Carbon dioxide absorption and desorption in a packed tower using water and solutions of sodium carbonate and of triethanolamine

Abstract

AbstractThe relative efficiencies of water, sodium carbonate solutions (0.025 to 0.4 M), and triethanolamine solutions (0.05 to 1.0 M) for the removal of carbon dioxide from air containing up to 12% of the gas, at 40–50°F., was determined using 12 in. diameter towers packed to a depth of 40 in. with 1‐in. Raschig rings. Coefficients of absorption for sodium carbonate and triethanolamine solutions were 30–60% less than comparable coefficients for water. Desorption coefficients for sodium carbonate and triethanolamine solutions were larger than absorption coefficients under comparable conditions but somewhat less than desorption coefficients for water, except for dilute conditions. Desorption coefficients for dilute solutions (less than 0.15 M) were up to three times as large as those for water. These results indicate that the use of sodium carbonate or triethanolamine solutions instead of water (as frequently used at present) would permit the use of smaller desorption equipment in applications such as scrubber systems for the removal of carbon dioxide from controlled atmosphere storage rooms for fruits and vegetables.Solubility data for carbon dioxide in sodium carbonate and triethanolamine solutions at temperatures and carbon dioxide partial pressures of interest in this study were also determined.