M.S.

This investigation dealt with the determination of the operating characteristics of an 18 stoneware absorption tower twenty-one feet high, fifteen feet of which were random packed with 1 ½ to 2 inch coke. The tower was located in the Unit Operation Laboratory of the Department of Chemical Engineering, Virginia Polytechnic Institute, Blacksburg, Virginia. Forty-five experiments, using carbon dioxide, in a flue gas mixture, as the solute and water as the solvent, were made to determine and to relate the overall liquid-film coefficient of absorption (K_La, lb.mols/(hr)(cu.ft.)(unit cone. diff.)) to the solvent rate (L, lb.mols/(hr)(sq.ft.)) and the partial pressure (p. mm. of Hg) of the inlet carbon dioxide. The following relations were developed: At a constant gas rate of 12.7 lb.mols/(hr.)(ft.²) log K_La = 0.793 log L + (0.000124L-0.00168)p-4.27 At a constant gas rate of 2.0 lb.mols/(hr.)(ft.²) log K_La = 0.816 log L + 10^{(0.63 logL-3.71)}p-4.08 K_La = [1357x10^-8 + (1.942 x 10^-8)p] L^{1.053p^0.0478} The accuracies of the above equations when applied to the data of this investigation are 7.5% 7.7% and 9.6% respectively within the following ranges of conditions: Solvent rate—66.1 to 400.0 lb.mols water/(hr.)(ft.²) Partial pressure of CO₂ in inlet gas—16.3 to 78.3 mm. of Hg Temperature of inlet absorbing water—54.5 to 59.9°F. Temperature of inlet gas—62.0 to 86.0°F. Room temperature—72.5 to 90.5°F. Barometric pressure—710.0 to 716.5 mm. of Hg It was found that at a solvent rate of 100 lb.mols/(hr.)(ft.²), and 84.3% reduction of the gas rate reduced the value of the overall liquid-film coefficient of absorption by an average of 20% and the pressure drop across the packed section of the tower 88.6% Results of this investigation indicated that the pressure drop across the tower increases slightly with an increase in solvent rate, but no correlation was found between the pressure drop and the overall liquid-film coefficient of absorption. / M.S.