Decarbonisation Technology August 2025 Issue

cracking, hydrogen at a cost acceptable to the market. A more sustainable use may be direct substitution of an existing ‘grey’ product with a zero-carbon alternative. For example, in fertiliser production, green hydrogen use enables the synthesis of ammonia with significantly reduced carbon intensity, addressing one of the most emissions- intensive areas of global agriculture. The maritime and aviation sectors are also beginning to explore zero-emission hydrogen- derived fuels such as ammonia and methanol as low-carbon alternatives to traditional bunker fuel and jet fuel. Each of these applications requires hydrogen to be available at scale and a very competitive cost. The recent measures agreed at the April 2025 International Maritime Organization’s Marine Environmental Protection Committee meeting (IMO MEPC83) outline a pathway for the adoption of low-carbon fuels to 2050, with significant demand anticipated from the mid-2030s. Green ammonia is being considered as a long- term option for marine fuels, as it is generated from established processes by reacting hydrogen with nitrogen sourced from the air to generate ammonia in a low-energy-intensity and relatively cheap process. A little chemistry is instructive, and the process for creating ammonia (NH₃) is simply the combination of hydrogen and nitrogen: 3H₂ + N₂ → 2NH₃ In this case, all the hydrogen created is embedded within the ammonia molecules. Other fuels, such as methanol (CH₃OH), require the addition of carbon dioxide. The This illustrates a key challenge for methanol: the conventional process results in one-third of all the hydrogen produced being reconverted back to water. As hydrogen production is the most expensive part of the process, this reconversion and loss mean that methanol, and further derivatives such as sustainable aviation fuel (e-SAF) will always carry a price premium. While markets such as aviation and local shipping may bear this premium, as the opportunities to use methanol and e-SAF as ‘drop-in’ fuels significantly reduce the costs of chemistry is illustrated as: 3H ₂ + CO₂ → CH₃OH + H₂O

supply infrastructure, the marine industry is not used to paying top dollar for its fuels. Traditionally, bunker fuel for international shipping (a market of ~300 million tonnes per annum) is designated as heavy fuel oil, and this is figuratively and literally the ‘bottom of the barrel’, being a tar-like residue, left at the base of distillation towers where more refined products are swept up. Against this background, the positioning of ammonia as one of the most cost- effective e-fuels is clear. With almost 50% of the ocean-going order book identified as dual-fuel or ‘alternative fuel ready’, it is apparent that the shipping industry is setting itself up to meet the challenges of future low-emission fuels. Meeting the challenge of scale The IMO MEPC83 decision is one of the first signals of multinational, coordinated action with respect to CO₂ emissions across a single industry. While no single fuel or technology is expected to dominate the long-distance shipping or aviation markets, there is a clear need to be able to produce zero-carbon fuels at scale, and in step with the transition to low- or zero-carbon fuels. This is where decentralised and modular systems can make a critical difference, as a shift to large-scale offtake in the 2030s will require not only supportive policies and investment but also practical, deployable systems designed for speed, efficiency, replication and, above all, scale. The P2(H₂)Node system exemplifies this approach, offering an integrated, modular solution that reduces project complexity and aligns with the needs of industry and infrastructure developers. Looking ahead, hydrogen will need to address a wide range of use cases, each with different requirements for cost, purity, and transportability. Flexible systems capable of adapting to diverse market conditions and geographies, are well- positioned to support this next phase of the energy transition. As hydrogen-based e-fuels become core components of the global fuel and feedstock mix, such practical solutions will help define the pace and direction of progress. P2(H 2 )Node is a trademark of InterContinental Energy.

Richard D Colwill