A review on thermal and catalytic pyrolysis of plastic solid waste (PSW) discusses the increasing reliance on plastics due to their versatility, low cost, and wide applications. However, plastic waste accumulation in landfills poses environmental and health risks. Pyrolysis, a thermochemical process, offers a solution by recovering energy and valuable products like oil and gas while reducing pollution. This paper examines existing pyrolysis techniques, factors affecting product yield and selectivity, and the role of catalysts. It also compares pyrolysis with other thermal and catalytic treatment methods. Plastics are categorized into thermoplastics and thermosets, with PSW mainly consisting of HDPE, LDPE, PP, PS, PVC, and PET. Pyrolysis produces products similar to fossil fuels, with high carbon content making it a preferred treatment. The process involves various setups, including fixed bed reactors, fluidized bed reactors, and microwave-assisted pyrolysis. Factors like residence time, temperature, and pressure significantly influence product yields. Catalysts enhance pyrolysis efficiency and product selectivity. Pyrolysis produces liquid oil, gas, and char, with liquid oil being the most valuable. The process is environmentally beneficial, reducing greenhouse gas emissions and carbon footprint compared to combustion. Financially, pyrolysis produces high calorific value fuels, making it economically viable. It is also more efficient than other thermal treatment methods, with high internal rate of return in industrial scale applications. The review highlights the importance of feedstock type, reactor design, and operational parameters in pyrolysis. Different plastics yield varying products, with PS and PET producing aromatic compounds and gases, respectively. PVC pyrolysis produces HCl, requiring dehydrochlorination steps. The degradation kinetics of plastics involve initiation, propagation, and termination steps, with free radicals and hydrogen transfer playing key roles. Understanding these mechanisms is crucial for optimizing pyrolysis processes and improving product yields. Overall, pyrolysis offers a sustainable solution for managing PSW, reducing environmental impact, and recovering valuable resources.A review on thermal and catalytic pyrolysis of plastic solid waste (PSW) discusses the increasing reliance on plastics due to their versatility, low cost, and wide applications. However, plastic waste accumulation in landfills poses environmental and health risks. Pyrolysis, a thermochemical process, offers a solution by recovering energy and valuable products like oil and gas while reducing pollution. This paper examines existing pyrolysis techniques, factors affecting product yield and selectivity, and the role of catalysts. It also compares pyrolysis with other thermal and catalytic treatment methods. Plastics are categorized into thermoplastics and thermosets, with PSW mainly consisting of HDPE, LDPE, PP, PS, PVC, and PET. Pyrolysis produces products similar to fossil fuels, with high carbon content making it a preferred treatment. The process involves various setups, including fixed bed reactors, fluidized bed reactors, and microwave-assisted pyrolysis. Factors like residence time, temperature, and pressure significantly influence product yields. Catalysts enhance pyrolysis efficiency and product selectivity. Pyrolysis produces liquid oil, gas, and char, with liquid oil being the most valuable. The process is environmentally beneficial, reducing greenhouse gas emissions and carbon footprint compared to combustion. Financially, pyrolysis produces high calorific value fuels, making it economically viable. It is also more efficient than other thermal treatment methods, with high internal rate of return in industrial scale applications. The review highlights the importance of feedstock type, reactor design, and operational parameters in pyrolysis. Different plastics yield varying products, with PS and PET producing aromatic compounds and gases, respectively. PVC pyrolysis produces HCl, requiring dehydrochlorination steps. The degradation kinetics of plastics involve initiation, propagation, and termination steps, with free radicals and hydrogen transfer playing key roles. Understanding these mechanisms is crucial for optimizing pyrolysis processes and improving product yields. Overall, pyrolysis offers a sustainable solution for managing PSW, reducing environmental impact, and recovering valuable resources.