Chemical Methods for Mitigating Plastic Pollution from the Environment
Abstract
Plastic pollution is a critical environmental concern that affects both terrestrial and marine ecosystems worldwide. Traditional recycling methods have been inadequate in tackling the escalating plastic waste problem, leading to an exploration of chemical recycling techniques as innovative solutions. Chemical recycling involves breaking down polymers into their monomers or converting them into valuable products, offering the potential for more sustainable waste management. This review examines key chemical recycling methods, including pyrolysis, hydrothermal liquefaction, catalytic depolymerization, glycolysis, methanolysis, enzymatic breakdown, and supercritical fluids. Pyrolysis and hydrothermal liquefaction involve thermal processes that convert plastics into fuels or chemical feedstocks, while catalytic depolymerization uses catalysts to lower the energy required for breaking down polymers. Glycolysis and methanolysis are chemical processes that revert plastics back to their monomers, facilitating the creation of new products. Enzymatic breakdown utilizes biological catalysts to degrade plastics in an environmentally friendly manner. Supercritical fluids offer a unique approach by using fluids at critical temperatures and pressures to dissolve and decompose polymers. Each method presents its own set of advantages, challenges, and environmental benefits, from reducing reliance on fossil fuels to minimizing waste in landfills. However, challenges such as high costs, energy requirements, and scalability remain to be addressed.
Keyword: Plastic pollution, glycolysis, methanolysis, enzymatic breakdown, and supercritical fluids
Refrences:
1. Singh, R. K., Ruj, B., & Arya, D. (2018). Pyrolysis of waste plastics and conversion of pyrolysis oil to diesel. Waste Management, 72, 62-74.
2. Miskolczi, N., Bartha, L., Deák, G., & Jövő, I. (2004). Thermal degradation of municipal plastic waste for production of fuel-like hydrocarbons. Polymer Degradation and Stability, 86(2), 357-366.
3. Savage, P. E. (2012). Organic chemical reactions in supercritical water. Chemical Reviews, 99(2), 603-621.
4. Elliott, D. C., Neuenschwander, G. G., Hart, T. R., Rotness, L. J., & Olarte, M. V. (2015). Hydrothermal liquefaction of biomass: Developments from batch to continuous process. Bioresource Technology, 178, 147-156.
5. Jehanno, C., Perez-Madrigal, M. M., Demarteau, J., Sardon, H., & Dove, A. P. (2019). Organocatalysis for depolymerisation. Polymer Chemistry, 10(13), 1724-1731.
6. Ragauskas, A. J., Beckham, G. T., Biddy, M. J., Chandra, R., Chen, F., Davis, M. F., & Wyman, C. E. (2014). Lignin valorization: improving lignin processing in the biorefinery. Science, 344(6185), 1246843.
7. Chen, J., & Wang, S. (2020). Chemical recycling of waste plastics to monomers and chemicals by glycolysis and methanolysis. Green Chemistry, 22(10), 3285-3301.
8. Kosloski-Oh, S. C., Wood, Z. A., Manjarrez, Y., Garcia, R., Martinez, A. M., Gallimore, A. D., & Sottos, N. R. (2021). Closed-loop recycling of plastics enabled by dynamic covalent diketoenamine bonds. Science, 373(6550), 166-171.
9. Okuwaki, A. (2004). Recycling of polyethylene terephthalate (PET) through methanolysis. Polymer Degradation and Stability, 86(1), 191-196.
10. Tournier, V., Topham, C. M., Gilles, A., David, B., Folgoas, C., Moya-Leclair, E., & Marty, A. (2020). An engineered PET depolymerase to break down and recycle plastic bottles. Nature, 580(7802), 216-219.
11. Yoshida, S., Hiraga, K., Takehana, T., Taniguchi, I., Yamaji, H., Maeda, Y., … & Oda, K. (2016). A bacterium that degrades and assimilates poly(ethylene terephthalate). Science, 351(6278), 1196 1199.