Process and Plant Design 1 •
Group 11
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Members: Andy Tan Tan Eng Tat Leonard Leonard Tan Jian Jian Zheng Lim Su Wei Leow Kok Chung Ong Ching Yeh
Production Of Ethyl Acetate
Production Of Ethyl Acetate
Purpose of The Presentation Presentation •
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To investigate the current problems or issues pertaining to the ethyl acetate production production process process and formulate formulate solutions in overcoming the problems Three Three parts - Task 1,2,3 1,2,3 Task 1 – Market Market Demand, Location, Pathwa Pathway y Task 2 – Process Process Description, Description, Preliminary Process Process Synthesis, Heuristics Task 3 – Unit Operation Operation and Simulation Simulation
Task 1 Outlines 1. Prope Propert rtie iess of Ethy Ethyll Acet Acetat ate e 2. Appli Applica cati tions ons of Eth Ethyl yl Acet Acetat ate e 3. Prob Proble lem m St Statemen ment 4. Globa Globall Mark Market et of Ethy Ethyll Ace Aceta tate te 5. Choo Choosi sing ng the the Righ Rightt Pla Plant nt Loca Locati tion on 6. Select Selecting ing the Most Most Pro Promis mising ing React Reaction ion Path Pathwa ways ys 7. Drawb Drawback ackss and Improv Improveme ements nts of Ester Esterific ificati ation on Reaction
Properties of Ethyl Acetate •
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Organic Compound Formula C4H8O2 Colorless Volatile Flammable Fruit Smell Slightly Soluble In Water/ Soluble In Organic Organic Solvents
Applications of Ethyl Acetate •
Artificial Fruit Enhancer
Applications of Ethyl Acetate •
Solvent/Thinner
Applications of Ethyl Acetate •
Flexible Packaging
Problem Statement Two Aspects 1. Business To Find The Most Promising Pathway Maximize Profits Minimize Production Cost Sustainability of Market 2. Social and Moral Environmental Concerns •
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Global and Regional Markets of Ethyl Acetate •
2005-2013
Global Markets of Ethyl Acetate
Choosing The Right Plant Location Consider following factors 1. Political Stability and Government Policies 2. Availability of Raw Materials 3. Connectivity/Transportation 4. Power and Water Supply 5. Waste Management Disposal 6. Flood and Fire Prevention 7. Human Resources (Skilled/Unskilled) 8. Proximity to The Market
Locations Considered 1. Yanbu Industrial City, Yanbu Al-Bahr, Saudi Arabia (THE SELECETED LOCATION) 2. Mount Kuring-Gai, New South Wales, Australia 3. YanTianGang Free Trade Zone, Yantian District, Shenzhen City, China
Why Yanbu Industrial City in Saudi Arabia ? •
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Petroleum derived raw materials are cheap in Saudi Arabia Shortage of ethyl acetate supply in Saudi Arabia Strategic Location(Located along Red Sea and near Suez Canal) which can cater for Western Asia and Europe markets China’s market is saturated Expensive labor cost in Australia
Yanbu Industrial City, Yanbu Al-Bahr Saudi Arabia
Yanbu Industrial City, Yanbu Al-Bahr Saudi Arabia
Selecting the Most Promising Reaction Pathways 1. Esterification (The Selected Pathway) 2. Tischenko Reaction 3. Addition of Ethylene and Acetic Acid 4. Dehydrogenation of Ethanol 5. Oxidation of Ethanol
Esterification .
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CH CH OH + CH COOH
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Reversible reaction
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Remove water by-product to drive reaction to the right Advantages •
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Ease of raw material availability Non-toxic, less harmful raw materials Less cost of catalyst
CH COOCH CH + H O( )
Disadvantages •
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Ethanol conventional air pollutant Water as waste product impeding reaction eventually
Tishchenko Reaction ‘
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Two equivalents of acetaldehydes Advantages •
Raw material acetaldehyde is not costly
Disadvantages •
Acetaldehyde is a very toxic substance
Addition of Ethylene and Acetic Acid •
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Avada H C = CH + CH COOH Advantages •
Energy efficient, environmentally friendly
CH COOCH CH
Disadvantages •
Ethylene requires special safety and fire fighting facilities
Oxidation of Ethanol •
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C H OH + O
CH CHO+ O
C H OH + CH COOH
CH COOH
CH COOC H + H O
Advantages •
CH CHO+H O
Availability of raw material ethanol
Disadvantages •
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Weak metal support interaction High risk of explosion requires larger reactor size and costs
Dehydrogenation of Ethanol •
Carried out in four process stages
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2CH CH OH g → CH COOCH CH g +2H g Advantages •
Ethanol is easily available
Disadvantages •
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Complicated Unit Operations Acetaldehyde has high toxicity
Why Esterification is Chosen ?
Why Esterification is Chosen? 6 Points •
Raw Material
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Safety, Health and Environment
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Utilities
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Simplicity of The Process
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Operating Conditions
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Conversion and Selectivity
Why Esterification is Chosen? •
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Raw Materials for Tishchenko Reaction cannot be found in Saudi Arabia Technology of dehydrogenation of ethanol is still developing Catalysts used in oxidation of ethanol are expensive despite the reaction gives highest profit
Why Esterification is Chosen? •
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Avada process has short reaction rate and depends highly on the performance of catalysts Avoid usage of Acetaldehyde as raw material as it is toxic and very harmful
Drawbacks and Improvements of Esterification Reaction •
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Heterogeneous catalyst replaces homogeneous catalyst Reactive Distillation is suggested for Esterification Reaction Heuristic studies are conducted to avoid repeating the same mistakes in the future
Drawbacks and Improvements of Esterification Reaction Reactive Distillation Shifting chemical equilibrium and thus results in an increase of conversion of raw material by simultaneous reaction and separation product. Suppression of side reaction and thus higher purity of desired product can be obtained. Utilization of heat of reaction (esterification is an exothermic reaction) for mass transfer operation. These features on the process can further lead to economic benefits which are shown below: Lower capital investment (reactive distillation combined both the function of reactor and distillation column) Lower energy cost (heat generated from the process in used as the mass transfer purpose) Higher product yield (Suppression of water by-product ) •
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Task 2 Outlines 1. Process Description 2. Preliminary Process Synthesis 3. Heuristics
Process Description •
EtOH + HAc ⇌ EtAc + H2O •
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Azeotropic mixture Total of 4 azeotropes
Mixtures
Compositions (mole fraction)
Temperature ( oC)
EtOH/H 2O
(0.9037, 0.0963)
78.18
EtAc/EtOH
(0.6885, 0.3115)
71.81
EtAc/H2O
(0.6885, 0.3115)
70.37
EtAc/EtOH/H 2O
(0.1126, 0.5879, 0.3085)
70.09
Compositions and Temperatures for EtAC System
Ternary Azeotrope Diagram
Process Description •
Single double-feed reactive distillation column incapable to produce high purity EtAc
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Two-column design with decanter
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Decanter as liquid-liquid separator
Preliminary Process Synthesis •
Step 1: Eliminate Differences in Molecular Types
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Step 2: Distribution of Chemicals
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Step 3: Eliminate Differences in Composition
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Step 4: Eliminate Differences in Temperature, Pressure and Phase Step 5: Task Integration
Step 1: Eliminate Differences in Molecular Types Reaction
Pathway 1
Pathway 2
Pathway 3
Pathway 4
Pathway 5
Availability
Easily
Not easily
Easily
Available
Available
available
available
available
0.3566
0.2951
0.3221
0.6667
0.6873
Corrosive
Highly toxic
Corrosive
Flammable
Flammable
and
and
and
raw material
raw material
flammable
flammable
flammable
raw material
raw material
raw material
Gross Profit ($/Ib EtAc)
Safety Consideration
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Reaction Pathway 1 (Esterification): CH3CH2OH + CH3COOH → CH3COOCH2CH3 + H2O Reaction Pathway 2 (Tishchenko Reaction): CH3CHO → CH3COOCH2CH3 Reaction Pathway 3 (Avada): C2H4 + CH3COOH → CH3COOCH2CH3 Reaction Pathway 4 (Oxidation of Ethanol): CH3CH2OH + CH3COOH → CH3COOCH2CH3 + H2O Reaction Pathway 5 (Dehydrogenation of Ethanol): 1 C H OH + O CH CHO+ H O 2 1 CH CHO+ O CH COOH 2 C H OH + CH COOH CH COOC H H
Step 2: Distribution of Chemicals •
Assumptions: 1) Conversion of acetic acid, HAc is 100% 2) Operation time for plant set to 8400 hours per year; 350 days per year: 6012.35 kg/hr for 10,000 tonnes of product 3) Outlet composition of the reactive distillation column is near minimum ternary azeotrope 4) Outlet composition of the stripper is obtained from the process design of the stripper 5) Components in the decanter is in equilibrium
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Overall balance:
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A = 3471.582068 kg Ethanol/hr
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B = 4198.91034 kg HAc/hr
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C = 1658.142408 kg/hr
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Ethyl acetate product at 6012.35 kg/hr
Step 3: Eliminate Differences in Composition •
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Reactive distillation column for reversible chemical reaction Simultaneous separation of products and recycle of incompletely consumed reactants
Part of Process Flow Diagram – Top of RDC and Decanter
Step 4: Eliminate Differences in Temperature, Pressure and Phase
Process Flow Diagram
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Reboiler heated up before feed stream is fed to reboiler Top RDC product as vapour passes through condenser and changed to liquid form Liquid phase to decanter Manipulating heat input to stripper to maintain same temperature of bottom temperature to stripper Final product stream passed through cooler to reduce temperature of final product
Step 5: Task Integration Condenser
Decanter
Reactive Distillation
Reboiler
Process Flow Diagram Stripping Tower
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Reactive Distillation (RD) Column and Condenser Separation being done; consist of two sections:1) Reactive section 2) Rectifying zone
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Stripper and Condenser
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Decanter
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Cooler
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Control Valves
Heuristics •
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Heuristic 1: “Select raw materials and chemical reactions to avoid, or reduce, the handling and storage of hazardous and toxic chemicals.” Heuristic 2: “Use an excess of one chemical reactant in a reaction operation to completely consume a second valuable, toxic, or hazardous chemical reactant.” Heuristics 8: “For reversible reactions, especially, consider conducting them in a separation device capable of removing the products, and hence, driving the reactions to the right. Such reaction-separation operations lead to very different distributions of chemicals.”
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Heuristics 9: “Separate liquid mixtures using distillation and stripping towers, and liquid-liquid extractors, among similar operations, and so on, with the unreacted chemicals recovered in a liquid phase and recycled to the reaction operation.” Heuristic 22: “ For less exothermic heats of reaction, circulate reactor fluid to an external cooler, or use a jacketed vessel or heating coils. Also, consider the use of intercoolers between adiabatic reaction stages.”
Task 3 Outline •
Mass and energy balance
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Hysys simulation
Mass Balance
Stream number
1 Acetic acid feed to C001
2 Ethanol feed to C001
3 RDC top product before condense r E002
Liquid
Liquid
Vapor
4 5 6 7 8 9 10 11 RDC top Organic Organic Organic Aqueous Stripper Stripper Ethyl product part feed to reflux to product top top acetate after from stripper C001 from product product product condens decante C002 FL001 before after before er E002 r FL001 condenser condenser cooler E003 E003 E005
12 Ethyl acetate product after cooler E005
Name of the stream
Phase
Mass flow rate (kg/hr)
Liquid
Liquid
Liquid
Liquid
Liquid
Vapor
Liquid
Liquid
Liquid
3471.58207 4198.91034 25940.15 25940.1 33310.4 16655.21 16655.21 1658.142 9028.4097 9028.4097 6012.35 6012.35
wt%
wt%
wt%
wt%
wt%
wt%
wt%
wt%
wt%
wt%
wt%
wt%
Ethyl acetate
0
0
82.6
82.6
92.03
92.03
92.03
1.58
95.77
95.77
99.5
99.5
Water
1
4.5
9
9
2.12
2.12
2.12
95.88
1.93
1.93
0
0
Ethanol
0
95.5
8.4
8.4
4.1
4.1
4.1
2.5
2.3
2.3
0.5
0.5
Acetic acid
99
0
0
0
0
0
0
0
0
0
0
0
Energy Balance
Enthalpy The enthalpy for each stream is given by
ˆ H ˆ H T ,i f , 298.15 K
T
C p ,i dT
298.15 K
Stream
1
2
3
Acetic Acid Ethanol RDC top before Feed Feed condenser 1 Phase
Liquid
4
RDC top after condenser 1
5
6
Organic part Organic feed from Decanter to Stripper
Liquid
Vapour
Liquid
Liquid
Liquid
Temperature (K) 298.15 298.15
342.8
313.15
313.15
313.15
-277.605
-277.755
-277.755
-277.755
-450.1
-457.7
-457.7
-457.7
-284.316
-285.332
-285.332
-285.332
Enthaply (kJ/mol) Ethanol
-277.63
Acetic Acid -486.18
Ethyl Acetate Water
-285.84 -285.84
Stream
7 Organic Reflux
8
9
Aqueous Stripper Top Product Product before condenser
10 Stripper Top Product after condenser
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12 Ethyl Acetate Ethyl Acetate Product after before cooler cooler
Phase
Liquid
Liquid
Vapour
Liquid
Liquid
Liquid
Temperature (K)
313.5
313.15
343.75
313.15
353.15
308.15
-277.755
-277.755
-277.615
-277.755
-277.47
-277.6105
-457.7
-449.2
-457.7
443.1
-460.15
-285.332
-284.1
-285.332
-283.977
-285.5
Enthaply (kJ/mol) Ethanol Acetic Acid Ethyl Acetate -457.7 Water
-285.332
Heat Duties Inlet Outlet Streams Streams
Difference in Enthaply (kJ/mol)
Heat Duty (kW)
Reboiler of RD
1,2,7
3
??
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Condenser of RDC
3
4
??
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Reboiler of Stripper
6
9,11
??
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Condenser of Stripper
9
10
??
???
Cooler
11
12
??
???
Aspen HYSYS Simulation
Hysys simulation (proposed flowsheet)
Hysys simulation
