In Brazil during the 1990s -- when oil prices were low, the national debt was high, and the state oil giant Petrobras was tapping into huge new oil reserves -- the backers of biofuels struggled to keep their industry afloat. Then came September 11, the Iraq War, soaring oil demand from China, dissent within OPEC, and the oil shock that pushed prices over $70 a barrel. All of a sudden, biofuels -- particularly ethanol -- were the new oil. Brazil, as the world's largest exporter of ethanol, is a leader in developing this energy source.

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