Combustion is the exothermic combination of hydrocarbons with oxygen. The heat for all processes is generated from combustion of the tars produced during pyrolysis. In addition, combustion produces carbon dioxide and hydrogen gas, which will become reactants in the reduction step. Adequate mixing and high temperature flame is key, since the lack of either could permit the tars to still be present in the wood gas, which in turn could lead to engine failure. Therefore, producing clean fuel is largely dependent on the combustion dynamics in the gasifier (www.gekgasifier.com) The United Nations Forestry and Agriculture Organization suggests that the combustion zone should reach a minimum of 1473 K to ensure a clean burning fuel