We all know that lithium has a short future because it is a non-renewable resource, and environmentally destructive both in extraction, production, and recycle or disposal. In contrast, hydrogen — the most abundant molecule in the universe — is becoming the sought-after energy opportunity among technologists. And the race is on.

Hydrogen is light, storable, energy-dense, and produces no direct emissions of pollutants or greenhouse gases. Hydrogen can be derived from several different resources, including fossil fuels, biomass, and water electrolysis with electricity. Use of fossil fuels for production is known as gray hydrogen. See brown, blue, green production.

Electrolysis

Electrolysis – the process of extracting oxygen and hydrogen out of water – is a promising option for carbon- free hydrogen production from renewable and carbon-free resources. The global shortage of freshwater limits its reasonable use for hydrogen generation by electrolysis. So what about seawater given that 70% of the earth’s surface is vibrant with oceans?

Seawater electrolysis was first discovered in the early 19th century. One major problem with seawater electrolysis is the formation of toxic constituents at the anode, such as chlorine, bromine, and further toxic byproducts. To first remove the dissolved salt from seawater (e.g. reverse osmosis) requires significant amounts of energy and capital. More recent approaches to hydrogen from seawater using membrane electrolyzers and/or catalytic electrode coatings can be complicated and expensive in addition to known durability and performance issues.

To overcome these challenges, researchers at UC Santa Cruz have developed cost-effective saltwater hydrolysis methods and system, featuring replenishable electrodes of certain geometry that are capable of safely sustaining a current density much higher than previously deemed practical, in support of a higher rate of hydrogen production on the cathode. The UC Santa Cruz approach leverages the higher conductivity environment of saltwater while avoiding concurrent generation of toxic byproducts such as hypochlorous acid, hypochlorite ions, and chlorine gas, and permitting reclamation of solid byproducts for recycling and or reuse.

According to Dustin G. Jolley, Founder & Principal of OurEnergy, tapping the ocean as a source of water for green hydrogen production while avoiding the parasitic losses, cost and waste of having to pre-treat that water holds the potential to be an absolute game changer. “The age of green hydrogen at scale for use as a next generation energy carrier is upon us and the timing could not be better for these advancements.”

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