Principles of distillation Flashcards
What is an interface?
A separation of phases
Why do we want a smaller interface?
Less resistance to mass transfer
What is Boyle’s law for an ideal gas?
pV = c p = pressure V = volume c = constant
What is Charles’ law for an ideal gas?
V / T = c
V = volume
T = temperature
c = constant
What is Avogadro’s law for an ideal gas?
V = c n V = volume c = constant n = moles
What is the ideal gas law?
pV = nRT
p = pressure V = volume n = moles R = Avogadro's constant T = temperature
What is Dalton’s law for an ideal gas?
pT = p1 + p2 + … = (n1 + n2 + …)RT / V
pT = Total pressure pn = Partial pressure of component n nn = moles of component n R = Avogadros's constant T = temperature V = volume
What is Amagat’s law for an ideal gas?
VT = V1 + V2 + … = (n1 + n2 + …)RT / p
VT = total volume Vn = volume of component n nn = moles of component n R = Avogadro's constant T = temperature p = pressure
Why does a real gas not follow the ideal gas laws?
Intermolecular bonds can cause the volume/pressure to be higher or lower than expected.
What is fugacity?
Partial pressure adjusted by a fugacity coefficient when in a real fluid.
What is activity?
Fugacity but in a liquid.
When does a liquid boil?
When it’s vapour pressure is equal to the surrounding pressure.
What are the three sections on a boiling point diagram?
- Subcooled/saturated liquid (below bubble curve)
- Vapour/liquid mixture (between bubble and dew curve)
- Superheated/saturated vapour (above dew curve)
How do you calculate the volatility of a component A in a binary mixture.
Volatility = pA(sat) = pA / xA
pA(sat) = saturated vapour pressure of A pA = partial pressure of A xA = liquid mol fraction of A
What is relative volatility?
The volatility of the most volatile compound / the volatility of the less volatile compound. Often shown as alpha. The larger alpha is above 1, the more separable the compounds.
