Des Moines Register: The Obama administration on Wednesday proposed a modest increase in the amount of ethanol that must be blended into America’s gasoline supply next year, angering producers of the renewable fuel who wanted the White House to adopt the much more aggressive targets set by Congress. The Environmental Protection Agency proposed that refiners blend an “ambitious yet achievable” 18.8 billion gallons of renewable fuels in 2017. That preliminary figure is a small increase from the 18.1 billion gallons mandated by the EPA for 2016, but well below the 24 billion gallon threshold established by Congress in 2007.