Equipment DesignDone by:

Sara Saad Al-Quhaim (Group leader)

Distillation Column ( C-201)Distillation Column ( C-202)Cooler (E-103)Compressor ( K-100)

Equipment Design:

Distillation Design:

Number of Stages

(No. of stages) min = 25 (from HYSYS)

Efficiency = 75% (Assumed)

Actual stages = (No. of stages) min / Efficiency

=33

Calculation of actual number of stages

( Short-cut Method):

Water ( heavy) a= -7.831b= 1.7399c= -2.2505d= -1.9828

API method:

Pr vap= Pc*100*EXP((Tr^-1)*( at+bt^1.5+ct^2.6+dt^5)Y= 18.9621182α= 1 (relative volatility)

Methanol ( light )

a= -8.6413b= 1.0671c= -2.3184d= -1.678XF= 0.096XD= 0.996XB= 0.0000005

API method:

Pr vap= Pc*100*EXP((Tr^-1)*( at+bt^1.5+ct^2.6+dt^5)Y= 79.90817981α= 4.21409565

  α F D B  

water 1 87.4 0.009602458 87.391972 heavy

Methanol 4.21409565 12.6 12.57922028 0.0192049 light

Nm = Log [ XLK/ XHK]d [XLK/ XHK]b ( minimum number of stages)

Log LK

( Fenske equation)

q=0.98909 (liquid)

[ xf - ] = 1-q

xf α α * xf ө=2.8 ө=3.1

0.874015748 1 0.874 -0.485564304 -0.416198

0.125984252 4.21409565 0.531 0.375441144 0.4765387

= 3.013 by interpolation

[ xd - ] = Rm +1

xd α α xd (α xd/α-ө)

0.000762777 1 8E-04 -0.000378925

0.999237223 4.21409565 4.211 3.505866695

Rm= 2.50548777Rm/(Rm+1)= 0.714732994

R= 2.8R/(R+1)= 0.736842105

Nm/N= 0.33

N= 32.866

Note: The actual number of stages =33 stages

Where:Lw: liquid flow rate, kmol/hrρL: liquid density,kg/m3Vw: vapor flow rate, kmol/hrρv :vapor density, kg/m3FLv: Liquid-vapor factor

5.0)(*l

v

VW

LWFLV

Tray spacing= 0.55 ( from hysys)

Using figure to find K1

5.0)(1v

vlKUf

uf : flooding vapor velocity, m/s

XUFUV *uv: maximum velocity, m/s.

x: percentage of flooding at max flowrate.( assume 85”% )

Maximum volumetric flow rate

3600*

*

v

MV WtW

Uv

VAnet

max Anet: Net area required, m2

Taking downcomer area

as 12 percent of total12.01

AnAdCross sectional area of

downcomer=

4*c

c

AD Column Diameter

diameterEfficieny

spacingtraystagesActualH

.*.Column Height

l

MLMVL wtbottom

*3600

*

Maximum volumetric liquid rate

Liquid flow arrangement

Ac = π/4 Dc2 Total column cross sectional area

Net area available for vapor liquid

Active or bubbling area

Ah = 0.1 AaHole area

Ad/Ac*100

Find lw/Dc from Figure

Find Weir Length (lw)

3600*)( Wt

WW

MLLMax

Minimum liquid rate = 0.7* Max (Lw)

Maximum how =750(Lw/(ρL lw))(2/3)Minimum how =750(Lw/(ρL lw))(2/3) Weir crest

At minimum rate hw=50mm + how, from Figure 11.30 Find K2

uh (min) =(K2-0.90(25.4-dh))/ρv0.5 Minimum vapor velocity

Hole diameter =5mm

actual minimum vapor velocity = min vapor rate /Ah

Hole area

Note: actual minimum vapor velocity should be greater than Uh

Taking;Plate thickness/hole dia. = 1 Ah/Ap ( perforated area) = Ah/Aa from figure ( orifice cofficient) Co = 0.84

Dry plate drop= hd = 51(uh/Co)2(ρv/ρL)

Vapor velocity

Residual head (hr) = (12.5*103)/ρL

Total plate pressure drop (ht) = hd+hw+how+hr

Downcomer pressure drop (hap) = hw-10Area under apron (Aap) = lw *hap*0.001

hdc =

2)*

(*166LAP

wd

A

L

hdc= Head loss in downcomer

Back-up in downcomer (hb) = hw+how+ht+hdc

Weir crest

hb less than tray spacing , so tray spacing is acceptable.

Residence Time

Uv = Bottom V / An Percent flooding=

flowmassliquid

hAtr Lbd

tr: residence time, should be > 3 s

Downcomer area

Down comer backup

f

vu

u

From figure, find ψ below 0.1( fractional entrainment)

Calculate lw/Dc

From figure find

180

.**)05.0(

subtendedangleDc

Angle subtended by the edge of the plate=180- θc

Mean length, unperforated edge strips =

Area of unperforated edge strips=0.05*mean lengthMean length of calming zone =

Area of calming zone =2*mean length of calming zone *0.05Total area for perforations, Ap =Aa - area of unperforated edge strips - area of

calming zone

)180

*2

(*)05.0( c

c SIND

Ah/Ap from figure, find lp/dh

satisfactory within 2.5 to 4

Number of holes:

Area of one hole= 23)10*5(*4

Total number of holes = Ah / 1.963E-05

Holes on one plate = total Number of holes/Area of one

For condenser:

Material Carbon SteelArea of condenser = TU

Q

*

For reboiler:

Material Carbon SteelArea of reboiler= TU

Q

*

CcPSE

priThickness

*6.0*

* Where:

ri = Inside radius of the shell, inP =Maximum allowable internal

pressureS = Maximum allowable working

stressE = Efficiency of joints

Cc = Allowance for corrosion, in

Equipment Name Distillation column

Objective To separate methanol from Alcohols

Equipment Number C-201

Designer Sara Al-Quhaim

Type Tray column

Location Ethanol Production

Material of Construction Carbon steel

Insulation Minral wool and glass fiber

Cost ($) $454,118

Column Flow Rates

Feed (kgmole/hr) 6176Recycle

(kgmole/hr)-

Distillate (kgmole/hr) 1317Bottoms

(kgmole/hr)5474

Key Components

Light Methanol Heavy Water

Dimensions

Diameter (m) 4.6 Height (m) 41.3

Number of Trays 69 Reflux Ratio 90

Tray Spacing 0.5 Type of tray Sieve trays

Number of Holes 64266

Cost

Vessel $194,400 Trays $63,333

Condenser Unit $89,000 Reboiler $105,208

Equipment Name Distillation column

Objective To separate water from Alcohols

Equipment Number C-202

Designer Sara Al-Quhaim

Type Tray column

Location After C-201

Material of Construction Carbon steel

Insulation minral wool and glass fiber

Cost ($) $420,218

Column Flow Rates

Feed (kgmole/hr) 5474 Recycle (kgmole/hr) -

Distillate (kgmole/hr) 1500 Bottoms (kgmole/hr) 3974

Key Components

Light Ethanol Heavy Water

Dimensions

Diameter (m) 3.59 Height (m) 31.5

Number of Trays 45 Reflux Ratio 2.5

Tray Spacing 0.5 Type of tray Sieve trays

Number of Holes 39097

Cost

Vessel $124,400 Trays $48,133

Condenser Unit $130,300 Reboiler $115,208

Cooler design (heat exchanger)

TmCQ p

hQ

m

T

-

= Heat load transfer in the hot side, KW.

Mass flow rate in Kg/s.

Temperature difference of the inlet and outlet.

)(

)(ln

)()(

12

21

1221

tT

tTtTtT

Tlm

1T

2T

1t

2t

Inlet shell side fluid temperature (oC).

Outlet shell side fluid temperature (oC).

Inlet tube side temperature (oC).

Outlet tube temperature (oC).

)(

)(

12

21

tt

TTR

)(

)(

11

12

tT

ttS

Measure of temperature efficiency

lmtm TFT -

tFTemperature correction factor.

At R and S

Estimate U from table 12.1

mTU

QA

Provisional area

Take: Tube outside diameter(do) =20mm

Tube inner diameter(di) =16mm

Tube length(L) =4.88m

DLA Area of one tube

tN A/ A one tube Number of tubes

1

1

10 )( nt

b K

NdD Bundle diameter

K1, n1 depend on number of passes

ClearanceDD bs Shell diameter

2)(4 ic dA

Tube cross sectional area

4tN

Pass

Tubes Tube per passes

Pass

TubesAA ct Total flow area

tm A

mU Tube mass velocity

ref

mt

UU

Tube linear velocity

2.0

8.0 )*)02.035.1(*4200(

i

ti

d

Uth

Heat transfer coefficient inside the tube

itdU

Ref

p

k

C Pr

i

hfi d

jkh

33.0Re(Pr)

ih

hj

fk

Inside coefficient (W/m2 oC).

Tube side heat transfer factor.

Thermal conductivity of stream.

From l/Di and Re

5s

B

Dl Shell baffle spacing

025.1 dpt Tube pitch

t

Bsts p

lDdpA

)( 0 Cross flow area

ss A

mG Mass velocity

)917.0(1.1 2

02

0

dpd

d te Equivalent diameter

esdG

Re Pr =Cp / kf At 25% baffle cut find jh

hs =

3

1

rehe

f PRjd

K

ii

o

idi

o

w

i

oo

odoo hd

d

hd

d

K

d

dLNd

hhU

11

2

111

Overall heat transfer coefficient

odh

idh

Outside coefficient (fouling factor).

Inside coefficient (fouling factor).

25.28

2t

m

wifpt

u

d

LjNP

Jf= friction factor

14.02

28

w

s

Be

sfs

u

l

L

d

DjP

CcPSEj

t i

6.0

PrShell Thickness

t

P

ir

jE

S

cC

-

Shell thickness (in).

Maximum allowable internal pressure (psig).

Internal radius of shell before allowance corrosion is added (in).

Efficiency of joints.

Working stress (psi).

Allowance for corrosion (in)

Equipment Name Cooler

ObjectiveTo cooled the feed stream entering the

reactor

Equipment Number E-101

Designer Sara Al-Quhaim

TypeShell and tube heat exchanger(Floting

head, large)

Location After the compressor K-102

Utility Chilled water

Material of Construction Carbon steel

Insulation Glass wool

Cost ($) $570,376 (for three)

Operating Condition

Shell Side

Inlet temperature (oC) 76.11Outlet temperature

(oC)52.738

Tube Side

Inlet temperature (oC) 25Outlet temperature

(oC)35

Number of Tube Rows 2 Number of Tubes 3022

Tube bundle Diameter (m) 0.9534365 Shell Diameter (m) 1.0234365

Q total (Kw) 5922.869045 LMTD (oC) 33.646828

U (W/m2 oC) 213..57628Heat Exchanger

Area (m2)926.47649

Compressor Design

11 1

2 2

n

nP T

P T

n = Compression factor

1 2( )

1

nR T TW

n

W = work done (Btu/Ibmol)

R = Cp/Cv

*Hp W M M= mol flow rate (Ibmol/hr)

1

1

nnEp

KK

K = (Mwt*CP)/(Mwt*CP-1.986)

Ep = Efficiency of compressor %

Equipment Name Compressor

Objective To increase the pressure of stream 25

Equipment Number K100

Designer Sara Saad Al-Quhaim

Type Air, centrifugal, 125 psi

Location After C-202

Material of Construction Carbon steel

Insulation Quartz wool

Cost $186176.25

Operating Condition

Inlet Temperature (oC) 67.132Outlet

Temperature (oC)

186.48

Inlet Pressure (psia) 8.7020Outlet

Pressure (psia)

60.0000

Efficiency (%) 133.3817 Power (Hp) 543.6356

Thank You