Endothermic atmosphere

An atmosphere which is manufactured by passing a hydrocarbon gas and air mixture through a converter or generator containing a catalyst, at a high temperature.

The advantage of endothermic atmospheres is that they are very flexible and can be tailored to suit the particular heat treatment process being carried out. A typical composition of an endothermic atmosphere generated from methane would be: approximately 39% nitrogen; 20% carbon monoxide and 39% hydrogen, together with small amounts of water vapour, carbon dioxide and residual methane.

The name is derived from endothermic, the term for a chemical reaction in which heat is absorbed.