The untreated flue gas flows in a reactor
(actually, a ductwork designed in order to assure a given residence
time), where the injection of a dry powder of calcium hydroxide
(Ca(OH)2, commercially known as hydrated lime or slaked lime)
takes place. This alkaline material acts as a sorbent towards the
acid pollutants, triggering the gas-solid reactions (R1)–(R3)
reported in Table 1