Rail accounts for nearly 25% of HGLs shipments in U.S.

Rail movements of propane, propylene, normal butane and isobutane reached 426,000 barrels per day in 2016, according to the U.S. Energy Information Administration. The four petroleum products account for the majority of hydrocarbon gas liquids (HGLs) moved by rail in the United States and to and from Canada, and the numbers reflect movements in those areas. By comparison, rail movements of ethanol and crude oil were 637,000 barrels per day and 478,000 barrels per day, respectively, in 2016.

EIA recently started tracking rail movements of HGLs, which are primarily transported across the United States through pipeline. The data will improve EIA’s petroleum statistics “by providing more accurate product supplied information for each region” in the Petroleum Administration for Defense Districts. The United States is divided into five PADD districts: East Coast, Midwest, Gulf Coast, Rocky Mountain and West Coast. “Rail shipments of propane, propylene, normal butane and isobutane account for nearly (25%) of all inter-PADD movements of these HGLs,” according to the EIA.

The amount of propane moved by rail rose 130% to 244,000 barrels per day in 2016, from 106,000 in 2010. Of the four HGLs, the volume of propane moved by rail is greater than the other HGLs, but the majority of propane is transported via pipeline. Rail shipments are “higher during the winter months when propane is used as a heating fuel.”

Normal butane is the second most transported HGL by volume and is also a seasonal commodity like propane. Between 2010 and 2016, rail shipments nearly quadrupled in and out of the East Coast region and more than doubled in and out of the Midwest. Propylene, which is used to produce plastics and resins, is largely shipped from the Midwest region, “where most propylene is produced at refineries, to petrochemical producers” in the Gulf Coast region, which includes Arkansas. In the region, pipelines are used to transport it, but outside the region, all propylene shipments are by rail. “Isobutane, along with propylene and butylenes, is used in refinery alkylation units, and the resulting product is blended into gasoline.” Rail shipments of isobutane have risen because of inadequate pipeline capacity and recent demand for high-octane gasoline additives.