| Description |
157 pages. |
| Summary |
"The performance of a continuous countercurrent extraction column with a packing -- that could be vibrated vertically at various amplitudes and frequencies by a variable speed motor -- was investigated under both non-flooding and flooding conditions using the high interfacial tension benzene-acetic acid-water ternary system. In all the experimental runs, which were sequenced randomly with a full-factorial experiment design, mass transfer of the solute (acetic acid) from the aqueous to the organic phase was studied. Column performance was evaluated in terms of the height of an overall transfer unit, HTU, based on the benzene phase. The variables studied were: amplitude of packing displacement, A, frequency of reciprocation, F, and combined stream throughput, G, at a 2:1 ratio of benzene to water flow rates. An increase in amplitude and/or frequency improved the performance of the column; an increase in total throughput caused poorer performance. With the benzene dispersed, HTU values decreased from 2 feet at no reciprocation to 0.5 foot at 3/16-inch amplitude and 750 cycles per minute frequency. With the aqueous phase dispersed, HTU values decreased from 2.5 feet at no reciprocation to 0.5 foot at 3/16-inch amplitude and 750 cycles per minute frequency. With the aqueous Phase dispersed, the flooding rates were observed to decrease with an increase in energy input from 12.800 to 10.800 pounds per hour per square root; however, with the benzene dispersed, a flooding rate of 10,250 pounds per hour per square foot was observed for all combinations of amplitude and frequency. Several attempts were made to correlate the column performance; the following correlation was recommended: H/HTU = [alpha]₁ + [alpha]₂(AF/G), where, with the benzene dispersed, [alpha]₁ = 0.985, [alpha]₂ = 0.328 and the average absolute percent deviation was 10.7, and with the aqueous phase dispersed [alpha]₁ = 0.784, [alpha]₂ = 0.374 and the average absolute percent deviation was 14.3. The experimental column showed a performance equivalent to or better than other columns using the benzene-acetic acid-water system reported in the literature"--Abstract, leaves ii-iii. |
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