Diffusion and convection of species between phases.
Mass transfer is the movement of species by diffusion and convection: flux N=k_c(C_s-C_∞); overall coefficients from two-film theory 1/K=1/k_G+H/k_L. Correlations with Sherwood number Sh=f(Re,Sc). Governs absorption, extraction, drying, membranes and heterogeneous reactions.
Oxygen transfer rate limits growth in aerobic fermenters.
Mass transfer limits many chemical processes, so knowing when it controls the rate prevents a poorly designed reactor or column.
Diffusion and convection of species between phases.
Mass transfer limits many chemical processes, so knowing when it controls the rate prevents a poorly designed reactor or column.
A number that relates the mass flux to the concentration difference across the boundary, and it depends on flow and geometry.
When transport to or from the reaction surface is slower than the reaction itself, so faster mixing or more area raises the overall rate.
Typical applications include estimating the rate of gas absorption into a liquid in a packed column, checking whether mixing is limiting a gas-liquid reaction and designing a membrane contactor for oxygen transfer in a bioreactor.
Study "Residence time distribution" first (topic 87 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
Fick's law. Two-film model. Analogy with heat transfer.
Oxygen transfer rate limits growth in aerobic fermenters.
The next topic is "Fluid handling in plants", which builds directly on this one.
It is classed as Advanced in Materials & Chemical (topic 88 of 100). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Materials & Chemical.
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