New system produces water, electricity and hydrogen fuel

Researchers at the St. Petersburg Polytechnic University have developed a novel system designed to produce fresh water, electricity and environmentally friendly hydrogen fuel in a single integrated process.

According to Progress in Energy, the system could offer low-cost production and operate independently. Unlike many existing systems, its hydrogen output would not depend on weather conditions.

University researchers say the high cost of clean fuel and the instability of its production are among the main obstacles to the transition to clean energy.

Dr. Yekaterina Sokolova, an associate professor at the university’s School of Nuclear and Thermal Energy, said most current clean-hydrogen projects rely on renewable sources such as solar and wind power. However, these sources are intermittent, meaning hydrogen production can be disrupted by conditions such as cloud cover. Electrolysis, the process of producing hydrogen from water, also requires large quantities of fresh water, creating an additional challenge in regions already facing water shortages.

A nuclear-powered approach

The researchers propose making hydrogen production less dependent on external conditions and resources. Their new concept is based on a small modular reactor using supercritical carbon dioxide, a state in which carbon dioxide exhibits properties of both a gas and a liquid.

The scientists modeled two operating scenarios: a fully self-sufficient system that produces its own water, and a market-based model in which desalinated water is sold as a separate product.

According to the researchers, the system’s key principle is efficient heat utilization.

Sokolova compared the concept to boiling water in a kettle and then using the same heat for other purposes. Similarly, heat generated by the nuclear reactor would first be used to produce electricity, with the remaining heat then used to produce hydrogen from purified water. If needed, additional residual heat could be used to boil seawater for desalination.

The proposed system would require relatively little space because of the reactor’s compact size and would not depend on external water supplies, as it could desalinate water itself. It could also provide more stable and predictable prices for hydrogen and electricity over decades.

Preliminary estimates suggest that hydrogen production costs could start at around $2.93 per kilogram, compared with approximately $6 per kilogram today.

Sokolova noted that the reactor used in the model is not yet ready for commercial production. Once it becomes commercially viable, the researchers plan to design hydrogen-production systems tailored to regions seeking to build such facilities.