Biomass Gasification Comes of Age
Common to all our solutions is the process of gasification. Unlike a conventional biomass boiler the core purpose of our biomass plant is not the generation of heat, but the generation of an energetic gas which can be used as a substitute for natural gas in a reciprocating engine similar to that found in commercial vehicles. Gasification of wood occurs at high temperature (around 1000 degrees Centigrade) and because of a limited supply of oxygen we retain the energy within the gas rather than burning it. Whereas a biomass boiler would emit carbon dioxide (CO2) and water vapour (H2O), a Gasifier with its limited oxygen supply will emit carbon monoxide (CO) and hydrogen (H2) – this mixture of gas has sufficient energy content to run an engine without any other fuel being required.
Most small scale gasifiers adopt what is known as a downdraft principle which characterises the way the air flows within the machine. Our products all adopt a proprietary adaptation of this principle in order to ensure the cleanest possible gas and minimising the need for gas cleaning.
Biomass is introduced to the top of the Gasifier, and the process is started by ignition of a small quantity of material. As the material gradually moves down the gasification chamber it enters hotter and hotter zones where the material starts to behave in a different manner. At the throat of the Gasifier and before the material forms ash the material reaches around 1000 degrees centigrade and it is in this zone where the solid matter is converted into a gaseous form. The need to achieve and maintain such a high temperature requires a very dry and consistent form of fuel in the form of wood chips.
For larger scale installations Arbor Heat and Power would recommend multi-unit smaller system installation for a variety of technical and commercial reasons due to the current market conditions. Please contact us for further information.