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Presentation PX
The production of p-xylene is important for Pakistan's domestic and foreign markets. P-xylene is a raw material used to produce terephthalic acid and polyethylene terephthalate (PET). There are three main processes for producing p-xylene: toluene methylation, PAREX process, and isomerization of meta-xylene. The toluene methylation process has the lowest initial investment cost but yields a lower purity of p-xylene compared to the other processes.
Presentation PX
- 3. The productionof large amounts of heavy naphtha is inevitable in refineries across Pakistan, amongst other components which are also of immense importance p- xylene holds extraordinary importance for Pakistan in virtue of its value in both foreign and domestic markets. P-xylene forms major raw material for the production of terephthalic acid (TPA) which further converts into polyethylene terephthalate (PET).
- 4. Toluene MethylationProcess PAREX Process Isomerization of meta-xylene 0 10 20 30 40 50 60 70 Initial Investment/ $ Million Initial Investment/ $ Million 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% Yield of Para-xylene Yield of Para-xylene
- 6. STEAM ID 12 3 4 5 6 7 8A 8C 8D H2 0 3318.4 3318.4 3301.1275 2.08 3298.8 0 2.079 0 0 ETHYL BENZENE 42.7 1.1 43.8 43.8 32.07 11.6 28.89 0.169 45 3 PARA XYLENE 84 2.3 86.3 142.587 139.9 2.61 132.6 0.3506 104.97 6.998 META XYLENE 293 5 298 211 207.24 3.72 198.6 0.4945 149.355 9.957 ORTHO XYLENE 21.4 1.6 23 52.0717 51.32 0.745 50.44 0 12.7695 0.8513
- 8. Material Carbon steel L:B:H Ratio 1:2:2 Height(H) 50 ft Air pre heat (F) 400 Furnace length (ft) 25 ft No. of tubes 32 Tubes skin temperature (F) 1000 Flux (Btu/hr.ft2) 11500 Furnace Duty (MMBtu/hr) 17.67 Stream tag 3 Description Octafiner Charge Temperature 135 oF Pressure 217 psig
- 9. M P M O 2MTOL + TMB ERGUN EQUATION: CHEMICAL REACTION: Meta Xylene Conversion = 29.19 % Para Xylene Selectivity = 65% Ortho Xylene Selectivity = 33.4% % COKE = e-αt REACTION TIME = 5.513 sec
- 10. Material Carbon steel Type OfColumn Packed Diameter Of Bed (ft) 7 Diameter Of Particle (in) 0.25 Porosity (φ) 0.45 Bulk Density Of Catalyst (lb/ft3) 25.82 Designed Height Of Packing (ft) 13.6 Catalyst Precoked ZSM-5 Stream tag 3 4 Description Reactor feed from furnace Reactor Effluent Temperature 135 oF 952 oF Pressure 217 psig 173 psig
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- 12. Material Carbon steel L/D 3.3 Lengthof Vessel (ft) 15.19 Diameter of Vessel (ft) 4.59 Volumetric Flow rate (ft3/s) 42.89 Terminal Velocity (ft/s) 2 Maximum Allowable Velocity (ft/s) 2.58 Height of Liquid Holdup Section (ft) 5 Retention Time (min) 2 Stream tag 4 5 6 Description Reactor Effluent Light Aromatic column feed Fuel gas Temperature 95 oF 95 oF 95 oF Pressure 160 psig 14 psig 140 psig
- 13. Heat Duty (MMBtu/hr)3.8 No. Of Tubes 408 Length Of Tube(ft) 16 Outer Diameter of Tube (in) 0.75 Pitch (in) 1 Tube Passes 8 Pressure Drop In Tubes (psi) 2.26 Heat Transfer Area (ft2) 1250 Internal Diameter of Shell (in) 27 Baffle Spacing (in) 5.4 Pressure Drop in Shell (psi) 1.34 Stream tag 5 7 Description Light Aromatic column feed Column Bottoms Temperature 95 oF 322 oF Pressure 14 psig 14 psig
- 14. Mass Flow Rate (lb/hr) 46895 Differential Pressure(psi) 280 Horsepower (KW) 13.116 Horsepower (HP) 17.65 Efficiency 54.8 Brake Horsepower (HP) 32.2 Stream tag 1 Description Octafiner charge Temperature oF 60 Pressure psig 0
- 16. Guide Words ParametersCauses Consequences Actions Less Less Flash drum pressure - Lower feed temperatur e Higher liquid level. Install pressure and temperature controller prior to the drum. - Leakage in the Flash drum Vapor lost and not recovered at the top. Install pressure indicator on the drum or replace vessel. Less level of liquid in the flash drum - Blockage in the inlet stream No separation occurs. Low level alarm. High High Flash drum pressure - Blockage in the vapor stream Risk of drum explosion. Install pressure alarm. High liquid level in the flash drum - Blockage in the liquid stream Less liquid leaving the flash drum. Install high level indicators and high level alarm should be installed. - Liquid stream too cold Less vapor fraction, chances non- condensable will enter the column that follows. - Install temperatur e controller on the feed stream.
- 17. Guide Words Parameter Causes ConsequencesActions Less Pressure - Leakage in the column - Vapor lost and not recovered at the top. Install pressure indicator on the column or replace vessel. Level - Blockage in the inlet stream - No separation occurs. Low level alarm. Flow - Pipe partially blocked - Pipe leakage - Level decrease in distillation column - Off specification product - Back flow of material Install check valve Temperature - Furnace Failure - Low power supply - Low energy steam - Reaction favor to reactant formation Install monitoring system and temperature sensor Supply enough energy High Level - Output pipe blockage - Overpressure of reflux drum - Condensed liquid flow back in liquid Install high level alarm Scheduling inspection Temperature - Furnace Malfunction - Temperature control failure - Difficult to remove excess heat - Steam become superheated Install temperature sensor Regular system checking Flow - High pressure from source - Flooding in Distillation Install bypass line with a manual
- 18. Methods of recovery Adsorption method Distillation Method Crystallization Method
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- 20. Stream ID 1 2 34 5 6 6a 6b 7 7a 7b 7c Total (LB/hr) 33000 36859 18429 18429 4213 33711 6742 26969 14037 11230 2807 7193 Ethyl Benzen e 2405 2687 1343 1343 313 2865 573 2292 196 157 39 100 Para Xylene 8283 9251 4625 4625 990 4180 836 3344 11932 9545 2386 6114 Meta Xylene 18734 20925 10462 10462 2443 22384 4476 17907 1586 1269 317 812 Ortho Xylene 3577 3995 1997 1997 466 4281 856 3425 308 247 61 158
- 21. Mass Flow rate ProcessStream 18000 lb/hour Mass Flow rate Ethylene Refrigerant 15000 lb/hour Inlet Temperature of Ethylene -71 F Outlet temperature of Ethylene -18 F Inlet temperature of Process Stream -11 F Outlet Temperature of Process Stream -45 F Mass Flow rate Process Stream 10375 lb/hour Mass Flow rate Propane Refrigerant 9000 lb/hour Inlet temperature of Propane -1 F Outlet Temperature of Propane 59 F Inlet temperature of Process Stream 64 F Outlet Temperature of Process Stream 25 F 2nd Stage Crystallizer1st Stage Crystallizer
- 23. Purchased Cost ofEquipments (PCE) 0 100000 200000 300000 400000 500000 600000 700000 Cost/ $ Cost/ $
- 24. Purchased Cost ofEquipments (PCE) $1394897.8 Physical Plant Cost (PPC) $3040976 Fixed Capital Investment (FCI) $4575263 Working Capital Investment (WCI) $823547 Variable Costs $21766416 Utilities Costs $55023 Fixed Costs $2276826 Annual Production Cost $33660539 Profit Per Year $184828 Payback period 13.59 years
- 25. Discounted Purchased Costof Equipments (DPCE) $209234 Discounted Physical Plant Cost (DPPC) $456129 Discounted Fixed Capital Investment (DFCI) $686286 Discounted Working Capital Investment (DWCI) $123531 Discounted Variable Costs $21766416 Discounted Utilities Costs $55023 Discounted Fixed Costs $2276826 Discounted Annual Production Cost $33660539 Discounted Profit Per Year $184828 Payback period 2.04 Years
- 26. 0 1000000 2000000 3000000 4000000 5000000 6000000 COST/$ DISCOUNTED VS NORMALCOST Normal Discounted DISCOUNTED VS NORMAL COST
- 27. SOURCE: United Nations CommodityTrade Statistics Database Pakistan Yearly Imports in US Dollars
- 28. 17% 83% BYCO’s POSSIBLE SHAREOF DOMESTIC PARA XYLENE MARKET BYCO'S SHARE IMPORTS
- 29.