Carbon Dioxide Fixation via the Synthesis of Sodium Ethyl Carbonate in NaOH-Dissolved Ethanol

Abstract

A CO2-fixing material, sodium ethyl carbonate (SEC), is systematically synthesized via the carbonation of NaOH-dissolved ethanol. The synthesis is conducted by injecting 33.3 vol % CO2 gas into the solution with a concentration of 1–4 g of NaOH/0.5 L of ethanol. The SEC composition is 97.3 wt %, and NaHCO3 is present in only minor amounts. When the synthesized SEC is dissolved in excess water, it is converted to a NaHCO3 precipitate, which can still fix CO2, and ethanol is reproduced in aqueous solution. Therefore, the SEC synthesis and ethanol regeneration process might be an effective means of carbon capture storage/utilization. In addition, SEC thermally decomposes to Na2CO3, CO2, and diethyl ether at 137 °C in an N2 atmosphere and slowly decomposes to Na2CO3·3NaHCO3 with a relatively small release of ethanol and 20% of CO2 fixed in SEC under atmospheric conditions. Furthermore, the main X-ray diffraction peaks of SEC are herein reported.