Gas generator for formation of endothermic gas, used for annealing, hardering and sintering of metals.

JTEKT Thermo Systems is represented in Europe by
Crystec Technology Trading GmbH

Endothermic Gas Generator

Endothermic gas or endo gas is used for the thermal treatment of metals as a protective gas. It can be generated in an endothermic gas generator by burning natural gas, consisting mainly of methane or other hydrocarbons with heavy lack of oxygen. The reaction takes place at the surface of a catalyst under external heating at around 1000░C. The process needs energy supply and is therefore endotherm.
        2 CH4  +  O2  →  CO  +  4 H2
Carbon monoxid and rather high amounts of hydrogen are formed. Nitrogen from the air is of course also available in larger quantities and can be further increased in order to dilute the hydrogen content. Carbon dioxid, water and unburnt hydrocarbons are included only in small amounts. Formation of soot can be avoided by selecting proper process conditions.
Hydrogen and carbon monoxide are reducing agents and avoid oxidation or corrosion of metal surfaces in a furnace. It has to be taken into account however, that carbon monoxid increases the carbon content of steel. Endothermic gas can therefore be used for surface hardening of steel by carbonisation or carburization. Carbon concentration can be increased up to the saturation level of austenite in surface close areas (around 1mm deep).
JTEKT (previously Koyo) can offer endothermic gas generators for the usage in industrial furnaces. JTEKT is a famous manufacturer of industrial furnace and has therefore much experience with design and adaption of gas generators.

Generator for the formation of endothermic gas


  • Carbonisation, Carbonization, Carburization, Carburisation
  • Sintering
  • Annealing of steel with high carbon content
  • Normalizing


  • Cheap formation of shielding gas
  • Stable gas supply
  • Energy saving heating by usage of Moldatherm® heaters
  • Customized design
Endothermer Gasgenerator

Further gas generators for the formation of exothermic gas and forming gas are also available.

JTEKT Thermo Systems and Crystec will be pleased to engineer a cost effective system to satisfy your most demanding and exacting requirements.