Höyrykaasua

Höyrykaasua, also known as producer gas or wood gas, is a combustible gas mixture that is created by the partial combustion of carbon-containing materials such as wood, coal, or biomass in a limited supply of oxygen. This process, known as gasification, typically occurs at high temperatures within a gasifier. The resulting gas is primarily composed of carbon monoxide (CO), hydrogen (H₂), nitrogen (N₂), and small amounts of carbon dioxide (CO₂) and methane (CH₄).

The composition of höyrykaasua varies depending on the feedstock and the gasification conditions. Carbon monoxide and hydrogen are the primary combustible components, providing the energy value of the gas. Nitrogen is largely inert but dilutes the fuel gas. The presence of water vapor also contributes to the "steam" aspect of the name, though it is not always the dominant component.

Historically, höyrykaasua was a significant energy source, particularly during times of fuel scarcity, such as wartime. It was used to power internal combustion engines, for heating, and in industrial processes. Modern applications include its use in small-scale power generation systems, particularly in rural areas with abundant biomass resources. It can also be a precursor for the synthesis of other chemicals.

The technology for producing and utilizing höyrykaasua has been refined over time. Gasifiers can be designed in various configurations, including updraft, downdraft, and crossdraft, each with different characteristics regarding efficiency and gas quality. Cleaning and filtering the gas is often necessary to remove tar and particulate matter before it can be used in engines or other sensitive equipment to prevent damage and ensure efficient operation.