Process engineering : unit operations

lbirc2109  2021-2022  Louvain-la-Neuve

Process engineering : unit operations
The version you’re consulting is not final. This course description may change. The final version will be published on 1st June.
5 credits
52.5 h + 15.0 h
 Transfer phenoma (for partim A)
Physical chemistry I and II + fuild mecanics (for partim B)
Main themes
Partim A
- Particles in flowing medium
- Study of a flowing liquid through porous media and membranes  
- Mechanical processes for physical separation: sedimentation, decantation, centrifugation, filtration, cycloning, membrane separation
- Drying processes : drying, lyophilisation, atomisation
Partim B
- Diffusion, mass transfer and energy transfer between phases (diffusion theory, mass transfer coefficients, film theory).
- Phase equilibrium
- Fluid/fluid and fluid/solid separation processes involving mass transfer : Distillation, liquid-liquid extraction, absorption, adsorption, crystallization

At the end of this learning unit, the student is able to :

1 a. Contribution of this course to the program's LO
1.1, 1.2
2.1, 2.2, 2.4
4.2, 4.5
7.1, 7.3
b. Specific LO of this course (maximum 10)
At the end of this course, the student will be able to :
- name the main unitary operations of separation and purification used in the industry, give specific definitions of them and sort them into relevant categories. The operations evoked in the course are (Partim A) sedimentation, decantation, centrifugation, filtration, cycloning, membrane separations, drying, lyophilization, atomization (spray drying), supercritical drying and (Partim B) distillation, liquid-liquid extraction, absorption, adsorption, crystallization. 
- name several precise examples of industrial applications for each unitary operation
- describe precisely the working principle of each unitary operation both at the macroscopic scale (in flow, out flow, energy flows) and at the microscopic level (particle, interface, molecule). This description will concern both the physical and chemical phenomena involved and the thermodynamic and kinetic constraints that dictate the separation.
- identify to operating parameters that determine the efficiency of each separation process
- calculate mass and energy balance for discontinuous, semi-continuous and continuous processes and dimensioning the facilities that allow to perform them  
- re-write and interpret the main mathematical developments that lead to the useful equations for process dimensioning and remember at the same time what are all the simplifying hypothesis that must sometimes be used to establish models and dimensioning methods.  
- apply empirical, analytical and graphical methods classically used for unitary operation dimensioning.
- gather information (field visits, literature search, interviews, etc.) on a unitary operation involved in an existing industrial process and elaborate a critical analysis of this step of the process, describing its interactions with previous and subsequent steps, evaluating if its operating conditions are optimal and providing recommendations for improvement (in addition to technical and economic criteria, the standards of 'sustainable development' will also be used as evaluation benchmarks).
Objectives ' instructions ' process engineering and unitary operations : definitions ' main working principles of unitary operations for separation ' the different operating modes ' context ' classification of unitary operations  
Partim A
Separation processes based on mechanical action
Particles in fluids (Context ' Description of a divided solid ' the isolated particle ' a bunch of particles ' Characterization of a bed of particles) / Sedimentation and Centrifugation (Definitions ' Interactions between the fluid and one particle ' flow regimes ' sedimentation rate) / Flows through porous media (the Darcy law ' the Kozeny Carman model ' turbulent flow ' the Ergun relation) / Filtration (Context ' Support filtration ' Coupling the variables ' Humidity ratio ' Cake dimensions ' Resistance to the flow ' Operating modes ' Filtration technologies) / Membrane separation (Description ' Applications ' Diffusion principles ' Materials ' Mass transfer ' Dialysis ' Electrodialysis ' Inverted osmosis ' Gas permeation ' Pervaporation ' Membranes in bioprocesses
Drying processes
Motivation / Definitions and concepts (wet solid ' gaz-liquid-solid equilibrium ' wetting enthalpy ' sorption isotherms ' equilibrium diagrams) / Techniques et set-up (classification ' machines often used in the industry ' drying by ebullition ' drying by flow ' lyophilisation ' drying of bio-products) / Theoretical principles of drying (drying kinetics ' hygrometry ' wet air diagram ' case study: the drying of cereals in a grain silo) / Alternative mode for providing energy / supercritical drying
Partim B
Fluid/fluid separation and fluid/solid separation involving mass transfer
Liquid-gaz equilibrium of binary systems (Reminders ' the Raoult law ' non ideal mixtures ' Influence of pressure ' Systems with more than two species) / Distillation (Basic working principles of distillation' Simple discontinuous distillation(batch)' Continuous distillation(flash distillation)' Fractionated distillation: working principle, Plate colonne, the method of Sorel, the method of Lewis, the method of Mc Cabe & Thiele, Study of the column with the equilibrium diagram, vapor injection, the method of Ponchon& Savarit, Study of the columns with the enthalpy diagram, Rectification of azeotropic mixtures, Rectification mixtures with more than two species, Column efficiency) / Liquid-liquid extraction (Reminders on ternary diagrams ' Extraction in one contact stage ' Extraction with multiple contact stages ' Countercurrent extraction with separate contact stages ' Countercurrent extraction with uninterrupted contact ' Countercurrent extraction with reflux) / Gas absorption by liquids (Equilibrium condition ' Graphical representation ' Number theoretical stages ' Continuous transfer ' Absorption of several species ' Absorption with chemical reaction) / Adsorption (Adsorption on a solid ' Adsorption equilibrium for a pure gas 'Adsorption equilibrium for a gaseous binary mixture ' Adsorption equilibrium for a liquid binary mixture - Adsorption separated stages ' Adsorption in fixed bed) / Crystallization (Definitions ' the crystalline state ' Solubility curves ' Sursaturation curves ' Basic principles of crystallization in solution ' Crystallization processes ' Purity and morphology of crystals
Teaching methods
Lecture with a powerpoint presentation as the main support (available via iCampus). Even if the slides are used as a support for the lectures, an important part of the course is given orally and on the blackboard (e.g. explanations, examples, mathematic developments, etc.).
Quantitative exercises of dimensioning with a tutor.
Scientific articles are recommended for reading as a complement to the course.   
Students may be instructed to visit a company of their choice and to study a unitary operation involved in the production process. A short, didactical and critical report is asked, in the form of a poster. The report is presented to other students.
Owing to the limited capacity of the class rooms, related to the restrictions of the COVID-19 crisis, some lecture may be given remotely (Teams).
Evaluation methods
Written exam systematically covering the LO (theory and exercises).
The written report concerning the field study in the industry weight 20% of the final grade.
Other information
This course can be given in English.
Online resources
- slides posted at the beginning of the semester
- list of exercices
- remainders for mathematical formula
- instructions for the plants visit
Aucun support payant n'est obligatoire.
Une impression des diapositives (powerpoint) utilisées au cours et préalablement mises à disposition sur Moodle est vivement recommandée.
Comme supports de cours facultatifs et disponibles en bibliothèque :
- Introduction au génie des procédés de D. Ronze (Editions Tec et Doc, 2008), ISBN : 978-2-7430-1066-9
- Separation process principles de E.J. Henley, J.D. Seader, D.K. Roper (Wiley, 2011) ISBN : 978-0-470-64611-3
- Le pétrole - Rafinage et genie chimique I de P. Wuithier (Editions Technip, 1972) ISBN : 2-7108-0198-1
- Procédés de séparation de J.P. Wauquier ((Editions Technip, 1998) ISBN : 2-7108-0671-1
Teaching materials
  • Slides (via Moodle)
Faculty or entity

Programmes / formations proposant cette unité d'enseignement (UE)

Title of the programme
Master [120] in Environmental Bioengineering

Master [120] in Chemistry and Bioindustries