Functionalized ionic liquid CO2 absorbent capable of realizing low-temperature self-extraction regeneration and application of functionalized ionic liquid CO2 absorbent

The embodiment of the invention discloses a low-temperature self-extraction regenerated functionalized ionic liquid CO2 absorbent and application thereof. The absorbent comprises functionalized ionic liquid di-n-butylamine imidazole ([DBAH] [Im]) as a main absorbent and a solvent. The main absorbent is the functionalized ionic liquid, and the anion and cation of the absorbent have group interaction, so that the absorption product has lower desorption free energy, low-temperature regeneration is realized, and the energy consumption is reduced. Meanwhile, the embodiment also has a self-extraction characteristic, namely in the regeneration process, the desorbed ionic liquid is collected at the top of the solution to form a layer of organic phase, and the organic phase is used as a self-extraction agent to extract the subsequently regenerated ionic liquid in the water phase. Due to the self-extraction effect of the functionalized ionic liquid in the desorption process, the absorbent can be rapidly separated from