Process for manufacturing highly porous slaked lime having a high BET specific surface area being comprised between 30 m 2 /g and 50 m 2 /g and a high BJH pore volume, composed by the pores with a diameter less than 1000 Angstroms, higher than or equal to 0.15 cm 3 /g, said process comprising - a feeding step of quicklime, a feeding step of water in a feeding zone of a hydrator,; - a slaking step of said quicklime in a slaking zone of said hydrator, and - a maturation step in a maturation zone of said hydrator to form slaked lime,; - a transportation of lime by means of transportation means along the slaking direction into the hydrator, from the quicklime feeding until a slaked lime withdrawal, said slaked lime withdrawal being downstream the slaking direction, characterized in that - said hydrator is equipped with an extraction hood; - said feeding step of quicklime and said feeding step of water are performed so as to obtain a water/quicklime ratio comprised between 0.8 and 1.3 by weight, preferably between 0.9 and 1.2; - said process further comprises a step of removing vapor generated during said slaking step, said step of removing vapor being performed over at least 90 % of the length of said slaking zone by means of the extraction hood which extends on a portion of the hydrator length which starts from at least 30% of the length of said hydrator, upstream the slaking direction, until at least 65% of the length of the hydrator, - said process comprises a step of forming a raw highly porous slaked lime being a high BET specific surface area being comprised between 30 m 2 /g and 50 m 2 /g and high BJH pore volume slaked lime composed by the pores with a diameter less than 1000 Angstroms, higher than or equal to 0.15 cm 3 /g. - a feeding step of quicklime, a feeding step of water in a feeding zone of a hydrator,; - a slaking step of said quicklime in a slaking zone of said hydrator, and - a maturation step in a maturation zone of said hydrator to form slaked lime,; - a transportation of lime by means of transportation means along the slaking direction into the hydrator, from the quicklime feeding until a slaked lime withdrawal, said slaked lime withdrawal being downstream the slaking direction, - said hydrator is equipped with an extraction hood; - said feeding step of quicklime and said feeding step of water are performed so as to obtain a water/quicklime ratio comprised between 0.8 and 1.3 by weight, preferably between 0.9 and 1.2; - said process further comprises a step of removing vapor generated during said slaking step, said step of removing vapor being performed over at least 90 % of the length of said slaking zone by means of the extraction hood which extends on a portion of the hydrator length which starts from at least 30% of the length of said hydrator, upstream the slaking direction, until at least 65% of the length of the hydrator, - said process comprises a step of forming a raw highly porous slaked lime being a high BET specific surface area being comprised between 30 m 2 /g and 50 m 2 /g and high BJH pore volume slaked lime composed by the pores with a diameter less than 1000 Angstroms, higher than or equal to 0.15 cm 3 /g. <EOS>