Mass Transfer
Mass transfer for chemical engineers, set in a fuel ethanol plant: concentrations and fluxes, Fick's law and diffusion coefficients, steady and unsteady diffusion in gases, liquids and solids, mass transfer coefficients and their correlations with the heat-mass transfer analogy, interphase transfer and overall coefficients, the design of packed absorbers and their hydraulics, humidification and cooling towers, drying, and absorption with chemical reaction, ending with the design of a fermentation vent scrubber.
CHE-314 Year 3 3 credits 12 lessons · 4 h 40 min ▶ Video lessons coming soon
Offered by HSM University · Chemical Engineering
This is the Canadian version of this course. See the American version.
What you'll learn
- Describe the mass transfer operations in a process plant, convert between concentrations, fractions, mole ratios and ppmv, and write fluxes as a coefficient times a driving force.
- Apply Fick's law and estimate gas and liquid diffusion coefficients with the Fuller and Wilke-Chang methods, correcting them for temperature and pressure.
- Solve steady diffusion problems for equimolar counterdiffusion, diffusion through a stagnant gas, pseudo-steady evaporation and diffusion with a first-order reaction.
- Calculate effective, Knudsen and polymer diffusion, and solve unsteady diffusion with the erfc and one-term series solutions borrowed from transient conduction.
- Convert between forms of the mass transfer coefficient, compare film, penetration and surface renewal theories, and measure and use kLa for oxygen transfer.
- Estimate mass transfer coefficients from Sherwood number correlations for plates, spheres, tubes and packed beds, and from heat transfer data with the Chilton-Colburn analogy.
- Use Henry's law and modified Raoult's law equilibrium, the two-film model and overall coefficients to find interface compositions and the controlling resistance.
- Design a dilute countercurrent packed absorber with material balances, operating lines, the minimum liquid rate, absorption factors and the transfer-unit method.
- Select packings and size packed columns for flooding, pressure drop, wetting rate and liquid distribution.
- Calculate humid air properties and wet-bulb temperatures, and evaluate cooling tower performance and water losses with the Merkel equation.
- Perform drying material balances, interpret drying rate curves and estimate drying times through the constant-rate and falling-rate periods.
- Analyse absorption with chemical reaction using the Hatta number and enhancement factor, apply the Thiele modulus to catalyst pellets, and assemble a reviewed scrubber design for an air permit.
Course content
12 lessons · 4 h 40 min total · final exam
- 1 Mass transfer in chemical engineering 26 min · quiz
- 2 Molecular diffusion and Fick's law 23 min · quiz
- 3 Steady diffusion in gases and liquids 24 min · quiz
- 4 Diffusion in solids, porous media and unsteady diffusion 24 min · quiz
- 5 Convective mass transfer and mass transfer coefficients 24 min · quiz
- 6 Mass transfer correlations and the heat-mass transfer analogy 23 min · quiz
- 7 Interphase mass transfer and overall coefficients 23 min · quiz
- 8 Gas absorption in packed towers 22 min · quiz
- 9 Packed column hydraulics: flooding, pressure drop and wetting 21 min · quiz
- 10 Humidification and water cooling 23 min · quiz
- 11 Drying of solids 23 min · quiz
- 12 Mass transfer with chemical reaction and the scrubber design 24 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
Mass transfer for chemical engineers, set in a fuel ethanol plant: concentrations and fluxes, Fick's law and diffusion coefficients, steady and unsteady diffusion in gases, liquids and solids, mass transfer coefficients and their correlations with the heat-mass transfer analogy, interphase transfer and overall coefficients, the design of packed absorbers and their hydraulics, humidification and cooling towers, drying, and absorption with chemical reaction, ending with the design of a fermentation vent scrubber.
Part of the Engineering stream, typically taken in year 3.