# Exact Calculation Procedures for Multicomponent Distillation Methodآ  for Multicomponent Distillation

• View
3

1

Embed Size (px)

### Text of Exact Calculation Procedures for Multicomponent Distillation Methodآ  for Multicomponent...

• Exact Calculation Procedures

for Multicomponent Distillation

1Binous - Exact Distillation Calculation

• Stage-by-stage calculations require good first guess of

compositions at some point in the column

Method using matrix methods will be described: not

restricted to cases where a good guess of composition is

available

We will describe a simple matrix method using:

θ−convergence method

2Binous - Exact Distillation Calculation

• MESH equations are the same (physical operation is unchanged)

We will rearrange the equations to enhance convergence

especially when one good first guess is available

Solve equation by type instead of stage-by-stage

All mass balance equations for component i are grouped and

solve simultaneously (equations are written in matrix form)

3Binous - Exact Distillation Calculation

• Specify F, zi, TF, N, NF, P, Treflux, L/D and D

Simulation problem with D specified

Design problem:

Run a series of simulation problems with good guess for N and NF.

4Binous - Exact Distillation Calculation

• 5Binous - Exact Distillation Calculation

• (1) Guess vapor and liquid flow rates: Lj and Vj for each stage j

(can use CMO) / Guess Tj for each stage j

(2) Calculate K values

(3) Solve component mass balance equations

(4) Use θ-convergence and bubble-point calculations to get T

If θ ≠ 1 go to step (2) with new Tj

(5) Solve energy balance to get Lj and Vj for each stage j

Convergence check not satisfied

then go to step (3) with new Lj and Vj 6Binous - Exact Distillation Calculation

• 7Binous - Exact Distillation Calculation

• 8Binous - Exact Distillation Calculation

• Component Mass Balance in Matrix Form

Mass balance for any component i at stage j:

Equilibrium relationships:

9Binous - Exact Distillation Calculation

• Liquid component flow rates:

New form of the mass balance:

10Binous - Exact Distillation Calculation

• 11Binous - Exact Distillation Calculation

• 12Binous - Exact Distillation Calculation

• Initial guess for the flow rates:

Assume CMO

Feed quality:

Rectifying section:

Stripping section:

13Binous - Exact Distillation Calculation

• Bubble point calculations

14Binous - Exact Distillation Calculation

• θ-convergence Method

This method defines a quantity θ that forces the

equation below to be verified:

with

15Binous - Exact Distillation Calculation

• 16Binous - Exact Distillation Calculation

• Once θ is found, one can compute the following:

17Binous - Exact Distillation Calculation

• Convergence Test:

Calculate new Tj

18Binous - Exact Distillation Calculation

• Energy Balance in Matrix From

Using the following equations, one gets a matrix equation:

19Binous - Exact Distillation Calculation

• 20Binous - Exact Distillation Calculation

• New values for Lj and Vj

If not use new values in step (3) (i.e., mass balance matrix equations)

21Binous - Exact Distillation Calculation

Slide Number 1 Slide Number 2 Slide Number 3 Slide Number 4 Slide Number 5 Slide Number 6 Slide Number 7 Slide Number 8 Slide Number 9 Slide Number 10 Slide Number 11 Slide Number 12 Slide Number 13 Slide Number 14 Slide Number 15 Slide Number 16 Slide Number 17 Slide Number 18 Slide Number 19 Slide Number 20 Slide Number 21

Recommended

Documents
Documents
Documents
Documents
Documents
Documents
Documents
Documents
Documents
Documents
Documents
Documents