Ellen Kullman, CEO for DuPont Co., in a speech Tuesday urged Congress and the Obama administration to preserve a law requiring ethanol to be blended into the gasoline supply, reports DesMoinesRegister.com. The Renewable Fuel Standard law of 2007 mandates that a growing amount of ethanol be blended into the country's gasoline supply each year through 2022.The Environmental Protection Agency, which last November proposed reducing the amount of ethanol to be blended in gasoline, is expected to set the mandated level for 2014 next month. DuPont's agriculture operations, including its DuPont Pioneer unit in Johnston, produce corn and soybean seeds and herbicides, among other products.