Supervised By:

Prof.Mohamed Fahim

Eng.Yusuf Ismail

Equipment Design

Done By:Lamya AL-Hussaini

Distillation Column

Distillation column is used to separate components according to their boiling point temperature.

The objective of this distillation is to separate styrene from water and ethylbenzene

Assumptions:

• Sieve plate.• Material of the distillation is carbon steel.• Plate spacing= 0.6 m• Efficiency = 50%• Flooding % = 85%• Weir height = 50 mm• Hole diameter = 5 mm• Plate thickness =5 mm

Design Procedure:

1) Number of stages:

Nm= )log(

])/(*)/log[(

avg

bottomxlxhtopxhxl

Where ,

bottomtopavg * Kh

Kltop

P

PiK

From Antoine equation:

CT

BAp

*log

Xl = mole fraction of light component (ethylbenzene)Xh = mole fraction of heavy component (styrene)

Actual Number of stage = Nm/ efficiency

Nm = 5Efficiency = 50%Actual number of stages =10 stages

2)Column Diameter:

D = (Ad *4/π)^0.5

Where: Ad: down comer area, m2

Ad = An/(1-.12)

Where: An: Net area required, m2

An = Mmax/uv

Mmax= mass flow rate /density

uv = uf*.85 where 85 flooding %,uv maximum vapor velocity

uf= K ((ρL- ρv)/ ρv) ^0.5 where uf flooding vapor velocity

Column Diameter,TOP= 1.7m BOTTOM= 6.2m

3) Column Height :

H= (Tray spacing * actual NO. stage ) + D

H = 12.2 m

4) Maximum volumetric liquid rate:

MVL =(Lbottom*Mwt)/(3600* ρL)

MVL =0.4 m3/s

5) Plate Design :

Column area Ac = (π/4)*D^2

Downcomer area Ad= 0.12*Ac

Net area An = Ac-Ad

Active area Aa = Ac-2Ad

Hole area Ah = 10%*Aa

Ac= 30.25 m2

Ad =3.63 m2

An = 26.63 m2

Aa =22.9 m2

Ah =2.3 m2

6) Residence Time:

tr = flowmassliquid

ρhA Lbd

Where, tr: downcomer residence time (S) hb: downcomer back-up (m ) Ad=downcomer area (m2)

ρL: liquid density (kg/m3)

tr = 8.25 s

7) Number of holes:

Area of one hole = (π/4)*(hole diameter^2) Total number of holes = Ah / area of one hole Holes on one plate = total Number of holes/number of stages

Area of one hole = 1.96E-5 m2

Total number of holes =117119Holes on one plate = 11712

8) Thickness Calculations:

Thickness = [(ri* P)/(Ej *S-0.6P)]+Cc

ri = Inside radius of the shell, in

P =Maximum allowable internal pressure(psi)

S = Maximum allowable working stress(13700 psi)

EJ = Efficiency of joints (0.85)

Cc = Allowance for corrosion, in (0.125 in)

Thickness = 0.2948 inThickness= 7.48 mm

9) Area of condenser and Reboiler:

Area of condenser& reboiler = Q/(U*∆T)

Q: Heat transfer (W)Where:

∆T: Temperature difference.(°C)

U: overall heat transfer coefficient(W/m2.°C)

Area of condenser =454216 ft2

Area of reboiler = 7010.79 ft2

10) Cost Calculations :

weight of metal = 31086.19 lb

cost of vessal = 117100 $

cost of reboiler = 125000 $

cost of condenser = 108100 $

cost of one tray = 1500 $

cost of total trays = 15000$

Total cost = 365200 $

Distillation Column

Equipment Name Distillation

ObjectiveSeparate styrene from water and

ethylbenzen

Equipment Number T – 100

Designer Lamya Al-Hussaini

Type Plate column

Location Last equipment in styrene plant

Material of Construction Carbon steel

Insulation Glass wool

Cost ($) 365200

Column Flow Rates

Feed (kgmole/hr) 1.541e4 Recycle (kgmole/hr) 3063

Distillate (kgmole/hr) 7657 Bottoms (kgmole/hr) 7752

Key Components

Lightethylbenzen

eHeavy styrene

Dimensions

Diameter (m) 6.20753298 Height (m) 12.207533

Number of Trays 10 Reflux Ratio 0.4

Tray Spacing 0.6 Type of traySieve

Double pass

Number of Holes 117119.637 Number of Caps/Holes 117119.637

Cost

Vessel 117100 Trays 15000

Condenser Unit 108100 Reboiler 125000