Stories tagged E85


Corn field: Corn is used to produce ethanol fuels, such as E85.  Photo courtesy killermart, Flickr Creative Commons.
Corn field: Corn is used to produce ethanol fuels, such as E85. Photo courtesy killermart, Flickr Creative Commons.
Biofuels are fuels that are derived from recently living organisms, such as corn or soybeans, or their byproducts, such as manure from cows. A recent study at the University of Minnesota examined the total life-cycle cost of all of the energy used for growing corn and soybeans and converting these crops into biofuels to determine what biofuel has the highest energy benefit and the least impact on the environment.
Corn grain ethanol vs. soybean biodisel
Two types of biofuels are becoming more visible as we look for alternatives to petroleum because of increasing gas prices: soybean biodisel and corn grain ethanol, such as E85. The study showed that both corn grain ethanol and soybean biodiesel produce more energy than is needed to grow the crops and convert them into biofuels. However, the amount of energy each fuel returns differs greatly. Soybean biodiesel returns 93 percent more energy than is used to produce it, while corn grain ethanol currently provides only 25 percent more energy than is used to produce it.
The study also compared the amount of greenhouse gases each biofuel released into the environment when used. Soybean biodiesel produces 41% less greenhouse gas emissions than diesel fuel while corn grain ethanol produces 12% less greenhouse gas emissions than gasoline.
Not a silver bullet
The researchers conducting this study caution that neither biofuel is ready to replace petroleum. Even if all current U.S. corn and soybean production were dedicated to biofuels production, it would still only meet 12 percent of gasoline demand and 6 percent of diesel demand, and we still need to produce these crops for food. Biofuels are steps in the right direction, however, and can be a piece of the overall puzzle needed to be put together to solve our energy needs.


E85 Logo: E85 Logo. Source-Wikipedia

What is E85?

The 85 refers to 85% ethanol and 15% gasoline. Regular gasoline in Minnesota is E10, 90% gasoline and 10% ethanol.

What are the benifits of E85?

    Reduces smog forming pollutants by 25%
    Reduces greenhouse gas emissions by 35% to 40%
    Increased vehicular horsepower by 5%

Why has the price of E85 gone up so much?

The price of ethanol has been driven up because major oil refiners are suddenly buying in bulk. They're stocking up on ethanol as a replacement for MTBE, a petroleum-based additive suspected of causing cancer. MTBE and ethanol boost the octane of gasoline and can reduce pollution.

Won't E85 production deplete human and animal food supplies?

No, actually the production of ethanol from corn uses only the starch of the corn kernel, all of the valuable protein, minerals and nutrients remain. One bushel of corn produces about 2.7 gallons of ethanol AND 11.4 pounds of gluten feed (20% protein) AND 3 pounds of gluten meal (60% protein) AND 1.6 pounds of corn oil.

What about E85 miles per gallon?

Unfortunately, because ethanol contains less energy than gasoline, fuel economy is reduced for most 2002 and earlier FFVs (flexible-fuel vehicles) that are currently on the road by about 30% (most after 2003 lose only 15-17%, or less) when operated on pure E85 (summer blend). Some of the newest vehicles can lessen this reduction to only 5-15%. It is important to note, however, that if the engine had been specifically tuned for consumption of ethanol (higher compression, different fuel-air mixture, etc.) the mileage would have been much better than the results above. The aforementioned fact leads some to believe that the "FFV" engine is more of an infant technology rather than fully mature.
In daily commute driving, mostly highway, 100% E85 in a turbocharged car can hit fuel mileages of over 90% of the normal gasoline fuel economy. Tests indicate approximately a 5% increase in engine performance is possible by switching to E85 fuel in high performance cars.

Does it take more energy to produce ethanol than it delivers?

Current technology fuel ethanol, returns 139% of the energy invested in its production and delivery for a net +39% energy return, due to the free solar energy captured by the plants used for its production. Current values for the energy balance of production show that gasoline returns only 80% of the energy invested in its production and delivery to the consumer. It has a negative energy balance of -20%.
Energy crops such as perennial switch grasses, timothy, and other high-output/low-input crops will be used in the future. This will improve the energy input/output ratio even more.

How are flex fuel vehicles (FFV) different from a gasoline-only vehicle?

"An FFV will contain a fuel sensor that detects the ethanol/gasoline ratio. In addition, a number of other parts on the FFV's fuel delivery system are modified so that they are ethanol compatible. The fuel tank, fuel lines, fuel injectors, computer system, anti-siphon device and dashboard gauges have been modified slightly to tolerate the alcohol. This normally includes a stainless steel fuel tank and Teflon-lined fuel hoses. The use of E-85 in gasoline-only vehicles is not recommended as it may cause damage due to the incompatibility of the alcohol fuel (ethanol) with the parts in gasoline-only engines. Performance and emissions will also be compromised."

How is ethanol purified from the fermentation mixture?

For blending with gasoline, ethanol purities of 99.5 to 99.9% are required, depending on temperature, to avoid separation. Currently, the most widely used purification method is a physical absorption process using molecular sieves.