Public Radio: The next few months are likely to be critical for the ethanol industry as two key subsidies for the alternative fuel expire in December — and it’s unclear if Congress will renew them. One subsidy, called the blenders credit, pays refiners to mix ethanol into their gasoline. The other limits competition from ethanol imports. Together the two cost taxpayers about $6 billion a year. So far Congress hasn’t shown much interest in renewing the subsidies, which date back decades. …