Absorbent for circularly absorbing sulfur dioxide gas in tail gas of natural gas and application of absorbent

The invention discloses an absorbent for circularly absorbing sulfur dioxide gas in tail gas of natural gas and an application of the absorbent. The absorbent comprises the following components in percentage by mass: 30-60wt% of cyclic tertiary amine compounds, 5-10wt% of a desulfurization fortifier, 10-30wt% of a latent solvent, 0.5-3wt% of an activating agent, 1-2wt% of an antioxidant, 0.5-2wt% of a corrosion inhibitor and the balance of water. The application refers to applying the absorbent to removal of the sulfur dioxide gas in the tail gas of the natural gas at an absorption temperature of 20-70 DEG C. According to the invention, by utilizing the structure characteristics of the cyclic tertiary amine compounds which are high in sulfur dioxide absorption capacity and low in desorption energy consumption, and adding corresponding auxiliary agents at the same time, the absorption of absorption liquid to sulfur dioxide has high efficiency and specificity; and the absorbent can selectively remove SO2 from t