Copper steam condenser pipes coated with F-DLC (top) and without a coating (bottom).
A new coating for steam condensers developed by researchers could lead to a huge reduction in carbon dioxide emissions thanks to just a 2% increase in efficiency.
Researchers from the University of Illinois Urbana-Champaign developed the coating for steam condensers used in fossil fuel steam-cycle generation that is made with fluorinated diamond-like carbon, or F-DLC. Improving coal and natural gas power generation efficiency by 2% could result in 460 million fewer tons of carbon dioxide released and 2 trillion fewer gallons of water used.
The findings come as steam power cycles, which either use fossil fuels or nuclear fission as their energy source, are used in as much as 70% of global electrical power generation.
In the steam cycle, fuel is burned to boil water and the resulting steam spins a turbine which drives an electric generator. The steam reaches a condenser that reclaims water and keeps pressure across the turbine so the steam flows. Improving the efficiency of the heat condenser would require burning less fuel, which the F-DLC coating accomplishes by forming droplets on the F-DLC surface and allowing the heat to be transferred directly.
“The reality is that fossil fuels aren’t going away for at least 100 years,” Nenad Miljkovic, a professor of mechanical science and engineering at UIUC and the project lead, said in a statement. “A lot of CO2 is going to be emitted before we get to a place where we can lean on renewables. If our F-DLC coating were adopted globally, it would noticeably curtail carbon emissions and water usage for the existing power infrastructure.”
Researchers published their findings in Nature Communications. As part of their study, they coated metals to steam condenser conditions for 1,095 days, revealing that the metals kept the coating for the entire study period. The hydrophobic properties were also maintained after 5,000 scratches in an abrasion test.
Next, researchers are collaborating with UIUC’s Abbott Power Plant to study the coating’s performance for six months of steady condensation exposure under industrial conditions.
“If all goes well, we hope to show everyone that this is an effective solution that is economically viable,” Miljkovic said. “We want our solution to be adopted, because, although the development of renewable energy should absolutely be a priority, it’s still very worthwhile to continue improving what we have now.”
Reducing greenhouse gas emissions has become a top priority for many countries and regions in the United States, and much of the focus has been on renewable energy technologies. Despite this, fossil fuels are still the majority of power sources in the U.S., with renewable energy accounting for just 25% of U.S. energy production by 2050.