Urban Energy Technical Note 16: Gasifier Stoves
Gasifiers produce wood gas which is a syngas fuel which can be used as a fuel for furnaces, stoves and vehicles in place of petrol, diesel or other fuels. During the production process biomass or other carbon-containing materials are gasified within the oxygen-limited environment of a wood gas generator to produce hydrogen and carbon monoxide. These gases can then be burnt as a fuel within an oxygen rich environment to produce carbon dioxide, water and heat. One of the main uses of wood gasification has been to power internal combustion engines. Wood gas stoves are actually wood gasifiers designed to produce heat which is ideal for cooking and meeting other heating needs.
There is a broad range of existing gasifier stove designs and development is on-going. In the ever-increasing areas where charcoal and firewood are becoming scarce and/or expensive, gasifiers will be of growing relevance as an option for the clean burning of alternative biomass fuels. The wood gas or gasifier stove is a simple and reliable solution for bringing down fuel costs. It is an advanced version of other biomass based improved cookstoves (ICS) and converts solid biomass into clean combustible gas (producer-gas) by means of a process known as thermal gasification. Gasifier stoves approach the concept of generating heat from wood and biomass in a completely different way, separating the generation of combustible gases from their subsequent combustion to create cooking heat. Gasification advantages have been known for a long time but only recently could they be reliably accomplished at the sufficiently small and micro-scales appropriate for household stoves.