Investigations on Bed Material Changes in a Dual Fluidized Bed Steam Gasification Plant in Güssing, Austria

Abstract

Bed material coating in fluidized biomass combustion plants is a precursor for bed agglomeration. While bed agglomeration is a well-described problem in connection with biomass combustion plants, the literature on bed agglomeration or bed material coating in gasification plants is sparse. Recently developed biomass gasification plants face similar ash-related problems, but inorganic matter is also linked to their catalytic activity to reduce the tar concentration in the product gas. This paper summarizes recent ash-related research activities at a dual fluidized bed steam gasification plant located in Gussing, Austria. The used fuel is forestry residues; the bed material is olivine. The setup of inorganic flows and loops is described. Bed material analyses were carried out and presented, such as X-ray fluorescence, X-ray diffraction, and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The analyses show the building of two calcium-rich layers around the bed particles. The inner laye...