Solving global warming with waste plastic bottles
Solving global warming with waste plastic bottles
Results published in Chemical Engineering Journal
Microporous carbons produced using PET waste plastic to capture CO2

▲ Dr. Yuan Xiangzhou (first author), Dr. Lee Jong-gyu (first author), Prof. Lee Ki-bong (corresponding author), Prof. Kwak Sang-kyu (corresponding author)

The research team led by Dr. Lee Ki-bong of the Department of Chemical and Biological Engineering under the College of Engineering at Korea University, Dr. Lee Jong-gyu of the Research Institute of Industrial Science and Technology, and the team led by Dr. Kwak Sang-kyu of Ulsan National Institute of Science and Technology derived microporous carbon materials from waste PET plastic bottles, and effectively applied them to capturing CO2, known as a main cause of global warming.

While plastic has been utilized in daily life due to its flexible physical properties, indiscriminate use of the material has led to only 25% of plastic being recycled out of the 8.3 billion tons used in total since the 1950s, and the remaining 75% or 6.3 billion tons being discarded or incinerated. Waste plastic becomes fragmented into microplastics if discarded in the ocean, and has a negative impact on not only the marine ecosystem but also human health. As such, developing methods of recycling waste plastic is essential to protect the environment. This study derived activated carbons from waste PET plastic bottles, thereby presenting a new solution to recycling waste plastic. The proposed method is especially useful as it can be applied to even dirty or contaminated waste plastic bottles.
 
Microporous carbons, also known as activated carbons, are used in atmospheric environment improvement, water treatment, and the catalysis of reactions. They are produced by applying heat treatment and chemical/physical activation to coconut shells or coal. Since Korea relies on imports for the raw materials of locally-produced activated carbons, the use of waste plastic is expected to lower the cost of raw materials and replace imports.

Activated carbons derived from waste PET plastic bottles were tested as having excellent, commercial-level performance at capturing CO2, and molecular simulation showed that such outstanding performance was enabled through the development of pores suitable for CO2 adsorption. The technique of applying waste plastic-derived activated carbons to CO2 capture is a revolutionary method that solves two environmental issues at the same time, namely, waste plastic and global warming.

In addition to CO2 capturing, activated carbons derived from waste PET plastic bottles have other varied uses in common with existing activated carbons. The KU research team is also conducting research on generating high value-addedness by transforming various types and forms of waste plastic, coffee grounds, and pitch-based cokes into activated carbons.

Supported by the National Research Foundation of Korea through the Basic Science Research Program (under Mid-Career Researcher Program) and the Ministry of Science and ICT of Korea through the C1 Gas Refinery Program, this study was published in Chemical Engineering Journal, a leading international journal in the field of chemical engineering.
* Title of paper :
Solving two environmental issues simultaneously: Waste polyethylene terephthalate plastic bottle-derived microporous carbons for capturing CO2
* Author information :
Xiangzhou Yuan, Jong Gyu Lee, Heesun Yun, Shuai Deng, Yu Jin Kim, Ji Eun Lee, Sang Kyu Kwak*, Ki Bong Lee*
* Journal :
Chemical Engineering Journal (2019 IF 10.652, top 2.8% (4/143) in chemical engineering, CiteScore: 15.2)

◈ Figure description ◈

▲ Schematic diagram of the derivation of activated carbons from waste plastic bottles and the capture of CO2

▲ SEM images of the microporous carbons derived from waste plastic bottles (top left),  
   cyclic tests of CO2 adsorption-desorption (top right), 
   CO2 and nitrogen adsorption in relation to the pore shape of the activated carbons (bottom)