What is the difference between pyrolysis and incineration?

If you have ever wondered how waste is dealt with, you may have heard of the terms "pyrolysis" and "incineration". They all seem to be methods of decomposing substances by using heat, but in fact, they are completely different processes.

Pyrolysis is a process in which organic materials (plastics, rubber, biomass) undergo thermal decomposition in an oxygen-free or hypoxic environment through high temperatures (typically 300-800°C). Pyrolysis does not directly burn materials but converts them into three main products: solid biochar, liquid pyrolysis oil and syngas, etc. It is often used for resource recovery and waste conversion.

Incineration is the process of completely or partially burning solid waste into gas and ash in an environment with sufficient oxygen. Modern incineration facilities often incorporate "waste-to-energy" technology, using the generated heat for power generation or heating. However, their primary function remains to safely handle difficult-to-recycle or toxic and harmful waste, such as medical waste and municipal garbage.

Difference between pyrolysis and incineration:

Advantages of Pyrolysis over Incineration

1. Diversified Energy Products: Pyrolysis can more efficiently convert waste into valuable products such as fuel oil, carbon black, and syngas. These end products can be stored and utilized, processed, and sold.
2. Low Environmental Impact: Because pyrolysis occurs in the absence of or low-oxygen conditions, it reduces emissions of greenhouse gases such as carbon dioxide and produces relatively few pollutants.
3. High Energy Conversion Efficiency: The energy released during pyrolysis can be more efficiently captured and utilized.
4. Wide Adaptability: Pyrolysis is suitable for treating a wide range of solid waste types, including plastics, tires, rubber, oil sludge, sewage sludge, and difficult-to-recycle biomass (rice husks, straw, nut shells, palm waste, wood waste, bamboo, etc.).

In conclusion, pyrolysis and incineration are two completely different processes with distinct goals: the former converts waste into resources, while the latter destroys waste for management purposes. Incineration is the main means to reduce the amount of waste, while pyrolysis is an innovative process that converts solid waste into fuel. Whether it is pyrolysis or incineration, as long as it is carefully considered and used responsibly, each process can play an important role.