Dynamic breakthrough curves of CO2 capture using hierarchically porous MOFs at different gas flow rates

https://doi.org/10.3390/ma15155292

“Moreover, in practical operations, gas separations are always conducted under a dynamic gas flow condition, in which the diffusions of gases within the adsorbents can impede the overall performance [14]. Hence, we conducted breakthrough measurements to test the separation ability of these two adsorbents under a dynamic flow condition. As displayed in Figure 4a–d, the breakthrough measurements for CuBTC-Water and CuBTC-DMF were conducted using a CO₂/N₂ gas mixture (20/20, v/v) under various gas flow rates at 298 K and 1 bar. The results show that CuBTC-Water demonstrated a much earlier breakthrough for N₂ and a similar CO₂ breakthrough time compared to CuBTC-DMF at the slow gas flow rate of 10 sccm (Figure 4a). At different gas flow rates, the hierarchically porous CuBTC-Water displayed an earlier nitrogen gas breakthrough and a greater amount of carbon dioxide adsorption than CuBTC-DMF.”

“Figure 4. The dynamic breakthrough curves of CuBTC-DMF and CuBTC-Water for the CO₂/N₂ mixture (The feed gas for the breakthrough measurement and chromatographic separation was composed of 20% CO₂, 20% N₂ and 60% He.) at room temperature with different mass flow rates of (a) 10 sccm, (b) 20 sccm, (c) 50 sccm and (d) 100 sccm.”