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DOE SBIR Winner Works With Academia to Produce Energy-Efficient Heat Pump

Prasad Chouhan HVAC Compressor 21

Through research funded by the Department of Energy, high-tech startup Xergy, Inc., of Seaford, Delaware, recently announced an innovative refrigeration system based on an electrochemical compressor to replace the conventional vapor compression systems found in typical heat pump units.

This new fuel-cell technology offers an innovative approach to energy-efficient heating and refrigeration by decreasing our use of fossil fuels and reducing emissions that contribute to climate change.

This significant R&D breakthrough happened with the help of researchers at the University of Delaware’s (UD) Center for Fuel Cell Research, particularly Center Director Ajay Prasad and his team.

“When Xergy approached us to collaborate on this idea, we recognized that electrochemical compressors [ECCs] are very similar to fuel cells,” said Prasad. “For example, ECCs employ many of the same components, including an ion-exchange membrane, gas diffusion layers, bipolar plates and catalysts.”

However, there are some key differences that pose challenges in transitioning this technology to heating, ventilation, and air conditioning (HVAC) applications.

Graduate student Ashish Chouhan, who is working with Prasad to address these challenges, explained that traditional ion-exchange membranes must be highly hydrated in order to permit proton conduction. However, Xergy’s design, which employs metal hydride heat exchangers, must be moisture-free as water can seriously degrade the metal hydride beds.

“We are testing various membrane and catalyst layer formulations that will pump hydrogen effectively in the complete absence of water,” Chouhan said. “We have tested several ion-exchange membranes and are now focused on membranes made from a high-performance polymer called polybenzimidazole for this task.”

Initial applications for the technology include hybrid water heaters and air conditioners—the top two energy-consuming appliances in homes. Unlike existing systems, ECCs are extremely efficient and quiet because they have no moving parts and, even more important, they allow the use of environmentally friendly refrigerants.

“It’s no longer a matter of if, but when, this technology will enter the market,” said Xergy president Bamdad Bahar in announcing the breakthrough. “We’ve proven that refrigeration systems based on electrochemical compression are a viable alternative. Now it’s just a matter of refinement to get the package smaller and cheaper so that it can see widespread adoption in a wide variety of appliances for global markets.”

Once the technology has been refined, Xergy plans to expand ECC applications to other markets, including home and commercial air conditioners, refrigeration systems, and numerous other heating and cooling applications.

“This technology has the potential to transform refrigeration systems worldwide and bring about significant environmental benefits,” said Prasad. “Improvements in HVAC system efficiencies will greatly reduce the electricity demand from power plants, leading to reductions in greenhouse gas emissions.

“In addition, widespread adoption of ECCs will bypass the 150 million electric motors that are required to drive mechanical compressors, which will reduce our dependence on critical raw materials that go into electric motors. Finally, ECCs do not require CFC-based refrigerants, which will help to protect and preserve the ozone layer.”

About Xergy, Inc. and UD’s Center for Fuel Cell Research

Xergy, Inc. is a high-technology start-up venture based in Sussex County, Delaware, with over 30 patents in process. It has entered into programs to commercialize this technology with a number of large global companies. Xergy, Inc. won a Department of Energy SBIR Phase I award in 2013 and a Phase II award in 2014. The first prototype electrochemical compressor was delivered to the company’s commercial partner in 2015.

Ajay Prasad is the College of Engineering Alumni Distinguished Professor in the Department of Mechanical Engineering and director of the Center for Fuel Cell Research at the University of Delaware. Ashish Chouhan is a doctoral student in mechanical engineering at UD. 

The Center for Fuel Cell Research conducts fundamental research on fuel cell and hydrogen infrastructure science and technology to improve performance and durability with novel materials, architectures and operating strategies, while enabling commercialization with technology transfer to industry. The center also conducts public outreach to educate the community about the benefits of fuel cells.

Original article featured on UDaily, March 16, 2016

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