sign in sign up
<<
Home , Azeotrope

Lecture 6: design, sizing & selection

Chapters 4, 7 (Textbook) plus additional material* • Part-1: Introduction • Part-II: Two-phase (equilibrium) separations • Part-III: Separation of azeotropic • Part-IV: Other separation processes

• See also ”Separation Process Principles” by Henley, Seader & Roper Chapters 7, 11 & 13 of book for & absorption, and chapter 14 for membrane based separation

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 1 Downstream Separations: The main issues

• When is separation necessary? • What are the mechansims of separation? • Which mechanisms and how many need to employed to achieve a desired separation? • How to configure/select/design the separation tasks? • How to verify if the desired separation can be achieved?

This lecture will provide a quick overview of the above topics – more details can be found in courses on separation process principles

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 2 When is separation necessary?

N2

N2, Argon Crude H2 separation … Reactor NH3 processes Argon H2, Methane Methane Crude Oil Oil products

Separating Recovery & different oil purification of products from chemicals crude oil (products)

Two Examples

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 3 Downstream Separation in Chemical Process Design - I

Chemical processes without reaction

Extraction Recovery Purification Finishing

• Crude oil based refinery for , and other fuel products • Seeds and other biomass based edible oil extraction processes • Herbs, plants based extraction of specialty chemicals • ......

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 4 Downstream Separation in Chemical Process Design - II EL, Pl, M recycle EL, Pl, M

EL, Pl, M DEE Reactor Separation W EA

Waste recycle

Identify and design the sequence of separation tasks that need to be performed in order to recover and purify the products, recycle the reactants and purge the inerts that enter the process Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 5 Which mechanisms of separation?

Phase 1 Phase 1 Phase 1

Feed Phase Feed Feed Barrier Creation (b) (a) MSA (c) Phase 2 (Solvent) Phase 2 Phase 2 Feed Phase 1

Phase 1 Feed Force field or gradient

(d) Phase 2 (e) Phase 2 a) Phase Creation (eg, distillation); b) Agent-based separation (eg, extraction); c) Barrier (eg, ; ); d) Solid agent (eg, adsorption); e) Force field or Gradient (eg, ion-exchange; centrifuge) Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 6 How many mechanisms and which mechanisms?

A, B, C, D, E, F • Depends on how many chemicals need to be separated (NS)? A, E, F / C, D, B A / B, C, D, E, F • Minimum number of separation tasks is NS-1 •For each separation task, A, F / F C / D, B find the appropriate separation mechanism

• Analyze to be separated (collect data or predict behaviour) • Identify relation between mechanism and system property (separation principles) • Generate and test alternatives (select, design, verify)

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 7 How to configure separation tasks? - Distillation Trains Separation of propane (A), i-butane (B), butane (C), i-pentane (D),

pentane (E) A B Secondary Separation Efficiencies at P=1 atm.

0.3 B/C A B 0.25 C D A/B E

0.2 C Propane iButane iButane nButane 0.15 C/D SSE iPentane nButane D nPentane iPentane

0.1

0.05

0 D/E 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 E composition, mole fractions of the lightest compounds

• Order the driving force diagrams in terms of fij| max = abs(yi – xi); • Configure the distillation train in terms of fij| max (easiest separation first – largest driving force equivalent to minimum energy); • Design each distillation column such that it uses the maximum driving force (note: only 4 separation tasks A-B; B-C; C-D; D-E) Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 8 How to configure separation tasks? – Extraction plus recovery Main Features: • Extraction (2-liquid phases); use of solvents • Recovery of solvents & solute (requires energy for VL separation) • Other forms of extraction could be membrane-based, ion- exchange, etc., that does not require the

recovery step) 9 Part-II: Two-phase (equilibrium) separations: Design issues

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 10 2-phase VLE based separation: design degrees of freedom?

Vapor, V T, P Feed, Z Liquid, L

Typical 2-Phase VLE-Model sat sat V Equilibrium relation xi gi ji Pi = yi ji P i = 1,2,….c Condition Si xi = Si yi = Si zi = 1 Mass Balance Z zi = V yi + L xi i = 1,2,….c Degree of Freedom Analysis F = c - p +2 For p = 2, F = c. There are 2c+3 Equations and 3c + 5 sat variables (not counting gi , ji , Pi ). Therefore, c + 2 variables need to be specified. For example, specify Z, T, P and (c-1) z compositions.

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 11 Some Definitions

Equilibrium Constant (VLE) Ki = yi/xi sat •Ideal System Ki = Pi (T) / P sat sat V •Non-ideal Liquid & Ki = gi ji Pi /( ji P) sat •Non-ideal Liquid, ideal vapor Ki = gi Pi /P L V •Any P & T Ki = ji / ji

sat sat Relative ij = yj xi / (xj yj) = Pi /Pj

Rewriting in terms of yi yi = xi ij/[1+ xi(ij - 1)]

Driving Force Dij = yi - xi

Rewriting in terms of yi Dij = xi ij/[1+ xi(ij - 1)] - xi

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 12 Binary systems with different volatility

0.30 Distillation, 1 atm. Distillation, 5 atm. Pervaporation 0.25

i 0.20

0.15

Driving Force,Driving FD 0.10

0.05

0.00 0.0 0.2 0.4 0.6 0.8 1.0

Liquid composition, xi

DX-(PT) (in XY-(PT) phase diagram (in terms of driving force) – shown terms of ) for different separation types)

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 13 VLE based separation: Model w.r.t. ij or Dij

Vapor, V T, P Feed, Z Liquid, L

Typical 2-Phase VLE-Model

Equilibrium condition yi = xi ij/[xi (ij - 1) + 1] w.r.t. relative volatility or (eq.1) Dij = xi ij /[xi (ij - 1) + 1] - xi w.r.t. driving force

Mass Balance Z zi = V yi + L xi i = 1,2,….c or yi = (R + 1) zi – R xi where R = L/V or (eq. 3) Dij = (R + 1) (zi –xi)

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 14 Graphical calculation technique for V-L based separation

Dij = yi - xi = xi ij / (1 + xi (ij - 1)) - xi

Dij = (R+1)(zi – xi)

When Dij = 0, there is no separation and zi = xi

When xi = 0 or L= 0; R= L/V= 0 & Dij = yi - xi = zi (everything is vaporized)

When R = specified; xi = Dij /(R + 1) + zi (point of intersection of Eqs. 1 & 3) Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 15 Visualization of 2-phase separations: P-XY & T-XY diagrams P-xy diagram at constant T T-xy diagram at constant P

Dew point L A C B V A V & L V & L C B V L

x1 and y1 x1 and y1 For a feed at C, L/V = CB/AC; at constant T, if you compress a vapor you get a liquid and vice versa. At constant P if you heat a liquid you get a vapor and vice versa. If you have a feed mixture in the 2-phase (V&L) region, it will split into a liquid and a vapor

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 16 VLE - Binary Systems: Azeotropic systems

Ethanol - Water - Toluene

y y1 1

x1 x1 XY-PT phase diagrams. At the azeotrope, xi= yi, therefore, Ki=1 and/or ij = 1. Separation beyond the azeotropic point is not possible

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 17 Visualization of 2-phase separations: azeotrope systems

T P

x , y 1 1 x1, y1 Methanol-Toluene T-xy & P-xy diagrams Generate these diagrams as a function of P to see if the location of the azeotrope can be moved Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 18 Types of VLE-phase separation models & approaches

Problem Specification Isothermal flash: fast solution Isothermal flash (T, P, F, z) Specified: F, z1, z2, ..zc-1, T, P *Bubble-point T (P, x) Solve for  = V/F with fixed Ki *Dew-point T (P, y) sat 1. Calculate Ki = Pi (T)/P *Bubble-point P (T, x) 2. f = Si zi(1-Ki)/[1+ (Ki-1)] = 0 *Dew-point P (T, y) 3. V = F ; L = F - V Adiabatic flash (Q=0, P, F, z) 4. xi = zi / [1+ (Ki-1)] Non-adiabatic flash (Q, P, F, z) 5. yi = ziKi / [1+ (Ki-1)] = xi Ki % Vaporization (V/F, P) 6. Q = hV V + hL L – hF F * Note: Degrees of freedom = c + 1

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 19 Separation of Binary Mixtures by Distillation: review

V1 Component Mass Balance Q Condenser C Overall 1 D F D B Recycle, L0 Distillate, D, x F z = D x + B x V2 L1 Rectifying section Feed VNF LNF-1 F D F, z yn+1= Ln/Vn+1 xn + D/Vn+1x NF y = [R/(R+1)] x + [1/(R+1)]xD

VNF+1 LNF Stripping section

B VNP LNP-1 ym+1= Lm/Vm+1 xm - B/Vm+1x Vapor boilup VNP+1 NP Reboiler B QR y = [(VB+1)/VB] x - 1/(VB+1)]x Equilibrium relation Bottom product, B, xB

yi = xi ij / (1 + xi (ij - 1)) Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 20 •Equilibrium relation

•yi = xi ij / (1 + xi (ij - 1)) •Component Mass Balance •Overall •F zF = D xD + B xB •Rectifying section

D •yn+1= Ln/Vn+1 xn + D/Vn+1x •y = [R/(R+1)] x + [1/(R+1)]xD •Stripping section

B •ym+1= Lm/Vm+1 xm - B/Vm+1x

B •y = [(VB+1)/VB] x - 1/(VB+1)]x

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 21 Driving force based design - I •Given a mixture to be separated into two products in a distillation column with N trays. What is the optimal (with respect to the costs of operation) feed plate location and the corresponding reflux ratio for different product purity specifications ?

0.4 A A

Pinch point 0.3 Slope correponding D Y D

Di to RR min Slope correponding I I to RR > RR 0.2 D' min

D D’ D N x F NF = N(1-Dx) 0.1 II

DrivingForce, F II

D B A X F ' F 0.0 X X B 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Light compound composition, x B i

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 22 Relation between ij, Dij(max), Xi (max)

0.6 0.6 Xi Max 0.5 Max FDi 0.5

0.4 0.4

0.3 0.3 Xi Max Xi

0.2 0.2 FDi Max

0.1 0.1

0.0 0.0 0 2 4 6 8 10 12 Alfa (Constant)

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 23 Identification of design targets

24 Simple and fast reverse design method

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 25 Problem Solution

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 26 Driving force based design - II

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 27 Part-III: Separation of azeotropic mixtures (chapter X of textbook, see also chapter 11 of Seader & Henley book)

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 28 Separation of an azeotropic mixture

• Mixture analysis Identification of an azeotrope. • Possible separation techniques Pressure swing. Extractive/. • Solvent identification and validation • Flowsheet configuration

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 29 Mixture analysis

Whenever you have the problem of separating a mixture, a good starting point is always to do a mixture anaysis. This can include both pure component and mixture properties. The mixture analysis will imediately give information both intuitively and to a computer aided system on what kind of separation is possible.

Binary Azeotrope: A binary azeotrope is when a 2 component, 2 phase system of gas and liquid in chemical equilibrium has the same composition in both phases.

Azeotropic condition: Gas phase, composition: ya, yb xa = ya, xb = yb

Liquid phase, composition: xa, xb

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 30 Identification of an azeotrope

Azeotropes is found by VLE (Vapor-Liquid Equilibria) mixture analysis. This can be either database lookup for VLE datapoints or the datapoints can be calculated with a thermodynamic model.

Comp A 1

By the definition of an azeo- trope, in a x-y plot the curve crosses the diagonal, at the y azeotrope composition.

0 0 x 1 Comp A

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 31 Possible separation techniques

Conventional distillation not possible, if 2 pure products are desired.

Possible to this problem: • Use separation techniques which are not exploiting differences in vapor vs. liquid phases, i.e. membranes or liquid- liquid extraction. • Pressure swing. • Extractive / azeotropic distillation.

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 32 -

VLE-PhaseDiagram: Pres.= 1.00 atm VLE-PhaseDiagram: Pres.= 1.00 atm

100

64 90 ACETONE

80 62 Temperature (°C) (°C) Temperature

70 60 60

58 50

40 56

30

CHCl3 mole % ACETONE ACETONE % mole CHCl3 54 20 52 10

0 50 0 20 40 60 80 100 0 20 40 60 80 100 CHCl3 mole % ACETONE CHCl3 CHCl3 ACETONE Azeotrope ~ 38 mole% acetone, 64.5 °C, maximum

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 33 Pressure swing

Pressure swing distillation is exploiting the fact that for some azeotropes the composition changes with pressure

VLE-PhaseDiagram: Pres.= 1.00 atm VLE-PhaseDiagram: Pres.= 6.00 atm

100 100

CH3-ACETATE CH3-ACETATE 80 80

60 60

40 40 METHANOL mole % mole %CH3-ACETATE METHANOL

METHANOL mole % CH3-ACETATE mole % METHANOL 20 20

0 0 0 20 40 60 80 100 0 20 40 60 80 100 METHANOL mole % CH3-ACETATE METHANOL mole % CH3-ACETATE METHANOL METHANOL

System: methanol – methyl acetate

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 34 Extractive distillation

The addition of a third component (solvent/entrainer) to the binary system in order to facilitate the separation by distillation.

VLE-PhaseDiagram: Pres.= 1.00 atm solvent mole %

100 Vapour Diagonal 90 Vapour 60.0 ACETONE 80

70

60

50

40

30

20

10

CHCl3 CHCl3 mole % ACETONE 0 0 20 40 60 80 100 CHCl3 mole % ACETONE CHCl3

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 35 Hybrid Separation: Driving force

Secondary Separation Efficiency, Methanol MTBE

0.30 Solvent based separation 0.25

0.20

0.15 Pervapo- ABS(yi-xi) Distillation 0.10 ration column 1

0.05

0.00 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 Liquid Composition, Mole Fraction Methanol Column 2 at P2 Column 1 at P1 Separation by single distillation operation not feasible; hybrid separation schemes (solvent based extraction or distillation plus pervaporation or pressure swing distillation) feasible

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 36 Solvent identification (I) The solvent can be found in a solvent database or by the use of a computer tool.

The computer tool must be able to solve the following problem: Given: A set of desired properties (pure and mixture) Needed: Description of compounds with these properties

Computer Aided Molecular Design (CAMD) programs can solve this. General functionality: 1. Combine molecular fragments to describe complete molecules 2. Predict the properties of the molecular descriptions 3. Reject descriptions with undesired properties

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 37 Solvent identification (II) Desired properties for the entrainer: 1. If it is a minimum boiling azeotrope the of the entrainer should be lower than the azeotropic temperature and vice versa. 2. The boiling point should not be to high in order to have small energy consumption. 3. Should not be harmful to the environment. 4. Should not form azeotropes with any of the two compounds.  g jS 5. High selectivety: Ss   g iS 1 6. Low solvent loss: S  sv.L g  7. ... sJ Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 38 Solvent validation (I): Identify distillation boundaries

1-PROPANAL ( 321.5 K) 1.0

0.9 Azeotrope 0.8

0.7

0.6

0.5 Residue curve 0.4

0.3

0.2 Distillation boundary 0.1

0.0 ( 331.0 K) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0( 338.0 K) METHYL-ACETATE METHANOL 328.1 K

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 39 Solvent validation (II): Separation feasibility

1-PROPANAL ( 321.5 K) 1.0 D2

0.9 Azeotrope 0.8

0.7

0.6

0.5 D1, Feed 2

0.4 Feed 1 0.3

0.2

0.1 B2 B1 0.0 ( 331.0 K) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0( 338.0 K) METHYL-ACETATE METHANOL 328.1 K

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 40 Solvent validation (III): Flowsheet configuration D2

1-PROPANAL ( 321.5 K) 1.0 D2 D1 0.9 S2 Azeotrope 0.8

0.7 mixer D3 0.6 S1

0.5 D1, Feed 2

0.4 Feed 1 S3 0.3 B2 B1 0.2

0.1 B3 B2 B1 0.0 D3 B3 ( 331.0 K) 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0( 338.0 K) METHYL-ACETATE METHANOL 328.1 K

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 41 Another flowsheet configuration: High boiling azeotrope How to identify feasible configurations & design?

4

feed

3 2 1 5

Identify the azeotropes, determine the distillation boundaries, generate the residue curves, design and analyze the separation scheme Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 42 Other flowsheet configurations

For different types of ternary diagrams, the Solvent flowsheet can be fixed in advance, consisting of A, Solvent minimum two distillation columns. What kind of distillation boundary and residue A, B, Solvent curves are needed to get A the flowsheet shown on the right? B

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 43 Part-IV: Other separation processes

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 44 Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 45 Graphical Design Technique Draw the ternary LLE diagram Locate F (feed) & S (solvent) streams & join them in a straight line Locate any point M that determines the mixing F point between F and S. E M Locate a tie-line that passes through M. The R end-points of the tie-line S indicates the composition of E and R streams

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 46 Graphical Design Technique for LL-extraction

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 47 Modelling and design of counter-current LL-extraction systems

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 48 Ternary saturation diagrams at Binary T-x diagram constant T & solvent-free Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 49 Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 50 Equipment design parameters (to be covered in next lecture)

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 51 • Distillation Column Design - Determine, Reflux ratio, Number of stages, Column diameter, Tray height, Heat duties for reboiler & condenser (following the example in the book)

• Use the lk/hk, lk, hk to calculate Ni & Ri

• Calculate Nt = 0.8 maxi(Ni) + (1-0.8) mini(Ni); use efficiency of 80%

• Calculate R = 0.8 maxi(Ni) + (1-0.8) mini(Ni)

• Calculate L´ and V´ and from it, Flv

• Use Flv and Fig 4.4 to obtain Csb,t (for a selected tray spacing)

• Calculate flooding velocity, Unf, and from it, the area A and diameter D of the column (use Eqs. 4.7 or 4.8 and 4.9) • Determine Tray stack height, extra feed space, disengagement space (top & bottom), skirt height

V L • Qcond = H V – h L

• Calculate Qreboil from total energy balance 52 • Distillation Column Design - Determine, Reflux ratio, Number of stages, Column diameter, Tray height, Heat duties for reboiler & condenser (Using PRO-II) • Use Short-Cut Fractionation (for column design) • Use rigorous simulation model to obtain the final design • Use the “sizing” calculation option for the column design • Select the column diameter, tray spacing, etc., from the output of PRO-II

• For condenser duty = Qcond (given by PRO-II), size a heat exchanger (determine area A)

• For reboiler duty = Qreboil (given by PRO-II), size a heat exchanger (kettle-type) – determine area • Determine Tray stack height, extra feed space, disengagement space (top & bottom), skirt height

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 53 • Absorption Column Design - Determine, absorption factor, Number of stages, Column diameter, Tray height, Heat duties for reboiler & condenser

• Use the lk/hk, lk, hk to calculate Nt

• Calculate Nt from Kremser equation (approx = 10) • Use efficiency of 20%

• Calculate L´ and V´ and from it, Flv

• Use Flv and Fig 4.4 to obtain Csb,t (for a selected tray spacing)

• Calculate flooding velocity, Unf, and from it, the area A and diameter D of the column (use Eqs. 4.7 or 4.8 and 4.9) • Determine Tray stack height, extra feed space, disengagement space (top & bottom), skirt height • Packed columns can also be calculated from the number of transfer units and height of transfer units

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 54 • Pumps, Compressors, Heat Exchangers, …. • The sizing parameters for each of these equipments can be obtained from PRO-II or calculated through the method used in the book (see the case study in chapter 4) • Pump – find the power needed (based on work) • Compressor - find the power needed (based on work) • Tank – volume (area and height) based on residence time • Heat Exchangers – area of the heat exchanger based on U, T, Q, Flowrate • …..

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 55 •Ethanol Process: Case Study (from Textbook) •We have now performed mass and energy balance. •We have added pumps/compressors, heat exchangers wherever necessary. •Now we need to do the sizing calculations for all unit operations in the flowhseet. •Costing & Economic analysis Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 56 •Sizing & Costing Calculations • Prepare a list of unit operations found in the flowsheet • For each , find a design that matches the calculated input-output conditions to obtain the sizing parameters • Use the sizing parameters to determine the cost of each unit operation •Decisions that need to be made •Choice of equipment type •Choice of pressure (already made) •Choice of material •Other parameters specific to the unit operation

Course: Process Design Principles & Methods, L6 PSE for SPEED, Rafiqul Gani 57