Research of lignite underground gasification

摘要

Underground Coal Gasification (UCG) is an in situ technique to recover the fuel or feedstock value of coal that is noteconomically available through conventional recovery technologies. First tentative works directed toward the utilization of the in situmethod of gasification under conditions of Northern Bohemian brown-coal basin date back to 1956 in formerly Czechoslovakia.6 experiments of UCG were realized later. The obtained results did not confirm the technological assumptions of gasification especiallyregarding the quality of the gas recovered. The average heating capacity reached the value from 1.59 – 3.44 MJ.m-3. Today, similarly allother countries in the world, in Slovakia there is an interest in the revival and perfection of the UCG technology. In this paperit is described a laboratory plant including monitoring and controlling system and some reached results.During these experiments were find out that the gasification process depends on many factors/parameters. Most the important aretopologies/methods, humidity of coal, heat losses, temperatures in relevant zones, composition of oxidation agents and permeability.The calorific value of syngas is 2 - 5 MJ.m-3 if the oxidation agent was used air only. In case of using the air + oxygen mix the calorificvalue to 10 MJ.m-3 has been obtained.