Clean Ammonia Roadmap

In 2022 approximately 11 Gigatonnes (Gt) of CO2 were emitted globally as a consequence of industrial processes, which contribute to global climate change. Industrial processes will gradually become more electrified to reduce the carbon footprint to approximate zero in 2050. In addition, low carbon fuels will most likely still be required in this future decarbonized energy landscape as not all industrial processes qualify for electrification. Green hydrogen is a zero-carbon fuel that is accepted as an important energy carrier to accommodate CO2 reduction. However, it also has some limitations due to its chemical properties. It has a relatively low energy density, which makes it less attractive for transport, storage and utilization. It also has a low ignition energy, increasing explosion risks. Hydrogen 'stored' in ammonia could help resolve these issues. Ammonia as a hydrogen carrier can be converted back to hydrogen again. Ammonia is one of the widely produced chemicals in the world and has been used in industry for over a hundred years. 80% of ammonia and its derivatives are used as feedstock for fertilizer production, thus sustaining close to half of the global food consumption. The remaining 20% is used as a building block in the chemical industry. Ammonia is currently produced by combining hydrogen with atmospheric nitrogen in a Haber-Bosch process, while hydrogen is produced from natural gas (about 75%) and coal (about 25%, mainly in China). This process results in about 500 million tonnes of CO2 emissions annually. The resulting product is called grey ammonia. This type of ammonia production can be decarbonized by carbon capture and storage or utilisation (CCS/U). In that case, it is called low-carbon or blue ammonia. Green hydrogen - produced through water electrolysis from renewable electricity - can be used for conversion to renewable or green ammonia.