MATERIALS / RECYCLING PETplanet Insider Vol. 26 No. 10/25 www.petpla.net 18 Scientists transform plastic waste into efficient CO2 capture materials The researcher team at the University of Copenhagen has developed a method in which decomposed PET plastic becomes the main ingredient in efficient and sustainable CO2 capture. It turns “one man’s trash into another man’s treasure”, they say, and go on to claim that their solution simultaneously addresses two of the world’s biggest challenges – plastic pollution and the climate crisis. These key global problems are often interconnected and, typically, the solution to one problem creates another one while the clock keeps ticking. PET plastic is one of the most widely used types of plastic in the world but, when it has served its purpose, it becomes a pressing global environmental issue. In many parts of the world it ends up in landfills, where it breaks down into polluting microplastics that spread to the air, soil and groundwater and a large proportion also end up in the oceans. “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,” says Margarita Poderyte from the Department of Chemistry at the University of Copenhagen, lead author of the research paper disclosing the invention. The solution is a potential winwin on a global scale, where plastic waste not only does not end up in nature but also becomes an active player in climate mitigation. BAETA: development and deployment The new chemical technology enables PET plastic waste to be transformed into a primary resource, a new form of CO2 sorbent they have developed. The process ‘upcycles’ the waste to a new material named BAETA, which can absorb CO2 out of the atmosphere so efficiently that it easily compares with existing carbon capture technologies. Over 60 per cent of PET (by weight) is carbon, which has an inherent chemical and physical ability to maintain the structure. This ability is enhanced by transforming the plastic by adding a quantity of ethylenediamine, a compound known for its ability to bind CO2. The newly-developed Copenhagen University process breaks down the plastic from polymer to a monomer, giving the material, which the team has named BAETA, a chemical composition that is claimed to be effective in pulling CO2 out of the air and binding it. The BAETA material has a powdery structure that can be pelletised, and a chemically ‘upgraded’ surface, which enables it to effectively bind and chemically capture CO2. Once saturated, CO2 can be released through a heating process allowing the CO2 to be concentrated, collected and stored or converted into a sustainable resource. Sustainable, flexible and scalable In industrial plants, exhaust gases can be transmitted through BAETA units, which will cleanse them of CO2. When the BAETA material is saturated, its efficiency decreases; however, CO2 can be released from the plastic through a heating process, restoring its efficiency. MATERIALS Fig. 1: Margarita Poderyte Margarita Poderyte, lead author of the research paper (photo: Max Emil Madsen)
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