Biodiesel can be made from vegetable oils, animal fats, or recycled restaurant oils and greases. It is biodegradable and less polluting than petroleum diesel. Common biodiesel feedstocks include virgin oils, used cooking oil, yellow grease, and brown grease. Biodiesel can be used in pure form or blended with petroleum diesel in vehicles and equipment. Common blends are B2, B5, and B20. Since used cooking oil is cheaper than virgin oils, it is a more economic feedstock choice for biodiesel producers. The estimated US demand for diesel fuel exceeds domestic vegetable and animal oil supply. Several companies in the Dallas-Fort Worth area produce