Gasification

Gasification is a process that converts <a href="/facts/Biomass/4VHjaya3">biomass</a>- or <a href="/facts/Fossil_fuel/BPgxAqB7">fossil fuel</a>-based <a href="/facts/Carbonaceous/ukrgQexo">carbonaceous</a> materials into gases, including as the largest fractions: <a href="/facts/Nitrogen/Nf1QpGDz">nitrogen</a> (N2), <a href="/facts/Carbon_monoxide/CKuLtEMJ">carbon monoxide</a> (CO), <a href="/facts/Hydrogen/BoYHjl0J">hydrogen</a> (H2), and <a href="/facts/Carbon_dioxide/xGzpppEp">carbon dioxide</a> (CO2). This is achieved by reacting the feedstock material at high temperatures (typically >700 °C), without combustion, via controlling the amount of <a href="/facts/Oxygen/acyn6o8r">oxygen</a> and/or <a href="/facts/Steam/RDGCdmzT">steam</a> present in the reaction. The resulting gas mixture is called <a href="/facts/Syngas/VfslxkIN">syngas</a> (from synthesis gas) or <a href="/facts/Producer_gas/U7nQHBMg">producer gas</a> and is itself a fuel due to the flammability of the H2 and CO of which the gas is largely composed. Power can be derived from the subsequent combustion of the resultant gas, and is considered to be a source of <a href="/facts/Renewable_energy/6Bu6IrpF">renewable energy</a> if the gasified compounds were obtained from biomass feedstock.
An advantage of gasification is that <a href="/facts/Syngas/VfslxkIN">syngas</a> can be more efficient than direct combustion of the original feedstock material because it can be combusted at higher temperatures so that the thermodynamic upper limit to the efficiency defined by <a href="/facts/Carnot%2527s_theorem_(thermodynamics)/MtLN7MfQ">Carnot's rule</a> is higher. Syngas may also be used as the hydrogen source in fuel cells, however the syngas produced by most gasification systems requires additional processing and reforming to remove the contaminants and other gases such as CO and CO2 to be suitable for low-temperature fuel cell use, but high-temperature <a href="/facts/Solid_oxide_fuel_cell/xmp3quI1">solid oxide fuel cells</a> are capable of directly accepting mixtures of H2, CO, CO2, steam, and methane.
Syngas is most commonly burned directly in <a href="/facts/Internal_combustion_engines/Ju4BXzj0">gas engines</a>, used to produce <a href="/facts/Methanol/EIfpoNCg">methanol</a> and hydrogen, or converted via the <a href="/facts/Fischer%25E2%2580%2593Tropsch_process/qx8noLlC">Fischer–Tropsch process</a> into <a href="/facts/Synthetic_fuel/H5UxNxQD">synthetic fuel</a>. For some materials gasification can be an alternative to <a href="/facts/Landfill/7K4efGgz">landfilling</a> and <a href="/facts/Incineration/ALwWqMlv">incineration</a>, resulting in lowered emissions of atmospheric pollutants such as <a href="/facts/Methane/kBHneYnh">methane</a> and <a href="/facts/Particulates/RleGr5E6">particulates</a>. Some gasification processes aim at refining out corrosive ash elements such as <a href="/facts/Chloride/m9NUaUDR">chloride</a> and <a href="/facts/Potassium/FWPwS7Rj">potassium</a>, allowing clean gas production from otherwise problematic feedstock material. Gasification of <a href="/facts/Fossil_fuels/BPgxAqB7">fossil fuels</a> is currently widely used on industrial scales to generate electricity. Gasification can generate lower amounts of some pollutants as SOx and NOx than combustion.

Gasification open-in-new

Gasification