CHICAGO, July 12 — Biodiesel produced from soybeans produces more usable energy and reduces greenhouse gases more than corn-based ethanol, making it more deserving of subsidies, according to a study being published this month in The Proceedings of the National Academy of Sciences.

The study, done by researchers at the University of Minnesota and at St. Olaf College in Northfield, Minn., points to the environmental benefits of the biodiesel over ethanol made from corn, stating that ethanol provides 25 percent more energy a gallon than is required for its production, while soybean biodiesel generates 93 percent more energy.

The study’s authors also found that ethanol, in its production and consumption, reduces greenhouse gas emissions by 12 percent, compared with fossil fuels. Biodiesel, they said, reduces such emissions 41 percent, compared with fossil fuels.

The study concludes that the future of replacing oil and gas lies with cellulosic ethanol produced from low-cost materials like switch grass or wheat straw, if it is grown on agriculturally marginal land or from waste plant material.

Indeed, the study published by the National Academy of Sciences found that neither ethanol nor biodiesel can replace much petroleum without having an impact on food supply. If all American corn and soybean production were dedicated to biofuels, that fuel would replace only 12 percent of gas demand and 6 percent of diesel demand, the study notes.

Researchers at universities and at the United States Agriculture Department have debated ethanol’s benefits as policy makers continue to struggle with how to respond to high gasoline prices and how to reduce America’s dependence on foreign oil.

Some lawmakers have urged an end to federal subsidies of 51 cents a gallon for ethanol refiners. The subsidies have helped create a boom in ethanol production and have made ethanol more profitable than ever.

The researchers in the latest study question ethanol’s environmental benefits, noting that despite the 12 percent reduction in greenhouse gases, ethanol has “greater environmental and human health impacts because of increased release of five air pollutants and nitrate, nitrite and pesticides.”

Neither biofuel was cost-competitive in 2005 without subsidies. Biodiesel cost 55 cents a liter to produce, or 20 percent more than ethanol. Wholesale gasoline prices in 2005 averaged 44 cents a liter, or 4 percent less a liter to produce than ethanol, the study said. Still, biodiesel receives a subsidy that is 45 percent greater a liter than ethanol.

Analysts agreed with the study’s conclusion that biodiesel compares favorably with ethanol from an environmental standpoint. “Biodiesel is much cleaner-burning fuel and much less harmful to the environment,” Daniel W. Basse, president of AgResource in Chicago, an economic forecasting firm, said Wednesday.

But Mr. Basse said ethanol production is far more efficient, with some 420 gallons of ethanol produced per acre of corn versus only 60 gallons of biodiesel per acre of soybeans. If biodiesel use ever increased greatly, Mr. Basse said, the cost of soybean oil would rise significantly.

Brent Erickson, executive vice president of the Biotechnology Industry Organization, based in Washington, agreed that biodiesel’s potential was limited. “If you look at the amount of biodiesel you can produce, it is a drop in the bucket compared to the amount of cellulosic ethanol that could be produced one day,” he said.

The Minnesota researchers write that with a projected doubling of global demand for food within 50 years and an even greater expected increase in demand for transportation fuels, “there is a great need for renewable energy supplies that do not cause significant harm and do not compete with food supply.”

If the Commander is coming out as an E85 jeep - I might wait on it - my wife really wants one - really baaaad

I'm not sure E85 will be any more that a flash in the pan and gone from the pumps in couple of years.

It has been offically announced by D/C as an '07 option on Commander, but I suspect it will not be available on the 5.7L V8 engine. I like the the idea of FFV but the problem is according to Chrysler lease site and a couple of people I know with GM PU trucks that when run on Methanol the mpg drops about 30% by second tank of fuel. The price break here is 21%, so that would leave you taking about a 10% loss just to drive the FFV on Methanol. That would make a vehicle like the small V8 a 13 mpg vehicle a 250 mile fuel range on the highway. The only thing I like about it is the $$$ stay in the US, but at a price that I really can't or won't pay then what happens when the tax break is pulled. For these reasons I see the E85 disappearing in the not to distant future.

The drop if fuel mileage and cruising range is very noticable. Last Fall, I was looking at a new Silverado. The dealer had two virtually identical trucks, one with a basic 5.3L, the other a 5.3L FFV. There was a significant difference in estimated fuel milage on the window sticker along with a another sign on the dashboard to explaing the situation. I would still like to know the mechanical difference between the two engines that makes one an FFV.

Not sure about all the changes, but there is an oxygen sensor for the fuel delivery system to tell the computer how to burn it efficiently. There are also stainless steel fuel lines, and no rubber fittings/lines/gaskets anywhere in the fuel delivery system as the E85 is very corrosive to it. Mechanically speaking, everything in the engine itself is already E85 compatible on most vehicles - maybe gasket material has to be looked at.

Would that work or am i just that crazy?

Hold on I thought that my gas KJ can burn E85, just not in the winter time because it is to cold to burn.

So all one would need to do to make their gas KJ a gas/e85 jk is to make a Y connector to the fuel lines from the tank and add in a smaller tank 2-5 gallons that good old 87 octane would be in to heat up the engine block so that when you threw the Y connector the otherway, the E85 can now burn instead of 87 octane.

Would that work or am i just that crazy?

darn because if my little plan would work then i;d save some money come when E85 is offered by the pumps near me.

This is an interesting topic, especially since we wrote a story on the future of fuel and the use of biofuels in our Aug/Sept issue of JPFreek. You can check out the O+WP, a biofuels education project, in the issue at:

http://www.jpfreek.com/Images/JPF-No3.PDF

So, do any of you actually use E85 or biofuels? I'm curious about its use and how it performs compared to regular petrol and diesel with Jeep owners.