Pyrolysis, like gasification, is also a thermo-chemical process. However, the main differences are the conditions under which the biomass is heated and the products that are produced.

For pyrolysis, organic materials are decomposed at high temperatures under the absence of oxygen. Pyrolysis of organic substances produces solid, liquid and gaseous products such as char, pyrolysis oils and biogases.

Fast pyrolysis, is the rapid conversion (less than 2 sec) at higher temperatures (~500°C). This process is optimized for bio-oil production and produces minimal char and gas. Slow pyrolysis, or carbonization, is the slower conversion (30 mins to days) at lower temperatures (200-400°C). The main product of this process is biochar (activated carbon).

Click here for a fact sheet on Pyrolysis.

Additional Resources:

What is Pyrolysis?
Pyrolysis and Gasification Factsheet
Pyrolysis of Woody Biomass