Synthesis gas (water gas) - combustible gas coming into existence during the reaction of coal, the natural gas or light hydrocarbons with steam in of the presences of suitable catalysts. It is mixture of the carbon monoxide (CO) and of hydrogen (H2), can contain nitrogen. Synthesis gas is applied as the raw material to many chemical syntheses (for example to receiving the methanol and the ethanol). Moreover they are obtaining from synthesis gas syntin (synthetic petrol).