Pyrolysis is a thermal decomposition of solid or liquid material into gas and solid phases in absence of the external oxygen (air) supply. The pyrolysis process takes place under the temperatures
typically around 500-600 C.
The gaseous product of pyrolysis can undergo the following transformations in downstream processes:
- Cooling down followed by oil condensing (commercailly viable liquefaction is applicable for a limited number of feedstock such as plastics)
- Secondary combustion and generation steam in boiler, which consequently will be sent to steam turbine to generate electricity: Modular Pyrolysis Steam Cycle (MPSC) system
In both case flue gas is cleaned prior to be disposed through stack
Pyrolysis process is self-sustainable, i.e part of energy generated by pyrolysis gas (and pyrolysis char) will be used for pyrolysis kiln heating and drying if required.
Pyrolysis gas could also be cracked and thoroughly cleaned in order to be used as fuel in a gas engine, however pyrolysis gas conditioning is a complicated problem. Extra energy reclaming from the pyrolysis char in this case requires high temperatures treatment - energy consumption and maintenance issues. Consequently this approach was not yet fully commercialized.