Synthesis of Formic Acid from Carbon Dioxide Absorption

Abstract

High temperature and warming are growing environmental issues in Pakistan. The main reason for this is the releases of carbon dioxide from industrial, transportation and various anthropogenic activities. Carbon dioxide is mostly coming from the burning of fossil fuels. It is a greenhouse gas and is a major concern to the environment. Best and economical methods to recover and effectively reuse carbon dioxide is through absorption and adsorption. Absorption can be performed with different chemicals. In this study gas bubble method was used to absorb carbon dioxide in sodium hydroxide solution having variable concentrations (0.01, 0.1, 0.5, 1.0, 3.0 and 5.0N) and the impact of the solution pH on the product formation was developed. The products formed at a different pH of the absorbing solution were sodium carbonate at pH 10, Trona at pH 9 and sodium hydrogen carbonate at pH 8. All products formed were confirmed through XRD (X-ray diffraction) analysis. After optimization, a 3.0 N solution of sodium hydroxide at pH 8 was selected for the sodium formate production. For this sodium hydrogen carbonate at pH 8 was converted into sodium formate through the hydrogenation in the presence of nickel ferrite catalyst at 80oC. Sodium formate was then used to synthesize the formic acid upon simple reaction with sulfuric acid, through vapors condensed which was later analyzed by HPLC (High-performance liquid chromatography). HPLC was used for the qualitative analysis of the synthesized produced. A reaction yield of 79±0.2 % is reported. Formic acid has multiple uses in the leather and textile industry as a hair removing and as a pH regulating agent. This research in this way has shown a way to convert a waste pollutant to a value-added marketable product.