Breaking through the global challenge:
Without desalination of seawater, direct electrolysis by offshore wind power to produce green hydrogen, turning marine resources into marine ENERGY.
The cost per ton is only 0.3-0.4 CNY（approx 0.066 AUD to 0.087 AUD), plus the financial cost, return on investment, employment opportunity cost, national interest cost, enterprise and citizen cost, the cost per kilogram of Green Hydrogen is only 1.9 AUD, which is a very high commercial value and return on investment. The price of Green Hydrogen is 15-20 USD per kilogram, Blue Hydrogen is 5-9 USD per kilogram and Grey Hydrogen is 3-5 USD per kilogram in the international market.
Hydrogen, as an efficient, low-carbon energy carrier and a green, clean industrial material, has a wide range of applications in transportation, industry, construction, power, and many other fields. It has become the most promising secondary clean energy for sustainable human development in the 21st century.
Hydrogen energy, as the next-generation clean energy source, is green and efficient when produced through water electrolysis. However, almost all systems currently use freshwater resources as the electrolyte. Global freshwater resources are extremely limited, accounting for only about 3.5% of the total water volume, undoubtedly exacerbating the issue of freshwater scarcity.
Meanwhile, the world is abundant in seawater resources. If seawater is directly electrolyzed to produce hydrogen, it can then be used as a fuel to generate high-purity freshwater, achieving the dual purposes of seawater purification and hydrogen production.
Unlike freshwater, the composition of seawater is very complex, involving 92 types of chemical substances and elements. The abundant ions, microorganisms, and particles present in seawater lead to problems during hydrogen production, such as competing side reactions, catalyst deactivation, and membrane clogging.
he principle of electrolyzing seawater to produce hydrogen is essentially the same as the electrolysis of ordinary water. However, due to the high salt content in seawater, there are some technical considerations and adjustments in practical applications.
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Simply put, during the process of electrolyzing water to produce hydrogen, when an electric current passes through water, water molecules are decomposed, producing hydrogen and oxygen gas. The specific reaction is as follows:
2H2​O(l)→2H2​(g)+O2​(g)
When using seawater for electrolysis, the presence of salt (mainly sodium chloride NaCl) will result in additional reactions. For example, sodium chloride when electrolyzed will produce chlorine gas and sodium hydroxide:
2NaCl(aq) → 2NaOH(aq) + Cl2(g)
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Therefore, when using seawater as an electrolyte medium, in addition to producing hydrogen and oxygen, chlorine gas might also be produced. This poses safety and environmental concerns, so technical adjustments are necessary to optimize this process.
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To avoid the aforementioned issues, our team holds a method of electrolysis that is efficient, stable, and does not produce harmful by-products. Furthermore, our team selects appropriate electrolysis materials, such as electrodes and electrolytes, to ensure the electrolysis process is efficient and stable.
Principle of hydrogen production by seawater electrolysis
How to produce hydrogen directly from seawater？
By integrating molecular diffusion, interfacial phase equilibrium, and other physical mechanics processes with electrochemical reactions, the complex challenge posed by the composition of seawater has been perfectly addressed.
Firstly, in the electrolysis technology for hydrogen production, the electrolyte is essentially a solution with about 30% concentration of potassium hydroxide, while seawater is a solution with a 3% salt concentration. The molar concentration of water in the potassium hydroxide solution is noticeably lower than that in seawater. Based on the basic principle driven by concentration differences, seawater will naturally flow towards the potassium hydroxide solution, creating a self-propelling process. Furthermore, a barrier layer is designed on the surface of the electrolyte, effectively using a membrane to separate the two. This membrane only allows water to pass and prevents other ions from doing so. In this manner, the process resembles replenishing water in an alkaline electrolyte, as the electrolysis for hydrogen production continuously consumes pure water. The movement of water from seawater to the alkaline electrolyte ensures the entire electrolysis process maintains a dynamic equilibrium. The success of seawater electrolysis for hydrogen can reduce a country's energy costs and can pave the way for a new oceanic green hydrogen industrial system, integrating offshore wind renewable energy utilization, seawater resource utilization, and hydrogen production. This essentially transforms seawater resources into what can genuinely be called "ocean energy."
Why is it more important to produce hydrogen directly from seawater than to produce hydrogen from seawater desalination?
Direct seawater hydrogen production uses molecular diffusion and membrane materials, allowing water to remain in the apparatus while vapor, with its low density, can flow freely through the membrane. This is achieved through mechanical principles and driven effects, applied to seawater desalination without the need for traditional catalysts, directly producing environmentally-friendly green hydrogen from undistilled seawater. This provides humanity with an optimal energy source, significantly reducing the cost of green hydrogen production.
This approach offers the best economic and social outcomes, maximizing the benefits for nations, entrepreneurs, and the general public. When considering the national strategic deployment, the execution brings tangible benefits to the state, enterprises, and the masses: employment opportunities, national fiscal revenue, and the maximization of economic and social benefits, maximizing the mutual interests of country, businesses, and citizens.