Classification society DNV has issued an Approval in Principle (AiP) to BW Offshore and McDermott for a floating blue ammonia production concept, the partners said through trade outlet iMarine.

The AiP confirms that the design, as documented, meets DNV's class rules and applicable international standards at the conceptual stage. The certificate sits ahead of any front-end engineering and design (FEED) award and well ahead of a final investment decision (FID); it is the customary first regulatory hurdle for offshore production units headed for deepwater or remote field service.

What an FPSO is doing in ammonia

The unit borrows the hull and storage layout of a floating production, storage and offloading (FPSO) vessel — the workhorse that has processed, treated and stored crude at sea since the 1970s.

Where the design departs from a conventional FPSO is at the process deck. The standard oil, gas and water separation train gives way to the unit operations blue ammonia requires: feedstock reforming, carbon dioxide recovery, ammonia synthesis and product handling.

"Blue ammonia" denotes ammonia (NH3) produced from natural gas in which the CO2 byproduct is stripped out and routed to geological storage or industrial use, rather than vented to atmosphere. The molecule carries the same hydrogen content as conventional ammonia, but at a fraction of its carbon intensity — the chemistry that has put ammonia in trials as a marine bunker fuel and a power-generation feedstock.

What does an AiP actually change?

An AiP does not authorize construction, does not commit the partners to a yard slot and does not pick a deployment basin. The certificate is a third-party statement that the concept, on the drawings DNV reviewed, is technically feasible under the rules in force.

For BW Offshore, the certificate extends a portfolio that has moved beyond oil-producing FPSOs into gas handling and carbon-capture service. For McDermott, which brought EPC and offshore execution capability, the AiP raises the design's standing ahead of any pre-FEED option a client may exercise.

Why floating, why now

Floating ammonia production targets offshore gas discoveries that sit beyond the reach of a host pipeline. Synthesizing ammonia at the wellhead and capturing CO2 in parallel removes the long subsea gas line and the capex that has kept smaller offshore accumulations undeveloped.

Several frontier gas plays — among them discoveries off Mauritania and Senegal, Suriname-Guyana, Mozambique and parts of the Eastern Mediterranean — sit far from gas markets and have struggled to reach FID because export infrastructure is the single largest line item in the development budget. A floating ammonia unit turns that stranded gas into a seaborne commodity that can reach ammonia-importing terminals in Europe and Asia directly.

Ammonia ships at atmospheric pressure with modest cooling, costs less to carry by vessel than LNG over shorter maritime distances, and unloads at conventional terminals without cryogenic equipment. The FPSO hull brings with it station-keeping, offloading and operations know-how that the oil and gas industry has built across West African, North Sea and Brazilian deepwater fields, where BW Offshore's existing fleet has accumulated its operating record.

What regulators will want to see next

Ammonia is classified as a toxic cargo under IMO rules, and bunkering codes have only begun to update for ammonia as a marine fuel. An AiP-graded design typically feeds into those rule updates, since classification work and bunkering standards evolve together when a new fuel molecule enters the offshore production stack.

Where the certificate leaves the project

The iMarine item does not name a deployment site, a nameplate ammonia capacity, a charterer or a carbon-storage partner. The partners have not, on the public record carried by iMarine, attached a quoted timeline to a pre-FEED phase, a yard selection or a reference gas field. The release carried by iMarine did not include executive comments from either BW Offshore or McDermott; it named only the certificate itself and the parties involved.

Watch items

• Pre-FEED option exercise or contract award on the design
• Selection of a specific gas discovery or basin as the reference case
• Identification of a carbon storage or CO2 utilization partner
• Publication of a nameplate ammonia capacity in tonnes per day
• A shipbuilder or yard named for the hull conversion or newbuild