Method for the preparation of highly reactive clay composites for the removal of SOx from flue gas streams

摘要

The use of base/clay composites materials as sorbents for the removal of SO2 and SO3 (SOx) from flue gas and other sulfur containing gas streams is described. The base is either an alkaline earth metal carbonate (eg. CaCO3) or hydroxide (eg. Ca(OH)2) is incorporated onto the clay by precipitating from corresponding metal oxide (eg. CaO) in an aqueous clay slurry. A second metal oxide or oxide precursor, preferably selected from transition metal ions, capable of promoting the oxidation of sulfur dioxide to sulfur trioxide, is incorporated to the base/clay composite during the synthesis in the form of finely divided metal oxide powder, metal oxide sol, water soluble metal salt or as clay-intercalated metal cation. The use of clay as dispersing agent for both the basic oxide and the second metal oxide component decreases the particle agglomeration of base particles and increases the rate of SOx uptake compared to the bulk bases in current use.