Process for manufacturing a sorbent for a flue gas treatment process, sorbent and use of said sorbent in such flue gas treatment process

A circulating dry scrubber lime based sorbent, the sorbent comprising:

• at least 50 weight % of Ca(OH)2 and at least 0.5 weight % of silicon or aluminum or a combination thereof expressed under its elemental form and at most 8 weight % of silicon or aluminum or a combination thereof expressed under their elemental form, with respect to the total weight of said sorbent under a dry form, and
• at least 0.1 weight % of sodium expressed under its equivalent Na2O oxide form with respect to the total weight of said sorbent under a dry form;
• wherein said sorbent further comprises 1 to 12 weight % of bound water with respect to the total weight of said sorbent under a dry form, said bound water being measured between 150° C. and 350° C., and in that from 1 to 40 mol % of calcium is neither under the form of Ca(OH)2 or CaCO3 nor CaO, in that the molar ratio (Si+Al)/Ca is of at least 0.02 and of maximum 0.2, and in that the molar ratio (Si+Al)/Na is of at least 0.4 and of maximum 10.