Influence of reaction parameters on thermal liquefaction of plastic wastes into oil: A review

The use-and-throw culture of plastic products has generated a massive amount of plastic wastes each year, posing a threat to the environment with the absence of proper disposal methods of the wastes. Conventional disposal methods including landfill and incineration cease to be the ultimate solution to the problem, in addition to further causing soil and air pollution. Liquefaction technology has emerged to become one of the alternatives in reducing the amount of accumulated wastes simultaneously generating valuable liquid products for applications such as transportation fuel and chemical feedstock in industries. Additionally, the recovery of plastics through this method poses great potential in reducing the dependency on non-renewable fossil fuels, creating an alternative energy source. This review exploits the liquefaction of common types of plastics found in the wastes and some key parameters affecting the yield and properties of end products including the type of reactor, temperature, pressure, reaction time, types of solvent, solvent to plastic ratio and the initial size of plastic used.