Chemists convert plastic waste into a powerful new tool to capture carbon dioxide

Carbon dioxide levels keep climbing, even after years of promises to cut emissions. At the same time, plastic waste pours into oceans, rivers, and landfills. These crises often feel separate, yet they share a common thread. Human activity created both, and time is running short to fix them. Now, researchers in Denmark report a discovery that links these problems in an unexpected way.

Chemists at the University of Copenhagen have found a method that turns discarded plastic into a powerful material that captures carbon dioxide. In this process, old plastic bottles and worn textiles gain a second life. Instead of polluting soil and seas, they help pull greenhouse gases from the air and factory exhaust. The work suggests waste itself can become part of the climate solution.

Plastic made from polyethylene terephthalate, known as PET, plays a central role. PET appears everywhere, from drink bottles to food trays to clothing fibers. Once used, much of it ends up buried or drifting in the ocean. There, it slowly breaks into microplastics that spread through water, air, and living tissue. Recycling systems recover only a small share, leaving billions of tons behind.

“The beauty of this method is that we solve a problem without creating a new one,” said Margarita Poderyte of the Department of Chemistry at the University of Copenhagen. “By turning waste into a raw material that can actively reduce greenhouse gases, we make an environmental issue part of the solution to the climate crisis.”

"Our research team developed a chemical process that transforms low-quality PET into a new substance that captures carbon dioxide with high efficiency. This method does not compete with traditional recycling. Instead, it targets plastic that recyclers usually reject because it is too degraded, mixed, or colored," Poderyte explained to The Brighter Side of News.

"Through a gentle chemical reaction, PET breaks down into smaller building blocks. We then add ethylenediamine, a compound known for binding carbon dioxide. This step reshapes the plastic into a powdery material we named BAETA, which performs as well as many advanced carbon capture materials," she added.

Measured by weight, PET already contains more than 60 percent carbon. Its structure stays strong even after chemical changes. When converted into BAETA, the material gains a surface rich in sites that attract and hold carbon dioxide molecules. This makes it highly effective at trapping the gas from air or industrial exhaust.

BAETA works across a wide range of conditions. It captures carbon dioxide at room temperature and continues to perform at temperatures up to about 150 degrees Celsius. This matters because exhaust gases from factories and power plants are often hot. Many existing capture materials fail under such conditions.

“One of the impressive things about this material is that it stays effective for a long time, and flexible,” said Jiwoong Lee, an associate professor of chemistry and co-author of the study. “With this kind of tolerance to high temperatures, the material can be used at the end of industrial plants where the exhausts are typically hot.”

In practice, BAETA would sit inside units attached to industrial chimneys. Exhaust gases pass through the material, and carbon dioxide sticks to its surface through chemical bonds. Once the material becomes saturated, heat releases the captured gas. This restores BAETA so it can be used again.

The released carbon dioxide does not need to go back into the air. It can be stored underground or used in industrial systems known as Power2X plants, where CO2 becomes fuel, chemicals, or other products. This reuse adds another layer of value to the process.

The chemical synthesis itself stands out for its mild conditions. Unlike some carbon capture materials that require high pressure or extreme heat to produce, BAETA forms at ambient temperatures. This lowers energy use and makes large-scale production more realistic.

Researchers have already shown the method works beyond small lab samples. They successfully converted one kilogram of untreated consumer PET waste into BAETA. That step signals the process could scale to industrial levels, where tons of plastic might become carbon capture material.

The potential reach of this discovery extends beyond landfills. Large amounts of PET float in oceans, damaging ecosystems and breaking into microplastics that enter food chains. This degraded plastic often cannot be recycled, yet it suits the new process well.

“If we can get our hands on the highly decomposed PET plastic floating in the world’s oceans, it will be a valuable resource for us,” Poderyte said. “It is so well suited for upcycling with our method.”

This possibility creates a new incentive to clean oceans. Plastic waste could gain economic value as a raw material for climate technology. Instead of seeing cleanup as a cost, governments and companies might view it as an investment.

The researchers stress their work does not undermine recycling. High-quality PET should still be recycled into new products. BAETA production focuses on plastic with no other sustainable future.

“In principle, we could use new plastic,” Poderyte said. “But our target is PET that is difficult to recycle or has decomposed too much. This will be a collaboration rather than competition with recycling efforts.”

The study appears in Science Advances and details the chemistry behind BAETA. With proof of concept complete, the team now looks toward industrial partnerships. Their next goal involves producing the material by the ton, not the gram.

“We see great potential for this material, not just in the lab, but in real-life industrial carbon capture plants,” Poderyte said. “The next big step is scaling up and making our invention a financially sustainable business venture.”

The scientists say the main challenge is not technical. Instead, success depends on investment and political will. Carbon capture projects require upfront funding, even when long-term benefits are clear. Convincing decision-makers remains the hardest task.

Still, the researchers believe their work can shift how society views environmental problems. Plastic pollution and climate change often appear as separate crises. This discovery shows they can intersect in meaningful ways.

“We’re not talking about stand-alone issues, nor will the solutions be,” Lee said. “Our material can create a very concrete economic incentive to cleanse the oceans of plastic.”

This research points toward a future where waste becomes a climate asset. By converting hard-to-recycle plastic into carbon capture material, industries could reduce emissions while shrinking plastic pollution.

The approach supports cleaner air, healthier oceans, and more efficient use of resources. It also encourages new economic models that reward cleanup and carbon reduction together.

For scientists, the work opens paths to design climate tools from existing waste streams rather than new raw materials.

Research findings are available online in the journal Science Advances.

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