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With the vitality and economic growth of the U.S. being linked to affordable transportation, the use of alternative fuels is beginning to play a larger role. The use "alternative fuel" has been used to describe any fuel suggested for use in transportation vehicles other than gasoline or diesel. Since 1998, more than half of the petroleum the U.S. economy requires has been supplied by imports. In addition, the climatological and scientific community has warned that increasing concentrations of greenhouse gases in the atmosphere will cause global change. Alternative Fuels examines the accepted alternative fuels, providing historical background, physical and chemical properties, production technology, and forecasts for each fuel. Alternative transportation fuels addressed include: methanol, ethanol, propane, natural gas, biodiesel, hydrogen, and electricity. Chapters include: The Argument for Alternative Fuels Methanol Ethanol Propane Natural Gas Electricity and more

This book presents the fundamentals needed to understand the physical and chemical properties of alternative fuels, and how they impact refueling system design and the modification of existing garages for safety. It covers a wide range of fuels including alcohols, gases, and vegetable oils. Chapters cover: Alternative Fuels and Their Origins Properties and Specifications Materials Compatibility Storage and Dispensing Refueling Facility Installation and Garage Facility Modifications and more

The Maryland Mass Transit Administration conducted an LNG transit bus demonstration in Baltimore, Maryland. A refueling facility was constructed and maintenance facilities were modified to provide support for the demonstration. During the demonstration operational data were collected on the buses and facilities. Problems encountered with the vehicle LNG fuel systems are reviewed and discussed. This paper summarizes the findings and operation of the LNG fleet during the demonstration and projects future LNG vehicle and operational costs.

The New York State Energy Research and Development Authority (NYSERDA), under its Alternative Fuels for Vehicles Fleet Demonstration Program (AFV-FDP), monitored the operation of 31 compressed natural gas (CNG) transit buses divided among five transit properties in New York State. The CNG buses were delivered in 1992 and have accumulated over 3.73 million kilometers (2.32 million miles) of operation through September 1995. Data collected included fuel consumption, maintenance histories, acceleration, driveability, and emissions. Several of these buses experienced problems with defective pressure relief valves though no accidents resulted from these failures. During the period of operation, various upgrades and learning experiences have contributed to improved operations and lower emissions, though variations in emissions were observed due to drift in fuel system calibration.

The New York State Energy Research and Development Authority (NYSERDA), under its Alternative Fuels for Vehicles Fleet Demonstration Program (AFV-FDP), established a number of light-duty CNG vehicle fleet demonstrations throughout New York State to collect data from CNG vehicle operation. The majority of the vehicles were converted from gasoline operation to bifuel1 operation, though dedicated CNG vehicles (new and converted) were also included. Pickups, vans, station wagons, and sport utility vehicles were all represented. The vehicles were tracked for mileage accumulation and service experience, and emissions were measured using the Federal Test Procedure. The types of CNG fuel system technologies represented were mechanical open-loop (MOL), mechanical closed-loop (MCL), electronic single-point injection closed-loop (ESPCL), and electronic multipoint injection closed-loop (EMPCL).

The Maryland Mass Transit Administration has operated four liquefied natural gas (LNG) transit buses since late 1993. LNG is unique among alternative fuels in that it has a short “shelf life.” As a result of heat gains, LNG fuel weathers at predictable rates, resulting in the potential loss of fuel mass and the potential loss of methane content. Early experience with LNG transit buses included engine failures due to insufficient octane caused by low methane content of the fuel. LNG systems can be managed to offset the effects of fuel weathering, given consistent fuel quality. Methods of predicting LNG fuel quality after weathering has occurred (both bulk and onboard storage tanks) are presented based on field experience. Vehicle operational management techniques that can reduce LNG weathering and possible engine damage are also presented.

An analysis of the additional fuel storage and distribution infrastructure that would be required if 51.9 billion liters (13.7 billion gallons) of LPG were used as transportation fuel in 2010 was completed. The LPG for transportation sector use was assumed to be produced from a network of LPG-producing refineries and gas plants similar to the one currently in place, but incorporating expanded production capabilities. Using the PADD districts as a guide, the net flow of LPG from the producing regions to the consumption regions was estimated. The LPG fuel was assumed to be moved by both new and existing systems of pipeline, barges, rail cars, and tank trucks. Additional storage capacity and other modifications were estimated to be required at LPG bulk terminal and plant locations. Approximately 15,800 retail service stations incorporating LPG storage and dispensing equipment were deemed necessary for supporting the assumed LPG transportation fuel sector in 2010.

The Maryland Mass Transit Administration (MTA) is demonstrating the use of liquefied natural gas (LNG) as a cost-effective and low emission transit bus fuel. The potential advantages of LNG as a transit bus fuel relative to using compressed natural gas (CNG) include lower fuel system weight, smaller volume required for the fuel system components, shorter time required for refueling and lower refueling facility cost, more uniform and higher fuel quality, and less demand on utility gas line flow limits. The LNG storage and dispensing system must be engineered in conjunction with the LNG fuel system on the bus to achieve fast, reliable and safe refueling. This paper describes the LNG storage and dispensing system designed and built to support the Maryland MTA demonstration of LNG transit buses.

A 1979 8V-71 model DDC two-stroke diesel transit bus engine was tested using ignition-improved methanol and ethanol. The testing was conducted using the Environmental Protection Agency heavy duty engine transient test procedure. The methanol and ethanol fuels were found to have very similar combustion characteristics and required the same percentage of ignition improver (7.5 volume percent) to obtain similar peak cylinder pressures and rates of pressure rise as were observed using diesel fuel. Emissions increased rapidly as the percentage of ignition improver was reduced below the optimum determined. Ignition-improved methanol and ethanol can greatly reduce fuel-produced particulate emissions with the trade-off of a small increase in total unburned fuel emissions. Carbon monoxide emissions were found to be dependent on stoichiometry only and not fuel type.

The progress and interim results of the New York State Energy Research and Development Authority's Flexible Fuel Vehicle (FFV) demonstration program are reported. Four FFVs have been operated for a total of more than 150,000 miles. Two FFVs were operated for 50,000 miles on gasoline and have switched over to using M85. The other two vehicles have been primarily using MB5. The FFVs were tested for exhaust emissions on a chassis dynamometer over the FTP, HFET and NYCC driving schedules. The vehicles were fueled with gasoline, M85 and in one test M60. In a series of tests they were also evaluated using inactive catalysts to measure catalyst effectiveness and deterioration. Results for the dependency of emissions on fuel composition, mileage and driving schedule are presented. In general, emissions decreased with increasing methanol content and increased with mileage.

The natural gas fuel delivery infrastructure required to support a fleet of vehicles large enough to displace 2 million bbl/day of petroleum consumption was estimated. The number and types of vehicles required to use this amount of natural gas was defined based on operational characteristics and technical feasibility. Existing natural gas pipeline and storage capacity was assessed and additions estimated. Natural gas refueling stations to serve the natural gas vehicles defined were estimated. The total cost of the natural gas infrastructure additions was estimated. The institutional and infrastructural barriers to widespread use of natural gas were identified and lead times to overcome them were estimated.

The concept of using alcohol fuels as alternatives to diesel fuel in diesel engines is a recent one. The scarcity of transportation petroleum fuels which developed in the early 1970's spurred many efforts to find alternatives. Alcohols were quickly recognized as prime candidates to displace or replace high octane petroleum fuels. However, alternatives to the large demand for diesel fuel in many countries were not as evident. Innovative thinking led to various techniques by which alcohol fuels can partially or completely displace diesel fuel in diesel transportation vehicles. The methods of using alcohol fuels in diesel engines (in order of increasing diesel fuel displacement) include solutions, emulsions, fumigation, dual injection, spark ignition, and ignition improvers. Power output, thermal efficiency and exhaust emissions can change significantly depending on the techniques employed. Reliability and durability still need to be demonstrated for most of these techniques.

With more and more fleet vehicles being converted to compressed natural gas operation, concerns have arisen about the safety of their fuel systems and the need for regulations to ensure safe operation. The potential for widespread operation of vehicles using compressed natural gas adds urgency to these concerns. Most of the safety concerns revolve around the high-pressure storage and fuel lines present in existing systems. Specific items in question are: the need for high-pressure automatic fuel cutoff switches, vehicle disablement during refueling, the need for methane sensors, cylinder specifications and venting requirements, location of refueling points, and system crash-worthiness. This paper examines these concerns.