Macon: Two years after Gov. Sonny Perdue called bioenergy “the cornerstone of the new Georgia,’ many Middle Georgia biofuel projects have been delayed or canceled, and biodiesel refineries have stopped production. Biofuels such as ethanol and biodiesel are renewable fuels made from organic sources such as crop wastes and animal fat. State and national politicians have voiced support for alternative fuels in recent years as a way to reduce pollution and dependence on foreign oil. With …