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Alternative Fuels for Transportation
harvesting or collecting the material and perhaps increasing its density to aid
in transport from the point of collection/harvest to the ethanol processing
plant. Also, since crop production is seasonal but ethanol processing plants
require a steady input of feedstocks, ways must be found to temporarily store
the cellulosic materials without subjecting them to excessive degradation.
The entire processes for converting starchy or sugary crops to fuel ethanol are now well established. Sustained research in this area has led to the
processes becoming much more efficient. Many of the processes for production of cellulosic fuel ethanol are still in the research stage. Plans for
constructing cellulosic ethanol plants are under consideration. In May 2008,
the Verenium Company of Cambridge, Massachusetts, opened a cellulosic
ethanol plant in Jennings, Louisiana, to convert sugar cane bagasse to ethanol (Bullis 2008). Over time, as more problems are worked out through
research, the processes to convert cellulosic materials to fuel ethanol will
likely become more efficient, just as they did for starchy or sugary crop conversion to ethanol.
5.3 Ethanol Properties
The quality of ethanol as a fuel has a major influence on factors such as
blend stability, materials compatibility in the engine and corrosion of engine
components. Quality standards for ethanol fuel blended with gasoline have
been established in a number of countries. ASTM D4806 and D5798 standards in the United States are two specifications addressing the quality of
ethanol blended with gasoline. D4806 was first published in 1999 and covers
anhydrous denatured fuel ethanol intended to be blended with unleaded
or leaded gasoline at 1–10 volumetric percentages for use as a SI automotive
engine fuel. D5798 was also published in 1999 to regulate the quality of E85, a
fuel blend specified as 75–85%v denatured fuel ethanol and 25–15%v hydrocarbons for use in automotive SI engines. ASTM D4806 has been used as the
basis for development of standards in countries such as Australia, Canada,
and China. In Europe, the EN 15376 standard was finalized in 2008 for use of
ethanol as a blending component for gasoline up to 5%v.
Gasoline is composed of C 4 –C 12 hydrocarbons, and therefore has wider
transitional properties than ethanol. The alcohol contains an oxygen atom so
that it can be viewed as a partially oxidized hydrocarbon. Ethanol is isomeric
with dimethyl ether (DME) and both ethanol and DME can be expressed
by the chemical formula C 2 H 6 O. The oxygen atom in ethanol possibly
induces three hydrogen bonds. Although, they may have the same physical
formula, the thermodynamic behavior of ethanol differs significantly from
that of DME on account of the stronger molecular association via hydrogen
bonds in ethanol. Ethanol contains about 35% of oxygen, which improves
Alternative Fuels for Transportation
harvesting or collecting the material and perhaps increasing its density to aid
in transport from the point of collection/harvest to the ethanol processing
plant. Also, since crop production is seasonal but ethanol processing plants
require a steady input of feedstocks, ways must be found to temporarily store
the cellulosic materials without subjecting them to excessive degradation.
The entire processes for converting starchy or sugary crops to fuel ethanol are now well established. Sustained research in this area has led to the
processes becoming much more efficient. Many of the processes for production of cellulosic fuel ethanol are still in the research stage. Plans for
constructing cellulosic ethanol plants are under consideration. In May 2008,
the Verenium Company of Cambridge, Massachusetts, opened a cellulosic
ethanol plant in Jennings, Louisiana, to convert sugar cane bagasse to ethanol (Bullis 2008). Over time, as more problems are worked out through
research, the processes to convert cellulosic materials to fuel ethanol will
likely become more efficient, just as they did for starchy or sugary crop conversion to ethanol.
5.3 Ethanol Properties
The quality of ethanol as a fuel has a major influence on factors such as
blend stability, materials compatibility in the engine and corrosion of engine
components. Quality standards for ethanol fuel blended with gasoline have
been established in a number of countries. ASTM D4806 and D5798 standards in the United States are two specifications addressing the quality of
ethanol blended with gasoline. D4806 was first published in 1999 and covers
anhydrous denatured fuel ethanol intended to be blended with unleaded
or leaded gasoline at 1–10 volumetric percentages for use as a SI automotive
engine fuel. D5798 was also published in 1999 to regulate the quality of E85, a
fuel blend specified as 75–85%v denatured fuel ethanol and 25–15%v hydrocarbons for use in automotive SI engines. ASTM D4806 has been used as the
basis for development of standards in countries such as Australia, Canada,
and China. In Europe, the EN 15376 standard was finalized in 2008 for use of
ethanol as a blending component for gasoline up to 5%v.
Gasoline is composed of C 4 –C 12 hydrocarbons, and therefore has wider
transitional properties than ethanol. The alcohol contains an oxygen atom so
that it can be viewed as a partially oxidized hydrocarbon. Ethanol is isomeric
with dimethyl ether (DME) and both ethanol and DME can be expressed
by the chemical formula C 2 H 6 O. The oxygen atom in ethanol possibly
induces three hydrogen bonds. Although, they may have the same physical
formula, the thermodynamic behavior of ethanol differs significantly from
that of DME on account of the stronger molecular association via hydrogen
bonds in ethanol. Ethanol contains about 35% of oxygen, which improves