Environmental Engineering Reference
In-Depth Information
Table 1.
Energy
Advantages
Disadvantages
Consumption
of Ethanol
• Positive Environmental Impacts: Life Cycle Analysis.
• Renewable Energy that can replace oil.
• High octane content gives particular value to consum-
ers using high performance engines.
• Not as toxic as MTBE and lead.
• A soluble deposit-controller, removing impurities in the
fuel system.
• An anti-icier, prevents fuel-lines from freezing in the
winter.
• The energy value of ethanol is lower than gasoline
• Takes more to drive the same distance.
• Pay more for ethanol fuel, more frequently.
• Adaptation of a non flex-fuel vehicle may cost as
much as $1,200 dollars.
• Not widely available.
• Easily absorbs water.
Consumption
of Gasoline
• More energy density than ethanol.
• Abundance of gas stations.
• Pay less for annual maintenance.
• A non-renewable energy
• Much more mature process for production than
ethanol.
Pollutants
Advantages
Disadvantages
Consumption
of Ethanol
• Reduces greenhouse gas emissions that caused the
climate change.
• Resolve local air pollution
• Far cleaner combustion than gasoline.
• Reduces exhaust emissions.
Consumption
of Gasoline
• Incomplete combustion, thus increasing greenhouse
gas emissions.
• Increases air pollution.
Economics
Advantages
Disadvantages
Consumption
of Ethanol
• Potentially replace crude oil, which is a finite non-
renewable resource.
• Can be domestically produced, so reduces dependency
on oil imports.
• Possible to cut oil import costs.
• Increase value added and price of agricultural products.
• Creates more jobs in the rural areas.
• Strength rural economies.
• Higher price to produce.
• Not enough for domestic consumption.
• Lack of raw materials.
• Need more knowledge to produce more efficiently.
Consumption
of Gasoline
• Active investment for oil companies.
• Motivates the world economy.
• Advantage for the oil producing countries.
• Unstable oil pricing, depending on the world
economy.
• Oil producing countries can negotiate unfairly for
trading.
It also takes a lot of energy to convert corn into
ethanol—nearly as much as the energy contained
in the ethanol produced. The ratio of energy output
to input is only about 1.3, after taking into account
the nitrogen fertilizer (made from petroleum), the
use of diesel-powered farm machinery to harvest
the corn, and the natural gas required to make steam
for distillation. Given the large investment of fossil
fuel required to make corn ethanol, the reduction
in green house gas emissions over gasoline is only
around 22% (Bourne, 2007).
Biodiesel
Biodiesel made from canola, soybean, or other
vegetable oils suffers from similar limitations as
corn, in that these energy crops can also be food
crops, and they are typically grown on land that can
also be used to grow other, potentially more valu-
able, crops. As an example of the market instability
this creates for biodiesel producers, when wheat
prices recently soared, farmers who had previously
planted soy or canola for biodiesel turned instead
to planting wheat, increasing the cost of feedstock
for biodiesel plants. For this reason, and because
