Ethanol vs Butanol



In a world that’s increasingly turning its attention toward sustainability; we are constantly looking for better ways to expand our energy supplies.


In recent years we have all become familiar with the term “gasohol”  We see stickers on the pumps of our local gas stations the advising of the possibility that the gasoline we are buying could contain up to 10% alcohol.  And some of the new cars have stickers indicating they will operate on E-85, which is a 15% alcohol blend.


What does it all mean to you and me???


The governments have gotten involved:


Back in 2005, here in the USA, Congress established the “Energy Policy Act” (RFS1).  This Act initially began by setting percentages of “renewable” fuels that must be used in the production of fuels, including fuels used by you and me to operate our cars.


The Energy Policy Act has been modified and refined since its introduction, with current goals extending out to the year 2022.  Impacts of the Act are intended to be:


  • Reduce consumption of petroleum based gas and diesel fuel
  • Reduction in imports of foreign oil
  • Lower the cost of gasoline and diesel at the pump
  • Reduce Green House Gas emissions (GHG)
  • Increase farm income
  • Decrease corn and soybean exports


So far, the most popular option alternative to accomplish these escalating goals has been to add ethanol alcohol to the fuels we use.  Ethanol is most commonly produced from cereal grains, corn, sugar beets, sugar cane, etc.  There are over 200 plants across the USA, currently producing ethanol.


What about all the bad stuff we’ve heard about gasoline with ethanol additives? 

While it’s true that the automotive industry has made good progress keeping up with the changing fuels we buy at the local pump, there are other products in our lives that are struggling, such as lawnmowers, small gasoline power tools, powerboats and more.  Ethanol can be destructive to some machinery, and can be detrimental to fuel tanks, fuel lines and injection systems as well.






Another type of alcohol, called “butanol” has been undergoing tests by several agencies, as a substitute for ethanol, as a fuel additive.  Butanol is known as a “4-carbon molecule” alcohol versus ethanol, as a “2-carbon molecule”.  In layman terms, this is explained as the number of atoms in the carbon molecule of the chain-structures that make up the final product of butanol or ethanol.


When blended with gasoline, butanol becomes “bio-butanol” and has some advantages over ethanol blends, when used as a transportation fuel.



  • 85% blends can be used in un-modified gasoline engines without modification.
  • Bio-butanol can be transported more easily than ethanol blends.
  • Bio-butanol doesn’t separate from gasoline, as does ethanol in extended storage.
  • Bio-butanol’s energy density is closer to that of gasoline; meaning better MPG
  • A 16% blend of bio-butanol yields the same fuel economy as ethanol (E 10), while providing 2X the energy from renewable resources, and 2X the green house benefits.*


A 16% blend of bio-butanol will displace usage of 16% of the hydrocarbon fuel we buy at the pump.  This calculates to approximately 17 million gallons per year; more than the current annual consumption of the entire state of California.*


*Per Butamax; a joint venture company owned by BP and Dupont, and producer of bio-butanol.



  • Although the energy density is higher, the yield per bushel of corn is lower than when producing ethanol.
  • Currently there are very few plants, set up to produce butanol; converting an ethanol plant costs $15M


Most recently, a group of boating manufacturers formed teams to analyze the effects of bio-butanol on their respective products.  Testing was performed on outboards, inboard engines, etc.  The competing manufacturers shared information and results of their tests, finding bio-butanol to be a better alternative than ethanol in the marine industry.


It is no secret that ethanol has caused some heart-ache in the marine environment.  I have first-hand experience in damages caused from using ethanol in a boat.  An interesting note is it continues to show up in trailer-able boats.


While marinas have done a good job, keeping alcohol away from the gas docks, some smaller boat owners tow their boat to the corner gas station to purchase fuel as a lower price.  Although they save at the gas pump, the end result is they are putting ethanol in the marine fuel tanks.


The bio-butanol testing results have been positive thus far, and there remains hope for the future.  Butanol is still made from farm products (i.e. corn), so the farmer still wins.  The switch to butanol appears to be a possibility, and is worth watching.

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