Carbon dioxide emissions captured using a novel method that utilises waste plastic

The process is a variation of the current pyrolysis-based plastic recycling process, and could provide a boost to efforts to reduce atmospheric CO2 levels

Spotted: A team of researchers from Rice University has developed a new chemical technique that can turn waste plastic into a carbon dioxide (CO2) ‘sorbent’ – a material that effectively adsorbs CO2 gas. The development of this technique comes at a critical time, as efforts to reduce atmospheric CO2 levels are ramping up.

James Tour, a Rice chemist, and his co-lead authors Wala Algozeeb, Paul Savas, and Zhe Yuan of the Rice graduate school reported in ACS Nano that exposing plastic waste to potassium acetate produced particles with nanometre-scale pores that captured carbon dioxide molecules. 

To produce the substance, researchers crushed waste plastic and combined it with potassium acetate for 45 minutes at 600 degrees Celsius (1,112 degrees Fahrenheit). The resulting porous particles can then be used to adsorb CO2 molecules from the atmosphere.

At room temperature, these porous particles can hold up to 18 per cent of their weight in CO2. When heated to about 75 degrees Celsius (167 degrees Fahrenheit), the trapped carbon dioxide is released from the pores, regenerating approximately 90 per cent of the material’s binding sites. The sorbent may then be reused. The process is relatively simple and could be easily scaled up for industrial applications.

Based on the researcher’s estimations, the cost of using the material to capture CO2 from a point source—such as post-combustion flue gas—would be $21 a tonne (around €19 ). This is significantly more economical than the processes currently being used to pull carbon dioxide from natural gas feeds – which cost around $80-$160 a tonne (around €74-148).

Carbon capture is a hot topic in the fight against climate change, and Springwise has spotted several related innovations. These include a process for storing CO2 in recycled concrete, an artificial leaf for capturing CO2, and a modular carbon capture system.