Carbon dioxide removal system

A carbon dioxide removal system, comprising:

• a treatment target gas acquisition unit that acquires a treatment target gas from a target space;
• a flow path that allows the acquired treatment target gas to flow through the flow path;
• a first treatment unit that includes two or more adsorption towers connected in series in the flow path along a flow of the treatment target gas;
• a second treatment unit that includes two or more adsorption towers connected in series in the flow path along a flow of the treatment target gas, and is disposed in parallel to the first treatment unit;
• and
• a control device that switches between paths of the treatment target gas, wherein
• the flow path includes:
• a first main path that supplies the treatment target gas to the first treatment unit;
• a second main path that is disposed in parallel to the first main path, and supplies the treatment target gas to the second treatment unit;
• a first recovery path that discharges, to the target space, the treatment target gas passed through the first main path and the second main path;
• a desorption path that is connected to the adsorption towers to be depressurized;
• a first branch path that connects a path between the adsorption tower on an upstream side of the first treatment unit and the adsorption tower on a downstream side of the first treatment unit to the first recovery path;
• and
• a switching mechanism that switches a path through which the treatment target gas flows, and
• the control device controls the switching mechanism disposed in the flow path, and is configured to switch between a mode of flowing the treatment target gas through all the adsorption towers of the first treatment unit and a mode of flowing the treatment target gas through the first branch path to allow the treatment target gas to flow through the adsorption tower disposed on the upstream side of the first treatment unit and not to allow the treatment target gas to flow through the adsorption tower disposed on the downstream side of the first treatment unit.