Shell Pennsylvania Petrochemicals Complex

The Shell Pennsylvania Petrochemicals Complex, formally known as Shell Polymers Monaca, is an ethylene cracker and three polyethylene production plants located in Potter Township, Pennsylvania, United States, owned and operated by Shell Oil Company, the American subsidiary of supermajor oil company Royal Dutch Shell. The plant is near the interchange of Interstate 376 and Pennsylvania Route 18, about 25 miles (40 km) from Pittsburgh. Operations began in November 2022. The nameplate capacity is 1.6 million tons per year of plastic pellets.

The site also includes a natural gas power plant to support both the plant and the local electric grid, a 900 ft (270 m)-long cooling tower, a rail system with over 3,000 freight cars, numerous loading facilities for both trains and trucks, a water treatment plant, an office building, a laboratory, and an innovation center. The complex cost around $14 billion to build. In July 2025 it was put up for sale by Shell.

The location of the plant has had a long history as an industrial site. Both Horsehead Corporation and Koppers had plants on the site; Koppers unofficially incorporated the area as Kobuta. Before its industrial use, the area had been farmland owned by a local family, which included a private cemetery (albeit with unmarked graves) that was discovered after Shell purchased the property for cleanup; the company informed living descendants in the area of th3e skeletal remains.

Pennsylvania, Ohio and West Virginia engaged in a tax competition for the plant. In 2012, Pennsylvania structured a deal requiring Shell to invest at least $1 billion in Pennsylvania and create at least 2,500 construction jobs in exchange for a 25-year tax incentive of $66 million per year and tied to production, reducing Shell's tax by up to 20 per cent. The combined incentive could reach $1.65 billion. Shell announced the Pennsylvania site on March 15, 2012. The deal was one of the largest tax incentives in Pennsylvania's history.

Shell began leasing the bulk of the property from Horsehead in 2012, which promptly closed the zinc plant on the site and began cleanup of the site in preparation of potentially opening a cracker plant on the site, which would be used to convert natural gas products into ethylene and then into plastics. Shell had selected the site due to the ongoing Marcellus natural gas trend and the site's prime location within the Marcellus Shale. By 2015, after executing several short-term lease extensions, Shell purchased the property outright from Horsehead, and subsequently purchasing other nearby properties, effectively absorbing all of Kobuta.

Shell pledged with Beaver County officials on environmental cleanup regardless if it opened the proposed plant, and in a worst-case scenario prepare the area land for at least some sort of future industrial use if Shell decided not to build there. This included building a massive bridge over PA 18, commenced in 2015, to connect both sides of the property without requiring an intersection along the route, as well as a Shell-funded rerouting of PA 18 and infrastructure improvements to I-376. Shell also gave a donation to the Beaver County recycling center so the center could extend its operating hours.

Despite a downturn in oil prices, on June 7, 2016, Shell announced it would build the plant. In a press release, Shell stated that 70% of polyethylene customers in North America were within a 700-mile (1,100 km) radius of Pittsburgh and that the location would be more cost-effective for its customers than at existing facilities along the Gulf Coast, which unlike North Central Appalachia are susceptible to the Atlantic hurricane season. Shell estimated the project would create 6,000 construction jobs to build the site and 600 permanent jobs for employees working at the plant.

In 2015, Shell began preparing the site for future construction, moving 7.2 million cubic yards of dirt, building new bridges and a new rail line, and completing a total relocation of PA Route 18. Docking and bulkhead facilities to be used during construction were created by Alberici. Construction on the plant itself began on November 8, 2017. As of 2019, over 5,000 employees were working on construction.