Flash Distillation of a Mixture of Four Hydrocarbons

flash pressure

180

heat load

0

Consider a liquid feed composed of

n

-butane,

n

-pentane,

n

-heptane, and

n

-octane at 50 °C and 1000 kPa. The feed has a flow rate of 10 kmol/hr and contains

25

mole% for each of the four hydrocarbons.

The Demonstration calculates the composition of the liquid and vapor leaving the flash vessel for user-selected values of the flash pressure,

P

, and the added heat rate,

Q

, expressed in kJ/hr. The adiabatic flash distillation case is recovered if one sets

Q=0

. Values of the flash pressure (in kPa) and temperature (in Kelvin) are also displayed.

Details

Fugacity coefficients as well as enthalpy correction functions are calculated using the Peng–Robinson equation of state[1, 2].

Expressions for ideal-gas constant-pressure heat capacities were obtained from Aspen-HYSYS.

References

[1] E. J. Henley and J. D. Seader, Equilibrium-Stage Separation Operations in Chemical Engineering, New York: Wiley, 1981.

[2] D-Y. Peng and D. B. Robinson, "A New Two-Constant Equation of State," Industrial and Engineering Chemistry Fundamentals, 15(1), 1976 pp. 59–64. DOI: 10.1021/i160057a011

Permanent Citation

Housam Binous, Naim Faqir, Brian G. Higgins

"Flash Distillation of a Mixture of Four Hydrocarbons"
http://demonstrations.wolfram.com/FlashDistillationOfAMixtureOfFourHydrocarbons/
Wolfram Demonstrations Project
Published: November 27, 2012