Des petits réacteurs nucléaires pour la production d'hydrogéne
Publié : 22 avr. 2023, 10:59
Nouveau fil pour un sujet amené à se développer d'ici 2030.
https://www.world-nuclear.org/informati ... -uses.aspxThe role of nuclear power
Nuclear power already produces electricity as a major energy carrier with well-known applications. Operating at very high capacity factors, nuclear energy is well placed to produce zero-carbon hydrogen as an emerging energy carrier with a wide range of applications. The evolution of nuclear energy's role in hydrogen production over perhaps two decades is seen to be:
Cold electrolysis of water, using off-peak capacity (needs 50-55 kWh/kg).
Low-temperature steam electrolysis, using heat and electricity from nuclear reactors.
High-temperature steam electrolysis, using heat and electricity from nuclear reactors.
High-temperature thermochemical production using nuclear heat.
In addition, nuclear heat can assist the process which provides most of the world's hydrogen today:
Use of nuclear heat to assist steam reforming of natural gas (methane).
Steam reforming of methane (SMR) requires temperatures of over 700 °C to combine methane and steam to produce hydrogen and carbon monoxide. A nuclear heat source would reduce natural gas consumption by about 30% (i.e. that portion of feed which would simply be for heat), and eliminate flue gas CO2 emissions.
Starting with electrolysis, the efficiency of the whole process (primary heat to hydrogen) moves from about 25% with today's reactors driving electrolysis (33% for reactor x 75% for cell) to 36% with more efficient reactors doing so, to 45% for high-temperature electrolysis of steam, to about 50% or more with direct thermochemical production.
Electrolysis at ambient temperature is being undertaken in at least four US projects at nuclear power plants and is planned for the Kola plant in Russia from 2023. Alkaline and proton exchange membrane (PEM) technology is employed. In August 2021 Nel Hydrogen was contracted to build a 1.25 MW PEM electrolyser at Exelon’s Nine Mile Point nuclear power plant to show integrated production, storage and normal use at the plant.
Low-temperature steam electrolysis improves the efficiency of electrolysis at ambient temperatures and utilizes waste heat at up to 200 °C from a conventional reactor. The US Department of Energy in October 2020 selected two projects to advance flexible operation of light water reactors with integrated hydrogen production systems to receive cost-shared funding. Two other projects are already under way.
The IEA’s Global Hydrogen Review 2021 described about a dozen projects that are intended to use electricity from nuclear power plants to produce hydrogen using electrolysis. Most of these projects are based in Canada, China, Russia, the USA and the UK. However, only a few of these were actually launched.
High-temperature steam electrolysis (HTSE, at 550-750 °C or more) in solid oxide electrolysis cells (SOEC) to use both heat and electricity has been demonstrated, and shows considerable promise. It is a reverse reaction of the solid oxide fuel cell technology. It requires about one-third less energy than low-temperature electrolysis but has not yet been commercialized due to the poor durability of the ceramic components in a hot hydrogen environment. US research is at Idaho National Laboratory in conjunction with Ceramatec and FuelCell Energy in a $12.5 million project part-funded by the US Department of Energy (DOE). LucidCatalyst shows it producing hydrogen at two-thirds the cost of low-temperature electrolysis across a range of capacity factors. One of the four DOE projects mentioned above will focus on a solid oxide electrolysis cell at high temperature. Idaho National Laboratory will work with Xcel Energy to demonstrate HTSE technology using heat and electricity from one of Xcel Energy’s nuclear plants.
The International Atomic Energy Agency (IAEA) has developed the Hydrogen Economic Evaluation Program (HEEP) to assess the economics of large-scale hydrogen production using nuclear energy.
Nuclear hybrid energy systems for hydrogen production
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