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LOGO FINAL YEAR DESIGN PROJECT 1
10478 Chan Choon Hoong8142 Hafizah Binti Ahmad Afif8108 Muhamad Rahimi Bin Ali
8145 Jazli Izzuddin Bin Jamaludin8146 Muhammad Emil Hakim Bin Khudri
PRODUCTION OF VINYL ACETATE396,000 tonne/year
1200 tonne/day
PRODUCTION OF VINYL ACETATE396,000 tonne/year
1200 tonne/day
SUPERVISED BY: ASSOC PROF DR. HILMI BIN MUKHTAR
Introduction
This project is designed for students to apply all necessary knowledge acquired throughout the program to conceptually design a new appropriate plant and also to learn to work as a team in order to be a well rounded engineer in the future.
Students may also improve their skills in using the related computer software such as iCON, Sprint, and Microsoft Visio.
Background of Project
Produce VAM via vapor fixed-bed ethylene/ acetic acid technology The reaction path for production would be as follows:
1. C2H4 + CH3COOH + ½O2 → CH2=CHOCOCH3 + H2O (1)
2. C2H4 + 3O2 → 2CO2 +2H2O (2)
Both reactions are parallel in which the first reaction is where the main product is produced (i.e. vinyl acetate).
The second reaction is the undesired reaction producing the undesired product which is carbon dioxide. Both reactions produce same side product which is water.
Case Study TO DESIGN THE PRODUCTION PATH OF VAM
Product Market Study: Vinyl Acetate Market in United States
31% of the world’s total capacity is produced in the United States. World production capacity is expected to reach about 5.8 million tons per
year by 2010 and keep increasing up to 6.4 million tons per year in 2015. Based from track records, in 2004, world’s vinyl acetate consumption was
4.4 million tons. In North America and Western Europe, it is mainly used in the production
of vinyl acetate polyvinyl acetate. Demand expected is about to reach 5.38 million tons and 6.2 million tons
in 2010 and 2015 respectively.
Source: http://www.fjfdi.com
Product Market Study: Vinyl Acetate Market in Europe
VAM mainly is used in production of polyvinylacetate, bonding agents, acrylic fibres, and nonwoven fabric.
Total volume of supplies into Europe is estimated at 150 000 tons per year. The main exporter is the USA. The deliveries on a regular basis are also realised from the countries of Asia as well.
In 2008, many manufacturers increase production and capacities at plant as shown in table in the next slide
Source: http://business.export.by
Capacities of Basic Vinyl Acetate Producers in 2008 (Source: ICIS)
Company Capacities (K tons)
Acetex Chimse (France) 165
Achema (Lithuania) 20
Celenese (Bay City, USA) 300
Celenese (Clear Lake, USA) 310
Celenese Germany) 285
Celenese (Mexico) 115
Celenese (Spain) 200
Companhia Alccoiquimica Nacional (Brazil) 80
Doljchim (Romania) 20
Dom Chemical (USA) 365
Duront (USA) 335
INEOS (Great Britain) 250
LyondellBasell (USA) 380
Stavrlen (Russia) 60
SSME Azot Association (Ukraine) 30
Wacker Chemie (Germany) 200
3115 K tons of VAM in Europe
2008
Location Selection
The factors that should be taken into consideration of selecting a suitable site :- Raw materials availability Market Transportation facilities Utilities Land price and availability Climate Special incentives Waste disposal facilities
Location Selection
After conducting the feasibility and site survey, three (3) main locations have been short-listed
i) Tanjung Langsat Industrial Estate, Johorii) Gebeng Industrial Estates, Kuantan, Pahangiii)Kerteh Industrial Area, Terengganu
Location Selection
Based on the matrix comparison made, Gebeng Industrial Estate has been chosen as the site for the VAM plant.
Justifications : Gebeng industrial estate is situates at east coast of peninsular
Malaysia and it is only 25 km from Kuantan City and 5 km from Kuantan Port
Low land prices compared to other location, RM 5.65 – 38.00 per metre square.
Location Selection East Coast Highway Peninsular Gas Utilisation (PGU) Project Attractive incentives given by the Malaysia government
and local government which is :• Five-year exemption on import duty. • 5 % discount on monthly electrical bills for first 2 years.• 85% tax exemption on gross profit
Constant supply of utilities such as cooling water, power supply, steam and waste management.
Excellent transportation link by railway, road and airport Good pipeline connection between Kerteh and Gebeng
Location Selection
Proposed plant location for VAM plant
Conceptual Design Analysis
Level 1 : Batch or Continuous
Level 2 : Input – Output Structure
Level 3 : Reactor Design & Network Synthesis
Level 4 : Separation System Synthesis
Level 5 :
Heat Integration
Hierarchy of Decisions(Douglas 1988)
1. Process operating mode2. Input-output structure of the flow sheet3. Reactor design and network synthesis4. Separation system synthesis
Separation of impurities Separation and purification of products
5. Heat-exchanger network
Level 1: Process Operating Mode
Criteria Requirement Current design Decision
Production rate
Batch if less than 1 X 106 lb/annum
Continuous if greater than 10 x 106 lb/annum
Production capacity ≈ 727.5 lb/annum Continuous process
Multiproduct plantsPlant is used for production of other product
Production is based on single product which is vinyl acetate
Continuous process
Seasonal production Product generated is of seasonal production
Has been a continuous demand daily for vinyl acetate
Continuous process
Short product lifetime The production is within limited time
Lifespan of the design plant is 20 years Continuous process
Level 2: Input-Output Structure
Decision : Should we purify the feed stream before they enter the
process? Should we remove or recycle a reversible by-product? Should we use a gas recycle and purge stream? Should we not bother to recover and recycle some reactants? How many product streams will there be? What are the design variables for the input-output structure,
and what economic trade-offs are associated with these variables?
Mixer
C2H4
C2H6
ReactionVaporization
HAc
O2
Separation
CO2 Removal
Purification VAM
HAcH2O
O2
HAcC2H4
C2H6
VAMH2OCO2
O2
C2H4
C2H6
Level 2: Input-Output Structure
Level 3: Reactor Design and Network Synthesis
Reactor Design : Selection criteria Reaction path Catalyst Size Operating conditions (Temp & Press) Phase Feed conditions (Temp & Conc.)
Multi Tubular Fixed Bed Reactor
Temperature : 140OC – 160OC (148.5OC)
Pressure : 8 bar – 10 bar (8.7 bar)
Phase : Vapor
Limiting Conditions
Oxygen concentration must not exceed 8 vol % to avoid gas mixtures capable of igniting
Reactor inlet temperature must > 1300C to prevent condensation in the reactor.
The peak reactor temperature along the length of the tube must remain below 2000C, avoid catalyst ageing
An excess of ethylene over acetic acid (3:1) must be guaranteed
The heat of reaction is removed by generating vapor in the shell section of the tubes. This vapor is used in other part of the process
Characteristics
Characteristics Multi tubular Fixed-Bed Reactor
Energy Transfer Mechanism
Shell and tube heat exchanger configuration with tubes packed with catalyst
Conversion Plug flow behavior ensures high conversion per unit mass of catalyst.
Operation Continuous operation
Maintenances
Fixed-bed device will have to be taken offline to regenerate the catalyst by means of shutting down the plant or using standby reactor. Not suitable for frequent catalyst regeneration.
Temperature Control Temperature control with liquid, gaseous or boiling heat transfer agent in shell side space.
Suitability for heterogeneous catalytic gas phase reaction
Catalyst attrition negligible.
Catalyst Lifetime For catalyst that is deactivated slowly
Selection Criteria
Selection criteria for catalysts: High durability High selectivity High production rates per unit volume of catalyst Low cost
Comparison Between Few Alternative
Technologies Phase Catalyst Features
A LiquidPdCl2 / CuCl2
Corrosion problem
B Gas Pd Highly undesired secondary reaction
C Gas Pd / Au Selectivity may reach 94% based on ethylene and 98-99% based on acetic acid
Mass Balance Around Reactor
C2H4 + CH3COOH + ½O2 → CH2=CHOCOCH3 + H2O (1)
C2H4 + 3O2 → 2CO2 +2H2O (2)
ReactionReactionn1 kmol/hr C2H4
n2 kmol/hr C2H6
n3 kmol/hr O2
n4 kmol/hr
CH3COOH
580.79 kmol/hr CH2=CHOCOCH3
n5 kmol/hr CO2
n6 kmol/hr H2O
n7 kmol/hr C2H4
n8 kmol/hr C2H6
n9 kmol/hr O2
n10 kmol/hr CH3COOH
The MEB around reactor as follows:
ξ1 = 580.79 kmol/hr CH2=CHOCOCH3
n5 kmol/hr CO2 = 2ξ2
n6 kmol/hr H2O = ξ1 + 2ξ2
n7 kmol/hr C2H4 = n2 kmol/hr C2H6 – (ξ1 + ξ2)
n8 kmol/hr C2H6 = n2 kmol/hr C2H6
n9 kmol/hr O2 = n3 kmol/hr O2 - (0.5ξ1 + 3ξ2)
n10 kmol/hr CH3COOH = n4 kmol/hr CH3COOH - ξ1
Mass Balance Around Reactor
Component Reactor inlet (kmol/hr)
Reactor outlet
(kmol/hr)
Reactant consumed (kmol/hr)
Product produced (kmol/hr)
Ethylene 6178.6 5560.74 617.86 -
Oxygen 489.83 147.16 342.67 -
Acetic acid 1935.97 1355.18 580.79 -
Vinyl acetate 0 580.79 - 580.79
Carbon Dioxide 0 34.85 - 34.85
Water 0 615.64 - 615.64
Mass Balance Around Reactor
Level 4: Separation System Synthesis
A. Distillation
Heuristic guidelines (Douglas 1988)
1. Separations in which the relative volatility of the key components is close to unity or which exhibit azeotropic behavior should be performed in the absence of non key components. In other words, perform the most difficult separation last.
2. Sequences that remove the lightest components alone one by one in column overheads should be favored. In other words favor the direct sequence.
3. A component composing a large fraction of the feed should be removed first. 4. Favor near-equimolar splits between top and bottom products in individual
columns.
Possible Sequence
A: Vinyl Acetate B: Water C: Acetic acid
SEQUENCE 1 SEQUENCE 2C
B
A B
A
A B C
B C
A B C
A
B
C
Separation
B. Phase separation Liquid-Vapor Separation System
Liquid-Liquid Separation System
Separation
Carbon Dioxide Removal Unit
Amine Treatment Unit Membrane Technology
Usually used to remove small amount of acid gas.
Usually used to remove bulk quantity of acid gas (more than
30%).
Need large amount of spaces usually area near the sea side.
Take only small amount of spaces which usually used in remote area.
Low transportation and maintenance cost.
High maintenance and transportation cost since it is
remote area.
Amine Treatment Unit
Amine solution
C2H6 + C2H4 + O2 + CO2
C2H6 + C2H4 + O2
Amine solution + CO2
Process Flow Diagram
Material Energy BalancesStream 1 2 3
Component Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
O2 616.36 489.83 20.53 148.06 147.16 0.61 148.06 147.16 0.61
HAc 1789.39 1935.97 -8.19 1333.17 1355.18 -1.65 1333.17 1355.18 -1.65
C2H4 6477.61 6178.60 4.62 5763.95 5560.74 3.53 5763.95 5560.74 3.53
C2H6 777.42 777.60 -0.02 738.96 777.60 -5.23 738.96 777.60 -5.23
VAM 1.88 0.00 100.00 594.25 580.79 2.27 594.24 580.79 2.26
H2O 49.44 0.00 100.00 738.84 615.64 16.67 738.84 615.64 16.67
CO2 10.46 0.00 100.00 109.22 34.85 68.09 109.22 34.85 68.09
Stream 4 5 6
Component Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
O2 147.84 147.16 0.46 0.02 0.00 100.00 0.00 0.00 100.00
HAc 60.54 0.00 100.00 53.26 0.00 100.00 0.00 0.00 100.00
C2H4 5724.46 5560.74 2.86 6.24 0.00 100.00 0.00 0.00 100.00
C2H6 732.64 777.60 -6.14 1.14 0.00 100.00 0.00 0.00 100.00
VAM 209.20 145.20 30.59 65.22 145.20 -122.63 0.00 0.00 100.00
H2O 167.04 307.82 -84.28 7.85 0.00 100.00 117.17 307.82 -162.71
CO2 107.58 34.85 67.61 0.20 0.00 100.00 0.01 0.00 100.00
Material Energy BalancesStream 7 8 9
Component Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
O2 147.82 147.16 0.45 147.82 147.16 0.45 147.68 147.16 0.35
HAc 10.55 0.00 100.00 10.55 0.00 100.00 19.20 0.00 100.00
C2H4 5717.98 5560.74 2.75 5717.98 5560.74 2.75 5682.15 5560.74 2.14
C2H6 731.45 777.60 -6.31 731.45 777.60 -6.31 725.06 777.60 -7.25
VAM 139.52 0.00 100.00 139.52 0.00 100.00 0.32 0.00 100.00
H2O 42.28 0.00 100.00 42.28 0.00 100.00 0.02 0.00 100.00
CO2 107.36 34.85 67.54 107.36 34.85 67.54 105.95 34.85 67.11
Stream 10 11 12
Component Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
Simulated (kgmol/hr)
Manual (kgmol/hr)
Deviation (%)
O2 0.01 0.00 100.00 147.67 147.16 0.35 0.24 0.00 100.00
HAc 8.98 0.00 100.00 10.22 0.00 100.00 1325.89 1355.18 -2.21
C2H4 3.21 0.00 100.00 5678.93 5560.74 2.08 45.73 0.00 100.00
C2H6 0.28 0.00 100.00 724.79 777.60 -7.29 7.45 0.00 100.00
VAM 0.00 0.00 100.00 0.32 0.00 100.00 450.26 580.79 -28.99
H2O 1828.46 0.00 100.00 47.88 0.00 100.00 579.65 307.82 46.90
CO2 96.75 34.85 63.98 9.19 0.00 100.00 1.84 0.00 100.00
Material Energy BalancesStream 13 14 15
Component Simulated (kgmol/hr)
Manual (kgmol/hr) Deviation (%) Simulated
(kgmol/hr)Manual
(kgmol/hr) Deviation (%) Simulated (kgmol/hr)
Manual (kgmol/hr) Deviation (%)
O2 0.24 0.00 100.00 0.39 0.00 100.00 0.37 0.00 100.00
HAc 1325.89 1355.18 -2.21 0.03 0.00 100.00 0.00 0.00 100.00
C2H4 45.73 0.00 100.00 101.69 0.00 100.00 75.10 0.00 100.00
C2H6 7.45 0.00 100.00 18.64 0.00 100.00 12.24 0.00 100.00
VAM 450.26 580.79 -28.99 2354.38 580.79 75.33 16.53 0.00 100.00
H2O 579.65 307.82 46.90 698.00 307.82 55.90 3.31 0.00 100.00
CO2 1.84 0.00 100.00 4.35 0.00 100.00 2.88 0.00 100.00
Stream 16 17 18
Component Simulated (kgmol/hr)
Manual (kgmol/hr) Deviation (%) Simulated
(kgmol/hr)Manual
(kgmol/hr) Deviation (%) Simulated (kgmol/hr)
Manual (kgmol/hr) Deviation (%)
O2 0.02 0.00 100.00 0.00 0.00 100.00 0.00 0.00 100.00
HAc 0.03 0.00 100.00 0.00 0.00 100.00 1707.83 1355.18 20.65
C2H4 26.59 0.00 100.00 0.00 0.00 100.00 0.00 0.00 100.00
C2H6 6.40 0.00 100.00 0.00 0.00 100.00 0.00 0.00 100.00
VAM 2337.85 580.79 75.16 16.53 0.00 100.00 1.71 0.00 100.00
H2O 100.84 0.00 100.00 593.94 698.00 -17.52 76.19 0.00 100.00
CO2 1.47 0.00 100.00 0.01 0.00 100.00 0.00 0.00 100.00
Economic Studies
To determine whether a project is feasible and attractive enough for investment.
Acceptable plant design must present a process that is capable of operating under conditions which will yield a profit (Peters M.S and Timmerhaus K.D., 1991).
Economic Studies
Economic Potential 1
EP1 = Revenue – Raw Material Compare between :
Recycle Stream NeglectedRecycle Stream Included
Recycle Stream Included gives a positive value of EP1
Sample calculation at the next page
Economic Studies
ComponentMass Flow Rate
(kg/hr)Price
RM/kg
Total Running Hours in Year
(Hrs)
Annual Value of Product RM/year
RAW MATERIALS
Acetic Acid 106,930.00 1.10 7920 931,574,160
Ethylene 211,880.00 1.95 7920 3,272,274,720
TOTAL RAW MATERIALS 4,203,848,880
PRODUCT
Vinyl Acetate
51,021.45 3.00 7920 1,212,269,652
TOTAL PRODUCT 1,212,269,652
Recycle Stream NEGLECTED
Economic Studies
Economic Potential 1 (EP1) calculation EP1 = Revenue – Raw Material EP1 = (Total VAM produced) – (Acetic Acid Cost + Ethylene
Cost) Assumptions:
Oxygen is obtained from atmosphere. Therefore, it is assumed that no raw material cost is incurred on oxygen feed.
So, before including recycle stream:EP 1 = RM 1,212,269,652 – RM 4,203,848,880 = - RM 2,991,579,228.00 (negative value)
Economic Studies
ComponentMass Flow
Rate (kg/hr)Price
RM/kg
Total Running Hours in Year
(Hrs)
Annual Value of Product RM/year
RAW MATERIALS
Acetic Acid 12,971.22 1.10 7920 113,005,268.60
Ethylene 15,189.02 1.95 7920 234,579,225.00
TOTAL RAW MATERIALS 347,584,493.60
PRODUCT
Vinyl Acetate
51,021.45 3.00 7920 1,212,269,652
TOTAL PRODUCT 1,212,269,652
Recycle Stream INCLUDED
Economic Studies
Economic Potential 1 (EP1) EP1 = Revenue – Raw Material
EP1 = (Total VAM produced) – (Acetic Acid Cost + Ethylene Cost)
Assumptions: Oxygen is obtained from atmosphere. Therefore, it is assumed that no raw material cost is incurred on oxygen feed.
So, by including recycle stream:EP 1 = RM 1,212,269,652 - RM 347,584,493.60 = RM 864,685,158.40 (positive value)
Economic Studies
Economic Potential 2
EP2 = [EP1 (Recycle Stream Included) + By Product] – (Waste Gas)
By product CO2 can be sold to the fertilizer plant and for oil & gas company which can be used for Enhanced Oil Recovery
Our target to achieve green plant technology Positive value of EP2 indicates that this project is feasible
Sample calculation at the next page
Economic Studies Waste Gas and By-product
Chemical InvolveMass flow rate
(kg/hr)Price
RM/kg
Total Running Hours in Year
(Hrs)
Annual Value of Product RM/year
Waste Gas (Stream 17)
Ethylene + Ethane 2474 1.95 7920 38,208,456
Acetic Acid 0 1.10 7920 0
Oxygen 11.84 0.50 7920 46,886
Vinyl Acetate 1423.33 3.00 7920 33,818,320
Carbon Dioxide 126.53 0.2 7920 200,423
TOTAL RM 72,274,085
By-products (Sub flow sheet 1_33)
Carbon Dioxide 4258 0.20 7920 6,744,672
Economic Studies
Since,EP2 = EP1 (Recycle Stream Included) + By Product – (Waste Gas)
Therefore, EP2 = (RM 864,685,158.40 + RM 6,744,672) – (RM 38,208,456
+ RM 46,886 + RM33,818,320 + RM 200,423) EP2 = RM 799,155,745 (positive value)
Economic Studies
Economic Potential 3 (EP3)
EP3 = EP2 – [(Installation Cost of Recycle Compressor 1 + Installation Cost of Recycle Compressor 2 + Installation Cost of Reactor 1)]
Based from EP3 , the value also indicates positive value which also means that the Vinyl Acetate production can be accepted
Sample calculation as per attached In the report
Economic Studies
Installation Costs Reactor 1 = RM 828,334.00 Compressor 1 = RM 22.5 million/year Compressor 2 = RM 2.71 million/year
Since,EP3 = EP2 – (Installation Cost of Recycle Compressor 1 + Installation Cost of Recycle Compressor 2 + Installation Cost of Reactor 1)
So, EP3 = (RM 799.2 million /year) – (RM 828,334.00/year + RM 22.5 million /year + RM 2.71 million /year)
≈ RM 773 million/year
Heat Integration
PURPOSE OF HEAT INTEGRATION The cost of the utilities and energy is one of the major costs
in a process plant. Hence, utilities and energy costs savings has become one of the major issues in plant design. Heat integration enables the plant to optimize the energy of utilities usage by exchanging heat using process stream instead of utilities or energy.
Pinch Technology Method
The amount of energy can be determined from the process plant by using the Pinch Technology Method.
The most common method to calculate the amount of energy recovered using the pinch technology are through plotting composite curve or using the problem table algorithm.
For our plant, the Problem Table Algorithm is used to calculate the energy recovery due to accuracy in the results as compared to the composite curve method.
Methodology of Heat Integration
Stream Data from Sprint
Composite Curve
Grand Composite Curve
Heat Integration
Design of HEN
C
C
C
C
C
DH: 2529.37T: 132.71
DH: 34147.102T: 42.51
DH: 295.698T: 42.51
DH: 4199.483T: 42.51
DH: 5081.95
DH: 5288.19
DH: 33341.6
DH: 1556.48
DH: 4984.8
CP: 378.068
CP:3.298
HDH: 38308.037
CP:161.894
CP:216.174
DH: 26.39T: 147.19
DH: 186.463T: 149.23
C
From Grid diagram generated using SPRINT, we can design the heat exchanger network. The table below shows the design of heat exchanger.
Cold 2
Cold 1
Cold 1
Heat Integration
THANK YOUQ & A SESSION
Plant Layout
referred to PTS 20.158B and PTS 20.152G
Site selectio
n
Site layout & develop
ment
Classification of hazardous areas
Safety distance
s