| Type of reactor | Chemical reactions | Reference |
| Downdraft reactor | Drying | [10] [35] |
| Pyrolysis | ||
| Combustion and tar cracking | ||
| Reduction | ||
| Updraft reactor | Drying | [25] |
| Pyrolysis | ||
| Char gasification or reduction | ||
| Combustion | ||
| Plasma reactor | Oxidation reaction with oxygen | [11] |
| Reduction with steam, H2 and CO2 | ||
| Decomposition of tar and hydrocarbons |