CO2 capture from the atmosphere (air capture) may play an important role in reduction of CO2 concentration in the atmosphere and offer a route to make carbon-neutral liquid hydrocarbon fuels for vehicles and aircrafts by converting CO2 to the synthetic fuels. In the present study, CO2 capture from the atmosphere using developed polyethylenimine (PEI) sorbents supported on nano pore-materials, including SBA-15 and silica gel, with 50 wt % PEI loading (PEI50/SBA-15 and PEI50/SG) was explored. Effects of the sorption temperature and sorption space velocity as well as regenerability of the sorbents were examined. It was found that both PEI50/SBA-15 and PEI50/SG sorbents were able to capture CO2 from the real air with the CO2 concentration of 400 ppmv. Interestingly, both sorbents showed a higher sorption capacity at the room temperature (25 °C, 83-85 mg-CO2/g-sorbent) than that at higher temperature (75 °C, 32-34 mg-CO2/g-sorbent) for CO2 capture from the real air, which is different from the CO2 capture from the flue gas with CO2 concentration around 14 v % reported in our previous study. The gas hourly space velocity (GHSV) in sorption had almost no effect on the sorption capacity when the GHSV increased from 1880 to 7500 h-1. The saturated at 90 °C without loss in the capacity. The results indicate that PEI50/SBA-15 and PEI50/SG is promising sorbents for CO2 capture from the atmosphere.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)