The following data were obtained by Chamber and Sherwood [Ind. Eng. Chem., 29, 1415 (1937)] on the absorption of ammonia from an ammonia-air mixture by a strong acid in a wetted-wall column 0.575 inch in diameter and 32.5 inches long:
Inlet acid (2-N H2SO4) temperature, °F: 76
Outlet acid temperature, °F: 81
Inlet air temperature, °F: 77
Outlet air temperature, °F: 84
Total pressure, atm: 1.00
Partial pressure NH3 in inlet gas, atm: 0.0807
Partial pressure NH3 in outlet gas, atm: 0.0205
Air rate, lbmol/h: 0.260
The operation was countercurrent with gas entering at the bottom of the vertical tower and the acid passing down in a thin film on the vertical, cylindrical inner wall. The change in acid strength was negligible, and the vapor pressure of ammonia over the liquid is negligible because of the use of a strong acid for absorption. Calculate the mass-transfer coefficient, kp, from the data.