A system and System for removing CO2 from an input gas stream. The system comprises a carboniser segment configured such that a solid sorbent reacts therein with the input gas stream to remove CO2 from the input gas stream; a calciner segment configured such that the solid sorbent from the carboniser segment reacts therein to release the CO2 into a substantially pure gas stream; a heat exchanger unit for exchanging heat between the carboniser and calciner segments; a first conditioning unit for controlling a CO2 partial pressure in the carboniser segment; and a second conditioning unit for controlling a CO2 partial pressure in the calciner segment; wherein the first and second conditioning units are configured such that a difference between the CO2 partial pressures in the carboniser and calciner segments respectively is controlled such that heat is provided from the carboniser to the calciner through the heat exchanging unit.