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Techno-economic and resource assessment of electrolytic hydrogen and ammonia production

par Tonelli, Davide
Président du jury Fisette, Paul
Promoteur Parente, Alessandro ;Contino, Francesco
Publication Non publié, 2024-02-26

Thèse de doctorat

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Résumé :

The summers of 2020 and 2022 have represented two crossroads in the expectations around the role of hydrogen in the European energy system, setting a target of low-carbon hydrogen supply by 2030 more than twofold compared to the current carbon-intensive levels. While one half of the European supply is planned to be domestically produced within Europe, the other half is envisioned to be sourced from international markets. Projections for low-carbon hydrogen demand in Europe by 2050 range from half the current carbon-intensive demand level to a tenfold increase. Globally, the expected demand for low-carbon hydrogen in 2050 varies from equaling the current carbon-intensive demand level to a sevenfold increase. Factors affecting the scaling of low-carbon hydrogen supply are diverse and vary from the need to enhance the readiness of emerging production technologies to the adoption of mature technologies which lack an economy of scale. Different dynamics surround the hydrogen demand in 2050. Currently, hydrogen is mainly produced and consumed in production plants to refine hydrocarbons, or to produce ammonia and methanol. Current trade mainly concerns the fossil fuels used for its production. In the effort of achieving the net-zero target, hydrogen's role is predicted to extend to demand sectors where it's never been deployed on a large scale and where direct electrification faces limitations, such as heavy-duty transport, aviation, shipping, steel production, and industrial heat generation for the manufacturing of cement and other industrial products. The use of hydrogen relies on the presence of infrastructure to facilitate its transportation between production sites and demand points. Due to hydrogen's low volumetric energy density and high volatility, its derived carriers, i.e., ammonia, methanol, or synthetic hydrocarbons, might be preferred for its transport and as molecules for its final use. The primary goal of this research has been to quantify the hydrogen demand per end-use sector and per country. These estimates have been used to identify countries where land and water constraints could prompt the import of hydrogen or its derived carriers instead of relying on domestic production based on inland renewable resources. Except for Trinidad and Tobago, where hydrogen production from solar panels can lead to water scarcity, the assumed scenarios for hydrogen demand do not create water scarcity anywhere in the world if water scarcity is not already present. Instead, hydrogen production can exacerbate water scarcity in regions where it's already present. Countries with intense chemical industries such as Japan, South Korea, Trinidad and Tobago, and Western European countries including Belgium, could face land shortages for renewable electricity production to supply water electrolysis. These countries face the risk of an industrial relocation of production plants to regions with greater renewable energy availability. Mitigation strategies to address this risk include increasing the use of offshore wind, nuclear energy, or the import of hydrogen or hydrogen derived carriers from abroad. By providing country-specific hydrogen demand in 2050, this work allows further analyses on the role of trade of hydrogen and hydrogen derived carriers based on global scale energy system models. Some industrial sectors for hydrogen use can undergo a restructuring which affects the location and density of their energy demand. The future location of industrial production plants and the structure of industrial supply chains might vary significantly compared to the current scenario, prompted by the dual objective of reducing carbon intensity and ensuring price competitiveness of their products. Some industries, in particular, might experience a restructuring from their historically centralized configuration, driven by the access to fossil resources, to a partially or fully decentralized configuration, in which the final product is directly produced at the points of demand. This is particularly relevant for the fertilizer industry which relies on ammonia production, one of the main end-use demand sectors for hydrogen production both today and in 2050. The second goal of this research has been to quantify the techno-economic potential for decentralized ammonia production. Regardless of the relocation of ammonia production plants, the industry can be restructured to supply a portion of fertilizer demand through decentralized ammonia production at or near the point of consumption. By relying on different predictions of the future cost of ammonia production from small-scale electrocatalysis or electrified Haber-Bosch, the cost-competitiveness of decentralized ammonia production was evaluated at a pixel-, country-, and continental-level. Should all the current ammonia production for fertilizers transition to decentralized production through electrocatalysis of nitrogen and water, hydrogen demand in this sector would become negligible. By comparing these findings to historical fertilizer production costs, the results of this research indicate that by 2030, decentralized ammonia production could supply up to 96% of global ammonia demand, at a lower cost than the peak historical market prices. Future research can expand upon these findings by analyzing the optimal configuration of a future low-carbon ammonia supply chain based on location-specific ammonia demand and existing production plants. In Belgium, a country predicted to depend on the import of molecules, like ammonia and hydrogen, the future supply of ammonia-based fertilizers might be achieved based on different routes. The choice of these routes largely depends on techno-economic considerations. The third goal of this research has been to assess the optimal route for the supply of ammonia-based fertilizers in 2050. Overall, four routes of supply have been considered: (i) import of ammonia from overseas countries and direct use, (ii) import of hydrogen from inland transport and domestic conversion into ammonia, (iii) centralized production of ammonia based on domestic renewable resources, and (iv) on-site decentralized production of ammonia directly at the demand point. The key parameters affecting the decision-making have been considered and varied over a wide range of options for 2050. Compared to the results at global scale, based on the historical cost of ammonia production from fossil fuels, on-site decentralized production of ammonia is cost-competitive in Belgium only if a lower-than-predicted cost of supply is achieved by 2050. Differently, the import of ammonia is the most cost-competitive option in the majority of the cases. Overall, this research provides crucial insights into the evolving landscape of hydrogen demand and the technologies associated to its end-use application. The results of this work can support policymakers and industrial stakeholders navigating the complexities behind the deployment of hydrogen within the energy transition.