A population balance model for mass transfer in lean liquid—liquid dispersions

✍ Scribed by B.H. Shah; D. Ramkrishna

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 864 KB
• Volume: 28
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(73)80038-7

✦ Synopsis

A population balance model is considered for the description of mass transfer in liquidliquid dispersions in a mechanically agitated vessel operated continuously. The dispersions considered are of low dispersed phase fraction in which coalescence processes may be assumed to be negligible. The model incorporates the dynamic nature of breakage processes among the droplet population together with mass transfer processes at the droplet level into the analysis which is accomplished by the use of a trivariate number density using size, concentration of diffusing solute and age of the droplets. Mass transfer in single drops is assumed to be by diffusion. Droplet breakage is assumed to be binary and even. The results of the model are compared with predictions made from an alternative approach (reflective of methods used in the past) which ignores the fact that droplet size distributions are attained in time. Several interesting deviations are predicted in the concentration distributions for drops of definite sizes and in the overall mass transfer rates. It is concluded that the dynamics of droplet phenomena may play an important role in the analysis of mass transfer in dispersions.