Carbon dioxide conversion into the reaction intermediate sodium formate for the synthesis of formic acid

Abstract

Increased carbon dioxide (CO2) emissions from anthropogenic activities are a contributing factor to the growing global warming worldwide. The economical method to recover and effectively reuse CO2 is through adsorption and absorption. In this study, CO2 is absorbed into the solution of sodium hydroxide having various concentrations (0.01, 0.1, 0.5, 1.0, 3.0 and 5.0 N), and the impact of the solution pH on the various product formation was observed. The resultant products formed at different pH of the absorbing solution are sodium carbonate at pH 10, Trona at pH 9, and sodium hydrogen carbonate at pH 8. The products formed are confirmed through X-ray diffraction analysis. After pH optimization, the sodium hydrogen carbonate formed at pH 8 is converted into sodium formate through hydrogenation in the presence of nickel ferrite catalyst at 80 °C and atmospheric pressure. The sodium formate produced is then used as a precursor to synthesize formic acid upon simple reaction with sulfuric acid. A reaction % age yield of 79 ± 0.2% formic acid is noted. Condensed formic acid vapors are later analyzed, using a high performance liquid chromatography for the qualitative analysis.