Electrochemical Acid-Catalyzed Desorption and Regeneration of MDEA CO2‑Rich Liquid by Hydroquinone Derivatives (Tiron)

The acid-catalyzed desorption of the MDEA CO2-rich liquid under the electrochemical reaction can lower the desorption temperature, thereby reducing the energy consumption for regeneration. In this work, disodium 4,5-dihydroxy-1,3-benzenedisulfonate (tiron) was used as an acidic medium for the electrocatalytic regeneration of the MDEA CO2-rich solution. The results show that the CO2 desorption efficiency reaches more than 90% at 25 °C for the 0.3 M MDEA (0.1 M tiron) system. At 50 °C, compared with 3 M MDEA (without tiron), the maximum CO2 desorption rate and desorption efficiency of the 3 M MDEA (with 0.1 M tiron) CO2-rich solution increased by 27.4 and 18.3%, respectively. Elevating the temperature can increase the quantity of CO2 desorption and the degree of MDEAH+ deprotonation as well as the reactivity of tiron on the electrode, so the desorption rate of CO2 can be further improved by the oxidation of tiron releasing H+ in coordination with thermal desorption.