LABORATORY FLUIDIZED BED TESTING OF ILMENITE AS BED MATERIAL FOR OXYGEN CARRIER AIDED COMBUSTION (OCAC)

摘要

Ilmenite is an iron titanium oxide, extensively studied as oxygen carrier in the context of Chemical-Looping Combustion (CLC) as written by Berguerand and Lyngfelt (2009) and Schwebel et al.(2012).When used as bed material in conventional circulating fluidized bed (CFB) combustion, ilmenite was found to lower the emissions of carbon monoxide (CO), unburned hydrocarbons (UHC) and nitrogen oxide (NO).The detail can be found in (Thunman et al.2013).This concept is referred to as Oxygen Carrier Aided Combustion (OCAC).In OCAC, the bed material is blended with or replaced by an oxygen carrier material.The oxygen carrier undergoes oxidation and reduction in different parts of the CFB boiler, as shown in Fig.1, which evens out the oxygen distribution temporarily, and spatially, resulting in less CO and UHC emission and thus in more efficient combustion.Furthermore, catalytic reduction of NOx can be achieved, simultaneously.The synergy effect on the fuel conversion of an oxygen carrier, in this case ilmenite, as bed material for conventional fluidized bed combustion is clearly illustrated.Oxygen carrier aided combustion (OCAC) opens a new door to advance fluidized bed combustion.