U.S. refinery crude oil processing capacity grew by nearly 40,000 bpd in 2024 to 18.4 MMbpd, the U.S. Energy Information Administration (EIA) said on Friday.

Motiva Enterprises' Port Arthur, Texas, plant became the largest single refinery by capacity at 640,500 bpd, passing Marathon Petroleum's Galveston Bay Refinery in Texas City, Texas, according to the report. Motiva's increase of 14,500 bpd from a year ago was due to improving operating efficiency.

National capacity may possibly fall by as much as 402,476 bpd by next year's report because of refinery closures: Lyondell Basell Industries permanently shuttered its 263,776-bpd Houston refinery in February (learn more), while Phillips 66 plans to close its 138,700-bpd Los Angeles refinery (learn more) by the end of this year.

In 2026, assuming no growth at refineries through efficiency improvements, referred to as de-bottlenecking, U.S. capacity would fall below the 2023 level of 18.06 MMbpd, as reported by the EIA.

Marathon, based in Findlay, Ohio, continues to be the largest single refiner in the United States with 13 refineries operating a combined production capacity of 2.96 MMbpd equal to 16% of the national total, according to the EIA report, which is issued annually.

Valero Energy Corp., based in San Antonio, Texas, is the second largest, with 13 refineries operating 2.2 million bpd, equal to 12% of U.S. capacity, according to the EIA.

ExxonMobil Corp. is the third-largest, with four refineries with 1.96 MMbpd in crude oil throughput, equal to 10.6% of national capacity, the EIA report said.

The EIA report reflects refinery capacity as of January 1, 2025 and is based on reports filed by refiners on individual capacities for each refinery by January 1. As such, it provides a portrait of growth in the previous year.

The long-term trend in U.S. refining has been for shrinking numbers of refineries to overcome increasing capacity at remaining ones.

The total number of refineries in the United States remained unchanged at 132 from 2024, but the EIA report lists the 32,000-bpd CPI Operations refinery in Paulsboro, New Jersey as idle.