ExxonMobil Sued Over Gulf Coast CO₂ Pipeline Access for Blue Ammonia Project
ExxonMobil faces expanded antitrust claims after a blue ammonia developer alleged the company blocked access to critical CO₂ pipelines following its acquisition of Denbury.
(P&GJ) — ExxonMobil and its Denbury subsidiary are facing expanded antitrust claims in Texas after a blue ammonia developer alleged the company used its control over carbon dioxide pipeline infrastructure to block a competing project.
Clean Hydrogen Works, a startup developing the Ascension Clean Energy (ACE) project in Louisiana, has added ExxonMobil as a defendant in a lawsuit originally filed last year against Denbury Carbon Solutions. According to Bloomberg Law, the amended petition filed in Texas Business Court characterizes ExxonMobil’s actions as a “Rockefeller-style power play.”
The lawsuit centers on the proposed $7.5 billion ACE blue ammonia facility in Ascension Parish, Louisiana. When fully built, the project is designed to produce up to 7.2 million metric tons of clean ammonia per year while capturing about 98% of its carbon dioxide emissions for permanent underground storage.
Clean Hydrogen Works alleges that after ExxonMobil acquired Denbury in late 2023, the company forced Denbury to terminate existing agreements that would have allowed the ACE project to access Denbury’s CO₂ pipeline network. That system spans roughly 1,300 miles across the Gulf Coast, making it the largest liquid CO₂ pipeline network in the United States.
Denbury and Clean Hydrogen Works announced their original partnership in October 2022. Under that agreement, Denbury secured exclusive rights to transport and sequester all CO₂ captured by the ACE project for 12 years after startup, with annual volumes expected to reach roughly 12 million metric tons.
Clean Hydrogen Works further claims ExxonMobil restricted pipeline access while advancing its own competing blue hydrogen and ammonia project at the company’s Baytown, Texas complex. That project, announced in 2022, was positioned to become one of the world’s largest low-carbon hydrogen facilities, with planned output of up to 1 billion cubic feet per day.
ExxonMobil paused development of the Baytown project in late 2025, citing weak customer demand and difficulty securing long-term offtake agreements. CEO Darren Woods said at the time that economic uncertainty and an industrial slowdown in Europe were limiting demand for low-carbon ammonia.
The lawsuit creates an unusual scenario in which Clean Hydrogen Works now appears better positioned to advance its project than ExxonMobil’s own paused development.
The ACE project had been designed around access to Denbury’s pipeline network, Mississippi River shipping access, and partnerships with Mitsui O.S.K. Lines and Hafnia to support global ammonia distribution.
ExxonMobil has not commented publicly on the lawsuit, consistent with its standard practice regarding ongoing litigation.
The case underscores the growing importance of CO₂ transportation and storage infrastructure as blue hydrogen and ammonia projects compete for limited pipeline capacity. Industry observers say the outcome could help shape how carbon capture infrastructure is shared among competing low-carbon developers.