Advanced dual fluidized bed steam gasification of wood and lignite with calcite as bed material

This paper presents experimental results with a new generation of a 100 kW (th) dual fluidized bed steam gasification pilot plant with calcite as bed material, converting wood and lignite in separate test runs into product gas. The results are compared to experiments with the same fuels with olivine as bed material and the previous generation of the gasification pilot plant at TU Wien. The highly catalytic active calcium oxide shifted the product gas composition towards higher hydrogen and carbon dioxide and lower carbon monoxide content. The tar amount was decreased and the tar composition changed, resulting in lower tar dew points. The dust content in the product gas was reduced with the advanced pilot plant design with calcite in comparison to the classic design with olivine. Therefore, attrition of bed material was decreased by utilizing the advanced design and calcite with its benefits can be used without profuse continuous replacement of bed material.