ångförgasning

Ångförgasning is a thermochemical process that converts carbon-containing materials into a synthesis gas, often referred to as syngas, using steam. This syngas is primarily composed of hydrogen (H2) and carbon monoxide (CO), with smaller amounts of other gases like carbon dioxide (CO2) and methane (CH4). The process typically involves heating the feedstock, such as coal, biomass, or waste materials, to high temperatures in the absence of or with limited oxygen. Steam is then introduced, which reacts with the hot carbonaceous material through a series of endothermic reactions, absorbing heat and producing the desired syngas.

The primary reactions in steam gasification include the reaction of carbon with steam to produce hydrogen and carbon monoxide, and the Boudouard reaction where carbon reacts with carbon dioxide to form more carbon monoxide. The overall process is endothermic, meaning it requires an external heat source to maintain the high temperatures needed for the reactions to occur efficiently. This heat can be supplied by partially oxidizing the feedstock or by external heating. The ratio of steam to feedstock, temperature, and pressure are critical parameters that influence the syngas composition and the efficiency of the process.

Ångförgasning has several applications, including the production of chemicals like methanol and ammonia, the generation of electricity, and the production of liquid fuels through processes like the Fischer-Tropsch synthesis. It is considered a cleaner alternative to direct combustion for energy generation as it can reduce the emission of pollutants. The flexibility of steam gasification in handling various feedstocks also makes it an attractive technology for waste-to-energy conversion and the utilization of renewable resources.