What is the Difference Between Pyrolysis and Gasification?

Pyrolysis and gasification are both thermal processes used to convert carbonaceous substances into various products, but they differ in terms of their oxygen supply, temperature, and product composition. Here are the main differences between the two processes:

1. Oxygen supply: Pyrolysis is performed in the absence of oxygen, while gasification requires a reduction of oxygen.
2. Temperature: Pyrolysis typically occurs at lower temperatures (around 400°C or more), while gasification requires higher temperatures (above 800°C) and moderate pressure.
3. Product composition: In pyrolysis, the products include char, tar, and gas, while gasification transforms carbon-containing products (e.g., the products from pyrolysis) into a primarily gaseous product called syngas.
4. Energy efficiency: Generally, gasification has a higher energy efficiency than pyrolysis, as it produces more syngas and less biochar and bio-oil, which have lower energy densities.
5. Applications: Pyrolysis is useful for applications such as caramelization, production of fuel from biomass, production of ethylene, and treating plastic waste. Gasification, on the other hand, is useful for heat production, production of electricity, and other energy-related applications.

In summary, while both pyrolysis and gasification are thermal processes for converting carbonaceous substances, they differ in terms of oxygen supply, temperature, product composition, energy efficiency, and applications.

Comparative Table: Pyrolysis vs Gasification

Here is a table summarizing the differences between pyrolysis and gasification: