Interaction behavior of sand-diluted and mixed Fe-based oxygen carriers with potassium salts

Oxygen carriers, in the form of metal oxide particles, are bed materials that transport oxygen solid fluidized applications, such as chemical-looping applications. In biofuel it is well known alkali from fuel ash can react with material and cause, among other operation issues, agglomeration. When using carriers a bed, likely either mixture different or partly diluted sand. This to improve combine chemical properties used simply for economic reasons. work investigates how three potassium salts K2CO3, K2SO4 KH2PO4 interact carriers: Steel converter slag (LD slag), ilmenite, mixtures two each carrier silica The were model compounds occur ash. set-up was fixed where small sample mixed salt equivalent 4 wt-% potassium. then exposed reducing (H2 steam) conditions at 900 °C during several hours tubular furnace. provides worst-case scenario solid–solid interaction bed. If reaction does not take place this setup, will most never LD ilmenite combined, would prefer accumulate rather than slag. Ca interacted resulting less severe agglomeration when separately same salt. sand, resulted both all salts. K2CO3 formed silicates, while phosphorus-containing melt. present, phosphorus located K-Ca-P phase present if present.