Carbon dioxide capturing system and method of operating the same

A carbon dioxide capturing system comprising:

• an absorber configured to absorb carbon dioxide from first gas into lean liquid, and configured to produce rich liquid that is the lean liquid absorbing the carbon dioxide and second gas that is the first gas removing the carbon dioxide;
• a regenerator configured to separate third gas including the carbon dioxide from the rich liquid flowing from the absorber, and configured to provide the lean liquid and the third gas;
• a flowmeter configured to measure a flow rate of the third gas;
• a liquid level gauge configured to measure a liquid level of at least one of the lean liquid and the rich liquid;
• and
• a controller configured to regulate a quantity of heat energy supplied to the regenerator based on the flow rate of the third gas, and configured to regulate a total amount of the lean liquid and the rich liquid in the carbon dioxide capturing system based on the liquid level.