Title: Design of an Ethylene Plant from Natural Gas Derived Feed
1United Arab Emirates University College of
Engineering Graduation Project 2
Design of an Ethylene Plant from Natural Gas
Derived Feed
Ismail Abdalla Al-Ali 199900293 Mohamed Saeed
Al-Ameri 199905057 Hassain Naje
199900270 Faculty Advisor Dr. Farid Benyahia
Coordinator Dr. Munjid Maraqa
2Content of presentation
- Introduction
- PID HAZOP Study of Section of the Plant
- Project Costing Economic Evaluation
- Mechanical Design of a Selection of Major Process
Equipment -
- Conclusion
3Objective
- To design, cost and evaluate safety and
environmental impacts of an ethylene plant in the
UAE.
4Introduction
- The work done in GP1
- Ethylene marketing
- Safety and environmental impact assessment
- Process technologies of ethylene production
(Licensed Petrochemical Processes) - and make a comparison between technologies
- Process description and representation by a PFD
- The plant site location
- Preliminary cost
- Completed material balance
- Completed energy balance
5- The work done in GPII
- Piping and instrumentation diagram (PID) and
HAZOP study of section of the plant - Detail economic evaluation of the process
- Mechanical design of a selection of major process
equipment
6PID HAZOP Study of Section of the Plant
- The Piping and Instrument Diagram (PID) shows the
engineering details of the equipment,
instruments, piping, valves and fittings and
their arrangement. - Instruments are provided to monitor the key
process variable during plant operation. - The primary objective of the designer when
specifying instrumentation and control schemes
are - Safe plant operation
- Production rate
- Product quality
- Cost
7- The Piping and Instrument Diagram (PID) as in
Figure 1 without HAZAP study. - Hazards and operability studies (HAZOP) involves
a systematic study of the process or parts of it.
- It is applying special guide words to generate
thought about the way deviations from the
intended operating conditions can cause dangerous
situations.
8Example of HAZOP study
HAZOP for cracking section Table 1 HAZOP study
in S1 for flow deviation
9- The PID has been upgraded after the HAZOP study
to improve the process safety as in Figure 2.
10Project Cost and Economic Evaluation
- Cost plays an active role for the engineering
life. - The design engineer needs to be able to make
quick, rough, cost estimates to decide between
alternative designs and for the project
evaluation. - Costing of the Project
- Preliminary (approximate) estimates, accuracy
typically 30 . - Authorization (Budgeting) estimates, accuracy
typically 10-15 . - Detailed (Quotation) estimates, accuracy
typically 5-10 .
11Fixed Capital
- It is the total cost of the plant ready for start
up. - This cost doesn't return back when the project is
finish and it paid one time. - It includes the cost of
- Design and other engineering and construction
supervision. - All items of equipment and their installation.
- All piping, instrumentation and control systems.
- Building and structure.
- Auxiliary facilities, such as utilities, land and
civil engineering work.
12Working Capital
- It is the additional investment needed
- includes the cost of
- Start-up.
- Initial catalyst charges.
- Raw materials and intermediates in the process.
- Finish product inventories.
- Funds to cover outstanding accounts from
customers. - Most of the working capital is recovered by the
end of the project. - The total investment needed for a project is the
sum of the fixed and the working capital.
13Step Counting Methods
The correlation of Timms, IChemE (1988) gives a
simple equation for gas phase processes.
- C 8000 N Q0.615
- C capital cost in US dollars
- N number of functional units
- Q plant capacity, tonne per year
14C 8000 18 (600000)0.615 515,140,282 US
Dollars
This cost is valid for 1998 according to the
correlation shown above
Cost 2003 (Cost Index 2003)/ (Cost Index 1998)
(Cost 1998) (398) / (390)
(515,140,282) 525,707,262 US Dollars
Cost of the plant in 2004 496501303 1.02
536,221,407 US dollars
Cost of the plant in 2005 496501303 1.02
546,945,835 US dollars or approximately 547
million US Dollars
15Total Investment
- Investment is spread over 4 years
- Total investment Year 1 Year 2 Year 3
Year 4 546,945,835 US Dollars
16Operating Cost
- Fixed Operating Cost
- For each year up to year 10
- Operating cost 0.037 Capital cost
20,236,996 - From year 10 up to year 17
- Operating cost 0.046 Capital cost
25,159,508 - From year 17 to year 30
- Operating cost 0.055 Capital cost
30,082,021 - Variable Operating Cost
- For each year up to year 17
- Variable cost 17 /tone
- From year 17 to year 30
- Variable cost 22 /tone
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18Rate of Return (ROR) and Discount Cash Flow (r)
Calculations
Where Cumulative net cash flow at end of the
project 6856.8 106 Life of the
project 30 year Original investment
546945835.2 ROR 41.79
The discount rate (r) 33.74
19Mechanical Design of a Selection of Major Process
Equipment Economic
- The chemical engineer is normally required to
specify the main dimensions of the pieces of
equipment. - The mechanical design is done to
- Shell and tube heat exchanger
- Column of DET
- Column of DEE
20Heat Exchanger
- The transfer of heat to and from process fluids
is an essential part of most chemical processes. - The shell and tube exchanger is far the most
commonly used type of heat transfer equipment
used in the chemical and allied industries.
21Results of calculation for different tube
diameters
Table The mechanical design result of HE 2 at
different tube inside diameter (30, 25 and 16 mm).
22Table 3 Insulation of HE 2 and the shell
thickness.
23Figure Shell and Tube Heat Exchanger
2
24Distillation Columns
- The separation of liquid mixtures into their
several components is one of the major processes
of the chemical and petroleum industries, and
distillation is the most widely used method of
achieving this end.
25The result of DEE calculations
Table Summary of the results for various plate
spacing
26Figure DEE Column
27The result of DET calculations
Table 5 The result of DET calculations
28Figure DET Column
29Conclusion
- The HAZOP study was done to enhance the level of
instrumentation in order to improve safety. This
was comprehensively achieved by applying
different guide words to process variable
deviations like temperature, pressure and flow
(No, Less and More). - The economic evaluation of the project was
carried out. The plant capital cost was found to
be approximately 547 million US Dollars. - The rate of return (ROR) was found to be 41.71
and the discount cash flow (r) was 33.37 . - The project was found to be economically viable
because ROR is larger than r. This means that the
plant can be built and operated at a good profit.
30- Since our process was rather large, the main
equipment considered for detailed mechanical
design were heat exchanger number 2 (HE 2) in the
cracking section, deethylenizer column (DET) and
deethanizer column (DEE) in the purification
section. - The design calculation of HE 2 showed that
- Inside tube diameter 16 mm,
- Shell diameter 3 m,
- Ethane velocity 6.32 m/s,
- Number of baffles 13,
- The insulation thickness 79 mm, and
- The shell thickness 10 mm.
- The design calculation of DET column showed that
- The diameter of column 2.50 m,
- The height of column 56 m, and
- The column shell thickness 4 mm.
- The design calculation design of DEE showed that
(at plate spacing 0.5 m) - The diameter of column 1.70 m,
- The height 11.5 m,
- The isolation 0.032 mm, and
31Thank YouFor Listening
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33The Diagram of Ethylene Process with PID
34The Diagram of Ethylene Process with PID After
HAZOP Study