Our Technologies: Pyrolysis and Gasification

Pyrolysis and gasification are thermal processes, which use high temperatures to break down any waste containing carbon.
Both technologies use less oxygen than traditional mass-burn incineration. Gasification involves using a small amount of oxygen whereas pyrolysis uses none.
The pyrolysis process degrades waste to produce ash (or char), pyrolysis oil and synthetic gas (called syngas). The gasification process then breaks down the hydrocarbons left into a syngas using a controlled amount of oxygen. 
Gasification and pyrolysis typically rely on carbon-based waste such as paper, petroleum-based wastes like plastics, and organic materials such as food scraps.
Both produce a syngas made up mainly of carbon monoxide (CO) and hydrogen (85%), with smaller amounts of CO2 and methane. Syngas has a significant calorific value, so it can be used as a fuel to generate electricity or steam, or used as a basic chemical in refining industries. Other by-products include liquids (mainly water used for washing the gas clean) and solid residues – ash, or char, usually to used in the production of cement for example.

Usually gasification and pyrolysis include four processes – and products: 

  • Pre-treating the waste, which involves sterilizing it and separating out some of the recyclables, especially glass, grit and metal (whit no calorific value, but end as a product too) 
  • Heating the remaining waste, mainly organic pulp, to produce gas, oils and char (ash) 
  • Cleaning the gas to remove some of particulates, hydrocarbons and other harmful substances when using the gas 
  • Using the cleaned gas to generate electricity and heat, through Combined Heat and Power (CHP) generators.