To recycle ethylene-vinyl acetate (EVA) and polyethylene glycol terephthalate (PET) in the solar panels at the end of its life cycle, scientists from Sun Yat-Sen University in China and Shanghai Jiao Tong University have suggested a vacuum-gasification-condensation process. For solar panel encapsulation, both materials are being used in PV production.

Academics contend that current PET and EVA disposal systems rely on toxic solvents to extract them, creating secondary contamination. Instead, their innovative methodology is believed to transform EVA and PET without secondary emissions into value-added goods and energy materials. In a waste solar cell, the two materials constitute about 15 percent of the overall material, with a 10 percent share for EVA and 5 percent for PET, respectively.

The Chinese community used a vacuum tube furnace supplied by Chinese specialist Alarge Furnace Company, Ltd. for the process implementation. A vacuum mechanical compressor, a diffusion pump, a vacuum ionization gauge and a control panel are part of the furnace. Tin, silicon, copper, and silicon dioxide, both delicate materials, have been compressed into particles smaller than 5 mm in size. The crusher can break PET and EVA fragments, which are ductile materials. It has been fragmented into larger particles ranging from 5 mm to 20 mm in size.

As the furnace temperature hit 490 degrees Celsius, the EVA and PET became decomposed. “The weight was not altered above 490 degrees Celsius, indicating that the EVA and PET were fully decayed and volatilized,” the scientists reported. The weight of blended PET and EVA slowly reduced at the 297-386 degrees Celsius level, suggesting that the long connection of PET and EVA fragmented at this stage. At the 386-490 degrees Celsius point, at 461 degrees Celsius, the decomposition procedure had the maximum mass loss.

As the temperature hit 505 degrees Celsius, the furnace’s pressure was able to return to the original stage, completely decomposing and gasifying the PET and EVA. A complete residue of 1.95kg, composed largely of a blocky-shaped particle as well as spherical particles, was obtained through this method. At 42.35 percent, carbon had the biggest share, led by silicon, at 36.99 percent, silver, 11.41 percent, and oxygen, at 6.63 percent. “In the residue, small amounts of iron, copper, and zinc were also identified,” the scientists said. “In the residue, an important Al content was provided so because the solar cell chip surface covered al electrode.”

By admin