Table 3.

Comprehensive evaluation of the various technologies in converting plastic waste to fuels.

Technologies	Function	Conditions
Chemo-lysis	Depolymerise plastic into its monomer through various	Methanolysis:
	depolymerisation routes: methanolysis, glycolysis, hydrolysis, ammonolysis and hydrogenation	Temperature: 180–280 °C
		Pressure: 20–40 atm
		Hydrolysis: the reaction of plastic with water under neutral, acidic or basic conditions at high temperature and pressure
		Glycolysis:
		Temperature: 180–250 °C
		With excess of glycol
Pyrolysis	Break down macrostructure of the polymer to form smaller molecules by depolymerisation or random fragmentation. The pyrolysis products of plastic waste can be in the forms of gas, liquid and solid residue.	Temperature: 500 °C
		Pressure: 1–2 atm
Fluid catalytic cracking	Convert plastic waste into fuel, commodity chemicals and fine chemicals through thermal and catalytic decomposition process.	Temperature: 300–350 °C
Hydrogen technologies	Convert plastic waste into liquid fuel through hydrocracking reactions.	Temperature: 375–400 °C
		Pressure: 70 atm
		With the addition of hydrogen gas
KDV process	Catalytic depolymerisation conversion of biomass and plastic waste into liquid fuels such as diesel oil.	Temperature: 250–320 °C
		Pressure: Atmospheric pressure
Gasification	Converts plastic waste to a gaseous mixture containing CO2, CO, H2, CH4 and other light hydrocarbons via partial oxidation. The gaseous mixture is known as syngas.	Temperature: 1200–1500 °C
		Pressure: 50–100 atm
		With oxygen and steam