Seawater as an Alternative for Green Hydrogen Generation

The generation of hydrogen – which is a light and highly reactive fuel alternative to traditional fossil fuels – is conducted through a chemical process known as electrolysis. This uses an electrical current to separate the hydrogen from the oxygen in the water, often through renewable sources.

Water electrolysis is an electrochemical process that splits water into hydrogen and oxygen. Less than 0.1% of dedicated hydrogen production globally comes from water electrolysis, and the hydrogen produced by this means is mostly used in markets where high-purity hydrogen is necessary (for example, electronics and polysilicon).

The International Energy Agency (IEA) reports that it needs nine litres of water for every kilogram of green hydrogen produced. The report said freshwater access is a concern in water-stressed areas for producing green hydrogen. Estimates claim that if solar energy is used as an electricity source for electrolysis, then the total water requirement for the energy source and water needed for electrolysis will come to around 32 kgs of water to produce each kg of green hydrogen. In contrast, if wind energy is used, the cumulative water requirement per kg of green hydrogen comes to 22 kg of water. According to the exact estimations, when natural gas is utilised to manufacture hydrogen (grey hydrogen), it takes 22 kg of water to produce one kg of hydrogen.

Seawater as an alternative

Seawater is an almost infinite resource and is considered a natural feedstock electrolyte – it is also far more sustainable than freshwater.

Seawater electrolysis producing green hydrogen is still in the early stages of development. Still, it has an efficiency rate of over 100%, making it useful for areas with extensive coasts and plenty of sunlight.

Globally, efforts are being made to manufacture green hydrogen using polluted or seawater. However, these initiatives are still in the experimental phase. Preliminary research on the electrolysis of treated freshwater to produce fresh water has been done in nations like Spain.

Analysts contend that most of these technologies will suffer additional expenditures because they are still in the pre-commercial stage. A Chinese scientific team recently created a seawater electrolyzer device based on membrane technology. This machine can release salty saltwater for the creation of hydrogen.

The future of Green Hydrogen depends on which water resource countries use to produce it, and they need to re-think acceptance in terms of energy.

Saloni Goyal, Account Executive, VeKommunicate