The rate of transfer of hydrogen sulfide and of carbon dioxide from an atmosphere of the gas saturated with water to a flowing stream of water in a horizontal channel was investigated over a range of water flow velocities and absolute pressures.
Mathematical models describing the system in terms of the penetration and boundary layer theories were inadequate when used to calculate the diffusivity of each gas in water at various conditions. The results of the hydrogen sulfide-water system study shows a relationship between the diffusivity, the interfacial concentration and the liquid flow rate. The calculated diffusivity of the carbon dioxide-water system is independent of liquid velocity, but can be correlated as a function of pressure above one atmosphere. The diffusivity-flow rate relationship may be due to the presence of an interfacial resistance which prevents the liquid surface from becoming saturated with gas.
If the diffusivity is assumed constant, the interfacial concentration of the hydrogen sulfide-water system at 25.20C and 1.23 atmospheres can be expressed by the following functional relationship.
Ci = F (VL) = f (CL)= 23.0 (CL) 0.455
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