Synthesis gas (syngas) is a gas mixture consisting mainly of hydrogen (H₂) and carbon monoxide (CO) in variable ratios. Depending on the raw materials used and the production processes, it may also contain small amounts of carbon dioxide (CO₂), methane (CH₄), and traces of other gases.
Syngas is primarily used for the production of hydrocarbon fuels such as diesel and methanol, as well as for the production of industrial chemicals, especially ammonia. Furthermore, synthesis gas can be produced from biomass or agricultural waste materials and is therefore considered a form of renewable energy, thus contributing to a sustainable resource and energy economy.
As a result of the increasing expansion of biomass gasification plants in recent years, a large proportion of the synthesis gas produced annually is already derived from renewable raw materials. The focus here is primarily on steam reforming of methane. Under high temperatures of 700–900 °C and pressures in the range of 200 to 300 bar, the conversion of carbon-containing materials (e.g., methane) into hydrogen (H₂), carbon monoxide (CO), and carbon dioxide (CO₂) takes place with the addition of steam or oxygen, without complete combustion (total oxidation).
After synthesis, the raw gas requires processing to remove impurities such as hydrogen chloride (HCl), hydrogen sulfide (H₂S), and tar. The purified synthesis gas has properties comparable to those of natural gas and can be used as a fuel for energy production. A portion of the syngas is used to operate the gasification plant itself, while the remaining portion is supplied to energy companies, which primarily use the syngas for electricity generation in gas-fired power plants.
The diverse applications of synthesis gas as an energy carrier and chemical feedstock highlight its key role in sustainable energy and chemical production. The further development of efficient and environmentally friendly synthesis gas processes is crucial for reducing fossil fuel consumption and promoting a carbon-neutral economy.
