Yellow hydrogen: America’s next green energy breakthrough

The discovery of yellow hydrogen in the United States could change the future of energy, thanks to an ecological method without greenhouse gas emissions

Imagine a world where we can generate energy using only water. This ambitious goal is now closer than ever, thanks to a groundbreaking discovery in the United States. Experts are referring to this innovation as “yellow hydrogen“, distinct from the more familiar green and blue hydrogen. This could become a revolutionary technology, much like red hydrogen has steadily progressed in Japan.

Yellow hydrogen, also known as photochemical hydrogen, is produced through a process called photocatalytic water splitting. This method utilizes solar energy and specialized catalysts to separate water molecules into hydrogen and oxygen, minimizing the number of reactions involved.

Unlike traditional methods that rely on fossil fuels, yellow hydrogen does not emit greenhouse gases, making it an environmentally friendly energy source. It is similar to orange hydrogen but differs in that it does not depend on wastewater.

How is yellow hydrogen produced?

The production of yellow hydrogen involves the following steps:

1. Semiconductor photocatalysts and sunlight are used to split water into hydrogen and oxygen, through a process similar to electrolysis, which is employed in producing green or blue hydrogen.
2. The hydrogen produced is collected and purified for use as a fuel or for other various applications. Oxygen, a byproduct of the reaction, is released into the atmosphere.
3. The photocatalysts used in this process include semiconductor materials such as titanium dioxide or cadmium sulfide. These materials capture sunlight and harness its energy, facilitating the water-splitting process on the catalyst’s surface.

Advantages and challenges of yellow hydrogen in the USA

Yellow hydrogen offers several benefits compared to other hydrogen production methods:

• It is a green energy source that does not emit greenhouse gases or use fossil fuels.
• Some studies suggest that energy conversion efficiency could reach 19%.
• It can be produced on a small scale using simple and inexpensive materials, enabling decentralized production.

However, there are also challenges:

• The process is not as refined or optimized as current methods, requiring further research and experimentation to improve practical outcomes.
• Some photocatalysts can be expensive, and their operational lifespan is often limited.
• The production rate is currently lower than methods like steam methane reforming or electrolysis.

Despite these challenges, there are ongoing projects in the United States exploring the potential of yellow hydrogen production:

• The National Renewable Energy Laboratory (NREL) is working on water splitting through photocatalysis, designing prototype systems for producing yellow hydrogen.
• The University of Colorado Boulder is developing a new, more efficient, and cost-effective photocatalyst material.
• The University of California, Berkeley, is conducting research in artificial photosynthesis, with plans to produce yellow hydrogen and other valuable chemicals.

Several U.S. states are particularly well-suited for developing yellow hydrogen:

• California: With abundant solar resources and goals for transitioning to renewable energy sources, California is highly suitable for yellow hydrogen production.
• Texas: The state has significant growth potential, given its established solar energy sector and hydrogen production capabilities.
• Arizona and New Mexico: These regions offer high potential due to their ample land and high levels of solar irradiation.

Conclusion

The concept of producing yellow hydrogen in America is both optimistic and ambitious. Researchers believe it could become a medium-term substitute for fossil fuels, provided it is used as a fuel to decarbonize transportation and combined with other “cleaner” colors, such as white, blue, or green.

Source: NREL – University of Colorado Boulder – ScienceDirect