Ilmakaasutus

Ilmakaasutus, often translated as atmospheric gasification, refers to a process where a fuel, typically a solid fuel like biomass or coal, is gasified using the oxygen present in the surrounding air. This distinguishes it from other gasification methods that use pure oxygen or steam as the gasifying agent. In ilmakaasutus, air is blown into the gasifier, reacting with the fuel at high temperatures.

The primary products of ilmakaasutus are a combustible gas mixture known as producer gas or syngas, along with byproducts like ash and tar. Producer gas is mainly composed of carbon monoxide (CO), hydrogen (H2), nitrogen (N2), and some carbon dioxide (CO2) and methane (CH4). The high nitrogen content from the air dilutes the heating value of the producer gas compared to syngas produced using pure oxygen or steam.

Ilmakaasutus is generally a simpler and less expensive technology due to the readily available and free nature of air. However, the lower calorific value of the producer gas can be a limitation for certain applications, particularly for direct combustion in engines or turbines without further processing. Despite this, it finds applications in areas where cost-effectiveness is paramount and a lower-grade fuel gas is acceptable, such as in some industrial heating processes or for powering gasifiers in remote locations. Control of the air-to-fuel ratio is crucial to manage the temperature and gas composition effectively.