Plastic waste management has emerged as a critical global challenge due to its environmental impact and persistence. Pyrolysis offers a promising route to convert plastic waste into valuable products such as liquid oil, gas, and char, thereby mitigating environmental pollution and resource depletion. This study investigates the influence of blending ratios, residence time, and catalysts on Polyethylene Terephthalate (PET) pyrolysis, High-Density Polyethylene (HDPE), and sawdust blends. Experimental results reveal that longer residence times enhance liquid oil yield while reducing solid char and gas production, which is consistent with previous studies. Adding catalysts, particularly clay, accelerates hydro-carbon breakdown, further optimizing product yields. These findings underscore the potential of pyrolysis as a sustainable solution for plastic waste valorization, suggesting avenues for refining process parameters to maximize efficiency and environmental benefits.
Keywords: plastic waste, pyrolysis, blending ratio, residence time, catalyst, liquid oil yield
The pyrolysis research team operations.
Many methods exist to extract fuel from waste plastic, but the most commonly preferred is the Pyrolysis process. It is an easy process that provides more effective results than other methods. The fuel extraction process of waste plastic is divided into three stages: I. Cleaning and Shredding, II. Pyrolysis Process, III. Distillation. The primary plastic waste preferred for Pyrolysis is Polyethylene Terephthalate (PET) bottles or Polyethene (PE) bags, which are cleaned and shredded into small pieces. This helps to melt the plastic quickly and form hydro-carbons in their or gaseous state, pending the required output. The second and most crucial step among them is the Pyrolysis process. This process requires a setup with equipment like; metal containers, condenser, and vessels to store the fuel. The metal container withstood high temperatures as the pyrolysis process started at 4500C (Rodriguez et al., 2021). The metal container should be provided with suitable heat source, the heat source should be good enough to attend high temperature in very short time as all the above conditions are satisfied, the cleaned and shredded plastic waste are transferred inside the container for further process.
As the cleaned and shredded plastic waste is transferred into the container, the container is heated by the preferable heat source without oxygen. When the waste plastic is burnt in the absence of oxygen it will not catch fire, instead it will burn and forms gaseous state. From the container the gaseous fuel is then sent to condenser to cool down the temperature, when the temperature cools down the gaseous state changes to liquid state which is partial fuel. After the extraction of partial fuel from waste plastic, the fuel is sent to the container where the distillation occurs. Distillation process is done because the partial fuel which we get after pyrolysis process does not have similar properties as Diesel or Gasoline, to get the properties of the fuel approximate similar to Diesel or Gasoline this process is done. In this process, the partial fuel we get again undergoes heating at a lower temperature than the pyrolysis process (Kuppusamy and Ashokkumar, 2019). Lastly, the fuel produced from the container after the distillation process is stored in a vessel. This vessel can be of any material.
Emmanuel Chukwuma as part of the performance evaluation of pyrolytic conversion of plastic waste to energy at the Environmental Cluster workshop in Ghana, May 2024.
