Plant Optimization

Researchers say new coating could boost efficiency at coal and gas plants

The coating will now be tested under industrial conditions at the University of Illinois Urbana-Champaign Abbott Power Plant.
Researchers say new coating could boost efficiency at coal and gas plants
Copper steam condenser pipes coated with F-DLC (top) and without a coating (bottom). The F-DLC coating allows the condensed water to form into droplets rather than a thin film covering the pipe. Source: University of Illinois Urbana-Champaign.

Researchers at the University of Illinois Urbana-Champaign say they’ve developed a coating for steam condensers used in steam-cycle generation that could boost process efficiency by 2% at coal- and natural gas-fired plants.

This research was originally published in the journal Nature Communications. Teams said the coating, made with fluorinated diamond-like carbon, or F-DLC, is suited for industrial use after researchers subjected coated metals to steam condenser conditions for 1,095 days, the longest durability test they’d reported. The coated metals maintained their hydrophobic properties for this entire length of time.

According to the university, the new F-DLC coating improves heat transfer because the material is hydrophobic. When the steam condenses into water, it does not form a thin film that coats the surface, like water does on many clean metals and their oxides.

Instead, researchers said the water forms droplets on the F-DLC surface, putting the steam into direct contact with the condenser and allowing heat to be directly transferred. The researchers reported this translating to a 2% overall process boost.

Researchers said if fossil-burning plants were 2% more efficient, then, every year, there could be 460 million fewer tons of carbon dioxide released and 2 trillion fewer gallons of water used.

“A lot of CO2 is going to be emitted before we get to a place where we can lean on renewable,” said Nenad Miljkovic, a professor of mechanical science and engineering at UIUC and the project lead.  If our F-DLC coating were adopted globally, it would noticeably curtail carbon emissions and water usage for the existing power infrastructure.”

The research team will now study the coating’s performance for six months of steady condensation exposure under industrial conditions at the university’s Abbott Power Plant.