Biomass fired power generation is a cost-effective technology to achieve carbon neutrality. Fluidized bed combustion technology has a prominent advantage in fuel adaptability which is suitable for biomass fuel. However, due to the high content of alkali metals, there are some serious problems such as agglomeration, fouling and corrosion in the process of biomass combustion. Recently, Oxygen carrier aided combustion (OCAC) technology has been proposed to enhance both fuel conversion and heat distribution, which is realized by replacing inert bed material with active oxygen carrier. OCAC technology also shows great potential in preventing alkali metal induced ash issues in previous research. In this work, potassium capturing performance of ilmenite ore oxygen carrier at high temperature were investigated in a small fluidized bed experimental facility. The content and distribution of potassium in the samples were analyzed by ICP-OES and SEM-mapping. The results revealed that the percentage of injected potassium that was captured is more than 30% in the first 6.5 h, and it remained about 22.6 wt% after 19.5 h. Under the condition of high temperature, potassium was first enriched on the surface of ilmenite ore particles, then was more likely to combine with titanium and migrated to the interior of particles.

OCAC,ilmenite ore,alkali metals,oxygen carrier,fluidized bed