Calumet, Inc. (NASDAQ: CLMT) is a publicly traded U.S. manufacturing company established in 1919, headquartered in Indianapolis, Indiana. The firm specializes in the manufacture of lubricating oils, solvents, waxes, packaged and synthetic specialty products, fuels, renewable diesel, and fuel-related products.

Vertex Energy is an energy transition company specializing in producing and marketing high-purity refined products including conventional fuels, renewable diesel, and other specialty products.

Darling Ingredients is a global developer and producer of sustainable natural ingredients from edible and inedible bio-nutrients, creating products for the food, pet food, feed, fuel, bioenergy, and fertilizer industries.

HF Sinclair is an independent energy company that produces and markets gasoline, diesel, jet fuel, specialty lubricant products, and renewable diesel fuel through refineries and a brand network of branded fuel stations.

Valero Energy Corporation is the world's largest independent petroleum refiner and a leading producer of low-carbon transportation fuels.