Hydrogen production
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South Korean scientists have recently announced a new technology for the direct and efficient conversion of liquid ammonia into hydrogen. According to a report by Physicists Organizing Network on the 12th, in this study scientists proposed a new process that uses liquid ammonia to produce large quantities of green hydrogen with a purity of nearly 100%, and this method requires only one-third of the energy needed for producing hydrogen through water electrolysis. Hydrogen is a clean fuel; when used in fuel cells, the only byproduct produced is water, which stands in contrast to fossil fuels, which emit greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Hydrogen energy is hailed as the \"ultimate energy source\" due to its environmental friendliness, and is seen as one of the solutions to energy resource issues and environmental crises. According to the predictions of the International Hydrogen Energy Committee, by 2050 hydrogen energy will help reduce carbon dioxide emissions by 6 billion tons, and its share in the global energy mix is expected to reach 18%. Ammonia is easier to liquefy than hydrogen, and it is also easier to store and transport. Moreover, ammonia is becoming a promising hydrogen transport medium thanks to its two advantages: high mass hydrogen storage density and high volume hydrogen storage density. Furthermore, the research team pointed out that theoretical calculations show that ammonia electrolysis to produce nitrogen and hydrogen requires only 0.06 volts of external voltage, which is much lower than the 1.23 volts needed for water electrolysis to produce hydrogen. In this new study, researchers from the National University of Ulsan in South Korea proposed a new technique that can be applied in gas chromatography analysis, enabling them to more reliably compare and evaluate new catalysts that can be used in the ammonia oxidation reaction. The research team says that with this method, they can, through real-time monitoring, clearly distinguish between the ammonia oxidation reaction and the oxygen evolution reaction – the competitive oxidation reactions that occur during the process of producing oxygen via a series of reactions. Ultimately, they used flower-shaped electrodeposited platinum catalysts to produce hydrogen efficiently, with energy consumption that was significantly lower than that of the water-splitting hydrogen production process.
How is ammonia obtained? Essentially, hydrogen production via this process route is similar to that using methanol, so it cannot be considered green hydrogen.
I agree with you; the synthesis of ammonia involves nitrogen and hydrogen, and its production relies on fossil fuels such as natural gas and coal. The production of hydrogen through ammonia decomposition existed long before large-scale hydrogen production from methanol; however, at that time the price of methanol was high, resulting in high costs for hydrogen production. Ammonia, on the other hand, had a lower cost. But the technology used for producing hydrogen via ammonia decomposition back then was not as advanced as it is today, which meant that the purity and yield of the hydrogen obtained were lower.
China has already begun building large-scale electrolyzer plants for hydrogen production, using electricity derived from solar energy – which is the true green energy source. Due to the instability of solar and wind energy, large-scale energy storage is not economically viable; it is much more convenient to convert wind and solar power directly into hydrogen for storage.