An investigation on the effects of organic additives on CO2 capture performance of Na2CO3 solution

BACKGROUND The large-scale practical application of CO 2 capture using carbonate solutions is mainly limited by their low CO 2 absorption rate. In view of this, it is feasible to improve CO 2 capture performance of carbonate solution by adding additives. In this paper, low-cost sodium carbonate (Na 2 CO 3 ) solution was selected as the main CO 2 absorbent, and the effects of different organic additives on CO 2 capture performance of Na 2 CO 3 solutions were systematically investigated. RESULTS The results showed that 0.04 mol/L tetrabutylammonium bromide (TBAB) could achieve a better enhancement effect on CO 2 capture performance of Na 2 CO 3 solution. After addition of TBAB, the maximum CO 2 absorption rate of Na 2 CO 3 solution was improved to 2.52 × 10 −3 mol/min, which increased by 105%. And the maximum CO 2 desorption rate could also be improved by 45%. TBAB/Na 2 CO 3 system not only realized a high CO 2 absorption capacity of 0.769 mol/mol, but also maintained 82% of the initial CO 2 absorption capacity after three cyclic tests. The regeneration heat duty of TBAB/Na 2 CO 3 solution was calculated to be 1136.6 kJ/mol, which was significantly lower than that of single Na 2 CO 3 solution and conventional MEA aqueous solution. The promotion mechanism of TBAB in Na 2 CO 3 solution was explored using Fourier transform infrared spectra (FTIR) and 13 C nuclear magnetic resonance (NMR) analysis. CONCLUSION The introduction of TBAB additive could significantly improve CO 2 capture performance of Na 2 CO 3 solution and reduce regeneration heat duty, making it a possible option in the field of post-combustion CO 2 capture. © 2023 Society of Chemical Industry (SCI).