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Types of Biofuels: Ethanol, Biodiesel, Biobutanol

Several companies are developing various types of biofuels.  We reveal the pros and cons of the top three: Ethanol, Biodiesel, and Biobutanol


Types of Biofuels—Ethanol, Biodiesel, Biobutanol—and the Companies Making Them



Ethanol is essentially pure alcohol—the same stuff that gets you into trouble on Saturday nights—and is perhaps the most ubiquitous of the alternative biofuels making their way into people’s gas tanks.  It can be made from various sources, but the most common are corn and sugarcane.  The U.S. government in early 2011 approved ethanol blends of up to 15 percent for use in vehicle models newer than 2001, and blends of 10 percent have been used for years now with no need for engine modification.  But there has been controversy surrounding just how sustainable ethanol actually is. 


  • It’s renewable! Ethanol can be regenerated given sufficient crop yield.
  • Domestic production reduces dependence on foreign fossil fuels and boosts rural farming economies.
  • Ethanol is cleaner burning than gasoline, releasing roughly 15 percent less greenhouse gas emissions
  • Advances in cellulosic ethanol can make ethanol fuel from waste cellulose like scrap wood, food byproducts, and non-food plants such as switchgrass


  • Ethanol derived from corn, beets, and sugarcane competes directly with food supply, and drive up the cost of other foods and grain-fed meats
  • Farmed ethanol crops tend to erode soil and use toxic industrial agrochemicals that can contaminate water supplies.
  • Ethanol has less stored energy than gasoline, reducing fuel mileage from between 15 to 30 percent
  • It currently requires more energy to create large quantities of ethanol than it produces; however, cellulosic ethanol may be the “magic bullet” to solve this and the food competition dilemma.
  • High blends or pure ethanol can be corrosive to engines not designed to run on it, and cannot be transported via existing oil pipelines due to corrosion restraints.
  • Converting a standard gasoline engine to run on high blends or pure ethanol can be costly, ranging from several hundreds to thousands of dollars.

Top Ethanol Companies

  • Archer Daniels Midland
  • Growth Energy
  • Aventine
  • Cosan



Gaining in popularity, biodiesel mimics petroleum-based diesel fuel and is derived from vegetable or animal oils.  In fact, several biodiesel companies simply collect used restaurant cooking oil and convert it into biodiesel.  What’s more exciting is the more recent promise of biodiesel-generating algae and bacteria strains.  Scientists are even genetically engineering these microorganisms to create biodiesel lipids with minimal or no feedstock necessary, just sunlight and CO2, much like plant photosynthesis!


  • It’s also renewable!  Sufficient plant, algae or bacteria crops can yield abundant biodiesel fuel.
  • It’s recycled!  Much of the biodiesel on the market is derived from used cooking vegetable oils.
  • Domestic production reduces dependence on foreign fossil fuels and boosts rural farming economies.
  • Reduces tailpipe emissions compared to petroleum-based diesel, is cleaner burning, and contains no sulfur, eliminating sulfur dioxide emissions.


  • Biodiesel is currently more expensive to commercially produce than petroleum diesel as production infrastructure is not yet on a mass-scale
  • Biodiesel is susceptible to cold weather, and can gel when the temperature drops, causing fuel injection problems (although this can be fixed with costly engine modifications). 
  • While several diesel vehicle engines can run on biodiesel with minimal or no modifications, biodiesel does not work in standard gasoline engines. 
  • Biodiesel production increases food costs, both in food crops used to generate biodiesel, as well as feedstocks for biodisel generating algae and bacteria.


Top Biodiesel Companies

  • Renewable Energy Group Inc.
  • DuPont
  • Australian Renewable Fuels Limited
  • Imperium Renewables Inc.
  • Cargill, Inc.



While it’s the less well known of the three biofuels featured, biobutanol holds the most promise.  Biobutanol is simply isobutanol derived from bacteria or algae, much like biodiesel.  However, the beauty of biobutanol is that it can potentially be directly used in standard gasoline engines with no modification!


  • It’s also renewable!  Biobutanol is produced from algae or bacteria.
  • It can be used directly in gasoline engines with no modification.
  • It can use existing pipeline and supply chain infrastructure for distribution.
  • It has a high octane level, so there’s little if any loss in fuel mileage.
  • Non-corrosive to engines and pipelines
  • Domestic production reduces dependence on foreign fossil fuels


  • Feedstocks are required for production, although non-food feedstocks and genetically modified bacteria and algae strains may resolve this issue.
  • Production costs are relatively high, but the industry is in its infancy, and as it grows costs will come down.

Top BioButanol Companies

  • Butamax: a DuPont and BP joint venture
  • Cobalt Technologies
  • Bioenergy International

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