Quiz Block 1 Flashcards
Give an example of a filter aid normally used in industry
Diatomaceous earth or perlite
In protein purification, what is the “salting out” process used for?
To precipitate the protein. The salt is added to decrease the solubility of protein submerged in liquid
What are the three different downstream steps in which unit operations are divided into?
Separation of biomass
Concentration of product
Purification
(for enzymes & proteins a formulation step is added)
What is chromatography used for?
Product purification and is normally used for expensive products
Which extra steps require the recovery of intracellular product as compared to extracellular in DSP?
Disruption of membrane
Extraction
Removal of cells and debris
The yield of product obtained by fermentation usually increases/decreases with increasing number of DP steps and increases/decreases as purity decreases
decreases - increases
Mention two enzymes of industrial interest and their application
Amylase - used for bread production
Pectinase - used for juice
In context of Process Design, Process Analysis usually comes before/after Process Synthesis?
after
True or False: During process design, it is usually recommended to make the most difficult separations first, sp the easiest- and more expensive purification steps come later
FALSE - Easier, Less expensive steps should come first to remove larger particle impurities
Name one (or more) disadvantage of centrifugation compared to filtration for removal of cells
Sterile operation is harder to use
Centrifugation is more energy intensive
Less safe on large-scale
What is the driving force in a liquid-liquid extraction process and distillation?
For LLE: Affinity for solute
For Distillation: Boiling points
How is the angular velocity of a rotor calculated to obtain units (s^(-1))?
angular velocity = omega * (2*pi/60)
Explain why distillation becomes expensive when water is present in the solution?
Water binds well and has a higher boiling point. Distillation becomes more energy intensive, making it more expensive
State the main advantage of using enzymes in detergent industry?
It is possible to clean clothes efficiently at a decreased temperature
What kind of chemical is an antibody?
An antibody is a protein
Write the equation used for the design of a centrfuge with units
Q [m^3/s]= Sigma [m^2] * Ug [m/s]
Flow rate/ Flux volumetric flow = Geometry of centrifuge * Characteristic velocity of solute
Name one microorganism commonly used to produce enzymes industrially
E.Coli
Asperigillus
Bacillus
What does the formulation step consist of during production of enzymes?
The formulation step for the stabilization of the product
UltraFiltration/DiaFiltration can be used for purification of lipids/proteins while ReverseOsmosis/Ultrafiltration can be used for removal of minerals/acids in a stream
Ultrafiltration - proteins
Reverse Osmosis - minerals and salts
Cross-flow/dead-end is the industrial operation mode usually preferred for membrane filtration, because x
Cross flow operation mode - because fouling is decreased. The pharmaceutical industry uses dead-end
Name the two typical unit operations that are used for biomass removal
Filtration
Centrifugation
True or False: Rotary vacuum filters may operate continuously for long periods of time
True
The feed stream of a centrifuge is (100 m^3/h) contains 10% cells. Calculate yield of supernatant if 45 m^3/h of liquid is present in the pellet (no cells in supernatant).
Feed = 100m^3/h and cells = 0.1100=10m^3/h so liquid = 90m^3/h. In supernatant liquid = 45 m^3/h since In pellet liquid = 45 m^3/h. Knowing yield = liquid in SUPERNATANT/ liquid in FEED meaning that yield = (45 m^3/h) / (90 m^3/h) = 0.5100 = 50%
In which units do you normally express the productivity of a certain product in a fermenter?
g/L*h (concentration (g/L) per time unit (h))
In the solution-diffusion equation, the flux of solvent is directly/inversely proportional to the osmotic pressure, and directly/inversely proportional to the applied pressure
Inversely proportional to osmotic pressure
Directly proportional to applied pressure
Divide related terms into two groups:
Centrifugation - Filter Aid - Stokes equation - Tubular bowl - Filtration - Angular velocity
Filtration, Filter Aid
Centrifugation, Tubular bowl, Stokes Equation, Angular velocity
Name the two types of membrane modules which are most used in industry and explain
Spiral
Hollow fibre: Possible to compress a large volume of membranes
What is concentration polarisation in the context of membrane technology?
Concentration gradient in feed solution
True or False: In Process Design, it is always preferable to use consecutive unit operations that use different driving forces.
True
In order to solubilize a protein, one should work far/near its isoelectric point
Far
