Mechanism study on CO 2 capture by [TETAH][HCOO]-PEG200 mixed system

CO2 is a greenhouse gas that contributes a lot to the global warming. Ionic liquid is a kind of green solvent that shows great potential in CO2 capture. The functionalized ionic liquid [TETAH][HCOO] was synthesized in this study, and CO2 absorption performance by the mixture system made up from [TETAH][HCOO] and polyethylene glycol 200 (PEG200) was investigated. Results showed that there was a significant synergistic effect between [TETAH][HCOO] and PEG200 on CO2 capture. PEG200 not only helped to increase CO2 absorption capacity, but also shortened the absorbing time. When the mass concentration of ionic liquid was 20 % and the temperature was 25 degrees C, CO2 absorption capacity in [TETAH][HCOO]-PEG200 system reached 1.340 mol CO2/mol IL, and its absorption rate was up to 12.768 mmol CO2/(mol IL.min). CO2 absorption in [TETAH][HCOO]-PEG200 system was mainly concentrated in the first 30 min, and CO2 absorption capacity accounted for about 80 % of the total during this period. The effects of temperature and PEG200 concentration on viscosity of [TETAH][HCOO]PEG200 were investigated, which indicated that the effect of temperature on viscosity was greater than that of PEG200. Regeneration performance of [TETAH][HCOO]-PEG200 showed that the fifth CO2 absorption still retained 70.10 % of the original performance.