348 Save for later Print Download Share LinkedIn Twitter Exxon Mobil is gearing up to reach a final investment decision (FID) in the next two years on what it claims will be the world’s largest low-carbon hydrogen plant, and may add ammonia production to its plans.The US major said Monday that it has awarded front-end engineering and design work for a “blue” hydrogen and ammonia scheme at its Baytown, Texas, refinery and petrochemical complex to French engineering firm Technip Energies.The project aims to add 1 billion cubic feet per day of hydrogen production capacity to the site using natural gas as a feedstock and carbon capture and storage (CCS) to mitigate most of the emissions.Ammonia Addition? Exxon first tipped the project last March. But the company this week added fresh plans to evaluate ammonia production on site as well, while laying out plans to reach FID on the scheme by 2024 and start production in 2027-28.Energy Intelligence understands that Exxon is still evaluating the size and scope of any ammonia addition, with everything from market demand to regulatory permitting and approvals to general economics influencing its final decision.Ammonia is increasingly being evaluated as a preferred vehicle for transporting hydrogen over long distances given the cheaper economics relative to hydrogen liquefaction, so Exxon’s consideration of ammonia capacity at Baytown, which sits on the Houston Ship Channel, suggests interest in future international exports.CCS in SightExxon expects to capture and permanently store more than 98% of the CO2 emissions associated with the hydrogen plant — equivalent to around 7 million tons per year — and will design the wider CCS network supporting the project to also handle third-party captured emissions. The major suggested previously that capacity could reach up to 10 million tons/yr of CO2, a tally that would make it one of the world’s largest CCS schemes.The major plans to consume part of the hydrogen output internally at its integrated refinery-petrochemical complex at Baytown, reducing its operational emissions there by up to 30%. The remaining volumes will be marketed to third parties. Exxon said Monday offtake agreements are already “under discussion.”One big unknown remains Exxon’s specific plans for sequestering the CO2.The major initially heralded the Baytown scheme as its foundational offering to a Houston CCS hub concept that could capture and store up to 100 million tons/yr across major emitters along the Houston Ship Channel.That concept has proven to be more of a conversation starter than a firm proposal, however, as various refiners, utilities and chemicals companies consider a variety of different partnerships to advance CCS in the region.Energy Intelligence understands that the Baytown CCS scheme is not dependent on the Houston CCS hub solidifying, with various on- and offshore storage options under evaluation.