Plant performance of a 13‐ft.‐diameter extractive‐distillation column

Abstract

AbstractPlant performance data are presented for a 13‐ft.‐diam., 100‐tray furfural extractive‐distillation column separating iso‐ and n‐butane from 1‐ and 2‐butene. In addition to composition, temperature, pressure, and flow rate of the external streams, values are presented for vapor and liquid compositions and flow rates at a number of different locations within the tower. With the exception of the vapor compositions, which were determined experimentally, the internal conditions were determined by heat and material balances. These data permitted calculation of plate efficiency over various small sections of the column. In the 50‐tray rectifying section, plate efficiency for the isobutane—1‐butene separation was constant at 20%, and in the stripping section the plate efficiency varied from 25 to 45%. The average for the entire column was 25%.The furfural‐column plate efficiencies compare favorably with those predicted from laboratory tests made before the construction of the column to evaluate the performance of the tray design to be employed. The laboratory plate efficiencies were obtained for the desorption of oxygen from oxygen‐rich water with air at the same conditions of volumetric gas and liquid rates to be encountered in the furfural column. When these values were suitably corrected for physical property differences between the two systems, the point efficiencies predicted from the laboratory data for the furfural column ranged from 35% near the top of the column to 25% near the bottom of the column, the average value being 29%.