Ethanol: How the Fuel is Produced, Growing Corn and Other Feedstocks, and More

Ethanol: who's making it
Brazil and the United States accounted for 90 percent of all ethanol production. Also, it should be noted that the United States, now producing at a rate of about 4.6 billion U.S. gallons per year, is widely considered the world's largest ethanol producer.

Corn ethanol
Of the feedstocks in wide use today, corn is the most popular in the US, and this makes it a very contentious subject. In the US, corn is widely grown, heavily subsidized and (often) heavily fertilized and sprayed with pesticides; the latter two are very unhealthy and energy-intensive (many of the fertilizers are petroleum-based). One bushel of corn (about 35 liters) nets about 2.8 gallons (10 liters) of fuel -- that translates to between 330 - 420 gallons per acre, leaving about 18 pounds of by-products known as distillers dried grains with solubles (DDGS), which can be used as feed for livestock. Ethanol produced from corn offers roughly a 10% - 20% reduction in greenhouse gas emissions when compared to gasoline.

Ethanol and fuel prices
Because ethanol contains approximately 34% less energy per unit volume than gasoline, burning it results in a reduction in miles per US gallon; that is to say, if your car gets 30 mpg and you switch to pure ethanol (that'd be E100), you'd likely get something like 20 miles per gallon, though exact conditions vary widely based on specific vehicles and their engines. Further, because corn-derived ethanol requires so much of the crop, the growth of this as a fuel source has wide-ranging agricultural implications, from the price of corn (which has risen by 50% in Mexico) to the substantial amount of land required to grow the crop. Additionally, prices for U.S. corn-based products, including animal feed, also rise. This translates to higher prices for animal products like chicken, beef, and cheese; for example, June 2007 cheese prices rose to $2 per pound on average, increasing 65% over the same period in 2006.

But that's just the story here in the States; ethanol is big business in Brazil, and has a handful of other advantages and disadvantages. Read on to learn more.

Ethanol: How the Fuel is Produced, Growing Corn and Other Feedstocks, and More
Ed. note: This post, about ethanol is now the third post (read about biodiesel and compost to catch up) in the Green Basics series of posts that TreeHugger is writing to provide basic information about important ideas, materials and technologies for new

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