Is chemical recycling the same as combustion/incineration of municipal solid waste for energy recovery?

No, chemical recycling and combustion/incineration are entirely different processes, each with different and distinct outputs and emission profiles. While both processes use high heat and are used to reduce the amount of waste disposed in a landfill (including hazardous waste and non-recyclable waste), they differ in almost every other aspect.

Combustion/Incineration EPA describes the combustion of non-hazardous waste (e.g., Municipal Solid Waste) as a form of energy recovery, along with technologies that convert non-recyclable waste materials into usable forms of energy including heat, electricity, or fuel through a variety of processes, including combustion, gasification, pyrolization and anaerobic digestion, and landfill gas recovery. (See: Energy Recovery from the Combustion of Municipal Solid Waste (MSW) | US EPA)  

Pyrolysis is a closed, oxygen-free process in which plastic waste is subjected to extremely high temperatures (400°C to 1000°C).  It differs from combustion/incineration because there is no oxygen involved[mjc1] . The pyrolysis process includes both energy and “resource” or “feedstock” recovery by creating gas or liquid raw materials, which can be used to make new products, offering greater circularity potential. 

Combustion processes are distinct from pyrolysis because they include oxygen, the combustion of which can generate hazardous air pollutants and particulate matter. However, the EPA requires that an incinerator destroy and remove “at least 99.99% of each harmful chemical in the waste it processes.” Additionally, the heat used in the incineration process can generate electric energy, which is known as the “waste to energy” process.

While this discussion focuses on pyrolysis—because it is the most publicly debated and frequently conflated with incineration—we recognize that advanced recycling encompasses a broader suite of technologies, including gasification, depolymerization, solvolysis, enzymatic hydrolysis, and others.

Each of these processes has its own technical profile, environmental footprint, and material recovery potential, and should be evaluated independently using science-based, data-driven assessments

Learn more:  

Incineration: Energy Recovery from the Combustion of Municipal Solid Waste (MSW) | US EPA