Mass transfer and kinetics in spray-tower-loop absorbers and reactors

In this work we have studied the kinetic and mass-transfer behavior of spra y-tower-loop absorbers and reactors. For this purpose, we have investigated mass-transfer rates in the physical absorption of CO2 in water and the eff ect on mass transfer of respectively a moderately fast reaction, such as th e ethoxylation of nonylphenol or fatty alcohol, and an extremely fast react ion, such as the one between CO2 and an aqueous NaOH solution. Spray nozzle s used have been geometrically and fluid-dynamically characterized. Experim ental results have been interpreted by considering the drops to be internal ly stagnant or well-mixed. We have shown that an internally well-mixed drop s model is more reliable. Moderately fast reactions, such as ethoxylation, (Hatta number of about 1) do not affect mass transfer, while extremely fast reactions require the introduction of an enhancement factor. We have propo sed a semiempirical correlation for calculating this factor. Our work could be useful for modeling and simulating spray-tower-loop absorbers and react ors.