Tomorrow's commercial refrigeration systems, such as those in supermarkets, could be cooled by carbon dioxide instead of hydrofluorocarbons.
Hydrofluorocarbons are a greenhouse gas that is nearly 4,000 times more potent than CO2 and a future with less of them could be important because millions of pounds of HFCs leak into the environment every year, said Brian Fricke, a researcher in Oak Ridge National Laboratory's Building Equipment Research Group.
To address the problem, Fricke and colleagues are experimenting with CO2 and other refrigerants, including a hydrofluoroolefin called R1234yf.
While by definition CO2 has a global warming potential of 1, the hydrofluoroolefin's is 4, so both are far less harmful to the environment than HFCs with a rating of 3,900. Still, while CO2-based systems work well in cold climates, they aren't as efficient in warmer climates, so Fricke is experimenting with various approaches to address the limitation
To further reduce fossil fuels usage, researchers have also found that reformulated plant matter could be at the roots of a revolution in 3-D printing projected that is expected to hit $5.2 billion by 2020.
Soydan Ozcan, a researcher in Oak Ridge National Laboratory's Carbon and Composite Group, leads a team that is testing plant material that has been reformed into neatly woven nanoscale crystals and fibers. Mixed with various plastics, including those that are bio-based, these needle-like crystals can produce feedstock polymers for 3-D printers with stiffness improvements already a factor of three over widely used structural materials.
They are also less expensive and mostly biodegradable. Potential applications include fuel-efficient car parts, batteries, packaging and building materials, furniture, disposable electronics and bulletproof suits.
