Decarbonisation Technology May 2026 Issue

Project drivers • Initiate decarbonisation through partial integration of green hydrogen. • Gain operational experience with green ammonia production technologies. Integration strategy The plant investigated injecting green hydrogen downstream of the methanator, along with moderate oxygen enrichment. However, the requirement for a dedicated oxygen compressor significantly increased capital and operating costs, rendering the oxygen enrichment pathway economically unfeasible. Implementation and outcomes The facility completed construction and start- up of the green hydrogen project, including the 20 MW electrolyser and integration equipment such as the hydrogen compressor. The system entered operation but encountered early performance challenges linked to design issues, and sustained operation was not achieved. Case 4: Green hydrogen integration to expand capacity in a small US plant This US-based ammonia facility, currently operating at 550 stpd, features a HP synloop (>4,000 psi) and reciprocating compressors. The plant recently installed a new, high-efficiency converter rated for approximately 120% of its nameplate capacity. However, the front- end reforming section remains unmodified. To capitalise on the converter’s latent capacity, the plant pursued a third-party offtake agreement for green hydrogen, aiming to expand production without major front-end upgrades. Project drivers • Replace ~100 stpd of trucked-in ammonia with on-site production to reduce logistics costs. • Leverage IRA incentives to lower carbon intensity and improve project economics. • Utilise existing downstream capacity to minimise capital investment and operational disruption. Integration study KPI conducted a detailed evaluation of green hydrogen integration strategies to support an additional 100 stpd of ammonia production.

As part of a broader decarbonisation initiative, the facility proposed installing a 20 MW electrolyser to integrate green hydrogen into the process. The primary objective was to reduce carbon emissions and leverage the Inflation Reduction Act (IRA) incentives to establish a viable economic case. Given the limitations of the arch burners and cryogenic purifier, KPI recommended a combined strategy: injecting green hydrogen downstream of the purifier, along with moderate oxygen enrichment. Key findings from the study: • Arch burner firing could be reduced by ~9%, bringing operation well within design limits. • Radiant tube outlet temperatures decreased by ~34°F, with even greater reductions in tube metal temperatures, enhancing reliability and extending tube life. • Cryogenic purifier loading was reduced, resulting in lower inert gas content in the make-up gas and a corresponding decrease in purge rate. • Post-combustion CO₂ emissions were reduced by ~9%. Additional CO₂ emissions from the auxiliary boiler (used to offset a minor MP steam shortfall) were fully accounted for in the net emissions balance. • Feed and fuel consumption decreased by ~0.3 MMBtu/ST compared to the base case. • Oxygen injection was deemed feasible without a dedicated compressor based on commercial precedent. However, if a separate compressor was required, the economic viability of oxygen enrichment would be compromised. Current status The electrolyser project is currently on indefinite hold due to uncertainty surrounding the availability of IRA incentives. Case 3: Partial green hydrogen integration in a legacy US plant This legacy US-based ammonia facility, operating at 1,800 stpd, evaluated the partial integration of green hydrogen and oxygen from a 20 MW electrolyser system to reduce carbon intensity and modestly increase production. The study conducted by KPI shared similar objectives with Case 2, though without the added benefits of cryogenic purification.