Polypropylene, a non-biodegradable plastic with a higher c-c bond disassociation energy than other conventional polymers like Polyethylene (PE), is used to manufacture these three-layered masks. The amount of plastic pollution in the environment has grown tremendously, nearing million tons in a short period of time. As a result, the purpose…
Polypropylene, a non-biodegradable plastic with a higher c-c bond disassociation energy than other conventional polymers like Polyethylene (PE), is used to manufacture these three-layered masks. The amount of plastic pollution in the environment has grown tremendously, nearing million tons in a short period of time. As a result, the purpose of this study is to reduce the environmental damage caused by facemasks. This M.S. thesis offers a concise overview of various thermochemical methods employed to depolymerize plastic waste materials. It emphasizes environmentally conscious and sustainable practices, specifically focusing on solvothermal processing. This innovative approach aims to convert discarded face masks into valuable resources, including hydrocarbons suitable for jet fuel and other useful products.
The thesis provides an in-depth exploration of experimental investigations into solvothermal liquefaction techniques. Operating under specific conditions, namely, a temperature of 350°C and a reaction duration of 90 minutes, the results were notably impressive. These results included an exceptional conversion rate of 99.8%, an oil yield of 39.3%, and higher heating values (HHV) of 46.81 MJ/kg for the generated oil samples. It's worth noting that the HHV of the oil samples obtained through the solvothermal liquefaction (STL) method, at 46.82 MJ/kg, surpasses the HHV of gasoline, which stands at 43.4 MJ/kg.
The significant role of the solvent in the depolymerization process involves the dissolution and dispersion of the feedstock through solvation. This reduces the required thermal cracking temperature by enhancing mass and thermal energy transfer. While solvolysis reactions between the solvent and feedstock are limited in thermal liquefaction, the primary depolymerization process follows thermal cracking. This involves the random scission of polypropylene (PP) molecules during heat treatment, with minimal polymerization, cyclization, and radical recombination reactions occurring through free radical mechanisms.
Overall, this work demonstrates the feasibility of a highly promising technique for the effective chemical upcycling of polypropylene-based plastics into valuable resources, particularly in the context of jet fuel hydrocarbons, showcasing the comprehensive analytical methods employed to characterize the products of this innovative process.
Plastic consumption has reached astronomical amounts. The issue is the single-use plastics that continue to harm the environment, degrading into microplastics that find their way into our environment. Finding sustainable, reliable, and safe methods to break down plastics is a complex but valuable endeavor. This research aims to assess the…
Plastic consumption has reached astronomical amounts. The issue is the single-use plastics that continue to harm the environment, degrading into microplastics that find their way into our environment. Finding sustainable, reliable, and safe methods to break down plastics is a complex but valuable endeavor. This research aims to assess the viability of using biochar as a catalyst to break down polyethylene terephthalate (PET) plastics under hydrothermal liquefaction conditions. PET is most commonly found in single-use plastic water bottles. Using glycolysis as the reaction, biochar is added and assessed based on yield and time duration of the reaction. This research suggests that temperatures of 300℃ and relatively short experimental times were enough to see the complete conversion of PET through glycolysis. Further research is necessary to determine the effectiveness of biochar as a catalyst and the potential of process industrialization to begin reducing plastic overflow.
