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An Minh Tran - Cheg 407 - Case 1

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An Minh Tran - Cheg 407 - Case 1

  1. 1. 1 CHEG 407 Spring-2016 Case 1: Vinyl Chloride Submitted to Dr. BORDEN BY An Minh Tran ID#: 000058739
  2. 2. 2 Contents I. 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
  3. 3. 3 I. Executive Summary Vinyl Chloride (VCM) is made from Ethylene (𝐶2 𝐻4) 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.
  4. 4. 4 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
  5. 5. 5 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.
  6. 6. 6 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.
  7. 7. 7 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.
  8. 8. 8 III. Flow Sheet: Flowsheet is shown in the following Excel File An Minh Tran - Cheg 407 - Case 1.xlsx 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
  9. 9. 9 459 kg of Ethylene will produce 1025 kg of VCM in theorical. Percent Yield is: 1000 𝑘𝑔 1025 𝑘𝑔 × 100% = 98% Reaction to produce VCM: Direct Chlorination: 𝐶2 𝐻4 + 𝐶𝑙2 → 𝐶2 𝐻3 𝐶𝑙 + 𝐻𝐶𝑙 Oxychlorination: 2𝐶2 𝐻4 + 𝐶𝑙2 + 1 2 𝑂2 → 2𝐶2 𝐻3 𝐶𝑙 + 𝐻2 𝑂 To produce 150000 lb/h VCM with 98% Yield, the process need: Ethylene 31229.81 kg/h Chlorine 39122.31 kg/h Oxygen 9457.390 kg/h Steam 17009.70 kg/h Fuel Gas 183.7048 GJ/h Assume that 75% VCM will be produce from Direct Chlorination, and 25% VCM will be produce from Oxychlorination: Direct Chlorination Oxychlorination Ethylene 23422.36 kg/h Ethylene 7807.45 kg/h Chlorine 29341.73 kg/h Chlorine 9780.58 kg/h Steam 12757.28 kg/h Steam 4252.43 kg/h Fuel Gas 137.7786 GJ/h Fuel Gas 45.9262 GJ/h Reaction to produce EDC: 𝐷𝑖𝑟𝑒𝑐𝑡 𝐶ℎ𝑙𝑜𝑟𝑖𝑛𝑎𝑡𝑖𝑜𝑛:2𝐶2 𝐻4 + 𝐶𝑙2 → 𝐶2 𝐻4 𝐶𝑙2 + 218 𝑘𝐽 𝑚𝑜𝑙𝑒 𝑂𝑥𝑦𝑐ℎ𝑙𝑜𝑟𝑖𝑛𝑎𝑡𝑖𝑜𝑛: 𝐶2 𝐻4 + 2𝐻𝐶𝑙 + 1 2 𝑂2 → 𝐶2 𝐻4 𝐶𝑙2 + 𝐻2 𝑂 + 238 𝑘𝐽 𝑚𝑜𝑙𝑒 Mass of EDC From Direct Chlorination 40415.05 kg/h From Oxychlorination 26943.36 kg/h 2. Energy Balance
  10. 10. 10 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 = 𝑚 𝑐̇ 𝑐 𝑝𝑐(𝑇𝑐,𝑜𝑢𝑡 − 𝑇𝑐,𝑖𝑛 ) = 𝐶𝑐(𝑇𝑐,𝑜𝑢𝑡 − 𝑇𝑐,𝑖𝑛) 𝑄 = 𝑚ℎ̇ 𝑐 𝑝ℎ(𝑇ℎ,𝑜𝑢𝑡 − 𝑇ℎ,𝑖𝑛) = 𝐶ℎ(𝑇ℎ,𝑜𝑢𝑡 − 𝑇ℎ,𝑖𝑛 ) 𝑄 = 𝑚ℎ̇ 𝑐 𝑝ℎ(𝑇ℎ,𝑜𝑢𝑡 − 𝑇ℎ,𝑖𝑛) = 𝑈𝐴 𝑆∆𝑇𝑙𝑚 𝑄: Rate of Heat Transfer (W) 𝑐 𝑝: Specific Heat at Constant Pressure (kJ/kg-C) 𝐶 = 𝑚̇ 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 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 = 𝑚̇ ∆𝐻𝑟𝑥𝑛 + 𝑚̇ 𝐶𝑝∆𝑇
  11. 11. 11 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 MMBTU $ 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 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 CNCReactor 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 Strippingcolumn Mass (kg) 11731.14699 1 $ 169,597.74 Tray of StrippingColumn Diameter (m) 1.5 50 $ 80,823.73 ProductVessel Mass (kg) 11731.14699 1 $ 109,417.90
  12. 12. 12 Oxychlorination HydrogenationReactor Volume (m3) 0.851282985 1 $ 90,072.12 OxychlorinationReactor Volume (m3) 3.678173287 1 $ 153,627.46 BoilerFeedWater Mass Flowrate (kg/h) 4252.425 1 $ 166,524.25 Vessel QuenchColumn Mass (kg) 14070.59392 1 $ 213,805.64 Tray of QuenchColumn Diameter (m) 2.7 39 $ 188,974.03 CatalystFiltration Volume (m3) 3.678173287 1 $ 298,689.22 CoolingWater 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 HeadColumn Mass (kg) 14656.67719 1 $ 214,166.24 Distillation PackingHeadColumn Volume (m3) 107.405584 1 $ 974,705.67 Vessel High-boilsColumn Mass (kg) 5909.873075 1 $ 109,256.50 Tray of High-boilsColumn Diameter (m) 2.9 14 $ 119,629.89 Vessel VacuumColumn Mass (kg) 987.2355475 1 $ 38,828.86 Trays of VacuumColumn Diameter (m) 1.6 8 $ 15,250.51 H.E Head Column Area (m2) 23.87373533 3 $ 91,294.90 H.E High-boils+VacuumCol Area (m2) 24.79641599 6 $ 183,269.04 EDC Heat Exchanger Area (m2) 37.65408623 4 $ 128,804.60 Cracking Vessel of QuenchColumn Mass (kg) 7389.440934 1 $ 128,103.92 Trays of QuenchColumn Diameter (m) 2.3 27 $ 93,574.51 Vertical Vessel Mass (kg) 7389.440934 1 $ 128,103.92 Horizontal Vessel Mass (kg) 7389.440934 1 $ 70,411.79 CrackingFurnace Duty (MW) 14.25776333 1 $ 993,413.91 EDC Evaporator Duty (kW) 839 1 $ 1,521,799.94 EDC cracker feedpump 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 VCMColumn Mass (kg) 2794.226778 1 $ 139,482.88 Packingof VCMColumn Volume (m3) 14.156376 1 $ 128,469.11 Vessel of HCl Stripper Mass (kg) 1195.932036 1 $ 82,557.01 Packingof 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 VCMColumn Area (m2) 30.65298463 5 $ 156,410.85 VCMproductpump 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
  13. 13. 13 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 Limit Hydrogen 4.1 74.2 Ethylene 3.1 32 Gasoline 1.3 7 3. Explosivity Properties Fuel Maximum Flame Speed (m/s) Adiabatic Flame Temperature (K) Expansion Factor Autoignition Temperature (◦C) Hydrogen 22.1 2318 6.9 400 Ethylene 6.5 2248 7.8 490
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