Principal contributor: Mickey Francis
The U.S. Energy Information Administration (EIA) recently improved multiple data series for hydrocarbon gas liquids (HGL) in its Monthly Energy Review. The updated data series reflect changes in how EIA defines liquefied petroleum gases to better align with industry practice.
HGL accounted for about 15% of total U.S. petroleum consumption in 2018, reaching a record-high 3 million barrels per day in 2018, a 47% increase from 2008. EIA’s Monthly Energy Review now includes longer historical time series, propane consumption seasonality by sector, HGL component thermal conversion factors, non-combustion use estimates, and updated carbon dioxide (CO2) emissions estimates.
Hydrocarbon gas liquids include nine petroleum products: alkanes (ethane, propane, normal butane, isobutane, and natural gasoline (formerly known as pentanes plus)) and olefins (ethylene, propylene, butylene, and isobutylene). Monthly and annual consumption data for each product are now available starting in 2010, except propane-only and propylene-only, which extend back to 1949. Combined consumption data for ethane/ethylene, butane/butylene, and isobutane/isobutylene begin in 1967, and natural gasoline consumption data begin in 1973.
Propane is one of the most commonly consumed HGL products in the United States. The U.S. residential and commercial sectors use more propane, mostly for space heating, in the winter. The industrial sector (especially the chemical industry) uses more propane in the summer, when propane prices are relatively lower. Only small amounts of propane are used for transportation. Propane is the only HGL product that is commonly used in all four end-use sectors; the other HGL products are assumed to be exclusively used in the industrial sector.
Note: HGL=hydrocarbon gas liquids
EIA updated thermal conversion factors for each HGL product in million British thermal units (Btu) per barrel. The updates lowered the heat content of aggregate HGL consumption in 2018 by 4% and natural gas plant liquids production by 2%.
EIA’s updated thermal conversion factors also resulted in a decrease in the calculated amount of CO2 emissions from total HGL products by 1% for 2018. The decrease to overall U.S. CO2 emissions from all energy sources is less than 1% because most HGL consumption is for non-combustion (nonfuel) use. For example, HGL products are commonly used for making plastics, paints, and resins; ethane for anti-freeze and detergents; butanes for synthetic rubber; and natural gasoline for solvents. In this way, the HGL are consumed but not combusted, so fewer emissions are generated in their consumption.