PROPYLEN OXIDE CO-PRODUCTION WITH t-BUTYL ALCOHOL BY THE TEXACO HYDROPEROXIDATION PROCESS Done by: Adel Abdullah Supervised by: Prof. M.Fahim. Eng. Yusuf Ismail. Date: Tue.6th ,Jan.2009

Overview: Distillation Columns. Heat Exchanger (Cooler). Separator. Pump. Valves.

1. Distillation Columns There are two distillation columns: 1.Propylene distillation column (C-302). 2.TBA distillation column (C-304). Objective: 1) To separate propylene from propylene oxide feed & Increase the purity of propylene oxide. 2) To separate TBA from TBHP/TBA feed & Increase the purity of TBA.

Assumptions: The efficiency of plates is takes as 70%. Taking downcomer area as 12% of total. Tray spacing =0.45 m weir height=50 mm Hole diameter=5 mm Plate thickness=5 mm Heavy key: Propylene oxide / TBHP. Light key : Propylene / TBA.

Calculation Procedure For column diameter 1-Calculate the liquid –vapors flow factor for top and bottom FLV= LW / Vw * (ρv / ρl) ½ Where:- LW = liquid mole flow rate in kmol /h Vw = vapors mole flow rate in kmol / h ρv = density of the vapors in kg / m³ ρl = density of the liquid in kg / m³

3-Calculate the correction factor for top and the bottom 2-From fig 11.27 get constant for the top and the bottom top k1 and bottom k1 3-Calculate the correction factor for top and the bottom K = (σ / 0.02) ^0.2 * K1 Where:- σ = liquid surface tension in N/m 4-calculate the flooding velocity for top and bottom Uf = K *( (ρl –ρV) / ρ v)½ Where:- Uf = flooding vapour velocity in m/s K= constant obtain from fig 11.27 ρl = density of liquid in kg / m³ ρv = density of vapour in kg / m³ 5-Assume the flooding percentage is 85% at max flow rate for the top and the bottom UV = 0.85 * Uf

6-Calculate the net area for the top and the bottom An = V / UV Where: An = net area in m² V = Volumetric flow rate in m³ / s UV = vapour velocity in m/s 7-Assume as first - trail take down comer as 12% of total cross sectional area for the top and the bottom Ad = An / 0.88 Where: Ad = area of the down comer in m² An = net area in m²

Max liquid volumetric flow rate = Lm *MW / ρL * 3600 8-Calculate the diameter for the top and the bottom D = ((4 /3.14) * Ad) ½ Where: D = Diameter in m Ad = area of the down comer in m² 9-calculate the liquid flow pattern Max liquid volumetric flow rate = Lm *MW / ρL * 3600

10-Calculate the areas Ac = (3.14 / 4)*D² Where: Ac = total cross sectional area in m² Ad = 0.12 * Ac Where: Ad = area of the down comer in m² An = Ac –A d Where: An = net area in m² Aa = Ac – 2Ad Where: Aa = active area in m² Ah = 0.1 * Aa Where: Ah = hole area in m²

11-Use fig 11.31 to get LW / D 12-Assume: weir length = 50 mm Hole diameter = 5 mm Plate thickness = 5 mm 13-Check weeping how max = 750 * (Lwd/ (Ad*ρl)) ^2/3 how min = 750 * (Lwd/ (LW*ρl)) ^2/3 At min rate = hw + how Where:- how=Weir liquid crest 14-Calculate the weep point Uh = k2- 0.9 *(25.4-dh)/ρv½ Where: Uh = min vapor velocity through the hole in m/s Dh = hole diameter in m K2 = constant from fig 11.30

15-Calculate the actual vapour velocity Calculate the actual vapour velocity = min vapour rate / Ah It should be above weep point 16-Calculate the pressure drop UH = Vv / Ah Where: Vv = volumetric flow rate in m³ / s Ah = net area in m² Hd = 51 * (Uh/ C0)² * ρV / ρL Where: Hd = dry plate drop Uh = min vapour velocity in m/s C0= 0.84

Continue of calculating the pressure drop Hr = 12.5E3 / ρL Where: Hr = residual head Ht = HD + HW + HOW + HR Where: Ht = total pressure drop in mm

17-down comer liquid backup Hap = Hw – 10 Where: Hw= Weir height Aap = LW * hap *0.001 Where: Aap = area of apron Hdc = 166 * LW / (ρ l * Aap) Backup down comer Hb = hdc + ht + how max + hw

18-Calculate the residence time TR = (Ad * hb * ρ l) / lwd TR should be >3 s 19-Calculate the flooding percentage Flooding percentage = Uv / Uf * 100 20-Calculate the area of one hole A = (3.14 / 4 ) * (dh * 0.001 )² Where dh is hole diameter 21-Calculate number of holes Number of hole = A h / A

22-Calculate the thickness Where: t: thickness of the separator in (in) P: operating pressure in Pisa ri: radius of the separator in (in) S: is the stress value of carbon steel = 13700 Pisa Ej: joint efficiency (Ej=0.85 for spot examined welding) C0: corrosion allowance = 0.125 23- calculate the cost

Specification Sheet of (C-302): Distillation Column Equipment Name To separate propylene from propylene oxide Objective C-302 Equipment Number Adel Abdullah Designer Continuous Distillation Column Type After mixture (MIX-103) Location Carbon Steel Material of Construction Minral wool and glass fiber Insulation $463,343 Cost ($) Column Flow Rates - Recycle (kgmole/hr) 402.5 Feed (kgmole/hr) 390.2 Bottoms (kgmole/hr) 12.32 Distillate (kgmole/hr) Key Components Propylene Oxide Heavy Propylene Light Dimensions 26.4 Height (m) 4.39 Diameter (m) 3 Reflux Ratio 34 Number of Trays Sieve trays Type of tray 0.45 Tray Spacing 58612 Number of Holes Cost $17,143 Trays $244,600 Vessel $180,900 Reboiler $20,700 Condenser Unit

Specification Sheet of (C-302): Distillation Column Equipment Name To separate TBA from TBHP Objective C-304 Equipment Number Adel Abdullah Designer Continuous Distillation Column Type After valve (VLV-101) Location Carbon Steel Material of Construction Minral wool and glass fiber Insulation $607,786 Cost ($) Column Flow Rates - Recycle (kgmole/hr) 598 Feed (kgmole/hr) 18.67 Bottoms (kgmole/hr) 579.3 Distillate (kgmole/hr) Key Components TBHP Heavy TBA Light Dimensions 24.1 Height (m) 8.48 Diameter (m) 3 Reflux Ratio 24 Number of Trays Sieve trays Type of tray 0.45 Tray Spacing 218523 Number of Holes Cost $48,686 Trays $355,300 Vessel $146,100 Reboiler $48,100 Condenser Unit

2. Heat Exchanger (Cooler) The cooler called (E-105) Objective: To decrease the temperature of outlet from (Mix104) and prepare it before interring the Reactor (R-201A&B)

Assumptions: For cooling the fluid, Chilled water has been used for many reasons, mostly because of its suitable temperature range in addition to its treatment. Assuming value for overall heat transfer coefficient based on table 12.1, which is close to the calculated value. Assuming two shell pass and four or multiple of four tube passes The type of heat exchanger is shell and tube, while the material of construction is carbon steel.

Calculation Procedure of (E-105): 1. Heat load ,(kW) Q = (m Cp ΔT)hot =(m Cp ΔT)cold 2. Log mean Temperature, (˚C) * ΔT1= Thi-Tco * ΔT2= Tho-Tci Where, Thi: inlet hot stream temperature (˚C) Tho: outlet stream temperature (˚C) Tci: inlet cold stream temperature (˚C) Tco: outlet cold temperature

3. Provisional Area, (m2) Where: ΔTm= Ft ΔTlm Where: Ft is a correction factor get it from figure(12.19) Area of one tube = Lt * do *p Where: Outer diameter (do), (mm) Length of tube (Lt), (mm)

4. Number of tubes: Nt= provisional area / area of one tube 5- Bundle diameter: Db = do( Nt / K1)^ (1/n1) Where: - Db: bundle diameter ,mm - Nt : number of tubes - K1 , n1 : constants from table (12.4) using triangular pitch of 1.25

6- Shell diameter : Ds = Db + (shell inside diameter -bundle diameter) ,mm Where: shell inside diameter - bundle diameter from figure (12.10) using split ring floating heat type.

7- overall heat transfer coefficient : 1/Uo =1/ho + 1/hod + do(ln(do/di))/2kw + do/di * 1/hid + do/di * 1/hi Where: - Uo : overall coefficient based on outside area of the tube ,w/m^2.C - ho : outside fluid film coefficient, w/m^2.C, from Table (12.2) - hi : inside fluid film coefficient ,w/m^2, from Table (12.2) - hod : outside dirt coefficient (fouling factor) ,w/m^2.C - hid : inside dirt coefficient (fouling factor),w/m^2.C - kw : thermal conductivity of the wall material w/m.Cs for cupronickel - di : tube inside diameter m - do : tube outside diameter m

8. Pressure drop: Tube side: ΔP = Np [ 8jf (L/di)(µ/µw)^(-m) +2.5 ] ρυ^2/2,kpa Where: - ΔP : tube side pressure drop, N/m^2(pa) - Np : number of tube side passes - υ : tube side velocity ,m/s - L : length of one tube , m - Jf : tube side friction factor (from figure(12.30) @Re

Continue Pressure drop: Shell side: ΔPs = 8jf (Ds/de)(L/lb)( ρυ^2/2)(µ/µw)^(-0.14),kpa Where: - L : tube length ,m - lb : baffle spacing ,m - jf : shell side friction factor (12.30)

9. Shell thickness: t = (P r i / S E - 0.6P) + Cc Where: - t : shell thickness,in - P : internal pressure,psi gage - r i : internal radius of shell,in - E : efficiency of joints - S : working stress,psi (for carbon steel) - Cc : allowance for corrosion,in

Specification Sheet of (E-105): Cooler Equipment Name To cooled the outlet stream from mix-104 and prepare it to inter the R-201A&B Objective E-105 Equipment Number Adel Abdullah Designer Shell and tube heat exchanger Type After the mixer (mix-104) Location Chilled water Utility Carbon steel Material of Construction Quartz wool – Glass wool Insulation $28,000 Cost ($) Operating Condition Shell Side 110 Outlet temperature (oC) 137.8 Inlet temperature (oC) Tube Side 35 30 245 Number of Tubes 4 Number of Tube Rows 0.533031888 Shell Diameter (m) 0.476031888 Tube bundle Diameter (m) 90.92406 LMTD (oC) 1207.6895 Q total (Kw) 46.1194369 Heat Exchanger Area (m2) 259.781615 U (W/m2 oC)

3. Separator: The separator called (V-101) Objective: To separate vapor gases from the liquid

Assumptions: Virtical separator Assume liquid height at half the vessel diameter

Calculation Procedure of (E-105): 1- Calculate setting velocity by knowing density of vapor and liquid: Ut = 0.07*((ρl-ρv)/ρv)^.5 Where: - Ut: settling velocity,m/s - ρl: liquid density,Kg/m3 - ρv: vapour density,Kg/m3 2- Calculate vapor volumetric flow rate :

3- Calculate liquid volumetric flowrate: 4- Determine the volume held in vessel using the above information's : 5- Calculate the minimum vessel diameter :

6- Determine the thickness of the wall : Where: TH: thickness (in) P: internal pressure (psig) RI: internal radius of shell (in) Ej: efficiency S: working stress (psi) =13700 for Carbon Steel Cc: allowance for corrosion (in)

7- Calculate volume of cylinder using Dv : VDv = (3.14/4)*(Dv^2)*h Where: - Dv: min vessel diameter. - h: total length. 8- Calculate volume of metal : Vm = t* A 9- Weight of metal : Wm=Vm* ρ Where: ρ: density of steel

TO separate gases (Oxygen & Nitrogen) from the feed Specification Sheet of (V-101): separator Equipment Name TO separate gases (Oxygen & Nitrogen) from the feed Objective V-101 Equipment Number Adel Abdullah Designer Vertical Type After E-101A&B Location Carbon Steel Material of Construction Glass wall and quartz Insulation $241,500 Cost ($) Operating Condition 305 Operating Pressure (psig) 117 Operating Temperature (oC) Design Considerations 36.078 Gas Density (kg/m3) 605.83 Liquid Density (kg/m3) 7933.8 Liquid Flow rate (kg/h) 54956 Gas Flow rate (kg/h) Dimensions 9.6 Height (m) 3.59 Diameter (m)

4. Pump: It called (P-102) Objective: To increase the pressure.

Assumptions: Centrifugal pump. Cast Iron materials.

Calculation Procedure of (P-102): 1- Calculate the flow rate : m= ρ *Q Where: ρ =Mass density Q= Volumetric flow rate 2- Calculate the work shift : Ws = -ha * g Where: Ha= head of pump g= Gravity 3- Calculate the break horse power : hp=(-Ws*m)/(ζ *1000) Where: m :mass flow rate in kg/h ζ: assumed 0.75m

4- Calculate the diameter :

To increase liquid pressure Specification Sheet of (P-102): Pump Equipment Name To increase liquid pressure Objective 102 Equipment Number Adel Abdullah Designer Centrifugal Pump Type After Tee-101 Location Cast Iron Material of Construction Quartz Wool , Glass Wool Insulation $1,800 Cost Operating Condition 117 Outlet Temperature (oC) Inlet Temperature (oC) 307 Outlet Pressure (psia) 305 Inlet Pressure (psia) 228.8 Power (Hp) 75% Efficiency (%)

5. Valves: There are two valves VLV (100 & 101) Objective: To decrease the pressure.

Assumptions: They are gate valves. The diameter is 5 in.

To decrease the pressure Specification Sheet of (VLV-100): Valve Equipment Name To decrease the pressure Objective 100 Equipment Number Adel Abdullah Designer Gate Valve Type Before C-101 Location Carbon Steal Material of Construction $700 Cost Operating Condition 102.6 Outlet Temperature (oC) 134 Inlet Temperature (oC) 50 Outlet Pressure (psia) 306.7 Inlet Pressure (psia)

To decrease the pressure Specification Sheet of (VLV-101): Valve Equipment Name To decrease the pressure Objective 101 Equipment Number Adel Abdullah Designer Gate Valve Type Before C-304 Location Carbon Steal Material of Construction $700 Cost Operating Condition 91 Outlet Temperature (oC) 126.7 Inlet Temperature (oC) 20 Outlet Pressure (psia) 65 Inlet Pressure (psia)

Thank you