Designing the next blue ammonia plant
Strategic technology selection for deep-decarbonised ammonia requires balancing carbon performance, energy integration, economics, and regulatory alignment
A mmonia production must decarbonise deeply while maintaining reliability and economics. For new facilities, the challenge is not simply how much CO₂ can be captured, but how to configure the process to minimise emissions without excessive energy or capital penalties. This study assesses eight configurations for a 3,500 metric tons per day Gulf Coast plant. The pathways include steam methane reforming, autothermal reforming, partial oxidation, and convective reforming, integrated with nitrogen wash or two-stage pressure swing adsorption, carbon recycle, hydrogen-rich firing, and pre- and post-combustion capture. Each configuration is evaluated for Scope 1 and 2 emissions, carbon capture, natural gas and oxygen consumption, and economics. Upstream natural gas emissions are excluded, so results are comparative plant-level metrics rather than lifecycle values. The analysis highlights how reformer choice, hydrogen recovery, steam and power integration, and electricity carbon intensity affect technology selection. Technology configurations The following blue ammonia process schemes were evaluated for high to deep decarbonisation: VK Arora Kinetics Process Improvements, Inc.
(CMP) is also included as an emerging low- carbon alternative. All cases were evaluated on a common basis. Each simulation estimated utilities, CO₂ capture performance, and Scope 1 and 2 emissions for a 3,500 metric tons per day ammonia plant, with captured CO₂ compressed to ~155 barg for sequestration. Post-combustion capture was set at 95%, while pre-combustion capture was set at ~99.9%. Scope 1 covers direct plant emissions, while Scope 2 reflects emissions associated with imported grid power for the ASU and major OSBL units. Hydrogen purification options included nitrogen wash and two-stage PSA, with recycle applied when appropriate, to assess impacts on hydrogen recovery, energy consumption, and process integration.
Abbrev. Definition ASU
Air-separation unit Autothermal reforming
ATR
Cl
Carbon intensity
CR Convective reforming H2RFire Hydrogen-rich firing HRC
Heat recovery combustor Hydrogen recovery unit
HRU NWU
Nitrogen wash unit NWUR Nitrogen wash unit with recycle OSBL Outside battery limits PCCS Pre-combustion CO2 capture, compression, and dehydration for sequestration PoCCS Post-combustion CO2 capture, compression, and dehydration for sequestration PoPCCS Combined post- and pre-combustion CO 2 capture, compression, and dehydration for sequestration POx Partial oxidation PSA + Two-stage pressure swing adsorption SMR Steam methane reforming SR Secondary reforming
• Case 1: SMR + SR + PCCS • Case 2: SMR + SR + PoPCCS • Case 3: ATR + NWU + PCCS
• Case 4: ATR + NWUR + H2RFire + PCCS • Case 5: ATR + PSA + + H2RFire + PCCS • Case 6: ATR + CR + PSA + + H2RFire + PCCS • Case 7: POx + PSA + + PCCS • Case 8: POx + NWU + PCCS A brief review of catalytic methane pyrolysis
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