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CHEG 407Spring-2016

Case 1: Vinyl ChlorideSubmitted to

Dr. BORDEN

BYAn Minh Tran

ID#: 000058739

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ContentsI. Executive Summary…………………………………………………………………..3

II. Process Description…………………………………………………………………...3

III. Flowsheet……………………………………………………………………………...8

IV. Overall Balance…...…………………………………………………………………...8

V. Process Economics…………………………………………………………………...11

VI. Major Equipment Lists and Capital Cost Estimate…...……………………………...11

VII. ISBL Estimate………………………………………………………………………..13

VIII. Safety………………………………………………………………………………...13

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I. Executive Summary

Vinyl Chloride (VCM) is made from Ethylene (C2 H 4) and Chloride(Cl2). Vinyl Chloride is used

to produce standard plastic material Polyvinyl Chloride (PVC). In this case, the Process of

making VCM by two methods that are Direct Chlorination and OxyChlorination is introduced;

and based on it, with information that is also given in the article, and calculation of Material and

Energy Balance to Estimate the Capital and Operating Cost for this Process. Besides, the safety

rules are given in this case to ensure safe operation and ensure efficient operation.

II. Process Description

1. General Process Description

The process to produce Vinyl Chloride monomer (VCM) from ethylene and chloride has three

main process sections.

The first section is produced Ethylene Dichloride (EDC) by direct chlorination

The second section, EDC is produced by oxychlorination.

The last section is cracking section to produce Vinyl Chloride (VCM) from EDC.

Both reactions in first and second section are exothermal, and the last section is endothermal.

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2. Direct Chlorination

This process operates at boiling condition with temperature of 1200C.

A big portion of the heat of reaction removes by boiling of EDC can be recover by process like

heating of Distillation Column or Heating of Fluidised Bed PVC Dryer.

Reaction is carried out in the riser section of CNC Reactor where gaseous ethylene is first

completely Pre-dissolved in the lower part of it.

Gaseous Chlorine is added through an injector nozzle in the lower section of CNC Reactor where

it is cooled to allow the chorine for better pre-dissolved. This pre-dissolved Chlorine is mixed

with Ethylene solution to react to EDC in a fast liquid-phase reaction.

The EDC is started boiling due to reduce statics pressure head in upper part of riser from where

excess EDC and product EDC are recover.

Thus, the energy efficiency of a HTC and EDC purity of LTC is combined by the process of

Vinnolit Direct Chlorination.

3. Oxychlorination

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EDC formation takes place in a fluidsed-bed reactor in Oxychlorination Process. The reaction

heat is used for steam generation and reaction gaseous is supplied to Quench Column after

Catalyst Filtration from where water is removed by condensation.

The reaction gaseous coming out of Quench Column is farther cooled and is feed to EDC

Distillation Column.

Moreover, depending on customer requirement, the gaseous coming out of the Quench Column

is refrigerated for waste water treatment.

4. EDC Distillation

The raw EDC produce from Oxychlorination Unit is feed to Head Column for EDC Distillation.

From Head Column, the gaseous substance is cooled with cooling water and supplied to

incineration unit.

The Dry Bottom Product from Head Column and uncovered EDC are supplied to high boiling

column and vacuum column. From here, High Boiling Compound is separated from unconverted

EDC. The High Volume Compound coming out of Vacuum Column is sent to incineration unit

and product from this process is supplied to cracking EDC Process.

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5. EDC Cracking

The cracking of product supplied from EDC Distillation Column takes place in Cracking

Furnace. Few and Combustion air is supplied to the cracking furnace to carry out that Cracking.

VCM, HCl and by product of various chemical structures and coke are formed and supplied to

EDC Evaporator where the formation of coke is reduced. The product are thus supplied to

Quench Column from where the Cracking Product goes to VCM Distillation.

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6. VCM Distillation

The product from Cracking Quench and the Cracking Unit Product are supplied to HCl Column

from where HCl is recovered and fed to VCM Column. Vinyl Chloride is obtained on top of

VCM Column which is supplied to HCl Stripper to remove any traces of HCl. The head product

of HCl is stripper ise supplied to HCl Column. The bottom product is cooled to form VCM

Product.

The bottom product of VCM Column (un-converted EDC) undergo heat recovery to return to

EDC Distillation Process.

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III. Flow Sheet:

Flowsheet is shown in the following Excel File

IV. Overall Balance

1. Material Balance

Following Table from the Article, to Produce 1000 kg VCM product:

Ethylene 459 kg

Chlorine 575 kg

Oxygen 139 kg

Steam 250 kg

Fuel Gas 2.7 GJ

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459 kg of Ethylene will produce 1025 kg of VCM in theorical. Percent Yield is:

1000 kg1025 kg

× 100 %=98 %

Reaction to produce VCM:

Direct Chlorination: C2 H 4+Cl2→ C2 H 3 Cl+HCl

Oxychlorination: 2 C2 H 4+Cl2+12

O2 →2C2 H3Cl+H2O

To produce 150000 lb/h VCM with 98% Yield, the process need:

Ethylene

31229.8

1 kg/h

Chlorine

39122.3

1 kg/h

Oxygen

9457.39

0 kg/h

Steam

17009.7

0 kg/h

Fuel Gas

183.704

8 GJ/h

Assume that 75% VCM will be produce from Direct Chlorination, and 25% VCM will be

produce from Oxychlorination:

Direct Chlorination

Oxychlorinatio

n

Ethylene

23422.3

6 kg/h Ethylene 7807.45 kg/h

Chlorine

29341.7

3 kg/h Chlorine 9780.58 kg/h

Steam

12757.2

8 kg/h Steam 4252.43 kg/h

Fuel Gas

137.778

6 GJ/h Fuel Gas 45.9262 GJ/h

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Reaction to produce EDC:

Direct Chlorination :2C2 H4+Cl2→ C2 H 4 Cl2+218 kJmole

Oxychlorination :C2 H 4+2HCl+ 12

O2 →C2 H4 Cl2+ H2O+238 kJmole

Mass of EDC

From Direct

Chlorination

40415.0

5

kg/

h

From Oxychlorination

26943.3

6

kg/

h

2. Energy Balance

a) Heat Exchanger:

To calculate the Area of the Heat Exchangers that are used in this Process, the equation is used

for Energy Balance:

Q=mc c pc¿

Q=mh c ph¿

Q=mh c ph¿

Q : Rate of Heat Transfer (W)

c p : Specific Heat at Constant Pressure (kJ/kg-C)

C=m c p (W/oC)

U : Overall Heat-transfer Coefficient (W/m2oC)

A s: Surface Area (m2)

∆ T m : Log mean Temperature Difference (oC)

Mass Flowrate is calculated by Mass Balance, Temperature is gotten from article and Overall

Heat-Transfer Coefficients is assumed 600 W/m2-C (from Chemical Engineering Design Book).

The Area of each type of Heat Exchange is shown following this table:

Process Heat Exchanger Area (m2)

Direct Chlorination Heat Recovery 30.00091371

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  Cooling Water 24.79641599

Oxychlorination Cooling Water 23.87373533

EDC Cracking Cooling Water 37.65408623

EDC Distillation Steam Cond. 37.65408623

VCM Distillation

 

Refrigerant (HCl Column) 37.65408623

Cooling Water (VCM Column) 30.65298463

b) Cracking Furnace:

To calculate the Duty of Cracking furnace that is shown in EDC Cracking Process, the following

equation is used:

Q=m∆ H rxn+m Cp ∆T

Following the article, ΔHrxn = -71 kJ/mole, and based on number of EDC Mass Flowrate that is

calculate in Mass Balance, the Duty of Cracking Furnace is: 14.26 MW.

V. Process Economics

Assume the Cost of each Material is following this table:

Natural Gas $ 2.50

MMBT

U

$

2.64 GJ

Steam $ 2.00 lb

$

4.41 kg

Ethylene $ 0.60 lb

$

1.32 kg

Chlorine $ 1.50 lb

$

3.31 kg

Capacity 150000 lb/h 68038.936 kg/h

Operating Year 8000 h/year

Based on Material Balance, total Cost to Produce 150000 lb/hr of VCM in a year:

Natural Gas $ 3,876,170.44

Steam $ 599,998,797.02

Ethylene $ 330,479,337.40

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Chlorine $ 1,034,997,924.87

Total $ 1,969,352,229.73

VI. Major Equipment Lists and Capital Cost Estimate

Process Equipment Unit for Size Number # of Equip. Total Cost ($)Direct CNC Reactor Volume (m3) 8.060762891 1 $ 216,044.61 Chlorination Condenser Area (m2) 30.00091371 2 $ 62,397.13 Heat Exchanger Area (m2) 24.79641599 2 $ 61,089.68 Vessel Stripping column Mass (kg) 11731.14699 1 $ 169,597.74 Tray of Stripping Column Diameter (m) 1.5 50 $ 80,823.73 Product Vessel Mass (kg) 11731.14699 1 $ 109,417.90

Oxychlorination Hydrogenation Reactor Volume (m3) 0.851282985 1 $ 90,072.12 Oxychlorination Reactor Volume (m3) 3.678173287 1 $ 153,627.46 Boiler Feed Water Mass Flowrate (kg/h) 4252.425 1 $ 166,524.25 Vessel Quench Column Mass (kg) 14070.59392 1 $ 213,805.64 Tray of Quench Column Diameter (m) 2.7 39 $ 188,974.03 Catalyst Filtration Volume (m3) 3.678173287 1 $ 298,689.22 Cooling Water Area (m2) 23.87373533 2 $ 60,863.27 Vertical Vessel Mass (kg) 14070.59392 1 $ 125,768.02 Horizontal Vessel Mass (kg) 14070.59392 1 $ 380,960.15 Pumps/compressors Power (kW) 500 1 $ 1,412,553.21 EDC Vessel Head Column Mass (kg) 14656.67719 1 $ 214,166.24 Distillation Packing Head Column Volume (m3) 107.405584 1 $ 974,705.67 Vessel High-boils Column Mass (kg) 5909.873075 1 $ 109,256.50 Tray of High-boils Column Diameter (m) 2.9 14 $ 119,629.89 Vessel Vacuum Column Mass (kg) 987.2355475 1 $ 38,828.86 Trays of Vacuum Column Diameter (m) 1.6 8 $ 15,250.51 H.E Head Column Area (m2) 23.87373533 3 $ 91,294.90 H.E High-boils + Vacuum Col Area (m2) 24.79641599 6 $ 183,269.04 EDC Heat Exchanger Area (m2) 37.65408623 4 $ 128,804.60 Cracking Vessel of Quench Column Mass (kg) 7389.440934 1 $ 128,103.92 Trays of Quench Column Diameter (m) 2.3 27 $ 93,574.51

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Vertical Vessel Mass (kg) 7389.440934 1 $ 128,103.92 Horizontal Vessel Mass (kg) 7389.440934 1 $ 70,411.79 Cracking Furnace Duty (MW) 14.25776333 1 $ 993,413.91 EDC Evaporator Duty (kW) 839 1 $ 1,521,799.94 EDC cracker feed pump Volume Flowrate (lit/s) 14.968536 1 $ 10,740.77 VCM Vessel of HCl Column Mass (kg) 594.9910627 1 $ 58,457.12 Distillation Trays of HCl Column Diameter (m) 0.4 50 $ 18,237.53 Vessel of VCM Column Mass (kg) 2794.226778 1 $ 139,482.88 Packing of VCM Column Volume (m3) 14.156376 1 $ 128,469.11 Vessel of HCl Stripper Mass (kg) 1195.932036 1 $ 82,557.01 Packing of HCl Stripper Volume (m3) 6.058944 1 $ 19,994.52 H.E of HCl Column Area (m2) 37.65408623 2 $ 64,402.30 H.E of VCM Column Area (m2) 30.65298463 5 $ 156,410.85 VCM product pump Volume Flowrate (lit/s) 20.74606659 1 $ 11,676.66

Total Cost (based on 2010) $ 9,292,251.11 Total Cost for 2016 (Fig 7.2/336) $ 11,150,701.34

VII. ISBL Estimate

Process Cost $ 1,969,352,229.73 Capital Cost $ 11,150,701.34 Land costs, infrastructure, piping, catalysts, maintenance $ 8,920,561.07 fees with construction:  insurance, or equipment rental $ 4,460,280.53

ISBL COST TOTAL $ 1,993,883,772.67

VIII. Safety

1. Toxicity

Compound PEL (ppm) LD50 (mg/kg)Chlorine 1 239

Hydrogen Chlorine 5 4701

2. Flammability

Material Lower Limit Upper LimitHydrogen 4.1 74.2Ethylene 3.1 32Gasoline 1.3 7

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3. Explosivity Properties

FuelMaximum Flame

Speed (m/s)Adiabatic Flame Temperature (K)

Expansion Factor

Autoignition Temperature (◦C)

Hydrogen 22.1 2318 6.9 400Ethylene 6.5 2248 7.8 490