Valero Energy Corporation is an American-based fuels producer mostly involved in manufacturing and marketing transportation fuels and other related products. It is headquartered in San Antonio, Texas, United States. Throughout the United States, Canada, and the United Kingdom, the company owns and operates 15 refineries with a combined throughput capacity of approximately 3.2 million barrels per day, two renewable diesel plants that produce approximately 1.2 billion gallons per year, and 12 ethanol plants with a combined production capacity of 1.6 billion gallons as its subsidiaries. According to a number of estimates, Valero has become a major producer of corn ethanol and renewable diesel, both low-carbon liquid transportation fuels. Wikipedia