition engine fuels are of interest both to reduce emissions and to reduce U.S. petroleum fuel demand. A Malaysian Fischer-Tropsch gas-to-liquid fuel was compared with California No.2 diesel by characterizing emissions from over the road Class 8 tractors with Caterpillar 3176 engines, using a chassis dynamometer and full scale dilution tunnel. The 5-Mile route was employed as the test schedule, with a test weight of 42,000 lb. Levels of oxides of nitrogen (NO{sub x}) were reduced by an average of 12% and particulate matter (PM) by 25% for the Fischer-Tropsch fuel over the California diesel fuel. Another distillate fuel produced catalytically from Fischer-Tropsch products originally derived from natural gas by Mossgas was also compared with 49-state No.2 diesel by characterizing emissions from Detroit Diesel 6V-92 powered transit buses, three of them equipped with catalytic converters and rebuilt engines, and three without. The CBD cycle was employed as the test schedule, with a test weight of 33,050 lb. For those buses with catalytic converters and rebuilt engines, NO x was reduced by 8% and PM was reduced by 31% on average, while for those buses without, NO x was reduced by 5% and PM was reduced by 20% on average. It is concluded that advanced compression ignition fuels from non-petroleum sources can offer environmental advantages in typical line haul and city transit applications.

The Fischer-Tropsch (F-T) catalytic conversion process can be used to synthesize diesel fuels from a variety of feedstocks, including coal, natural gas and biomass.Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics.Moreover, Fischer-Tropsch diesel fuels mav also be economicallv competiiive with California Bdiesel fuel if produced in large volumes.I overview of Fischer-Tropsch diesel fuel production and engine emissions testing is presented.Previous engine laboratory tests indicate that F-T diesel is a promising alternative fuel because it can be used in unmodified diesel engines, and substantial exhaust emissions reductions can be realized.The authors have performed preliminary tests to assess the real-world performance of F-T diesel fuels in heavyduty trucks.Seven White-GMC Class 8 trucks equipped with Caterpillar 10.3 liter engines were tested using F-T diesel fuel.Vehicle emissions tests were performed using West Virginia University's unique transportable chassis dynamometer.* The trucks were found to perform adequately on neat F-T diesel fuel.Compared to a California diesel fuel baseline, neat F-T diesel fuel emitted about 12% tower J oxides of nitrogen (NOx) and 24% lower particulate matter over a five-mile driving cycle.

An ideal catalyst for the FCC process offers tremendous savings in both construction and operating costs. Total savings for feedstock and process energy for a process designed around the ideal catalyst are 0.34 mmBtu/bbl of gasoline produced compared with current reduced crude conversion catalytic cracking. A new FCC unit using ideal catalyst to produce 19,950 bpsd gasoline would save approximately 2.4 x 10/sup 12/ Btu/y(0.25 x 10/sup 15/Btu/y if all FCC gasoline were produced in an ideal catalyst process). In addition, payback period for the ideal FCC unit would be half that of a unit using existing technology.

This paper documents methods and results of an investigation of the options for and year 2010 consequences of possible new limitations on the use of diesel fuel in California, USA. California's Air Resources Board will undertake a risk management process to determine steps necessary to protect the health and safety of the public from carcinogenic species resident on diesel combustion exhaust particles. Environmental activist groups continue to call for the elimination of diesel fuel in California and other populous states. It is the declared intention of CARB not to ban or restrict diesel fuel, per se, at this time. Thus, two ''mid-course'' strategies now appear feasible: (1) Increased penetration of natural gas, LPG, and possibly lower alcohols into the transportation fuels market, to the extent that some Cl applications would revert to spark-ignition (SI) engines. (2) New specifications requiring diesel fuel reformulation based on more detailed investigation of exhaust products of individual diesel fuel constituents.