Scientific developments that could open up a market for recycled EPS came not from chemists in academia or a large corporation. Instead, the breakthroughs were developed by three dedicated 14-year-olds in 8th grade in Columbus, Ohio.
Ashton Cofer, Luke Clay and Julia Bray developed a way to recycle EPS into activated carbon for use as a water filtration medium. The project earned a spot as one of the 2016 global finalists in the Google Science Fair competition.
Google Science Fair is an online competition open to students ages 13-18 around the world. The 16 global finalists were announced out of thousands of entries on Aug. 11. An awards celebration is scheduled for Sept. 27.
The trio’s project involved using a mix of low-tech and high-tech approaches, combined with trial and error, to develop what they call the Styro-Filter process.
Because more than 95 percent of EPS volume is air, the students’ first step was to densify the material. They did this using a low-tech solution: using C-clamps and an outdoor grill to heat it to 120 degrees celsius. The next step was to pyrolyze the PS using laboratory furnaces at the Battelle Memorial Institute, heating the material to 300 degrees celsius in closed containers for five hours.
Then the 8th-grade innovators washed the material in chemical reagents to increase its surface area by creating small pockets and micropores, which effectively filtered out contaminants. After trial and error, they discovered washing it in a 50 percent concentration of phosphoric acid worked best, producing a surface area of 108 square meters per gram of material. It was then heated again at 400 degrees celsius for five hours. They used a Micromeritics ASAP 2020 Surface Area Analyzer to compare its surface area to commercially available activated carbon.
The results showed the EPS-derived activated carbon could remove significant amounts of iron, copper and chlorine from water, although it wasn’t as effective as a control sample of activated carbon from Calgon Carbon Corp.
“Our experimental results provide an exciting proof-of-concept showing that it is possible to convert Styrofoam waste into activated carbon,” the students wrote. “We were furthermore able to demonstrate that our activated carbon was effective in reducing the quantities of several chemical contaminants in water.”
They now plan to protect Styro-Filter with a full patent, perform further experiments to improve its performance and run an industrial trial with Calgon Carbon.
Because the process users temperatures that are far lower than current technologies for converting bituminous coal into activated carbon, the approach could lower energy and equipment costs, according to the project.
“Through discussions with academic and industrial experts, we were advised that our Styro-Filter process would be relatively easy to commercialize and implement in existing activated carbon facilities,” they wrote.