Process Technology	Functional Role
Separators: a) Batch distillation b) Continuous distillation c) Absorption d) Stripping e) Liquid-liquid extraction f) Leaching g) Crystallization h) Drying i) Flash separator j) Membrane separator k) Packed bed contactor	- Most important process technology - Provides desired separation between phases and streams - Located next to the reactor as 100 % conversions are very rare in industrial practice
a) Batch distillation column	- Used to separate a liquid mixture based on relative volatility (differences in boiling points) - Operated in batch mode
b) Continuous distillation (Fractionator)	- The most important separation technology in process flow sheets - Provides very pure products - Differences in boiling points is the working principle - Energy intensive operation - Usually multi-component distillation is apparent in industrial practice

c) Absorption column

- Used to absorb components from gaseous stream
- Solvent is used
- Usually followed with stripper to re-generate the fresh solvent
- Operated at low temperature and moderate/high pressure

d) Stripper

- Steam/Hot gas is used to strip the gas
- Regenerated solvent used for absorption

e) Liquid Liquid extraction

- Used to separate components from a liquid with a liquid solvent
- Consists of a series of mixers and separators
- Produces extract (rich with solvent and components extracted) and raffinate (product with lean extractants)

f) Leaching

- A liquid solvent extracts components from a solid
- High interfacial area between solid/liquid is required to enhance extraction capability

g) Crystallization

- Used to crystallize solids from a slurry/super-saturated solution

- Fine crystals added to serve as nucleating agent

h) Spray drier

- Liquid slurry is sprayed in the form of droplets

- Hot gas (air) dries the solid

- Enables very good control over the product particle size

i) Rotary drier	- Through rotation, an agitated liquid film is dried to obtain the dried solid.
j) Flash separator	- Very common technology to separate liquid streams at high pressure and lower temperatures. - Upon pressure reduction/heating, low boiling components separate as vapor phase and yield a liquid phase. - Complete separation only possible for fewer components
k) Membrane separation	- A semi-permeable barrier (membrane) is used to separate feed streams based on concentration difference/pressure difference. - Various types of processes available - New technology in process industries.
l) Packed bed contactor	- Used for absorption/stripping operations - Packing serves to enhance gas/liquid interfacial area