CO2 SEPARATION DEVICE OF INTERNAL COMBUSTION ENGINE

To provide a CO2 separation device of an internal combustion engine capable of improving a CO2 recovery rate while securing a high concentration of recovered CO2.SOLUTION: A CO2 separation device of an internal combustion engine comprises: CO2 adsorption devices 6A and 6B having CO2 adsorbents 11A and 11B; a storage tank 9 provided in a first branch passage 4C branching off from the downstream side with respect to the CO2 adsorption device of an exhaust passage 4; and a downstream CO2 adsorbent 11C that is provided in a second branch passage 4D branching off from the upstream side with respect to the storage tank 9 of the first branch passage 4C. During CO2 desorption control, the CO2 separation device switches the flow of exhaust gas on the downstream side of the CO2 adsorption device to the storage tank 9 side. The CO2 separation device switches the flow of the exhaust gas in the first branch passage 4C to the storage tank 9 side when detected CO2 concentrations CCO2A and CCO2B on the downstream side of the CO2 adsorption device are equal to or higher than a predetermined value CREF1, and switches the flow to the downstream CO2 adsorbent 11C side when the CO2 concentrations are lower than the predetermined value (Fig.7).SELECTED DRAWING: Figure 8 【課題】高い回収ＣＯ２濃度を確保しながら、ＣＯ２回収率を高めることができる内燃機関のＣＯ２分離装置を提供する。【解決手段】本発明の内燃機関のＣＯ２分離装置は、ＣＯ２吸着材１１Ａ、１１Ｂを有するＣＯ２吸着装置６Ａ、６Ｂと、排気通路４のＣＯ２吸着装置よりも下流側から分岐する第１分岐通路４Ｃに設けられた貯蔵タンク９と、第１分岐通路４Ｃの貯蔵タンク９よりも上流側から分岐する第２分岐通路４Ｄに設けられた下流ＣＯ２吸着材１１Ｃと、を備え、ＣＯ２脱離制御時に、ＣＯ２吸着装置の下流側における排気ガスの流れを、貯蔵タンク９側に切り替えるとともに、第１分岐通路４Ｃにおける排気ガスの流れを、検出されたＣＯ２吸着装置の下流側のＣＯ２濃度ＣＣＯ２Ａ、ＣＣＯ２Ｂが所定値ＣＲＥＦ１以上のときに貯蔵タンク９側に切り替え、ＣＯ２濃度が所定値よりも小さいときに下流ＣＯ２吸着材１１Ｃ側に切り替える（図７）。【選択図】図８