Butane
Butane is used in the petrochemical industry as Normal Butane and Iso Butane. Both are naturally occurring by-products of Natural Gas production and Crude refining. Normal butane is primarily used for unleaded blending (roughly 85%) and this is almost exclusively in the winter when the RVP specs are the easiest. Cracking demand is steady throughout the year, and is responsible for most of the remaining demand, aside from the chain smokers butane lighter demand. The largest traded location for butane is at Mt. Belvieu, Texas. This location includes refinery grade "TET" product, and fractionation grade "NON-TET" product.