Carbon dioxide recovery system

A carbon dioxide recovery system for separating and recovering CO2 from a supply gas containing CO2 and non-CO2 gas other than CO2, the carbon dioxide recovery system comprising:

• an adsorber configured to adsorb or desorb CO2;
• a supply channel through which the supply gas passes;
• a storage tank configured to store CO2 desorbed from the adsorber;
• a gas supply device configured to supply CO2 stored in the storage section to the adsorber;
• a throttle valve provided in the supply channel;
• and
• a controller configured to switch an operation mode, among an adsorption mode in which the adsorber adsorbs CO2 contained in the supply gas supplied through the supply channel, a desorption mode in which CO2 adsorbed by the adsorber is desorbed and the storage tank stores therein the desorbed CO2 desorbed from the adsorber, and a desorption preparation mode in which the gas supply device supplies CO2 stored in the storage tank to the adsorber during a period from an end of the adsorption mode to a start of the desorption mode, wherein during the desorption preparation mode, the throttle valve has a smaller opening degree than an opening degree in the adsorption mode, wherein
• the controller controls the gas supply device to switch the desorption mode from the desorption preparation mode, in response to a result in which the controller determines that a predetermined condition is satisfied, and
• the throttle valve is located downstream of the adsorber in a flow direction of the gas when CO2 stored in the storage section is supplied to the adsorber in the desorption preparation mode.