Engine automotive fuel

K. Owen and T. Coley, Automotive Fuels Handbook, Society of Automotive Engineers, Warrendale, Pa., p. 116. 

Kukkone, C.A. and M. Shelef, Hydrogen as an alternative automotive fuel, in Alternate Fuels, Bata, R.M., Ed., National Research Council and National Academy of Engineering, National Academies Press, Washington, 1992. 

The report noted that the automotive fuel cell is being pushed along due to the almost 2 billion international investment and that fuel cells would provide an environmentally superior and more efficient automobile engine. 

Dynamic characteristics of a fuel cell engine are of paramount importance for automotive application. Three primary processes govern the time response of a PEFC. They are (1) electrochemical double-layer discharging, (2) gas transport through channel and GDL, and (3) membrane hydration or dehydration (i.e., between a dry and a hydrated state). The time constant of double-layer discharging is between micro- and milliseconds, sufficiently short to be safely ignored for automotive fuel cells. The time constant for a reactant gas to transport through GDL can be estimated simply by its diffusion time, i.e.,... 

Lead-free gasoline an automotive fuel containing no more than 0.05 g of lead per gallon, designed for use in engines equipped with catalytic converters. 

Of these chemicals, the EPA has traditionally focused its monitoring efforts on only one, lead. The reason is that lead (in the form of tetraethyl lead (C2H5) Pb) was once used extensively as a fuel additive to reduce the problems of engine "knocking in automotive vehicles. Because of the health problems posed by lead, however, tetraethyl lead was banned from use in automotive fuels in 1976. 

Winter grade diesel fuel oil is recommended for use in ambient temperature environments as low as -25.6°F (-32°C). It is intended for use in high-speed automotive-type diesel engines and nonaircraft-type turbine engines. This fuel may be used for medium-speed stationary engine applications. 

From Owen, Keith and Trevor Cooley. 1995. Automotive Fuels Reference Book. 2nd Ed. Warrendale, Pa.rSociety of Automotive Engineers.)... 

In practice, short-chain alkanes and alkenes are normally used as feedstock for shape-selective catalytic formation of isooctanes at relatively low temperatures. Until the 1980s, lead alkyls (Section 18.1) were added to most automotive fuels to help suppress engine knock, but they have been phased out in North America because of the chronic toxicity of lead and lead compounds. The most commonly used nonlead antiknock additive is now methyl tert-butyl ether [MTBE CH30C(CH3)3], which is made by the reaction of methanol with 2-methylpropene, (CHs C—CH2 (see Section 7.4). The latter is obtained by catalytic cracking of petroleum fractions to give 1-butene, which is then shape-selectively isomerized on zeolitic catalysts. 

Ethanol is widely acknowledged to be less aggressive toward metals and elastomers than methanol, but little research and development has been devoted to the specific problems posed by ethanol. Ethanol typically has more water in it than methanol (an artifact of production) which may affect solubility of contaminants and corrosion potential. One ethanol contaminant that can arise from production is acetic acid, which is water-soluble and will corrode some automotive fuel system components. For instance, General Motors found that E85 caused more corrosion in fuel pumps than M85, presumably because of a higher level of dissolved contaminants [3.2]. Since much more development has been devoted to compatibility with methanol fuels, the general approach for ethanol has been to use materials developed for methanol, even though they may be over-engineered. ... 

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