Posted on 07/13/2006 11:33:47 PM PDT by neverdem
Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels
Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies. We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans. Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies. Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels.
What's this "more deserving of subsidies" crap? If it's a viable product, people should be lining up around the block to invest.
WORLD ENDS: MINORITIES, SOYBEANS HARDEST HIT
I have read elsewhere that Ethanol requires 30% More energy to produce than it yields when burned.
This includes farm production (including fertilizer, herbicides and pesticides), distillation and transportation.
My daughter is one of many individuals strongly allergic to anything that has any soy in it. It paralyzes her respiratory system as well as interferes with brain functioning. What on earth will the fumes do for people like her?
If it were only possible to harness the energy, it would be found that Navy beans produce the most usable energy of anything on planet earth.
Human Hair Could be New Source of Special Adult Stem Cells for Research
FReepmail me if you want on or off my health and science ping list.
These decisions will not be made in the penthouses of NY skyscrapers. In fact, farmers alternate planting corn and soybeans because soybeans fix nitrogen in the soil that corn uses.
Believe nothing without independent verification unless it is congruent with your prejudices.
Which is the point of the current study---to actually lay to rest that false notion. The most recent and most thorough studies show pretty much the same as this one--both ethanol and biodiesel are net energy producers.
"These studies also assume that all farm equipment will always run off of petroleum based fuels. But many farmers like to buy their own product and run it in their farm equipment. Now if we can just get the ethanol plants to burn ethanol for heating their mash we'll have a much greener system."
But you still miss the point that you are getting diddly/squat net ENERGY production from corn ethanol.
My bet is the company that farms the largest amount of soybeans is also one of the larger contributors to the DNC.
"No, you actually come out ahead."
Again, you miss the point. It is doodly/squat ahead. They are saying that even if you devote the entire corn harvest to ethanol production it will only marginally affect the amount of petroleum used. Even if your tractors use methanol, the net energy to be gained is trivial.
With soybeans you have a chance, but you still don't get a petroleum independent society.
They are working, at the University of New Hampshire, on various strains of algae as feedstocks for biodiesel production, which have a much higher oil efficiency than even soybeans, and can be grown quickly and easily in vats of sunny water.
100% correct. The US uses over 22 million barrels of oil a day. And the supply is now in decline. Even the tar sands at max production will only produce 2-2.5 million barrels a day. The hurt is coming.
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