Researchers from Yale University Department of Chemical and Environmental Engineering have developed a new technology that can turn wasted heat into power.


The new technology, which uses nanobubble membrane, is designed to generate energy from the low-temperature wasted heat produced by industrial sources and power plants.

Researchers said that the nanobubble membrane, which is made from highly hydrophobic (water-repelling) polymer nanofibers, can trap tiny air bubbles within its pores when submerged in water.

However, upon heating one side of the membrane it causes water to evaporate which will travel across the air gap, and condense on the opposite side of the membrane.

The temperature-driven flow of water is directed to a turbine to generate power.

Yale Chemical and Environmental Engineering Roberto Goizueta Professor and corresponding author on the paper Menachem Elimelech said: "It was critical to identify robust air-trapping membranes that facilitate pressure generation.

"Without the right membrane, water would displace the air in the pores, and the process would not be feasible."

In order to validate the concept, the researchers developed a small-scale system and demonstrated that the ability of nanobubble membranes to produce pressurized flows of water.

The system generated power even with heat fluctuations and temperature differences as small as 20 degrees Celsius.

This makes the technology feasible for use with the wasted heat from industrial sources, the researchers said.

Yale chemical and environmental engineering doctoral student Anthony Straub said: "We found that the efficiency of this system can exceed that of comparable technologies.

"The process also only uses water, so it is cost-effective and environmentally friendly."

The researchers are planning to develop improved membranes which can better trap air bubbles and also assessing the performance of large-scale future systems.

Image: Illustration of new technology which can turn wasted heat into power. Photo: courtesy of Yale University.