Equipment designEthylbenzene production by liquid phase

Done by: Mohammed Almohsen

Supervised By:

Prof. M. A. Fahim

Eng. Yusuf Ismail

KUWAIT UNIVERSITYCOLLEGE OF ENGINEERING & PETROLEUMCHEMICAL ENGINEERING DEPARTMENT

Distillation column:

Distillation T-101

Separate and recycle Ethylbenzene

COLUMN DIAMETER:

LIQUID VAPOR FLOW FACTOR

FOR BOTTOMS FOR TOP

TAKE PLATE SPACING AS 0.6 M

BASE K1 = 0.08TOP K1 = 0.12

BASE K1 = 0.066TOP K1 = 0.1078

CORRECTION FOR SURFACE TENSIONS

FROM FIGURE

FLOODING VELOCITY:

DESIGN FOR 85% FLOODING AT MAXIMUM FLOW RATE

BASE

TOP

MAXIMUM VOLUMETRIC FLOW RATE

BOTTOM TOP

NET AREA REQUIRED:

TAKING DOWNCOMER AREA AS 12 per cent OF TOTAL AREA

COLUMN CROSS-SECTIONAL AREA

COLUMN DIAMETER:

USE SAME DIAMETER ABOVE AND BELOW FEED =6.328M=20.76FT

COLUMN HEIGHT:

Column height = (Number of stage * Plate spacing) + Column Diameter

H = 27.9m =91.6 FT

LIQUID FLOW PATTERN:MAXIMUM VOLUMETRIC LIQUID

RATE

DOUBLE PASS PLATE IS USED

FROM FIGURE

PROVISIONAL PLATE DESIGN:

•Column diameter =

•Column area =

•Downcomer area =

•Net area =

•Active area =

•Hole area =

WEIR LENGTH

FROM FIGURE

•Take weir height =

•Hole diameter =

•Plate thickness =

ASSUME

CHECK WEEPING:

MAXIMUM LIQUID RATE

TURNDOWN PERCENTAGE = 0.80

MINIMUM LIQUID RATE

MAXIMUM WEIR CREST:

MINIMUM WEIR CREST:

AT MINIMUM RATE

FROM FIGURE

MINIMUM VAPOR VELOCITY THROUGH HOLE:

ACTUAL MINIMUM VAPOR VELOCITY

SO MINIMUM OPERATING RATE WILL BE ABOVE WEEP POINT.

PLATE PRESSURE DROP:MAXIMUM VAPOR VELOCITY THROUGH

HOLES

Plate thickness / hole dia. = 1.25

FROM FIGURE

DRY PLATE DROP

RESIDUAL DROP

TOTAL PLATE PRESSURE DROP

DOWN COMER LIQUID BACK-UP:DOWNCOMER PRESSURE

LOSSTAKE

AREA UNDER APRON

HEAD LOSS IN THE DOWNCOMER

BACK-UP IN DOWNCOMER

CHECK RESIDENCE TIME

SATISFACTORY

CHECK ENTRAINMENT

ψ =0.013 , well below 0.1

FROM FIGURE

PERFORATED AREA:

FROM FIGURE

•Angle subtended by the edge of the plate = 85

•Mean length, unperforated edge strips = 9.3136

•Area of unperforated edge strips=0.4191 m

•Mean length of calming zone,approx =4.7738

•Area of calming zones =0.4296 m

•Total area for perforations, Ap =23.0532

FROM FIGURE

NUMBER OF HOLES:AREA OF ONE HOLE:

NUMBER OF HOLES:

AREA OF CONDENSER

AREA OF REBOILER

Inlet temperature T1 231.8769 Co

Outlet temperature T2 230.4711 Co

Mean overall heat transfer coefficient U

1000.0000 W/m2.Co

Heat flow Q 50810.0000 KW

Inlet temperature T1 159.8721 Co

Outlet temperature T2 158.5811 Co

Mean overall heat transfer coefficient U

1000.0000 W/m2.Co

Heat flow Q 52720.0000 KW

THICKNESS CALCULATIONS:

Internal raduis of shell before allowance corrosion is added ri

124.567 in

Maximum allowable internal pressure P 100.000 psi

Working stress for carbon steel S 13706.660 psi

Efficincy of joients EJ 0.850  

Allowance for corrosin Cc 0.125 in

Equipment Name Benzene Column

Objective Separate and recycle Benzene to the reactor

Equipment Number T-101

Designer Mohammed Al-Mohsen

Type Continuous Distillation Column

Location After Mixer (MIX-108)

Material of Construction Carbon steel

Insulation Mineral wool

Cost ($) $711,828

Operating Condition

Operating Temperature (oC) 171

Operating Pressure (psi) 100

Feed Flow Rate (kg/h) 451181

Diameter (m) 6.328

Height (m) 27.9

Thickness (mm) 30.47

SPECIFICATION SHEET OF BENZENE COLUMN T-101

COST CALCULATIONS:

• Column cost:

• Cost of tray = 1,100 $/trays

• Cost of trays = 52,800$

• Cost of Vessel:

• Diameter outside=6m

• Volume outside=895

• Volume inside=878

• Volume of metal=17

• Weight of metal=296,080lb

• Cost of vessel 2007 =547,200$

• Vessel type: Large ,No Internals , Medium

• Cost of reboiler:

• Cost 2007 = 39,300$

• Cost of condenser:

• Cost 2007 =19,800$

• Total cost of without insulation=659,100$

• Insulation cost = 52,728$

• Total cost of T-101=711,828$

FROM:WWW.MATCHE.COM

Heat exchanger:

3 heat exchanger has been designE-102 ,E103 and e-105.

The type of the 3 heat exchanger are shell and tube.

Cooler E-102 detailed calculation:

• Heat load:

•

COOLING FLOW:

ASSUMETRY AND ERROR

BECAUSE THERE IS PHASE CHANGE

TEMPERATURE CORRECTION FACTOR: CALCULATION:

USING ONE SHELL PASS AND TWO TUBE PASSES

FROM FIGURE

ASSUME

PROVISIONAL AREA:

CHOOSE TUBE MATERIAL TO BE carbon steel WITH THE FOLLOWING PROPERTYOUTER DIAMETER Do = 25 MMINNER DIAMETER Di = 20 MMTUBE LENGTH = 4.88 M

AREA OF ONE TUBE

NUMBER OF TUBES

Nt = provisinal area / area of one tube = 792.36 = 793

USING 1.25 TRIANGULAR PITCH

TUBE BUNDLE DIAMETER:

CONSTANT

USING SPLIT RING FLOATING HEAD TYPE

Bundle diametrical clearance = 71 mm

FROM FIGURE

Shell diameter =Bundle diameter+Bundle diametrical clearance

=1037.13 mm=1.037

TUBE-SIDE COEFFICIENT: METHOD 1

• Mean water temperature =

• Tube cross sectional area =

• Total flow area=Tubes per pass x Cross

sectional area=

• Water mass velocity=mass flow rate/total flow

area=

• Water linear velocity Ut = mass velocity /

density =

• Inside coefficient for water hi:

TUBE-SIDE COEFFICIENT: METHOD 1I

•REYNALDO NUMBER

•PRANDTL NUMBER

HEAT TRANSFER FACTOR

FROM FIGURE

•INSIDE COEFFICIENT FOR WATER

Hs:

SHELL-SIDE COEFFICIENT:

• Choose baffle spacing =

• Tube pitch =

• Cross flow area=

• Mass velocity Gs= mass flow rate/cross flow

area =

• Equivalent diameter for triangular arrangement

• Mean shell side diameter temperature:

• Reynaldo number

• Prandtl number

CHOOSE 25% BAFFLE CUT

FROM FIGURE

HEAT TRANSFER FACTOR

OVERALL HEAT TRANSFER COEFFICIENT:

• Thermal conductivity of steel =

• Outside coefficient (fouling factor) =

• Inside coefficient (fouling factor) =

CLOSE TO INITIAL VALUE ASSUMED

PRESSURE DROP:

TUBE SIDE:

FROM FIGURE

HEAT TRANSFER FACTOR

SHELL SIDE:

FROM FIGURE

Linear velocity =

Internal raduis of shell before allowance

corrosion is added ri 20.416 in

Maximum allowable internal pressure P

85 psi

Working stress for carbon steel S

13706.66 psi

Efficincy of joients EJ 0.85  

Allowance for corrosin Cc

0.125 in

SHELL THICKNESS CALCULATIONS:

• Cost Calculations:

•From www.matche.com

•Heat transfer area = 3,269 ft2

•Exchanger Type: Carbon steel

•Internal Pressure: 450 psi

•Cost with out insulation: 110,900$

•Insulation cost: 8,872$

•Final cost 2007:119,772$

Equipment Name Heat exchanger

Objective Heat the Benzene recycled stream before feed to the distillation

Equipment Number E-102

Designer Mohammed Al-Mohsen

Type Shell and Tube Heat Exchanger

Location After E-103 Heat Exchanger

Utility Cooling Water

Material of Construction Cupro Nickel for shell sideCarbon Steel for tube side

Insulation Glass wool

Cost ($) $110,900

Operating Condition

Shell Side

Inlet temperature (C) 159.38Outlet temperature

(C)158.58

Tube Side

Inlet temperature (C) 27Outlet temperature

(C)78

Number of Tube Rows 2 Number of Tubes 793

Tube bundle Diameter (m)

0.966 Shell Diameter (m) 1.037

Q total (kW) 22617 LMTD (oC) 104.48

U (W/m2C) 738Heat Exchanger Area

(m2)303.69

Equipment Name Heat exchanger

Objective Heat the polyethylbenzen recycled stream before feed to Trans-reactor

Equipment Number E-105

Designer Mohammed Al-Mohsen

Type Shell and Tube Heat Exchanger

Location After P-101 pump

Utility Cooling Water

Material of Construction Cupro Nickel for shell sideCarbon Steel for tube side

Insulation Glass wool

Cost ($) $110,880

Operating Condition

Shell Side

Inlet temperature (C) 247.8Outlet temperature

(C)127.5

Tube Side

Inlet temperature (C) 27Outlet temperature

(C)45

Number of Tube Rows 4 Number of Tubes 12

Tube bundle Diameter (m)

0.157 Shell Diameter (m) 0.205

Q total (kW) 256.5 LMTD (oC) 145.69

U (W/m2oC) 608.4Heat Exchanger Area

(m2)2.736

Equipment Name Heat exchanger

Objective Heat the Benzene recycled stream using the hot product stream from the reactor

Equipment Number E-103

Designer Mohammed Al-Mohsen

Type Shell and Tube Heat Exchanger

Location Between Mix-106 and Flash drums V-100

Utility Cooling Water

Material of Construction Cupro Nickel for shell sideCarbon Steel for tube side

Insulation Glass wool

Cost ($) $354,996

Operating Condition

Shell Side

Inlet temperature (oC) 158.6Outlet temperature

(oC)159.4

Tube Side

Inlet temperature (oC) 267.9Outlet temperature

(oC)190

Number of Tube Rows 2 Number of Tubes 3026

Tube bundle Diameter (m)

1.844 Shell Diameter (m) 1.942

Q total (kW) 22294 LMTD (oC) 62.2

U (W/m2oC) 334.755Heat Exchanger Area

(m2)12987