From Ocean Waste to Carbon Capture Weapon! BAETA Technology Gives PET Plastic a New Environmental Mission

The two major global environmental challenges, the increasing plastic waste and the rising concentration of carbon dioxide, may have a common solution. Researchers at the University of Copenhagen have recently developed a new type of material that uses waste PET plastic as a raw material, capable of converting carbon dioxide into a solid form for storage, and can be reused in both industrial production and air purification.

New Value of PET Waste: Innovative Solutions for Capturing Carbon Dioxide from Air

Every year, millions of tons of plastic waste are generated globally, most of which is not recycled — instead, it is either incinerated, landfilled, or ultimately ends up in the ocean, causing pollution. Meanwhile, the concentration of carbon dioxide in the atmosphere continues to rise. To achieve global climate goals, large-scale carbon dioxide removal and sequestration technologies are crucial. Now, a research team in Denmark has developed a method that simultaneously addresses these two major issues: converting waste PET plastic into carbon dioxide adsorbents.

This new type of material is called BAETA, which is made by chemically transforming PET plastic (commonly found in plastic bottles, packaging materials, and textiles). In its new form, BAETA can capture industrial emissions and carbon dioxide from the air in solid form without the need for any solvents or carrier materials.

From Plastic Waste to Carbon Dioxide Sequestration: The Preparation Principle of BAETA

BAETA is synthesized through the "amine hydrolysis method," which involves the following process: First, polyethylene terephthalate (PET) plastic is treated with ethylenediamine, breaking down its polymer structure into smaller molecular units. These molecular units then react to ultimately form a fine powder—BAETA—that has a strong chemical affinity for carbon dioxide. The core advantage of this technology is that the entire reaction can be conducted at room temperature and does not require metal catalysts, resulting in lower energy consumption compared to many traditional processes.

The research team confirmed that even using mixed waste, approximately 800 grams of BAETA can be produced from every 1 kilogram of PET waste. Even if PET waste contains food residues, aluminum foil, paper, or polystyrene, a high material yield can still be maintained. This method specifically targets low-quality or severely degraded PET plastics that traditional recycling technologies cannot process, achieving a breakthrough in "waste reutilization."

Stable, reusable, and with industrialization potential.

BAETA exhibits excellent thermal and oxidative stability: it can retain its functionality at temperatures as high as 250°C, making it highly suitable for capturing carbon dioxide directly from industrial exhaust gases. Laboratory tests indicate that, under conditions of 150°C, the material's carbon dioxide adsorption capacity remains unchanged after more than 150 cycles of use; even when exposed to oxidative environments such as air, its stability is unaffected.

By heating, the captured carbon dioxide can be released for controlled recovery. This feature opens up possibilities for the permanent sequestration of carbon dioxide or its reuse in industrial processes such as "Power-to-X". With these advantages, BAETA is expected to become an important component of the "Circular Carbon Management Strategy."

Capturing Carbon Dioxide from Air: The Multifaceted Applications of BAETA

Apart from industrial scenarios, BAETA also performs well in the field of direct air capture (DAC). In a test, only 1.5 grams of BAETA were able to continuously filter indoor air for 13 days, with a carbon dioxide capture efficiency of up to 88%. Notably, the higher the humidity, the better BAETA's performance—because moisture can facilitate the chemical bonding reaction of carbon dioxide, giving this material special application potential in humid environments.

In addition, BAETA can be made into granules without the need for any additives, and it can maintain its original properties even after being compressed and formed. This feature allows it to be flexibly applied in modular filtration systems, suitable for both large-scale industrial processing and decentralized small-scale applications.

Marine Plastics: From Pollutants to Valuable Resources

One major unique advantage of this technology is that severely degraded PET plastics (such as those commonly found in marine pollution) are particularly suitable for conversion into BAETA. The research team believes this provides a tangible economic incentive to remove plastic waste from the environment—waste that is virtually useless in traditional recycling has now become a valuable raw material for mitigating climate change.

"If we can collect highly degraded PET plastics floating in the world's oceans, they will become our valuable resource, as such plastics are very suitable for 'upcycling' through our technology," said the project leader Margarita Poderyte.

Researchers also emphasized that this method does not compete with traditional recycling processes, but rather complements them. It is specifically designed for plastics that would otherwise be discarded, providing a new pathway for low-quality or non-recyclable PET plastics to re-enter the value chain.

From laboratory to industrial application

Currently, this technology has moved out of the laboratory: the research team plans to conduct pilot applications in industrial-scale carbon dioxide capture systems and is committed to scaling up the production of BAETA to a "ton-level" scale. The current technical conditions are basically mature, and investment is urgently needed to promote industrialization.

"Our material can provide very specific economic incentives for cleaning up ocean plastic," said Jiwoong Lee, co-author of the paper. "It also has the potential to integrate two of the most pressing environmental issues of our time—plastic pollution and climate change—into a single solution."