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Kurdistan Regional Government
Ministry of Higher Education and Scientific Research
Koya University
Faculty of Engineering
...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
IABSTRACT
ABSTRACT
Methyl tertiary butyl ether (MTBE) is primarily used i...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
IITABLE OF CONTENTS
1. TABLE OF CONTENTS
I. CHAPTER ONE: INTRODUCTION ......
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
IIITABLE OF CONTENTS
4.3.4. Energy balance around heat exchanger (E901): ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
IVTABLE OF CONTENTS
LIST OF FIGURES
Figure 1 Global MTBE Demand by Region...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
1INTRODUCTION
CHAPTER ONE
1. INTRODUCTION
Methyl tertiary butyl ether (MT...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
2INTRODUCTION
History of MTBE1.2.
In the late 1970s and 1980s, oxygenates...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
3INTRODUCTION
legislation that would partially or completely ban or restr...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
4INTRODUCTION
Properties (chemical and physical)1.4.
Properties of MTBE a...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
5INTRODUCTION
MTBE competitive strengths and weaknesses Table 2
Strengths...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
6INTRODUCTION
Figure 1 Global MTBE Demand by Region (2014)
Methyl Tertiar...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
7MTBE PRODUCTION
CHAPTER TWO
2. MTBE PRODUCTION
Introduction2.1.
We work ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
8MTBE PRODUCTION
99.2%. The process which we select in our project is Rea...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
9MTBE PRODUCTION
2.2.1. Possibility of Changing Process Feed Conditions
T...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
10MTBE PRODUCTION
FIC
FIC
FIC
cw
cw
hps
lps
mps
LIC
LIC
LIC
LIC
butylenes...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
11MTBE PRODUCTION
Process Details2.3.
Feed Stream and Effluent Streams
St...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
12MTBE PRODUCTION
Reactor (R-901)
This is where the reaction occurs. The ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
13MTBE PRODUCTION
Heat Exchanger (E-903)
In this heat exchanger, the cont...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
14MTBE PRODUCTION
vaporize the stream; this is a utility cost. The steam ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
15MTBE PRODUCTION
Stream No. 5 6 7 8
Temp C 25.93 26.91 85.00 127.57
Pre...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
16MTBE PRODUCTION
Stream No. 13 14 15 16
Temp C 83.49 83.12 70.73 56.27
...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
17MTBE PRODUCTION
Table 4 Utility Stream Flow Summary for Unit 900
E-901 ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
18MTBE PRODUCTION
E-902
A = 50.9 m2
1-2 exchanger, fixed head, carbon ste...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
19MTBE PRODUCTION
Towers
T-901
carbon steel
97 sieve trays plus reboiler ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
20MATERIAL BALANCE
CHAPTER THREE
3. MATERIAL BALANCE
Introduction:3.1.
Th...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
21MATERIAL BALANCE
Symbols used in this chapter:
Total mole flow of strea...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
22MATERIAL BALANCE
Other butane balance:
F1 ∗ 0+F2 ∗ 0.77+F11 ∗ 0 = F8 ∗ ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
23MATERIAL BALANCE
mmeth F6 – 1660 = M7F7
Isobutene:
misoF6-1660= ISO7F7
...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
24MATERIAL BALANCE
From equation:
F4 = F5 = F6
F4 =13254.53
F2 + F3 = F4
...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
25MATERIAL BALANCE
3.2.4. Material balance around methanol absorber (T-90...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
26MATERIAL BALANCE
0 ∗ F10+1 ∗ F11 = 0 ∗ F12+W12 ∗ 14572.39
W13F13=12143....
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
27MATERIAL BALANCE
Table 9 Summary of material balance calculation by usi...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
28ENERGY BALANCE
CHAPTER FOUR
4. ENERGY BALANCE
Introduction:4.1.
As with...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
29ENERGY BALANCE
Energy balance calculations:4.3.
Symbols used in this ch...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
30ENERGY BALANCE
4.3.2. Heat capacity constant for liquid:
Componene
t
A ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
31ENERGY BALANCE
Pi = EXP (A+B/T+C LnT+DTE
).
Where:
Pi: is vapor presser...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
32ENERGY BALANCE
MM15 from material balance calculation=2053.16Kmol/h.
HM...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
33ENERGY BALANCE
Miso6 from material balance calculation =2088.05Kmol/h.
...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
34ENERGY BALANCE
4.3.5. Energy balance around reactor (R901):
The convers...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
35ENERGY BALANCE
HMTBE7 = MMTBE7 ∫ + λ298].
MMTBE7 from material balance ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
36ENERGY BALANCE
M2−but7 from material balance calculation =5172.917692Km...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
37ENERGY BALANCE
HISO9 = 8.84E5KJ/h.
H1−but9 = M1−but9 ∫ 𝑝 𝑡
M1−but9 from...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
38ENERGY BALANCE
→ HV9 = 18886227.06KJ/h.
∴ Qc = 2.8(18886227.06 − 178290...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
39ENERGY BALANCE
Qr = Qc + H9 + H8 − H7
Qr = 258116146.6KJ/h.
-Amount of ...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
40ENERGY BALANCE
M1−but12 from material balance calculation =1817.511622K...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
41ENERGY BALANCE
H13 = 1972318662KJ/h.
Energy balance around distillation...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
42ENERGY BALANCE
H16=Hw16+HM16
HM16= MM16∫ 𝑝 𝑡
MM16 from material balance...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
43ENERGY BALANCE
Component 1 2 3 4 5 6
P (bar) 4.9512 4.9512 4.9 4.9 20 2...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
44CONCLUSION & RECOMMENDATIONS
CHAPTER FIVE
5. DESIGN
Distillation design...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
45CONCLUSION & RECOMMENDATIONS
horizontal direction from the slots . With...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
46CONCLUSION & RECOMMENDATIONS
-Bottom product stream:
At 440 o K, 1925.1...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
47CONCLUSION & RECOMMENDATIONS
5.1.5. Determination of minimum reflux rat...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
48CONCLUSION & RECOMMENDATIONS
+ + = Rm+1
Rm= 1.494995
5.1.6. Calculation...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
49CONCLUSION & RECOMMENDATIONS
5.1.9. Calculation of the column efficienc...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
50CONCLUSION & RECOMMENDATIONS
5.1.13. Calculation of the tower diameter(...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
51CONCLUSION & RECOMMENDATIONS
𝑉
𝑉
𝑚
𝐹 √ = 0.160
K=0.05
𝑈 ∗ √
Design velo...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
52CONCLUSION & RECOMMENDATIONS
Design velocity (U) = 80% of flooding velo...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
53CONCLUSION & RECOMMENDATIONS
= (1.3172 −50×10−3 ) π × ( ) = 1.813 m
Are...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
54CONCLUSION & RECOMMENDATIONS
Taking 70% turn down.
𝑈𝑜 (min) = 0.7×𝑈𝑜= 0...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
55CONCLUSION & RECOMMENDATIONS
(𝑚𝑖𝑛) ∗ ( )
⁄
𝑚𝑚
𝑤=23mm
𝑡=21.31+36.23+23+1...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
56CONCLUSION & RECOMMENDATIONS
5.1.18. Down comer residence time:
𝑡
𝑝
𝐿 (...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
57CONCLUSION & RECOMMENDATIONS
J =1(No joint in head).
E
( )
= 0.01224mm....
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
58CONCLUSION & RECOMMENDATIONS
CHAPTER SIX
6. CONCLUSION & RECOMMENDATION...
PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
59REFERENCES
7. REFERENCES
Adjeroh, D. A., 2015. DESIGN OF AN MTBE PRODUC...
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PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)

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this project submitted in partial fulfilment of the requirements for the degree of bachelor in science in Chemical engineering at Koya University.

The main purpose of our project is to describe and design the production of MTBE, and using it as an additive to gasoline in order to increase its quality.

We work at this plant to produce 112,200tons / year (112,200,000 kg/y) of methyl tertiary butyl ether (MTBE)

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PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)

  1. 1. Kurdistan Regional Government Ministry of Higher Education and Scientific Research Koya University Faculty of Engineering Chemical Engineering Department Author: Alan Mawlud Amin Aree Salah Tahir Supervisor: Abdul Majid Osman 2015 - 2016 “A project submitted in partial fulfilment of the requirements for the degree of bachelor in science in Chemical engineering at Koya University” PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE)
  2. 2. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) IABSTRACT ABSTRACT Methyl tertiary butyl ether (MTBE) is primarily used in gasoline blending as an octane enhancer to improve hydrocarbon combustion efficiency. Of all the Oxygenates, MTBE is the most attractive for a variety of technical reasons. It has a low vapor pressure. It can be blended with other fuels without phase separation. It has the desirable octane characteristics. MTBE is produced via direct addition methanol to isobutylene using ion exchange resin as a catalyst. In order to improve the quality of the gasoline produced in the Kurdistan refineries, this project studies the implantation of an MTBE plant with a capacity that suffices the production rate of Kurdistan gasoline. The project based on conducting material and energy balances, designing reaction and distillation equipment According to this study, it is possible to obtain an overall conversion of around 80% with a purity of MTBE that reaches 95% and a payback period (PBP) that is estimated to be 3.7 years. Keywords: Production of MTBE, material balance, energy balance, process design.
  3. 3. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) IITABLE OF CONTENTS 1. TABLE OF CONTENTS I. CHAPTER ONE: INTRODUCTION .................................. 1 Methyl tertiary butyl ether (MTBE).............................................................................11.1. History of MTBE...........................................................................................................21.2. Importance and applications of MTBE........................................................................31.3. Properties (chemical and physical) .............................................................................41.4. 1.5 World market demand................................................................................................5. Objectives of this project ............................................................................................61.6. II. CHAPTER TWO: MTBE PRODUCTION........................... 7 Introduction.................................................................................................................72.1. Process Description.....................................................................................................82.2. 2.2.1. Possibility of Changing Process Feed Conditions ....................................................9 Process Details ..........................................................................................................112.3. 2.3.1. Equipment .............................................................................................................11 III. CHAPTER THREE: MATERIAL BALANCE...................... 20 Introduction: .............................................................................................................203.1. Calculations: ..............................................................................................................213.2. 3.2.1. Over all material balance:......................................................................................21 3.2.2. Material balance around reactor(R-901):..............................................................22 3.2.3. Material balance around distillation column (T-901):...........................................24 3.2.4. Material balance around methanol absorber (T-902):..........................................25 3.2.5. Material balance around tower (T-903):...............................................................26 IV. CHAPTER FOUR: ENERGY BALANCE .......................... 28 Introduction: .............................................................................................................284.1. Conservation of energy:............................................................................................284.2. Energy balance calculations:.....................................................................................294.3. 4.3.1. Heat capacity equation for ideal gases: ................................................................29 4.3.2. Heat capacity constant for liquid: .........................................................................30 4.3.3. Energy balance around summing point: ...............................................................30
  4. 4. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) IIITABLE OF CONTENTS 4.3.4. Energy balance around heat exchanger (E901): ...................................................32 4.3.5. Energy balance around reactor (R901):.................................................................34 4.3.6. Energy balance around distillation column (T901): ..............................................36 4.3.7. Energy balance around methanol absorber (T902): .............................................39 V. CHAPTER FIVE: DESIGN................................. 44 Distillation design:.....................................................................................................445.1. 5.1.1. Introduction:..........................................................................................................44 5.1.2. Collect the data of fluid to be distillated and distillated.......................................45 5.1.3. Heavy and light key:...............................................................................................46 5.1.4. Type of tray:...........................................................................................................46 5.1.5. Determination of minimum reflux ratio:...............................................................47 5.1.6. Calculation of the actual ratio(R)...........................................................................48 5.1.7. Calculation of the minimum number of theoretical stages: .................................48 5.1.8. Calculation of the number of theoretical stages:..................................................48 5.1.9. Calculation of the column efficiency (E˳): .............................................................49 5.1.10. Calculation of the number of actual stages (Na):..............................................49 5.1.11. Calculation of the height of the column (Ht):....................................................49 5.1.12. Determination of the feed plate location (m): ..................................................49 5.1.13. Calculation of the tower diameter(D):...............................................................50 5.1.14. Determination of fractional entrainment (ϕ):...................................................53 5.1.15. Weeping point: ..................................................................................................53 5.1.16. Pressure drop calculation: .................................................................................54 5.1.17. Down comer liquid back up: ..............................................................................55 5.1.18. Down comer residence time:.............................................................................56 VI. CHAPTER SIX: CONCLUSION & RECOMMENDATIONS............................... 58 Conclusion:................................................................................................................586.1. Recommendations: ...................................................................................................586.2. VII. 7. ............................................................... REFERENCES 59
  5. 5. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) IVTABLE OF CONTENTS LIST OF FIGURES Figure 1 Global MTBE Demand by Region (2014) .......................................................................... 6 Figure 2 MTBE Production Facility................................................................................................ 10 LIST OF TABLES Table 1 Properties of MTBE ............................................................................................................ 4 Table 2 MTBE competitive strengths and weaknesses .................................................................. 5 Table 3 Stream Tables for Unit 900 .............................................................................................. 14 Table 4 Utility Stream Flow Summary for Unit 900...................................................................... 17 Table 5 Partial Equipment Summary............................................................................................ 18 Table 6 Reactors and Vessels........................................................................................................ 18 Table 7 Pumps............................................................................................................................... 18 Table 8 Towers.............................................................................................................................. 19 Table 9 Summary of material balance calculation by using Excel sheet..................................... 27 Table 10 Heat capacity constants for ideal gases......................................................................... 29 Table 11 Heat capacity constants for liquid. ................................................................................ 30 Table 12 summarizes the results: bubble point calculation of stream 15. .................................. 31 Table 13 Ratio of component (i) in the feed to isobutylene feed. ............................................... 34 Table 14 Summary of agent amount............................................................................................ 42 Table 15 Summary of energy balance calculation made by using Excel sheet ............................ 43 Table 16 Feed stream composition. ............................................................................................. 45 Table 17 Top stream composition ............................................................................................... 45 Table 18 Bottom stream composition.......................................................................................... 46 Table 19 Average relative volatility of composition..................................................................... 46 Table 20 Summary of design calculation...................................................................................... 57
  6. 6. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 1INTRODUCTION CHAPTER ONE 1. INTRODUCTION Methyl tertiary butyl ether (MTBE)1.1. MTBE is a commonly used acronym for the chemical compound methyl tertiary-butyl ether. At room temperature, MTBE is a volatile, flammable, colorless liquid that is highly soluble in water. It is produced by the chemical reaction of methanol, generally manufactured from natural gas, and isobutylene. MTBE has a very distinct taste and odor, similar to turpentine. MTBE has been used as a gasoline additive since 1979. However, MTBE was not widely used as a gasoline additive in Connecticut until the mid-1980s and was not discovered in our ground water until 1987. Initially, it was added to gasoline as a. replacement for tetraethyl lead to increase the octane rating of the fuel. This action has resulted in a. significant reduction in ambient air levels of lead. As an octane enhancing additive, MTBE is blended into conventional gasoline at concentrations ranging from approximately 3 to 5 percent, by volume. More recently, MTBE has also been used as an oxygenate, an additive that increases the oxygen content of gasoline. Oxygenates are added to gasoline to produce more complete fitel combustion, resulting in reductions of carbon monoxide and ozone forming emissions. As an oxygenate, MTBE is currently blended into gasoline at concentrations ranging from 2.0 to 2.7 percent weight oxygen, the equivalent of 11 to 15 percent MTBE, by volume (Rocque, 2000).
  7. 7. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 2INTRODUCTION History of MTBE1.2. In the late 1970s and 1980s, oxygenates such as MTBE and ethanol were added to fuels to improve efficiency while meeting lead phase-out requirements. The use of MTBE became prevalent because of its low cost, ease of production, and favorable transfer and blending characteristics. Other less commonly used oxygenates include methanol, ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), diisopropyl ether (DIPE), and tertiary-butyl alcohol (TBA). In 1987, the Colorado Air Quality Control Commission adopted the first regulations in the country requiring that oxygenated fuels be sold along much of the Colorado Front Range. The purpose of the oxygenated fuels program was to make gasoline burn more cleanly in order to reduce air emissions and smog. Based in part on the successful oxygenated fuels program that had been ongoing along the Colorado Front Range, the Clean Air Act Amendments of 1990 required that oxygenated fuels be used at service stations and gasoline retail businesses in regions of the United States where ozone or carbon monoxide air quality standards were exceeded. Beginning in 1992, the winter oxygenated fuel program required 2.7% oxygen by weight in gasoline (equivalent to 15% MTBE or 7.3% ethanol by volume) in 40 U.S. metropolitan areas, including those located along the Colorado Front Range. In 1995, the U.S. implemented Reformulated Gasoline Phase I, requiring 2.0% oxygen by weight in gasoline year-round in 28 U.S. metropolitan areas. Reformulated Gasoline Phase II, beginning January 1, 2000, continued to require 2.0% oxygen by weight. As a result of concerns regarding MTBE (Section 3.0), efforts have been made in several States to discontinue the use of MTBE in gasoline. As of June 2004,
  8. 8. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 3INTRODUCTION legislation that would partially or completely ban or restrict the use of MTBE in gasoline has been passed in 19 states. Colorado Senate Bill 190 was signed into law on May 23, 2000 ordering the phase-out of MTBE as a fuel component or additive by April 30, 2002. This legislation declared “it is the intent of the general assembly…to halt further contamination and pollution of this state’s groundwater supplies by MTBE” (Lidderdale, 2000). Importance and applications of MTBE1.3.  As anti-knocking agent In the US it has been used in gasoline at low levels since 1979 to replace tetraethyl lead and to increase its octane rating helping prevent engine knocking. Oxygenates help gasoline burn more completely, reducing tailpipe emissions from pre-1984 motor vehicles; dilutes or displaces gasoline components such as aromatics (e.g., benzene) and sulfur; and optimizes the oxidation during combustion. Most refiners chose MTBE over other oxygenates primarily for its blending characteristics and low cost.  As a solvent Despite the popularity of MTBE in industrial settings, it is rarely used as a solvent in academia with some exceptions. MTBE forms azeotropes with water (52.6 °C; 96.5% MTBE) and methanol (51.3 °C; 68.6% MTBE). Although an ether, MTBE is a poor Lewis base and does not support formation of Grignard reagents. It is also unstable toward strong acids. It reacts dangerously with bromine (Winterberg, et al., 2010).
  9. 9. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 4INTRODUCTION Properties (chemical and physical)1.4. Properties of MTBE are listed in the Table 1. TABLE 1 Chemical and Physical Data Characteristic/Property Data Common Name Methyl tertiary-butyl ether Synonyms MTBE, tert-butyl methyl ether Cas registry No. 1634-04-4 Chemical formula C5H12O Molecular weight 88.2 Physical state Colorless liquid with characteristic terpene-like odor. Vapor pressure 245 mm Hg @ 25° C Density (water = 1) 0.7 Specific gravity 0.74 Solubility (in water) 4.8 g/100 ml at 20° C Melting point -109 ° C Boiling point 55° C Flash point -28° C Explosive limits (air, vol%) LEL - 1.6% UEL - 8.4% Conversion factors 1 mg/m3 = 0.28 ppm 1ppm= 3.61 mg/m3 Table 1 Properties of MTBE
  10. 10. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 5INTRODUCTION MTBE competitive strengths and weaknesses Table 2 Strengths Weaknesses - Low volatility Availability of economical isobutylene feedstock is limited. - Blending characteristics similar to gasoline - Health hazard - Widely accepted in marketplace by consumers and refiners - Possible methanol supply constraints - Reduces carbon monoxide and exhaust - hydrocarbon emissions Table 2 MTBE competitive strengths and weaknesses World market demand1.5.  As methyl tertiary butyl ether (MTBE) has been recognized dangerous to the environment, USA, Canada, Japan and Western Europe countries shift to ETBE, ethanol and other alternatives and close MTBE facilities  On the contrary, Eastern Europe and Asia Pacific countries build new MTBE capacity  global MTBE market has been flat in the past years; on the one hand, developed countries lowered MTBE consumption, but on the other hand the demand grew in Asia Pacific, Latin America and the Middle East due to increased gasoline consumption and requirements for cleaner fuel in those areas  World methyl tertiary butyl ether production is foreseen to decrease; China will continue to introduce new capacity but operation rates will go down  Overall MTBE demand growth will be low: USA, Canada, Japan and Western Europe markets will keep on decreasing, but Asia Pacific, Latin America and the Middle East MTBE industries will post growth.
  11. 11. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 6INTRODUCTION Figure 1 Global MTBE Demand by Region (2014) Methyl Tertiary Butyl Ether (MTBE) 2015 World Market Outlook and Forecast up to 2019 grants access to the unique data on the examined market. Having used a large variety of primary and secondary sources, our research team combined, canvassed and presented all available information on product in an all-encompassing research report clearly and coherently. The market report not only contains a detailed market overview but also offers a rich collection of tables and figures, thus providing an up-close look at country, regional and world markets for product. It also includes a five-year forecast showing how the product market is set to develop (Matyash, et al., 2016). Objectives of this project1.6. The main purpose of our project is to describe and design the production of MTBE, and using it as an additive to gasoline in order to increase its quality.
  12. 12. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 7MTBE PRODUCTION CHAPTER TWO 2. MTBE PRODUCTION Introduction2.1. We work at this plant to produce 112,200tons / year (112,200,000 kg/y) of methyl tertiary butyl ether (MTBE). MTBE is an oxygenated fuel additive that is blended with gasoline to promote CO2 formation over CO formation during combustion. The facility manufactures MTBE from methanol and isobutylene. Isobutylene is obtained from a refinery cut, and it also contains 1-butene and 2-butene, both of which do not react with methanol. Process Selection MTBE is produced via direct addition of methanol to isobutylene using sulphonated ion Exchange resin as catalysts. There are two ways to produce MTBE:  Conventional Process Which is mainly a reactor and separate distillation column with conversion range 87 - 92%.  Reactive Distillation Process It’s a newly method for the production of MTBE which is established and date back to the way in 1980 as the scientist Smith recorded the first patent for the production of MTBE, through this method, this method called Reactive Distillation Process, and there are a lot of features that makes this process attractive and practical with a conversion reached
  13. 13. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 8MTBE PRODUCTION 99.2%. The process which we select in our project is Reactive Distillation Process because it has more conversion rate of MTBE. Process Description2.2. The process flow diagram is shown in Figure 2 Methanol and the mixed butylenes feed is pumped and heated to reaction conditions. Both the methanol and the mixed butylenes are made in on-site units, and are sent to this unit at the desired conditions. The reactor operates in the vicinity of 30 bar, to ensure that the reaction occurs in the liquid phase. The reaction is reversible. The feed temperature to the reactor is usually maintained below 90C to obtain favorable equilibrium behavior. Any side reactions involving 1- butene and 2-butene form small amounts of products with similar fuel blending characteristics, so side reactions are assumed to be unimportant. Other side reactions are minimized by keeping the methanol present in excess. The reactor effluent is distilled, with MTBE as the bottom product. Methanol is recovered from the mixed butylenes in a water scrubber, and the methanol is subsequently separated from water so that unreacted methanol can be recycled. Unreacted butylenes are sent back to the refinery for further processing. The MTBE product is further purified (not shown), mostly to remove the trace amounts of water. The product stream from Unit 900 must contain at least 94 mol % MTBE, with the MTBE portion of the stream flowrate at specifications (Al-Harthi, 2008.). Tables 3 and 4 contain the stream and utility flows for the process as designed. Table 5, 6, 7 and 8 contains an equipment list other pertinent information and calculations are obtained based on Chemical Engineering books.
  14. 14. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 9MTBE PRODUCTION 2.2.1. Possibility of Changing Process Feed Conditions This plant receives the mixed butylenes feed from a neighboring refinery, which has recently changed ownership. The new owners are planning to implement changes based on their proprietary technology. The changes will occur after a regularly scheduled plant shut down (for both plants) within the next six months. The effect on our plant is that they have proposed that the mixed butylenes feed that we receive will contain 23 wt% isobutylene (isobutene), 20 wt% 1-butene, and 57 wt% 2-butene. Our current contract for mixed butylenes expires at the next plant shut down, so we are in the process of negotiating a new contract with the new owners. An additional complication is that MTBE is in the process of being phased out as a fuel additive because of ground water contamination from leaky gasoline storage tanks.
  15. 15. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 10MTBE PRODUCTION FIC FIC FIC cw cw hps lps mps LIC LIC LIC LIC butylenes feed methanol process water waste butylenes waste water MTBE V-903 V-902 V-901 P-901 A/B P-903 A/B P-902 A/B P-904 A/B E-902 E-904 E-905 E-903 E-901 R-901 T-901 T-902 T-903 Figure 1: Unit 900 - MTBE Production Facility V-901 Methanol Feed Vessel P-901 A/B Feed Pump E-901 Feed Preheater R-901 MTBE Reactor T-901 MTBE Tower T-903 Methanol Recovery Tower T-902 Methanol Absorber E-902 MTBE Tower Reboiler E-904 Methanol Tower Reboiler E-903 MTBE Tower Condenser E-905 Methanol Tower Condenser V-902 MTBE Tower Reflux Drum V-903 Methanol Tower Reflux Drum P-902 A/B MTBE Tower Reflux Pump P-904 A/B MTBE Tower Reflux Pump P-903 A/B MTBE Tower Feed Pump Figure 2 MTBE Production Facility (Adjeroh, 2015)
  16. 16. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 11MTBE PRODUCTION Process Details2.3. Feed Stream and Effluent Streams Stream 1: Methanol – stored as a liquid at the desired pressure of the reaction. Stream 2: Mixed butene stream – 23% isobutene, 20% 1-butene, 57% 2- butene. Stream 8: MTBE product – must be 95 wt% pure. Stream 11: Process water – see utility list for more information Stream 12: Waste butenes – returned to refinery – contains 1-butene and 2- butene with less than 1 wt% other impurities. Stream 16: Waste water – must be treated – must contain 99 wt% water – See the utility list for more information (Winterberg, et al., 2010). 2.3.1. Equipment Pump (P-901 A/B, includes spare pump) The pump increases the pressure of the mixed feed to the reaction conditions. The liquid density may be estimated using a linear average of the pure component densities, weighted by their mass fractions in the mixture. The cost of electricity to run the pump is a utility cost based on the required power for the pump. The required power is the work multiplied by the mass flowrate of Stream 4. Heat Exchanger (E-901) This heat exchanger heats the feed to the reactor feed temperature. Each component must remain in the liquid phase at the chosen pressure. The cost of the heat source is a utility cost.
  17. 17. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 12MTBE PRODUCTION Reactor (R-901) This is where the reaction occurs. The reactor is adiabatic, and the reaction is exothermic. Therefore, the heat generated by the reaction raises the temperature of the exit stream. The exit temperature is a function of the conversion. The reaction must be run at a pressure and temperature to ensure that all components remain in the liquid phase in the reactor. Methanol must be present in the reactor feed at a minimum 200% excess to suppress undesired side reactions that produce undesired products. The reactor operating conditions (feed and exit temperatures, pressure) are to be optimized. An operating pressure must be chosen. An optimum temperature and conversion must be determined. Distillation Column (T-901) This column runs at 19 atm. (The pressure is controlled by a valve, that is not shown on the PFD, in the product stream from R-901.) Separation of methanol and MTBE occurs in this column. Of the methanol in Stream 7, 98% enters Stream 9. Similarly, 99% of MTBE in Stream 7 enters Stream 8. Heat Exchanger (E-902) In this heat exchanger, the some of the contents of the stream leaving the bottom of T-901 going to E-902 are vaporized and returned to the column. The amount returned to the column is equal to the amount in Stream 8. The temperature of these streams is the boiling point of MTBE at the column pressure. There is a cost for the amount of steam needed to provide energy to vaporize the stream; this is a utility cost. The steam temperature must always be higher than the temperature of the stream being vaporized.
  18. 18. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 13MTBE PRODUCTION Heat Exchanger (E-903) In this heat exchanger, the contents of the top of T-901 are partially condensed from saturated vapor to saturated liquid at the column pressure. 99% of the MTBE and water condense and 99% of all other components remain in the vapor phase. The remaining 1% of all other components condense with the MTBE. It may be assumed that this stream condenses at the boiling point of methanol at the column pressure. There is a cost for the amount of cooling water needed; this is a utility cost. The cooling water leaving E-903 must always be at a lower temperature than that of the stream being condensed. Absorber (T-902) The absorber runs at 5 atm and 90C (outlet streams and Stream 11). In the absorber, 99% of the methanol in Stream 9 is absorbed into the water. All other components enter Stream 12. The cost of Stream 9 is a raw material cost. Process water sent to scrubber is controlled so that 5.0 kmol of water are used for every 1.0 kmol of methanol. Distillation Column (T-903) This column runs at 5 atm. (The pressure is controlled by a valve in the product stream from T-903, which is not shown on the PFD.) Separation of methanol and water occurs in this column. Of the methanol in Stream 14, 99% enters Stream 15. Similarly, 99% of water in Stream 14 enters Stream 16. Heat Exchanger (E-904) In this heat exchanger, the some of the contents of the stream leaving the bottom of T-903 going to E-904 are vaporized and returned to the column. The amount returned to the column is equal to the amount in Stream 16. The temperature of these streams is the boiling point of water at the column pressure. There is a cost for the amount of steam needed to provide energy to
  19. 19. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 14MTBE PRODUCTION vaporize the stream; this is a utility cost. The steam temperature must always be higher than the temperature of the stream being vaporized. Heat Exchanger (E-905) In this heat exchanger, the contents of the top of T-903 are completely condensed from saturated vapor to saturated liquid at the column pressure. It may be assumed that this stream condenses at the boiling point of methanol at the column pressure. The flowrate of the stream from T-902 to E-905 is three times the flowrate of Stream 15. There is a cost for the amount of cooling water needed; this is a utility cost. The cooling water leaving E-905 must always be at a lower temperature than that of the stream being condensed. Table 3 Stream Tables for Unit 900 Stream No 1 2 3 4 Temp C 25.00 49.84 25.00 45.70 Pres kPa 400.00 400.00 390.00 390.00 Vapor fraction 0.00 0.045 0.00 0.00 Total kg/h 5600.00 16590.16 21875.00 22190.70 Total kmol/h 174.77 427.75 389.88 602.54 Component kmol/h Methanol 174.77 322.15 496.96 i-Butene 3.73 155.95 3.73 1-Butene 14.59 46.79 14.59 Trans-2-Butene 74.43 187.14 74.43 MTBE 11.86 11.86 Water 0.98 0.98
  20. 20. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 15MTBE PRODUCTION Stream No. 5 6 7 8 Temp C 25.93 26.91 85.00 127.57 Pres kPa 380.00 3000.00 2965.00 2915.00 Vapor fraction 0.00 0.00 0.00 0.00 Total kmol/h 992.42 992.42 992.42 848.70 Total kg/h 44065.70 44065.70 44065.70 44065.70 Component kmol/h Methanol 496.96 496.96 496.96 353.23 i-Butene 159.68 159.68 159.68 15.95 1-Butene 61.38 61.38 61.38 61.38 Trans-2-Butene 261.58 261.58 261.58 261.58 MTBE 11.86 11.860 11.86 155.59 Water 0.97 0.97 0.97 0.97 Stream No. 9 10 11 12 Temp C 178.46 134.37 110.36 30.00 Pres kPa 1925.00 1900.00 500.00 450.00 Vapor fraction 0.00 1.00 1.00 0.00 Total kg/h 12973.05 31272.80 31272.80 21618.00 Total kmol/h 150.40 698.30 698.30 1200.00 Component kmol/h Methanol 7.06 346.17 346.17 i-Butene 0.00 15.95 15.95 1-Butene 0.00 61.38 61.38 Trans-2-Butene 0.00 261.58 261.58 MTBE 142.36 13.22 13.22 Water 0.97 0.00 0.00 1200.00
  21. 21. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 16MTBE PRODUCTION Stream No. 13 14 15 16 Temp C 83.49 83.12 70.73 56.27 Pres kPa 110.00 160.00 500.00 500.00 Vapor mole fraction 1.00 0.00 0.00 0.00 Total kg/h 18828.85 34061.93 34061.93 16590.16 Total kmol/h 500.96 1397.34 1397.34 427.75 Component kmol/h Methanol 23.69 322.48 322.48 322.16 i-Butene 12.23 3.72 3.72 3.72 1-Butene 46.78 14.60 14.60 14.60 Trans-2-Butene 187.13 74.44 74.44 74.44 MTBE 1.36 11.86 11.86 11.86 Water 229.76 970.24 970.24 0.97 Stream No. 17 Temp C 155.61 Pres kPa 550.00 Vapor mole fraction 0.00 Total kg/h 17471.77 Total kmol/h 969.60 Component kmol/h Methanol 0.32 i-Butene 1-Butene Trans-2-Butene MTBE Water 969.27
  22. 22. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 17MTBE PRODUCTION Table 4 Utility Stream Flow Summary for Unit 900 E-901 E-902 E-903 lps hps cw 3572 kg/h 25,828 kg/h 6.31105 kg/h E-904 E-905 mps cw 32,433 kg/h 1.44106 kg/h Table 5 Reactors and Vessels Heat Exchangers E-901 A = 44.6 m2 1-2 exchanger, floating head, carbon steel process stream in tubes Q = 7502 MJ/h maximum pressure rating of 35 bar E-904 A = 209 m2 1-2 exchanger, fixed head, carbon steel process stream in shell Q = 64,542 MJ/h maximum pressure rating of 6.5 bar Reactors and Vessels R-901 carbon steel packed bed, Amberlyst 15 catalyst V = 9.35 m3 10 m long, 1.1 m diameter maximum pressure rating of 32 bar V-901 stainless steel V = 11.215 m3 maximum pressure rating of 5 bar
  23. 23. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 18MTBE PRODUCTION E-902 A = 50.9 m2 1-2 exchanger, fixed head, carbon steel process stream in shell Q = 43,908 MJ/h maximum pressure rating of 23 bar E-905 A = 1003 m2 1-2 exchanger, floating head, carbon steel process stream in shell Q = 60,347 MJ/h maximum pressure rating of 6.5 bar E-903 A = 92.4 m2 1-2 exchanger, floating head, carbon steel process stream in shell Q = 26,417 MJ/h maximum pressure rating of 23 bar Table 6 Partial Equipment Summary Pumps P-901 A/B carbon steel power = 220.53 MJ/h (actual) 80% efficient P-903 A/B carbon steel power = 18.65MJ/h (actual) 80% efficient Table 7 Pumps
  24. 24. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 19MTBE PRODUCTION Towers T-901 carbon steel 97 sieve trays plus reboiler and partial condenser 70% efficient trays feed on tray 27 additional feeds ports on 23 and 30 reflux ratio = 1.62 12 in tray spacing, 2 in weirs column height 30 m diameter = 2.8 m above feed, 4.7 m below feed maximum pressure rating of 23 bar T-903 carbon steel 42 sieve trays plus reboiler and total condenser 48% efficient trays feed on tray 21 additional feed ports on 16 and 23 reflux ratio = 3.44 24 in tray spacing, 6.8 in weirs column height = 26 m diameter = 2.6 m maximum pressure rating of 6.5 bar T-902 carbon steel 7.3 m of packing 5 theoretical stages 6.86 kPa/m pressure drop diameter = 2.9 m packing factor – 500 maximum pressure rating of 5 bar Table 8 Towers
  25. 25. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 20MATERIAL BALANCE CHAPTER THREE 3. MATERIAL BALANCE Introduction:3.1. The material balance taken over the complete process will determine the quantities of raw materials required and products produced. Balance over individual process units set the process stream flow and composition. A good understanding of material balance calculation is essential in process design. Material balance are also useful tools for the study of plant operation and trouble shooting. They can be used to check performance against design; to extend the often limited data available from plant instrumentation; to check instrument calibrations; and to locate sources of material loss (Himmelblau & Riggs, 2004). The general conservation equation for any process system can be written as: Material out =material in+ generation –consumption –accumulation ASSUMPTIONS: The material balance calculation will be based on the following assumption: - The basis one hour.  The plant works 330 day in a year and 24 hour per day. -steady state operation.  Single pass conversion is 80%. The material balance calculation will be based on flow sheet in figure 2.
  26. 26. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 21MATERIAL BALANCE Symbols used in this chapter: Total mole flow of stream i MTBEi, Mi, Wi, ISOi, BUTEi ≡ Mole fraction of MTBE, Methanol, Water, isobutene and butene respectively. Calculations:3.2. Amount of stream 8 =1660 Kmol Average molecular weight of stream 8: = MW (MTBE) × mMTBE+ MW (Methanol) × mmeth = 88.15×0.95 + 32.04×0.05 = 85.34 kg/kmol 3.2.1. Over all material balance: F1+F2+F11 = F8+F12+F16 Methanol balance: F1 ∗ 1+F2 ∗ 0+F11 ∗ 0 = F8 ∗ 0+F12 ∗ 0+F16 ∗ 0.03 + 1747.37 ∗ 0.05 + 1660 F1- 0.03F16 =1747.3685 Isobutylene balance: F1 ∗ 0+F2 ∗ ISO2+F11 ∗ 0 = F8 ∗ 0+F12 ∗ ISO12+F16 ∗ 0 + 1660 0.23F2 − ISO12F12 = 1660 Water balance: F1 ∗ 0+F2 ∗ 0+F11 ∗ 1 = F8 ∗ 0+F12 ∗ 0+F16 ∗ 0.97 F11 − 0.97F16=0
  27. 27. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 22MATERIAL BALANCE Other butane balance: F1 ∗ 0+F2 ∗ 0.77+F11 ∗ 0 = F8 ∗ 0+F12 ∗ BUTE12+F16 ∗ 0 F2 ∗ 0.77-BUTE 12F12=0 F1+F15 = F3 Methanol balance: F1 ∗ 1+F15 ∗ 1 = F3∗1 F2+F3 = F4 Methanol balance: F2 ∗ 0+F3 ∗ 1 = F4 ∗ M4 Isobutene: F2 ∗ 0.23+F3 ∗ 0 = F4 ∗ ISO4 Other butane: F2 ∗ 0.77+F3 ∗ 0 = F4 ∗ BUTE4 F4 = F5 = F6 3.2.2. Material balance around reactor(R-901): F6-Reacted= F7 Methanol balance: From equation Given MTBE generated=1660 then
  28. 28. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 23MATERIAL BALANCE mmeth F6 – 1660 = M7F7 Isobutene: misoF6-1660= ISO7F7 misoF6= 2088.05-1660=ISO7F7 = 428.05 Butane balance: BUTE6F6 = BUTE7F7 MTBE balance: 0∗F6-1660=MTBE7F7 MTBE7F7 =1660 Note: At stream F6: (2*ISO)*F6=4176.1 4176.1-1660=M7F7 =2516.10 Given: At F2: ISO2 = 32%, BUTE2= 77% Amount of ISO =2088.05 Amount of butenes= ∗ F2 = 9078 F7 =1660+428.05+2516.10+6990.43=11594.53 From F6- Reacted=F7 F6- 1660=F7 F6 =11594.53+1660=13254.53
  29. 29. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 24MATERIAL BALANCE From equation: F4 = F5 = F6 F4 =13254.53 F2 + F3 = F4 9078 + F3 =13254.53, F3 = 4176.53 3.2.3. Material balance around distillation column (T-901): F7=F8 + F9 11594.53-1747.37=9847.21=F9 Methanol balance: M7F7=M8F8 + M9F9 2516.10-87.37=2428.73=M7F7=M7F9 Isobutene balance: ISOisoF7=ISOisoF8 + ISOisoF9 428.05=0+ISO9F9 , ISO9F9=428.05 Other butane balance: BUTE7 F7=BUTE8 F8 + BUTE9F9 6990.43= 0+BUTE9 F9 BUTE9 F9=6990.43 F9=F10 F10 = 6990.4
  30. 30. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 25MATERIAL BALANCE 3.2.4. Material balance around methanol absorber (T-902): F10+ F11 = F12+ F13 To calculate F12 0.23F2+ISO12F12 = 1660 ISO12F12 = 428.05 0.77F2-BUTE12F12=0 BUTE12F12=6990.43 Given mixed butane only component in this F12 = ISO12F12 + BUTE12F12 =7418.48 F11 = 5 ∗ 2428.732 = 12143.66 F12 =7418.48 Methanol balance: M 10F 10+M 11F 11 = M 12F 12+M 13F 13 2428.73+0 ∗ F11 = 0 ∗ F12+M13F13 M13F13 = 2428.73 Isobutene balance: ISO10F10+ISO11F11 = ISO12F12+ISO13F13 428.05+0 ∗ F11 = ISO12F12+0 ∗ F13 ISO12F12=3.51 Other butane balance: BUTE10F10+BUTE11F11 = BUTE12F12+BUTE13F13 6990.43+0 ∗ F11 = BUTE12F12+0 ∗ F13 BUTE12F12=6990.43 Water balance: W10F10+W11F11 = W12F12+W13F13
  31. 31. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 26MATERIAL BALANCE 0 ∗ F10+1 ∗ F11 = 0 ∗ F12+W12 ∗ 14572.39 W13F13=12143.66 F13=F14 3.2.5. Material balance around tower (T-903): F14 = F15+F16 14572.39 = F15+F16 Methanol balance: 2428.73 = 1 ∗ F15+0.03 ∗ F16 Water balance: 12143.66 = 0 ∗ F15+0.97 ∗ F16 F16=12519.24 W16F16=12143.66 0.03 ∗ F16=0.03*12519.24=375.58 F15=2053.16 F1 + F15 = F3 F1 = F3 − F15 = 4176.10-2053.16=2122.95
  32. 32. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 27MATERIAL BALANCE Table 9 Summary of material balance calculation by using Excel sheet Component 1 2 3 4 5 6 7 methanol 2122.9455 0 4176.10 4176.10 4176.10062 4176.1006 2516.10062 isobutylene 0 2088.0503 0 2088.05 2088.05031 2088.0503 428.050314 1-butenes 0 1817.5116 0 1817.51 1817.51162 1817.5116 1817.51162 2-butenes 0 5172.9176 0 5172.91 5172.91769 5172.9176 5172.91769 MTBE 0 0 0 0 0 0 1660 water 0 0 0 0 0 0 0 Total 2122.9455 9078.4796 4176.10 13254.5 13254.5802 13254.580 11594.5802 8 9 10 11 12 13 14 87.36842 2428.732 2428.732 0 0 2428.732 2428.732208 0 428.0503 428.0503 0 428.0503 0 0 0 1817.512 1817.512 0 1817.512 0 0 0 5172.918 5172.918 0 5172.918 0 0 1660 0 0 0 0 0 0 0 0 0 12143.66 0 12143.66 12143.6610 1747.368 9847.212 9847.212 12143.66 7418.48 14572.39 14572.39325 15 16 2053.155062 375.5771 0 0 0 0 0 0 0 0 0 12143.66 2053.155062 12519.24
  33. 33. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 28ENERGY BALANCE CHAPTER FOUR 4. ENERGY BALANCE Introduction:4.1. As with mass, energy can be considered to be separately conserved in all but nuclear process. The conservation of energy, however, differ from that of mass in that energy can be generated (or consumed) in a chemical process. The Total enthalpy of the outlet streams will not be equal that of the inlet streams if energy is generated or consumed in the processes; such as that due to heat of reaction. In process design, energy balance is made to determine the energy requirements of the process: the heating, cooling and power required. Inplant operation, an energy balance on the plant operation will show the pattern of energy usage and suggest areas for conservation and savings (Himmelblau & Riggs, 2004). Conservation of energy:4.2. The general equation can be written for conservation of energy is: Energy out = Energy in – Generation – Consumption – Accumulation. This is a statement of the first law of thermodynamics. Chemical reaction will evolve energy (exothermic) or consume energy (endothermic).For steady State process the accumulation of both mass and energy will be zero.
  34. 34. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 29ENERGY BALANCE Energy balance calculations:4.3. Symbols used in this chapter: Cpi = Heat capacity of component (i). T = Temperature of stream in degree Kelvin. Mij = Mole flow of component (i) in stream (j). Hj =Total enthalpy of stream (j). Hij = enthalpy of component (i) in stream (j). -Heat capacity constants for ideal gases. component A B C D E methanol 3.93E-01 8.79E-01 1.92E+00 5.37E-01 896.7 isobutylene 6.13E-06 2.07E-05 1.55E-03 1.21E-05 6.76E+02 1-butenes 6.43E-06 2.06E-05 1.68E-03 1.33E-05 757.06 2-butenes 5.77E-06 2.12E-05 1.63E-03 1.29E-05 739.1 MTBE 9.78E-06 3.09E-05 1.64E-03 2.10E-05 731.191 H2O 3.34E-06 2.68E-06 2.61E-03 8.90E-07 100 Table 10 Heat capacity constants for ideal gases 4.3.1. Heat capacity equation for ideal gases: C C C * ⁄ ( ⁄ ) + C ⁄ ( ⁄ )
  35. 35. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 30ENERGY BALANCE 4.3.2. Heat capacity constant for liquid: Componene t A B C D E methanol 106 -0.362 0.938E-3 0 0 isobutylene 179.34 -1.467 0.01032 3 -0.3E-4 3.40E-08 1-butenes 140.12 -0.55487 0.00262 42 -3.00E-06 0 2-butenes 112.76 -0.1047 0.00052 1 0 0 MTBE 140.12 -0.0009 0.00056 3 0 0 H2O 276 2.09 0.00825 1.41E-05 9.37E-09 Table 11 Heat capacity constants for liquid. Heat capacity equation for liquid: 4.3.3. Energy balance around summing point: Q-W = ∆H W = 0, Q = 0(adiabatic mixing). ∆H = Hout H1 + H15 = H3 H2 + H3 = H4 H1 = H2 = 0; so: H15 = H3 = H4 H15 = HMTBE15 + HM15 + HISO15 + H1−BUT15 + H2−BUT15 − HW15 PT = 4.95 bar. T= 314.3°K (bubble point), this temperature gives: ∑ Yi = ∑Pi(T)Xi/PT = 1
  36. 36. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 31ENERGY BALANCE Pi = EXP (A+B/T+C LnT+DTE ). Where: Pi: is vapor presser of component (i). Compone nt A B C D E P* Xi Yi methanol 81.76 8 6876 -8.71 7.19E- 06 2 495.24 72 1 1.000 2isobutyle ne 9.52E 4876 - 12.6 1.78E-2 1 3.74E4 0 0 1-butenes 67.78 4429 -7.20 8.40E- 06 2 3.80E4 0 0 2-butenes 77.55 1 4848 -8.78 1.17E- 05 2 2.47E4 0 0 MTBE 55.87 5 5132 -4.96 1.91E- 17 6 2.05E3 0 0 water 73.64 9 7258.2 -7.30 4.17E- 06 2 58.311 0 0 0 ∑ 𝒀𝒊 1 1.000 Table 12 summarizes the results: bubble point calculation of stream 15. HMTBE15=MMTBE15 ∫ 𝑝 𝑡 MMTBE15 from material balance calculation = 0.00Kmol/h. HMTBE15 = 0.00KJ/h Also, from material balance calculation: MISO15 = M1−BUT15 = M2−BUT15 = MW15 = 0.00Kmol/h; so: HISO15 = H1−BUT15 = H2−BUT15 = HW15 =0.00KJ/h HM15 = M M15 ∫ 𝑝 𝑡
  37. 37. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 32ENERGY BALANCE MM15 from material balance calculation=2053.16Kmol/h. HM15= 2053.16*[106(314.3-298) - 0.362/2(314.32 -2982 ) +0.938E-3/3(314.33 - 2983 )] HM15= 2781433.8KJ/h. H4 = H5 (No change in enthalpy through the pump) 4.3.4. Energy balance around heat exchanger (E901): Q-W = ∆H W=0 Q = ∆H = H6 − H5 H6 =HMTBE6 +HM6 + HISO6 + H1−BUT6 + H2−BUT6 − HW6 V/F =1(completely vapor), T6 =358°K HMTBE6 = MMTBE6 [∫ 𝑝 𝑡 + λ298]. MMTBE6 from material balance calculation = 0.00Kmol/h. HMTBE6 = 0.00KJ/h. HM6 = MM6 [∫ 𝑝 𝑡+ λ298]. MMTBE6 from material balance calculation =4176.10Kmol/h. HM6 = 4176.1*[106(358-298) - 0.362/2(3582 -2982 ) +0.938E-3/3(3583 -2983 ) - 200.66] HM6 = 21326949.95KJ/h. HISO6 = Miso6 [∫ 𝑝 𝑡+ λ298].
  38. 38. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 33ENERGY BALANCE Miso6 from material balance calculation =2088.05Kmol/h. HISO6 = 2088.05*[179.34 (358-298) - 1.467/2(3582 -2982 ) +0.010323/3(3583 - 2983 ) -0.3E-4/4(3584 -2984 ) +3.40E-08/5(3585 -2985 )-16.9059]. HISO6 = 17992470.95KJ/h. H1−but6 = M1−but6 [∫ 𝑝 𝑡+ λ298]. M1−but6 from material balance calculation =1817.511622Kmol/h. H1−but6 = 1817.511622*[140.12 (358-298) - 0.55487/2(3582 -2982 ) +0.26242E- 2/3(3583 -2983 ) -3.00E-06/4(3584 -2984 ) -0.53974]. H1−but6 = 14664582.86KJ/h. H2−but6 = M2−but6 [∫ 𝑝 𝑡+ λ298]. M2−but6 from material balance calculation =5172.917692Kmol/h. H2−but6 = 5172.917692*[112.76 (358-298) -0.1047 /2(3582 -2982 ) +0.521E-3 /3(3583 -2983 )-8.78031] H2−but6 = 41739225.95KJ/h. H6 = 21326949.95 + 17992470.95 + 14664582.86 + 41739225.95 H6 = 95723229.71KJ/h. Q =m*λsteam Q = 114767838.5 m = 114767838.5 *18/36098.259 = 57227.7Kg/h.
  39. 39. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 34ENERGY BALANCE 4.3.5. Energy balance around reactor (R901): The conversion in the reactor is 80% and the reactor is adiabatic. So we calculate the adiabatic temperature (T7) from equation below. Conversion(x) = ∑ ∫ Where: θi = ratio of component(i)in the feed to reference component(isobutylene feed). Compone nt 𝛉 𝐢 methanol 2.00 isobutyle ne 1.00 1-butenes 0.87 2-butenes 2.48 MTBE 0.00 water 0.00 ∆HR = heat of reaction at the adiabatic temperature (T7): ∆HR(T7) = ∆H°R+∫ ∆H°R = HMTB6 − HM − HISO ∆H°R = -2.80E+04 KJ/Kmol. ∫ = ∫ 𝑛(cpMTB6 − cpM − cpISO) dt. Solving for T7 by trial and error, By using excel sheet: T7 = 403°K. H7 = HMTBE7 + HM7 + HISO7 + H1−BUT7 + H2−BUT7 − HW7 Table 13 Ratio of component (i) in the feed to isobutylene feed.
  40. 40. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 35ENERGY BALANCE HMTBE7 = MMTBE7 ∫ + λ298]. MMTBE7 from material balance caculation = 1660Kmol/h. HMTBE7 =1660*[140.12 (403-298)-0.9E-3/2(4032 -2982 ) +0.563E-3/3(4033 -2983 )- 283.4992]. HMTBE7 = 16066714.2KJ/h. HM7 = MM7 [∫ + λ298]. MM7 from material balance calculation =2516.10Kmol/h. HM7 = 2516.1*[106(304-298) - 0.362/2(4032 -2982 ) +0.938E-3/3(4033 -2983 ) - 200.66]. HM7 = 11295476.78KJ/h. HISO7 = Miso7 ∫ +λ298]. Miso7 from material balance calculation = 428.05Kmol/h. HISO6 =428.05*[179.34 (403-298) - 1.467/2(4032 -2982 ) +0.010323/3(4033 -2983 ) - 0.3E-4/4(4034 -2984 ) +3.40E-08/5(4035 -2985 )-16.9059]. HISO6 = 3375687.845KJ/h. H1−but7 = M1−but7 [∫ λ298] M1−but7 from material balance calculation =1817.511622Kmol/h. H1−but7 = 1817.511622*[140.12 (403-298) - 0.55487/2(4032 -2982 ) +0.26242E- 2/3(4033 -2983 ) -3.00E-06/4(4304 -2984 ) -0.53974]. H1−but7 = 11737411.97KJ/h. H2−but7 = M2−but7[∫ λ298].
  41. 41. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 36ENERGY BALANCE M2−but7 from material balance calculation =5172.917692Kmol/h. H2−but7 = 5172.917692*[112.76(403-298) -0.1047 /2(4032 -2982 ) +0.521E-3 /3(4033 -2983 )-8.78031] H2−but7 = 34508550.26KJ/h. H7 = 1.4672E11KJ/h. 4.3.6. Energy balance around distillation column (T901): Qr − Qc = H9 + H8 − H7 H9 = HMTBE9 + HM9 + HISO9 + H1−BUT9 + H2−BUT9 − HW9 PT = 19 bar. T= 313.3°K (bubble point). HMTBE9 = MMTBE9∫ 𝑝 𝑡 MMTBE9 from material balance calculation = 0.00Kmol/h. HMTBE7 = 0.00KJ/h. HM9 = ∫ 𝑝 𝑡 MM9 from material balance calculation = 2428.73Kmol/h. HM9 = 2428.73*[106(313.3-298) - 0.362/2(313.32 -2982 ) +0.938E-3/3(313.33 - 2983 )]. HM9 = 3084349.641KJ/h. HISO9 = Miso9∫ 𝑝 𝑡 Miso9 from material balance calculation =428.05Kmol/h. HISO9 =428.05*[179.34 (313.3-298) - 1.467/2(313.32 -2982 ) +0.010323/3(313.33 - 2983 ) -0.3E-4/4(313.34 -2984 ) +3.40E-08/5(313.35 -2985 )].
  42. 42. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 37ENERGY BALANCE HISO9 = 8.84E5KJ/h. H1−but9 = M1−but9 ∫ 𝑝 𝑡 M1−but9 from material balance calculation =1817.511622Kmol/h. H1−but9 = 1817.511622*[140.12 (313.3-298) - 0.55487/2(313.32 -2982 ) +0.26242E-2/3(313.33 -2983 ) -3.00E-06/4(313.34 -2984 )]. H1−but9 = 3615478.074KJ/h. H2−but9 = M2−but9 ∫ 𝑝 𝑡 M2−but9 from material balance calculation =5172.917692Kmol/h. H2−but9 = 5172.917692*[112.76(313.3-298) -0.1047 /2(313.32 -2982 ) +0.521E-3 /3(313.33 - 2983 )]. H2−but9 = 10244724.91KJ/h. H9 = 17829041.27KJ/h. Condenser duty calculation: Vapor temp. = 319.8°K(dew point). Qc = (1 + R)(HV9 − H9). R = 1.8 HV9Can be calculated by using heat capacity constants for ideal gases, with the fallowing equation: HiV9 = Mi9 [∫ 𝑝 𝑡+ λ298].
  43. 43. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 38ENERGY BALANCE → HV9 = 18886227.06KJ/h. ∴ Qc = 2.8(18886227.06 − 17829041.27) Qc = 2960120.19KJ/h. -Amount of cooling water: M ∗ = ( ) = 70816.27kg/h. H8 = HMTBE8 + HM8 + HISO8 + H1−BUT8 + H2−BUT8 − HW8 HMTBE8 = MMTBE8 ∫ 𝑝 𝑡 MMTBE8 from material balance calculation = 1660Kmol/h. HMTBE8 = 1660*[140.12 (314.74-298)-0.9E-3/2(314.742 -2982 ) +0.563E- 3/3(314.743 -2983 )]. HMTBE8 = 5356128.348KJ/h. HM8 = MM8 ∫ 𝑝 𝑡 MM8 from material balance calculation = 87.37Kmol/h. HM8 = 87.37*[106(314.74-298) - 0.362/2(314.742 -2982 ) +0.938E-3/3(314.743 - 2983 )]. HM8 = 121652.5772KJ/h. From material balance calculation: MISO8 = M1−BUT8 = M2−BUT8 = MW8 = 0.00Kmol/h; so: HISO8 = H1−BUT8 = H2−BUT8 = HW8 = 0.00KJ/h. ∴ H8 = 5477780.925KJ/h. Reboiler duty calculation:
  44. 44. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 39ENERGY BALANCE Qr = Qc + H9 + H8 − H7 Qr = 258116146.6KJ/h. -Amount of stream needed: M 4.3.7. Energy balance around methanol absorber (T902): This column run at 5bar and 363°. H10 =H9 H11 = H11w Hw11 = Mw11 ∫ 𝑝 𝑡 Mw11 from material balance calculation = 12143.66Kmol/h. Hw11 =12143.66 *[276 (363-298)-2.09/2(3632 -2982 ) +0.00825/3(3633 -2983 ) +1.41E-05/4(3634 -2984 ) +9.37E-09/5(3635 -2985 )]. Hw11 = 1972318662KJ/h. H12 = HISO12 + H1−BUT12 + H2−BUT12 − HW12 HISO12 = Miso12 ∫ 𝑝 𝑡 Miso12 from material balance calculation =428.05Kmol/h. HISO12 =428.05*[179.34 (363-298) - 1.467/2(3632 -2982 ) +0.010323/3(3633 -2983 ) -0.3E-4/4(3634 -2984 ) +3.40E-08/5(3635 -2985 )]. HISO12 = 4038036.682KJ/h. H1−but12 = M1−but12 ∫ 𝑝 𝑡
  45. 45. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 40ENERGY BALANCE M1−but12 from material balance calculation =1817.511622Kmol/h. H1−but12 = 1817.511622*[140.12 (363-298) - 0.55487/2(3632 -2982 ) +0.26242E- 2/3(3633 -2983 ) -3.00E-06/4(3634 -2984 )]. H1−but12 = 15943036.3KJ/h. H2−but12 = M2−but12∫ 𝑝 𝑡 M2−but12 from material balance calculation =5172.917692Kmol/h. H2−but12 = 5172.917692*[112.76(363-298) -0.1047 /2(3632 -2982 ) +0.521E-3 /3633 -2983 )]. H2−but12 = 45476091.78KJ/h. H12 = 4038036.682 + 159 43036.3 + 45476091.78 H12 = 65457164.76KJ/h. H13 = HM13 + Hw13 HM13 = MM13 ∫ 𝑝 𝑡 MM13 from material balance calculation = 2428.73Kmol/h. HM13 = 2428.73*[106(363-298) - 0.362/2(3632 -2982 ) +0.938E-3/3(3633 -2983 )]. HM13 = 14073458.46KJ/h. Hw13 = Mw13 ∫ 𝑝 𝑡 Mw13 from material balance calculation = 12143.66Kmol/h. Hw13 = 12143.66 *[276 (363-298) -2.09/2(3632 -2982 ) +0.00825/3(3633 -2983 ) +1.41E-05/4(3634 -2984 ) +9.37E-09/5(3635 -2985 )]. Hw13 = 1972318662KJ/h. H13 = 14073458.46 + 1972318662
  46. 46. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 41ENERGY BALANCE H13 = 1972318662KJ/h. Energy balance around distillation column (T903): Qr − Qc = H15 + H16 − H14 H14 = H13 = 1972318662KJ/h (o change in enthalpy through the pump). H15 = 2781433.8KJ/h. - Condencer duty calculation: Vapor temp. = 322.1°K(dew point). Qc = (1 + R)(HV15 − H15). R = 3.84. HV15 Can be calculated by using Heat capacity constants for ideal gases, with the fallowing equation: HiV15 = Mi15 ∫ 𝑝 𝑡+ λ298]. → HV15 = 3744574.894KJ/h. ∴ Qc = 4.84(3744574.894 − 2781433.8) Qc = 4661602.895KJ/h. -Amount of cooling water: M ∗ = ( ) = 111521.6kg/h. H16=HMTBE16+HM16+HISO16+ H1−BUT16+H2−BUT16−HW16 from material balance calculation: MMTBE16 = MISO16=M1−BUT16=M2−BUT16=0.00Kmol/h; so: HMTBE16 = HISO16=H1−BUT16=H2−BUT16=0.00KJ/h.
  47. 47. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 42ENERGY BALANCE H16=Hw16+HM16 HM16= MM16∫ 𝑝 𝑡 MM16 from material balance calculation=375.58Kmol/h. HM16= 375.58*[106(430.2-298) - 0.362/2(v2-2982) +0.938E-3/3(430.23- 2983)]. HM16=16824464.12KJ/h. Hw16= Mw16∫ 𝑝 𝑡 Mw16 from material balance calculation=12143.66Kmol/h. Hw16=12143.66 *[276 (430.2-298) -2.09/2(430.22-2982) +0.00825/3(430.23- 2983) +1.41E- 05/4(430.24 -2984 ) +9.37E-09/5(430.25 -2985 )]. Hw16 = 5849089008KJ/h. H16 = 16824464.12 + 5849089008 H16 = 5865913472KJ/h. Reboiler duty calculation: Qr − Qc = H15 + H16 − H14 Qr = 48907569980KJ/h. -Amount of stream needed: M Equipment E901 E902 E903 E904 E905 Agent mps mps cw mps cw Temp.in (℃) 254 254 30 254 30 Temp.out( ℃) 254 254 40 254 40 Flow(Kg/h) 57227.7 128706.77 70816.27 24387222. 1 111521.6 Table 14 Summary of agent amount.
  48. 48. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 43ENERGY BALANCE Component 1 2 3 4 5 6 P (bar) 4.9512 4.9512 4.9 4.9 20 20 T (K) 298 298 297.24 298.00 298.0001 358.0001 methanol 2122.94 556 0 4176.1 4176.1 4176.100 4176.100 isobutylene 0 2088.05031 0 2088.0 2088.050 2088.050 1-butenes 0 1817.51162 0 1817.5 1817.511 1817.511 2-butenes 0 5172.91769 2 0 5172.91 8 5172.917 692 5172.917 692MTBE 0 0 0 0 0 0 water 0 0 0 0 0 0 Total 2122.94 55 9078.47962 4176.1 13254 13254.58 13254.58 Table 15 Summary of energy balance calculation made by using Excel sheet 7 8 9 10 11 12 13 14 15 16 20 19.25 19 10 5 5 5 5.89132 4.9512 5.687 403 314.7 43 8 313.3 310.2 363 363 363 405.32 314.3 430.2 2516 87.36 84 2 2428. 73 2 2428. 73 2 0 0 2428.7 3 2 2428.73 220 8 2053.1 5506 2 375.5 77 1 428 0 428.0 50 3 428.0 50 3 0 428.0 50 3 0 0 0 0 1817 0 1817 2 1817 2 0 1817 2 0 0 0 0 5172 0 5172 5172 0 5172 0 0 0 0 1660 1660 0 0 0 0 0 0 0 0 0 0 0 0 12143 .6 6 0 12143. 6 6 12143.6 610 4 0 12143 .6 6 1159 4.58 1747 9847 9847 12143 7418 14572 14572 2053.1 55 12519 4
  49. 49. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 44CONCLUSION & RECOMMENDATIONS CHAPTER FIVE 5. DESIGN Distillation design:5.1. 5.1.1. Introduction: Distillation is most common class of separation processes and properly of the better-understand unit operation that uses the difference in relative volatilities , or differences in boiling of the component to be separated, it is the most widely used method of separation in the process industries Types of distillation column:  Single flash vaporization.  Packed towers.  Plates towers. a) Bubble cap towers. b) Sieve pates. c) Valve plates towers. Sieve trays: Sieve trays offer several advantage over bubble-cap trays, and their simpler and cheaper construction has led to their increasing use. The general form of the flow on a sieve tray is typical of a cross flow system with perforation in the tray taking the place of the more complex bubble caps. The key differences in operation between these two types of tray should be noted. With the sieve tray the vapor passes vertically through the holes into the liquid on the tray, whereas with the bubble cap the vapor issues in an approximately
  50. 50. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 45CONCLUSION & RECOMMENDATIONS horizontal direction from the slots . With the sieve plate the vapor velocity through the perforation must be greater than a certain minimum value in order to prevent the weeping of the liquid stream down through the holes. At the other extreme, a very high vapor velocity leads to excessive entrainment and loss off tray efficiency. 5.1.2. Collect the data of fluid to be distillated and distillated Fluids: -Feed stream: At 4030 K, 2000 KPa. Component Moleflow (kmol/h) Mole% Mass flow (kg/h) Wt% methanol 2516.10 0.2170066 16 80615.844 0.125340067 isobutylene 428.05 0.0369181 38 24017.8855 0.037342577 1-butene 1817.511 622 0.1567552 75 101977.3431 0.158552542 2-butene 5172.917 692 0.4461496 3 290236.8929 0.451255111 MTBE 1660.00 0.1431703 4 146329 0.227509702 water 0 0 0 0 Total 11594.58 1 643176.9655 1 Table 16 Feed stream composition. -Top product stream: At400 o K, 1900KPa. Component Mole flow (kmol/h) Mole% Mass flow (kg/h) Wt% methanol 2428.7308 0.246641 613 77816.57994 0.15750861 5 isobutylene 428.0505 0.043468 9 24017.914 0.0486161 1-butene 1817.512 0.184579 2 101975.46 0.2064048 2-butene 5172.912 0.525310 7 290236.83 0.5874676 MTBEs 0 0 0 0 water 0 0 0 0 Total 9847.236 1 494046.06 1 Table 17 Top stream composition
  51. 51. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 46CONCLUSION & RECOMMENDATIONS -Bottom product stream: At 440 o K, 1925.175 KPa Component Mole flow (kmol/h) Mole% Mass flow (kg/h) Wt% methanol 87.36842 105 0.05 2799.284211 0.018770981 isobutylene 0 0 0 0 1-butene 0 0 0 0 2-butene 0 0 0 0 MTBE 1660 0.95 146329 0.981229019 water 0 0 0 0 Total 1747.368 421 1 149128.2842 1 Table 18 Bottom stream composition -Relative volatility: Component αfeed αtop αbottom Αav methanol 1.186110 097 1.162297499 1.448866438 1.265758 isobutylene 4.214615 978 4.270349142 3.743897719 4.076288 1-butene 4.281515 808 4.345063797 3.73236071 4.119647 2-butene 3.479708 054 3.515657126 3.194453855 3.396606 MTBE 1 1 1 1 water 0.381770 611 0.369823631 0.51937441 0.423656 Table 19 Average relative volatility of composition. 5.1.3. Heavy and light key: Heavy key: MTBE Light key: methanol. 5.1.4. Type of tray: Sieve tray.
  52. 52. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 47CONCLUSION & RECOMMENDATIONS 5.1.5. Determination of minimum reflux ratio: ∑ 𝑚 (1) α= average Relative volatility of any component. X= mole faction of component in Distillate. Ø= Constant. Rm = Minimum reflux ratio. ∑ 𝑞 (2) Where: Zf= mole faction of component in feed stream. q= feed quality q= HG=Enthalpy of gas at the feed dew point (KJ/Kmol) HL=Enthalpy of liquid at the feed bubble point (KJ/Kmol) HF=Enthalpy of feed at 403o K. q= =1.86 Substitute in equation (2) to find (Ø) ∑ =1-1.86 ∑ -0.86 + + + + + = 0 Solving Ø By try &error: Ø =1.047365 Substitute in equation (1) to find Rm: + + +
  53. 53. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 48CONCLUSION & RECOMMENDATIONS + + = Rm+1 Rm= 1.494995 5.1.6. Calculation of the actual ratio(R) The rule of thumb is: R = (1.2 ------- 1.5) R min R=1.2Rm =1.2×1.5 = 1.8 5.1.7. Calculation of the minimum number of theoretical stages: N L ( ) ∗ ( ) L 𝑋 𝑙𝑘=mole fraction of light key. 𝑋 𝑘= mole fraction of heavy key. 𝛼𝑙𝑘= average relative volatility of light key. Nmin= 26 stagess 5.1.8. Calculation of the number of theoretical stages: [ ( ) ] R R R From Gilland relation. → N=57.695 stages
  54. 54. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 49CONCLUSION & RECOMMENDATIONS 5.1.9. Calculation of the column efficiency (E˳): E˳= 0.5278-0.27511 log(αlk*μF)+0.04493(log(αlk* μF))2 μF=0.2161 E˳=69.29% 5.1.10. Calculation of the number of actual stages (Na): E = = 83.265 𝑠𝑡 𝑒𝑠 5.1.11. Calculation of the height of the column (Ht): Ht=N×C+ ( ) + 0.2 × 𝐻𝑡 C: tray spacing = 0.609(so as to ensue accessibility for cleaning) 0.8Ht= 84×0.3+ ( ) = 27.69 Ht=34.6 m. 5.1.12. Determination of the feed plate location (m): {( ) ∗ ( ) ∗ }0.206 D=9847.2118Kmol/h B=1747.368 Kmol/h {( ) ∗ ( ) ∗ }0.206 = 2.7561 m = m=22 stage The feed enter the column at tray no 22 from the Bottom.
  55. 55. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 50CONCLUSION & RECOMMENDATIONS 5.1.13. Calculation of the tower diameter(D): The following areas terms are used in the plate design procedure: At=Total column cross- sectional area, Ad=cross-sectional area of down comer, An=Net area available for vapor-liquid disengement , normally equal to Ac-Ad for asingle pass plate, Aa= Active or bubbing, area, equal to Ac-2Ad for single- pass plates, Ao=Hole area, the total area of all the active holes, Ap= perforated area (including blanked areas), Aap= The clearance area under the down comer apron. -Top diameter calculation: UF =K√ Where: 𝑈 𝐹= floading vapor velocity (m/s) based on the net column cross sectional area 𝑛. K=constant FLV = ̅ ̅ √ Where: 𝐹 𝐿𝑉 = the vapor liquid flow 𝐿̅= Liquid mass flow rate kg/s 𝑉̅= Vapor mass flow rate kg/s Top Diameter calculations: ̅ ̅ = From ideal gas law: PV= nRT
  56. 56. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 51CONCLUSION & RECOMMENDATIONS 𝑉 𝑉 𝑚 𝐹 √ = 0.160 K=0.05 𝑈 ∗ √ Design velocity (U)= 80% of (𝑈 𝐹) U = 0.8* 0.753 = 0.602m/s = ∗ ∗ ( ) ∗ ∗ ( )∗ 𝑚 = 0.12 𝑡 𝑛= 𝑡− 0.12 𝑡 = 0.88 𝑡 𝑚 D=( ) -Bottom diameter calculations: 𝐿̅ (𝑞 ∗ 𝐹) 𝐿 Ideal gas law:PV= nRT 𝑉 𝑉 𝐹 ∗ √ At FLV= O.261 and spacing 60 mm K=0.046 𝑈 ∗ √
  57. 57. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 52CONCLUSION & RECOMMENDATIONS Design velocity (U) = 80% of flooding velocity (𝑈 𝐹) 0.8×0.178=0.1424m/s 𝑉 𝑉 ∗ 𝑈 ∗ 𝑚 Down comer area =12% from total area=0.88 𝑡 𝑚 D=( ) Taking the bottom diameter for the entire tower since it is the greatest diameter. 𝑡= 1.36 𝑚2 = 0.12 𝑡 =0.12×1.36=0.1632 𝑚2 = 1.36 – 2(0.1632) = 1.0336𝑚2. o = 0.1× = 0.10336𝑚2. = 0.07× 𝑡= 0.07 × 1.36 = 0.0952𝑚2. -𝑨 𝒑=Preformatted area: When down comer area = 0.12× 𝑡 0.75 Where 𝐿 𝑊: Weir length. 𝐿 𝑊 =0.75×D= 0.75 × 1.3172=0.9879 M Angle subtended at plate edge by imperforated strip=180- 98=82 𝑜 Calming zones width=50mm Mean Length, imperforated edage strips
  58. 58. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 53CONCLUSION & RECOMMENDATIONS = (1.3172 −50×10−3 ) π × ( ) = 1.813 m Area of imperforated edge strips= 50 * 10−3 × 1.813 = 0.0906 𝑚2 Mean length of calming zone = (1.3172−50*10−3 ) sin( )= 0.9563𝑚 Area of calming zone =2(0.9563*50*10−3 ) = 0.09563𝑚2 Total area for perforatins, 𝑝 = 1.336− 0.0906 −0.09563 = 0.8473𝑚2 ( ) ( ) ( 𝐿 ) Where 𝐿 𝑝: hole pitch. ( 𝐿 ) ( ) =0.1355 ( ) =2.716. 2.716 are satisfactory, within 2.5 to 4.0. 5.1.14. Determination of fractional entrainment (ϕ): 𝑡 𝐹 𝐿𝑉=0.261 and80% flooding ϕ= 0.09(well below 0.1). e = ∗ = =160.973kg/h. 5.1.15. Weeping point: Weeping will occur when 𝑈 𝑂 (min) < 𝑈 𝑜 (min) calculated. 𝑈 𝑉 𝑉 ∗
  59. 59. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 54CONCLUSION & RECOMMENDATIONS Taking 70% turn down. 𝑈𝑜 (min) = 0.7×𝑈𝑜= 0.7 ×2.3175 = 1.624 m/s. 𝑈 𝑂(min)calculated= ( ) 𝑜=5mm 𝑘2is a function of ( 𝑤 + 𝑜𝑤 (min)) 𝑤: weir hight = 23 mm 𝑜𝑤 (min): minimum weir crest =750× ( ) 𝐿 𝑚𝑖𝑛= o.7×17724.98 = 12407.486kg/h. (𝑚𝑖𝑛) ∗ ( ) ⁄ 𝑤+ 𝑜𝑤 (min)=23+21.31= 44.31mm. 𝑘2=30 𝑈 𝑂(min)calculated= ( ) ( ) ∴Weeping will not occur. 5.1.16. Pressure drop calculation: ∆P=9.81 × 𝑡 ×10−3× 𝑙 𝑡 = +( 𝑤+ 𝑜𝑤)+ 𝑟 =51( ) ( ) At = 12.198%& =1 𝑂=0.859 ( ) ( )
  60. 60. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 55CONCLUSION & RECOMMENDATIONS (𝑚𝑖𝑛) ∗ ( ) ⁄ 𝑚𝑚 𝑤=23mm 𝑡=21.31+36.23+23+17.16=97.7mm ∆P=9.81 ×97.7×10−3×728.228=0.007 bar/tray. 5.1.17. Down comer liquid back up: For safe design and to avoid flooding ( ) 𝑏= 𝑡 + + 𝑤 + 𝑜𝑤 + 𝑟 + =166( ) 𝑝= 𝑝×𝐿 𝑊 𝑝= 𝑊-10mm 23-10=13mm 𝑝=0.9879 ×10−3×13=0.013mm =166( ) 𝑚𝑚 𝑏=97.7+36.23+23+4.67=201.83mm (C+ )= (0.3+23×10−3) =0.323m. (C+ ) no floading will occure.
  61. 61. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 56CONCLUSION & RECOMMENDATIONS 5.1.18. Down comer residence time: 𝑡 𝑝 𝐿 ( ) 𝑠𝑒 4.8>3 so it is acceptaple 5.1.19, Thickness calculation: - columan thickness: Highest operating temperature is 166.850C. Design stress at 166.850C = 111 N/𝑚𝑚2. Joint efficiency = 0.85. e = 𝑚𝑚 Corrosion allowance 2mm. ∴ 𝑜𝑙𝑢𝑚𝑛 𝑡 𝑖 𝑘𝑛𝑒𝑠𝑠=2.01357𝑚𝑚. -Head thickness: - Ellipsoidal heads: e = 𝑚 -Tori spherical head e = ( ) Stress concentration factor for torispherical head = ( √ ⁄ ) Crown radius. =no less than 0.6 =knukle radius = ( √ ⁄ ) =1.072
  62. 62. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 57CONCLUSION & RECOMMENDATIONS J =1(No joint in head). E ( ) = 0.01224mm. Ellipsoidal heads IS recommended since it has the smallest thickness ∴ 𝑒 𝑡 𝑖 𝑘𝑛𝑒𝑠𝑠=0.011𝑚𝑚. Parameter Value Tower diameter 1.3172m Tray spacing 0.30 Tower Height 34.6m Total area(cross sectional area) 1.36𝑚2 Down comer area 0.1632𝑚2 Net area 1.19𝑚2 Active area 1.0336𝑚2 Hole area 0.10336𝑚2 Number of theoretical stages 57.695 stages Tower efficiency 69.29% Plate thickness 0.005m Weir height 0.005m Weir length 0.987m Hole diameter 0.005m Fractional entrainment 0.09 Weeping velocity 1.5m/s Total presser drop head 0.007 bar thickness Of column 2.01357mm thickness Of head 0.011mm Table 20 Summary of design calculation.
  63. 63. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 58CONCLUSION & RECOMMENDATIONS CHAPTER SIX 6. CONCLUSION & RECOMMENDATIONS Conclusion:6.1. • As shown in this study it is possible to produce 112,200tons /y of MTBE with a purity of about 95% at a conversion of 80%. • The design parameters of the selected distillation are: height 34.6 m, number of trays 84 and diameter 1.32m. • The specifications of the reactor needed for the process are: volume 65 m3, height 24.8.m, and diameter 1.8m. Recommendations:6.2.  Increasing annual frequency of renewing the catalyst increases conversion and reduces the flow rate of the limited-supply isobutylene. However, this may affect negatively costs and profitability due to the high price of the catalyst hence an optimization technique must be applied to determine the optimum values of these parameters.  It is recommended to perform an effective control study to construct effective system controlling the critical parameters. This study can be extended to investigate the feasibility of planning a process that meets the foreign markets demand of MTBE.
  64. 64. PRODUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE) 59REFERENCES 7. REFERENCES Adjeroh, D. A., 2015. DESIGN OF AN MTBE PRODUCTION PROCESS. West Virginia: West Virginia University. Al-Harthi, F., 2008.. Modeling and simulation of a reactive distillation unit for production of MTBE. s.l.:King Saud University,. Himmelblau, D. M. & Riggs, J. B., 2004. Basic Principles and Calculations in Chemical. 7th Edition ed. Englewood Cliffs: Prentice Hall. Lidderdale, T., 2000. MTBE, Oxygenates, and Motor Gasoline, s.l.: Energy Information Administration . Matyash, V. et al., 2016. Methyl Tertiary Butyl Ether (MTBE): 2016 World Market Outlook and Forecast up to 2020. Birmingham : Merchant Research & Consulting, Ltd.. Rocque, A. J., 2000. Use of Methyl Tertiray Butyl Ether (MTBE) as a Gasoline Additive, Connecticut: Departmant of Enviromental Protection. Winterberg, M., Schulte-Korne, E., Peters, U. & Nierlich, F., 2010. Methyl Tert- Butyl Ether. In: Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH.

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