The highly touted “closed loop” ethanol plant in Nebraska shut its doors last week and filed for bankruptcy. E3 BioFuels used biogas generated from cattle manure, provided by a nearby feedlot containing 25,000 head of feeder cattle. Distillers grain, a byproduct of ethanol production, was fed to the cattle and the process started all over again. As a result, the plant used almost no fossil fuels and carbon emissions from the manure were minimized. Mechanical problems are blamed for the shutdown. Plant officials said they couldn’t reach full production and lost money. There’s no word on whether the plant will open again. In the meantime, E3 BioFuels is expected to file lawsuits against construction contractors.