Method and system for removing carbon dioxide from reaction gas, and use thereof

A method for removing carbon dioxide from a reaction gas, comprising:

• S1. performing a heating treatment on a reaction gas from which carbon dioxide is to be removed by heat exchanging the reaction gas with a washing water and a regeneration gas;
• and the step S1 comprises the following steps:
• 1A. dividing the reaction gas from which carbon dioxide is to be removed into a gas stream I and a gas stream II;
• 1B. heating the gas stream I by heat exchanging with a regeneration gas exiting from the top of a regeneration tower to obtain a gas stream Ia;
• 1C. heating the gas stream II by heat exchanging with the washing water to obtain a gas stream IIa;
• and
• 1D. mixing the gas stream Ia with the gas stream IIa to obtain the gas stream III;
• S2. performing a decarbonizing treatment on the gas stream III obtained in step S1 by using a decarburizing solution to obtain a gas stream IV;
• and
• S3. cooling the gas stream IV to obtain a CO2-removed purified gas,
• wherein the washing water is first cooled by a cooling device, then exchanges heat with the gas stream IV, subsequently exchanges heat with the decarburizing solution, finally exchanges heat with the reaction gas from which carbon dioxide is to be removed, and after that returns to the cooling device for cooling circulation.