Gasification is a process that converts organic or fossil based carbonaceous materials into carbon monoxide, hydrogen and carbon dioxide. This is achieved by reacting the material at high temperatures (>700 °C), without combustion, with a controlled amount of oxygen and/or steam. The resulting gas mixture is called syngas (from synthesis gas or synthetic gas), wood gas or producer gas and is itself a fuel. The power derived from gasification and combustion of the resultant gas is considered to be a source of renewable energy if the gasified compounds were obtained from biomass
One of the most typical applications for this energy is combined heat and power generation (CHP). Wood gas contains plenty of hydrogen and carbon monoxide, and does not generate any emissions hazardous for the environment when burning. Wood gas is a particularly environment-friendly renewable and emission-free energy source.
Wood gasification technologies have been tested and developed for over 100 years, however challenges in managing a controlled and sufficiently clean gasification process have complicated the implementation of commercial applications, e.g. power plant solutions. The greatest obstacle to the development has been tar resulting from the pyrolysis process, which has been damaging engines during long-term use. Furthermore, wood chip quality, in particular its moisture content, has been setting tough requirements to the selection and handling of chopped biomass.
Solution – a Novel Pyrolysis Method
GASEK’s wood gasifier is a so-called co-current gasifier; it is based on the pyrolysis technique, which has been developed and refined for 30 years. The processed biomass is moving in the reactor in the same direction as the gasification air, which is fed in quantities that are considerably lower than is required for combustion.
The greatest differences vis-à-vis the old and problematic technique can be found in the temperature and the product gas purification methods. The key factor in the gasification process is achieving a high temperature (800-1200°C), which prevents formation of damaging tar compounds. This results in tar compounds cracking into lighter fractions, which do not cause engine problems. Wood gas that is run through the GASEK purification line is completely colourless and odourless, and its combustion causes no hazardous particle emissions.
Clean wood gas provides a possibility for manufacturing efficient, maintenance-friendly and long-serving power plant solutions. A number of international patents have been obtained for the GASEK gasification technology.