Allothermal method for the gasification of solid fuels in a rotary kiln

摘要

The present invention concerns a new gasification method of solid fuels of any quality.The method is characterized in that the gasification is carried out in an indirectly heated rotary kiln, using as the gasification agent the steam produced from drying of the solid fuel itself, which is taking place inside the gasification chamber and -if necessary- additional steam from an outside source. The maximum gasification temperatures may range from 650-1000°C, and the operating pressure inside the kiln is slightly lower than the ambient.The method is capable of gasifying solid fuels of any quality with no limitations regarding the moisture content or the particle size of the fuel, and regardless of whether it can be ignited and burnt as fed.The method is especially suitable for the gasification of low quality coals, like for example the Greek coal, that cannot be gasified without pre-treatment using the classical industrial gasification methods, because of its very low content of combustible matter and its high moisture and ash contents.