Liquefied Petroleum Gas plant design Faculty Advisor: Dr. Mohamed A. Nakoua Group members

1. Training and Graduation Project UnitGraduation Project II Fall 2010 Liquefied Petroleum Gas plant design Faculty Advisor: Dr. Mohamed A. Nakoua Group members

2. Acknowledgment • We would like to express our deepest gratitude and appreciation to our project advisor Dr. Mohamed Nakoua for his guidance, continuous encouragement and support to complete this work.

3. Outline • Introduction to LPG • Process alternatives • Material and energy balance • Equipment detailed design • HAZOP study • Cost estimations • Conclusions

4. Introduction to LPG • Liquefied petroleum gas (LPG) is a term describing a group of hydrocarbon-based gases derived from crude oil or natural gas. • LPG is mainly a mixture of two gases: propane and butane. • LPG has wide uses in the world such as: • fuel • heating and cooking • Transportation

5. LPG in UAE • UAE holds the 6th largest proven natural gas reserves in the world. • Natural Gas consumption is increasing in UAE .

6. LPG Needs • Economically valuable because of its wide uses and considerable energy content • A single pound of propane can generate 21,548 BTU (British Thermal Units) of energy, while butane can produce 21,221 BTU per pound. • LPG carbon emission is less than CO2 emission from crude oil fuels.

7. Two Alternatives for Plant Processes • First alternative • Second alternative

8. Material and Energy Balance • Material Balance: Molar flow rates and compositions for each stream were found. • Energy Balance: Heat duties and temperatures were found.

9. Decided Plant Flow Chart

10. Process Streams

11. Cont. Process Streams

12. Equipment Design • Design of main equipment was carried out • Main equipment designed are : distillation column, absorber, reboiler and heat exchanger • Different methods were used: • Mathematical equations • Graphical method • HYSYS software • Results for different methods were compared

13. Distillation Column Design • Deethanizer is the selected distillation column to be design • Underwood method was used

14. Design Results

15. Other Distillation Columns Design • Distillation design results :

16. Absorber and Stripper Design H2S: 0.0% CO2: 3% H2S: 0.6% CO2: 7%

17. Required Data • H2S entering is much less than CO2 • Reaction rate of H2S in amine solutions is higher than that of CO2

18. Number of trays calculation Number of trays was calculated by:

19. Edmister Method (1947) • K (equilibrium constant of CO2 in DEA) values were obtained from HYSYS.

20. Graphical Method • Two curves were plotted: • Over all material balance. • Equilibrium data (CO2 in DEA)

21. HYSYS Simulation • Number of trays was changed until required separation was achieved.

22. Final Results • Comparison between the three methods: • Final results

23. Comparison with Existing Plant

24. Pump Design • The type is centrifugal pumps • Power is given by: Discharge Suction

25. Pump Calculations’ Results

26. Reflux Drums Design • Drums are horizontally mounted. • Volume is calculated by: • Τ (residence time) = 5 min • Diameter is found by:

27. Design of Heat Exchanger

28. Design of Heat Exchanger T = 27 oC T = - 6 oC

29. Shell and tube heat exchanger • Consists of one shell pass, with numbers of tubes in six passes attached to an end plate called bundle.

30. Standards • Overall heat transfer coefficient (U),( 30 – 300 W/m2.oC) • Heat exchanger length (L), ( 2.5 – 6.5 m) • Heat transfer area (A), (10 – 1000 m2) • Tube velocity (ut) for gases, (3 – 10 m/s) • Pressure drop (∆P), ( <= 3 psi )

31. Different Design Alternatives

32. Design Results U assumed = 67.1 W/m2.oC

33. Reboiler Design

34. Reboiler Design

35. Kettle Reboiler • Consists of one shell pass, with U tubes arrangementattached to an end plate called bundle.

36. Design Result • Final results for designed reboiler

37. Safety & HAZOP Considerations • HAZOP is important to prevent all possible dangers present in the plant • Operating plant deals with H2S and CO2(toxic gases) • Safeguards should be considered

38. Reboiler HAZOP Study

39. Cost Estimation • Cost estimation is the most important point to study and evaluate in project management • Cost estimation is divided into: • Capital cost • Manufacturing cost (COM)

40. Capital Cost • Capital cost was calculated by: • Bare module cost equations • CAPCOST program

42. Capital Cost • Total bare module cost:

43. Cost of Manufacturing (COM) • COM is the cumulative total of resources that are directly used in the process • Fixed Capital Investment (FCI) • Operation labour (UT) • Waste treatment (WT) • Raw material (RM)

44. Results of COM • The following table shows the COM:

45. Profitability of Project • Profit =∑ Income from sales – COM • Cash = Profit + depreciation (COMd)

46. Summary Of Cost Estimation

47. Conclusions • An LPG Plant process flow diagram was prepared • Main units were designed • Environmental issues were considered • HAZOP study was carried for main units • Plant cost was estimated • LPG Plant project is feasible • LPG production rate is 16746054 ton/yr • Yearly profit is 6.473 x 109 $/yr • The project is able to achieve its requirements.

48. Recommendations • Other capital cost is to be considered: land, working capital and installation of units • Communicate with industry for the acheived work

49. Thank you for listening