Today is St. Patrick’s Day – tomorrow is St. Diesel’s Day. Well, he hasn’t actually been canonized yet – at least not by the Pope, but maybe by the Biodiesel industry. March 18 is the fifth annual National Biodiesel Day, celebrated on the birthday of Rudolf Diesel – inventor of the diesel engine. According to a press release from the National Biodiesel Board, they chose Diesel’s birthday to honor him for his foresight in recognizing the valuable role of vegetable-oil-based fuel. In the late 19th Century, Diesel ran early versions of his engine on peanut oil and paved the path for today’s biodiesel. Biodiesel is now made from soybean oil, as well as other vegetable oils and fats.