bio-diesel production from waste vegetable (soybean) oil
TRANSCRIPT
Final Year Design Project
A Plant Design Report on The Production of
Biodiesel from 30 TPD Waste Cooking Oil
Project SupervisorDr. Maria Mustafa
Muhammad AbubakarDDP-SP13-BEC-043
Muhammad Hashim KhanDDP-SP13-BEC-053
Shahzaib YounasDDP-SP13-BEC-085
Zohaib UzairDDP-SP13-BEC-101
Department of Chemical Engineering
Biodiesel Production Using Waste Cooking Oils
Muhammad Abubakar
DDP-SP13-BEC-043
Muhammad Hashim Khan
DDP-SP13-BEC-053
Shahzaib Younas
DDP-SP13-BEC-085
Zohaib Uzair
DDP-SP13-BEC-101
A report submitted in partial fulfilment of the
requirements for the award of the degree of
Bachelor of Science in Chemical Engineering
Department of Chemical Engineering
I declare that this I declare that this thesis entitled “title of the thesis” is the result of my own research
except as cited in the references. The thesis has not been accepted for any degree and
is not concurrently submitted in candidature of any other degree.
Signature: ....................................................
Name: ....................................................
Date: ....................................................
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ACKNOWLEDGEMENTWe would like to express our sincere gratitude to all those who have assisted and guided
us during our project study. First of all, we would like to thank our supervisor, Doctor
Maria Mustafa for her guidance and support during the course of this project. She
provided us with invaluable supervision from the beginning until the completion of our
project. We would also like to thank the lab engineers and technicians, who have assisted
us through this project. They have catered to our equipment needs during the project. I
would also like to express my most sincere feelings of gratitude towards Doctor Fahad
who helped the group in designing the reactors. Last but not the least, we also express our
honest gratitude to all our colleagues, friends and beloved family for their endless love
and support throughout the project.
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ABSTRACTBiodiesel is a type of bio fuel which can be derived from new or used vegetable oils and
animal fats. It is a biodegradable, renewable energy and clean burning alternative. Due to
the price hike in conventional fuels in the last decade studies have been made to
introduce biodiesel as a feasible alternative to conventional diesel. Diesel Engines can
also be made to run on cooking oils as such but due to their high viscosity and carbon
content they cause some undesirable problems in diesel engines. To make these cooking
oils more suitable for diesel engine consumption we turn them into esters via the process
of transesterification. This reduces their molecular weight to one thirds and lowers their
viscosity, essentially making them more suitable as engine fuels. But even then, it is
mostly recommended that this biofuel be used with commercial diesel as a mixture i.e.
20% biodiesel 80% diesel. The process we’ve worked upon is the base-catalysed trans-
esterification method, which will be used to produce biodiesel from waste oils. This
process is initially assisted by acid catalysed esterification for the reduction of free fatty
acids to acceptable limits. To induce simplicity and understanding we have assumed
waste soya bean oil to be our raw material.
The core objective of this paper would to design and develop a profitable biodiesel
production plant. Relying on the conventional mass and energy balances we can estimate
the real-life construction of this plant.
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List of FiguresFigure 3.1.1-Process Flow Diagram....................................................................................9
Figure 4.1.1 Material Balance (Filter)...............................................................................18
Figure 4.2.1 Material Balance (R-1)..................................................................................19
Figure 4.3.1 Material Balance (R-2)..................................................................................21
Figure 4.4.1 Material Balance (C-1)..................................................................................22
Figure 4.5.1 Material Balance (C-2)..................................................................................24
Figure 4.6.1 Material Balance (MT-1)..............................................................................26
Figure 4.7.1 Material Balance (C-3)..................................................................................27
Figure 4.8.1 Material Balance (FT)...................................................................................28
Figure 4.9.1 Material Balance (MT-2)..............................................................................29
Figure 4.10.1 Material Balance (C-4)................................................................................31
Figure 4.11.1 Material Balance (MT-3)............................................................................32
Figure 4.12.1 Material Balance (D-1)................................................................................33
Figure 4.13.1 Material Balance (D-2)................................................................................34
Figure 5.2.1 Steam Properties............................................................................................36
Figure 5.3.1 Energy Balance (HE-1).................................................................................37
Figure 5.4.1 Energy Balance (HE-2).................................................................................38
Figure 5.5.1 Energy Balance (HE-3).................................................................................39
Figure 5.5.1 Energy Balance (HE-4).................................................................................40
Figure 5.7.1 Energy Balance (R-1)....................................................................................41
Figure 5.8.1 Energy Balance (R-2)....................................................................................43
Figure 5.9.1 Energy Balance (FT).....................................................................................44
Figure 5.10.1 Energy Balance (Condenser).......................................................................45
Figure 5.11.1 Energy Balance (HE-5)...............................................................................46
Figure 5.12.1 Energy Balance (DC-1)...............................................................................48
Figure 5.13.1 Energy Balance (DC-2)...............................................................................50
Figure 6.3.1 Flash Tank.....................................................................................................68
Figure 7.2.1 Reactor Control.............................................................................................99
Figure 7.3.1 Heat Exchanger Control..............................................................................100
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Figure 7.4.1 Distillation Column Control........................................................................101
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List of TablesTable 4.1-1 Material Balance (Filter)................................................................................18
Table 4.2-1 Reactor1 Parameters.......................................................................................19
Table 4.2-2 Material Balance (R-1)...................................................................................19
Table 4.3-1 Reactor2 Parameters.......................................................................................20
Table 4.3-2 Material Balance (R-2)...................................................................................20
Table 4.4-1 Centrifuge1 Parameters..................................................................................21
Table 4.4-2 Material Balance (C-1)...................................................................................22
Table 4.5-1 Centrifuge1 Parameters..................................................................................23
Table 4.5-2 Material Balance (C-2)...................................................................................24
Table 4.6-1 Mixing Tank Parameters................................................................................24
Table 4.6-2 Material Balance (MT-1)...............................................................................25
Table 4.7-1 Centrifuge3 Parameters..................................................................................26
Table 4.7-2 Material Balance (C-3)...................................................................................27
Table 4.8-1 Material Balance (FT)....................................................................................28
Table 4.9-1 Material Balance (MT-2)...............................................................................29
Table 4.10-1 Centrifuge4 Parameters................................................................................30
Table 4.10-2 Material Balance (C-4).................................................................................30
Table 4.11-1 Material Balance (MT-3).............................................................................32
Table 4.12-1 Material Balance (D-1).................................................................................32
Table 4.13-1 Material Balance (D-2).................................................................................33
Table 5.3-1 Energy Balance (HE-1)..................................................................................37
Table 5.4-1 Energy Balance (HE-2)..................................................................................38
Table 5.5-1 Energy Balance (HE-3)..................................................................................39
Table 5.6-1 Energy Balance (HE-4)..................................................................................40
Table 5.7-1 Reactor1 Parameters.......................................................................................41
Table 5.7-2 Energy Balance (R-1).....................................................................................42
Table 5.8-1 Reactor2 Parameters.......................................................................................43
Table 5.8-2 Energy Balance (R-2).....................................................................................44
Table 5.9-1 Energy Balance (FT)......................................................................................45
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Table 5.10-1 Energy Balance (Condenser)........................................................................46
Table 5.11-1 Energy Balance (HE-5)................................................................................47
Table 5.12-1 Energy Balance for Boiler of DC-1..............................................................49
Table 5.12-2 Energy Balance for Condenser of DC-1......................................................49
Table 5.13-1 Energy Balance for Boiler of DC-2..............................................................51
Table 5.13-2 Energy Balance for Condenser of DC-2......................................................51
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Table of Contents
Chapter 1 INTRODUCTION_____________________________________________1
1.1 Biofuels_________________________________________________________1
1.2 What Is Biodiesel?_________________________________________________1
1.3 Advantages & Disadvantages________________________________________2
1.4 What Are Oils?____________________________________________________3
1.5 Vegetable Oils as Fuels (Properties)___________________________________3
Chapter 2 LITERATURE REVIEW________________________________________4
2.1 Process Selection__________________________________________________4
2.2 Transesterification_________________________________________________4
2.3 Pre-treatment_____________________________________________________4
2.4 Standard Practices & Their Flowsheets_________________________________5
2.5 Raw Materials____________________________________________________6
2.5.1 Choice of Oil__________________________________________________6
2.5.2 Catalyst______________________________________________________6
2.5.3 Alcohol______________________________________________________7
2.5.4 Factors Affecting the Transesterification Process_____________________7
Chapter 3 PROCESS DESCRIPTION & FLOWSHEET________________________9
3.1 Process Flow Diagram & Description__________________________________9
3.1.1 Filter________________________________________________________9
3.1.2 Heat Exchanger (HE-1)________________________________________10
3.1.3 Pre-Treatment Reactor_________________________________________10
3.1.4 Heat Exchanger (HE-2)________________________________________10
3.1.5 Heat Exchanger (HE-3)________________________________________10
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3.1.6 Pre-treatment Heat Exchanger (PT_HE-1)__________________________10
3.1.7 Pre-treatment Heat Exchanger (PT_HE-2)__________________________10
3.1.8 Pre-treatment Distillation (P_D)__________________________________11
3.1.9 Reactor1 (R1)________________________________________________11
3.1.10 Heat Exchanger (HE-4)________________________________________11
3.1.11 Reactor2 (R2)________________________________________________11
3.1.12 Centrifuge1 (C1)______________________________________________11
3.1.13 Centrifuge2 (C2)______________________________________________11
3.1.14 Mixing Tank1 (Wash Tank)_____________________________________12
3.1.15 Centrifuge 3 (C3)_____________________________________________12
3.1.16 Flash Tank (FT1)_____________________________________________12
3.1.17 Mixing Tank2 (MT2)__________________________________________12
3.1.18 Centrifuge4 (C4)______________________________________________12
3.1.19 Mixing Tank3 (MT3)__________________________________________12
3.1.20 Heat Exchanger (HE-5)________________________________________12
3.1.21 Distillation Column 1 (D1)______________________________________12
3.1.22 Distillation Column 2 (D2)______________________________________13
3.2 Products________________________________________________________13
3.1.23 Glycerine____________________________________________________13
3.3 Testing of Used Oil_______________________________________________13
Chapter 4 MATERIAL BALANCE_______________________________________16
4.1 Survey for Waste Cooking Oil Collection________________________________16
3.1.24 Capacity Selection____________________________________________17
4.2 Material Balance (Filter)___________________________________________17
4.3 Material Balance Reactor1 (R-1)_____________________________________18
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4.4 Material Balance (Reactor 2)________________________________________20
4.5 Material Balance (Centrifuge1)______________________________________21
4.6 Material Balance (Centrifuge 2)_____________________________________22
4.7 Material Balance (Mixing Tank 1)____________________________________24
4.8 Material Balance (Centrifuge 3)_____________________________________26
4.9 Material Balance (Flash Tank)_______________________________________27
4.10 Material Balance (Mixing Tank 2)__________________________________28
4.11 Material Balance (Centrifuge 4)____________________________________29
4.12 Material Balance (Mixing Tank 3)__________________________________31
4.13 Material Balance (Distillation Column 1)____________________________32
4.14 Material Balance (Distillation Column 2)____________________________33
Chapter 5 ENERGY BALANCE_________________________________________35
5.1 Cp Calculation___________________________________________________35
5.2 Equipment______________________________________________________36
5.3 Energy Balance Heater (HE-1)______________________________________37
5.4 Energy Balance Heater (HE-2)______________________________________38
5.5 Energy Balance Heater (HE-3)______________________________________39
5.6 Energy Balance Heater (HE-4)______________________________________40
5.7 Energy Balance (Reactor 1)_________________________________________41
5.8 Energy Balance (Reactor 2)_________________________________________42
5.9 Energy Balance (Flash Tank)________________________________________44
5.10 Energy Balance Condenser_______________________________________45
5.11 Energy Balance Heater (HE-5)_____________________________________46
5.12 Energy Balance Distillation Column (DC-1)__________________________48
5.13 Energy Balance Distillation Column (DC-2)__________________________50
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Chapter 6 EQUIPMENT DESIGN________________________________________52
6.1 Reactor Design___________________________________________________52
6.1.1 Reactor Selection_____________________________________________54
6.1.2 Rate Constants_______________________________________________55
6.1.3 Reactor Impeller______________________________________________57
6.1.4 Specifications Sheet___________________________________________57
6.1.5 Pressure Drop________________________________________________58
6.2 Heat Exchanger Design____________________________________________58
6.2.1 Types with respect to Structure__________________________________58
6.2.2 Principal Parts________________________________________________59
6.2.3 Working Principle of Double Pipe Heat Exchanger___________________60
6.2.4 HEAT TRANSFER MODES____________________________________60
6.2.5 Types of Double Pipe Heat Exchanger_____________________________60
6.2.6 Double Pipe Heat Exchangers___________________________________60
6.2.7 Operation of Double Pipe Heat Exchanger_________________________61
6.2.8 Heat Exchanger Design________________________________________62
6.2.9 Mechanical Design____________________________________________67
6.3 Flash Tank______________________________________________________68
6.4 Distillation Column Design (D-1)____________________________________70
6.4.1 Choice between Plate and Packed Column_________________________70
6.4.2 Choice of Plate Type__________________________________________71
6.4.3 Design Steps for A Distillation Column____________________________71
6.4.4 From which the theoretical no. of stages to be 7_____________________75
6.4.5 Feed plate location____________________________________________75
6.4.6 Column Diameter_____________________________________________75
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6.5 DISTILLATION COLUMN DESIGN________________________________79
6.5.1 Top Operating Line____________________________________________81
6.5.2 Bottom Operating Line_________________________________________82
6.5.3 Ideal no of trays is 8___________________________________________83
6.5.4 Efficiency And Total Number Of Real Stages_______________________83
6.5.5 Superficial Vapor Velocity______________________________________85
6.5.6 Net Area Required____________________________________________85
6.5.7 Column Diameter_____________________________________________86
6.5.8 Height of the column :_________________________________________86
6.5.9 Plate Pressure Drop____________________________________________88
6.5.10 Residual Head________________________________________________89
6.5.11 Check Residence Time_________________________________________89
6.5.12 Check Entrainment____________________________________________89
6.6 Mixing Tank Design______________________________________________91
6.6.1 Volume Calculation___________________________________________91
6.6.2 Thickness___________________________________________________91
6.6.3 choice of closure :-____________________________________________92
6.6.4 Impeller design_______________________________________________93
6.6.5 Design Data_________________________________________________96
Chapter 7 INSTRUMENTATION & PROCESS CONTROL___________________97
7.1 Introduction_____________________________________________________97
7.1.1 Requirements of Control________________________________________97
7.1.2 Safety______________________________________________________97
7.1.3 Product Specification__________________________________________97
7.1.4 Environmental Regulation______________________________________97
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7.1.5 Operational Constraints________________________________________97
7.1.6 Economics___________________________________________________98
7.2 Reactors________________________________________________________98
7.3 Heat Exchanger__________________________________________________99
7.4 Distillation Column______________________________________________100
Chapter 8 COST ESTIMATION_________________________________________102
8.1 Introduction____________________________________________________102
8.2 Equipment Cost Estimation________________________________________103
8.1.1 Reactor Cost Estimation_______________________________________103
8.1.2 Flash Tank Cost Estimation____________________________________103
8.1.3 Heat Exchanger Cost Estimation________________________________104
8.1.4 Centrifuge Cost Estimation_____________________________________105
8.1.5 Distillation Column Cost Estimation (D-1)________________________106
8.1.6 Distillation Column Cost Estimation (D-2)________________________108
8.3 Total Equipment Cost____________________________________________110
8.4 Total Physical Plant Cost (PPC)____________________________________110
8.5 Total Investment________________________________________________111
8.6 Annual Operating Cost____________________________________________111
8.7 Direct Production Costs___________________________________________112
8.8 Annual Production Cost___________________________________________113
8.9 Production Cost_________________________________________________113
Chapter 9 SITE & MATERIAL SELECTION______________________________114
9.1 The Project_____________________________________________________114
9.2 Proposal for Site Location_________________________________________114
9.2.1 Raw Materials_______________________________________________114
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9.2.2 Climate____________________________________________________115
9.2.3 Market_____________________________________________________115
9.2.4 Waste Disposal______________________________________________115
9.2.5 Transport___________________________________________________115
9.2.6 Water Supply_______________________________________________115
9.2.7 Labour Supply______________________________________________116
9.3 Conclusion_____________________________________________________116
Chapter 10 HAZOP STUDY_____________________________________________117
10.1 HAZOP On Double Pipe Heat Exchanger___________________________117
10.2 HAZOP On Distillation Column (Parameter Pressure)_________________118
10.3 HAZOP On Distillation Column (Parameter Temperature)______________119
10.4 Hazard Analysis_______________________________________________120
Appendix A Matlab Program____________________________________________124
Appendix B Flash Tank Data___________________________________________128
Appendix C D-1 Data_________________________________________________130
Appendix D D-2 Data_________________________________________________135
Appendix E Heat Exchanger Charts & Graphs ______________________________139
Appendix F Costing Indices____________________________________________143
References_____________________________________________________________145
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Chapter 1 INTRODUCTION
1.1 BiofuelsSuch fuels which are usually obtained from the flora and fauna around us are usually
called as biofuels. Ever since the start of the industrial revolution people have had the
idea of running automobiles on edible oils. In that sense biodiesel is also a biofuel. It
dates back to 1853 and was coined by E. Duffy and J. Patrick. At the Paris, International
Exhibition in 1900, Rudolf Diesel demonstrated a test engine sample working on peanuts
oil. In 1912, Rudolf Diesel said, “The use of vegetable oils for engine fuels may seem
insignificant today. But such oils may become in course of time as important as
petroleum and the coal tar products of the present time” (Marco Aurélio, 2011).
Diesel was indeed right as in the previous decade we saw conventional fuel prices sky
rocketing. This immensely helped the sustainable energy sector as it put in the minds of
people, the fear of economic shakedown both on an individual as well as on a national
basis.
1.2 What Is Biodiesel?To a layman term biodiesel implies diesel obtained from biological sources such as plant
or animals. It is a type of biofuel. As it turns out there are essentially 4 ways of
converting organic sources into biodiesel. These are listed as.
1. Direct use or blending of oils
2. Micro-emulsion
3. Pyrolysis (gasification)
4. Trans-esterification
Biodiesel or fatty acid methylated esters are derived or obtained from animal or plant
stocks, due to their renewability they form a sustainable class of fuels. This very reason
makes them a very viable choice for future fuels and hence they are receiving
considerable importance from the scientific community. One of the very simple
production methods of biodiesel is transesterification in which the triolein sources are
reacted with methanol under appropriate conditions, often in the presence of a catalyst.
The catalyst even through it is not consumed during the reaction helps decrease the
reaction times. The main product of these reactions is simply biodiesel while glycerol is
produced as a by-product in the aftermath of the reaction. Due to higher conversions in
this reaction it is understood that very little oil is wasted. In order to bypass the catalyst,
use we can run the reaction under supercritical conditions however this amounts to
increased costs. Another method is via the use of biochemical routes.
Now looking at the point number one the confusion persists that whether or not vegetable
oil is or is not an alternative of conventional fuels in pure form. Actually, vegetable is a
whole lot more viscous that biodiesel, it also has very high flash point due to this very
reason and some others vegetable cannot be used as an alternative to diesel as it is and
has to be processed before usage. One of the methods as listed above is the
transesterification of the oils. This involves the conversion of the triglycerides (oils) into
methylated or ethylated esters. However due to the efficiency and other concerns
methylated ester are often preferred. Also, that they burn efficiently and provide more
power.
Because of the lesser energy costs and greater viability as opposed to the other processes
we will prefer the method of transesterification.
1.3 Advantages & Disadvantages 1. One of the key advantages of this biofuel is sustainability. The fact that we grow
cooking oil sources means that an abundance can theoretically be made.
2. Biodegradability is another important factor which contributes to the pro camp of
biodiesel. A simple proof of that is when left in open atmospheric conditions biodiesel
degrades much more rapidly as compared to commercial diesel.
3. There is less sulphur in biodiesel as compared to commercial diesel. This leads to
some major environmental pros while the greater amount of oxygen ensures that this
biofuel burns completely deceasing the emission of CO2.
Biodiesel despite being “greener” has its own demerits some of which are discussed
below.
1. Greater NOx emissions.
2
2. Despite being less viscous that cooking oils biodiesel is still more viscous than
diesel, this is the reason we still have to mix biodiesel with commercial grade diesel.
Viscosity leads to stresses and large droplets which can cause wear on the fuel injector
systems.
3. Remember the degradation part, here is when it becomes a problem. When
exposed to the open environment for longer periods these esters degrade into smaller
components and decrease some of the desirable properties of our fuel.
4. Except for a few countries vegetable oils are generally very expensive. Even in
Pakistan which is an agricultural economy the price of vegetable oil is higher than that of
commercial diesel. This takes a huge toll on the economic viability of the whole process.
1.4 What Are Oils?Fats and oils are primarily water-insoluble, hydrophobic substances in the plant and
animal kingdom that are made up of one mole of glycerol and three moles of fatty acids
and are commonly referred to as triglycerides. The difference between a fat and oil is
signified by their physical states at room temperature. A triglyceride that is a liquid at
room temperature is called as oil while a triglyceride that is solid at room temperature is
called as a fat. One important thing to note here is that triglycerides derived from
mammals are usually fats while those derived from cold blooded animals as well as
plants are oils.
1.5 Vegetable Oils as Fuels (Properties)Vegetable cooking oils have viscosities 11-17times that of diesel fuel. Volumetric heating
values is about 39-40 Mega Joule/kg while for diesel it is 45 Mega Joule/kg. The flash
point for vegetable oils is very high, more than 200 degrees centigrade. It has been found
that the utilization of vegetable oils as fuels led to problems related to type and grade of
oil as well as climate conditions. Some common problems are carbon deposits, plugging
if the fuel lines, gelling of lubricating oils, foiled piston heads and ring sticking. Cetane
number of vegetable oils is very high hence reducing the ignition delay. In addition to all
this they have high iodine value which increases their oxidation rate. Therefore, long time
storage is not recommended for vegetable oils.
3
Chapter 2 LITERATURE REVIEW
2.1 Process Selection Of the several methods, available for producing bio- diesel, transesterification of natural
oils and fats is currently the method of choice. The purpose of the process is to lower the
viscosity of the oil or fat. As far as the other processes are concerned, although blending
of oils and other solvents and micro emulsions of vegetable oils lowers the viscosity it
causes engine performance problems, such as carbon deposit and lubricating oil
contamination. Meanwhile, pyrolysis produces more bio gasoline than biodiesel fuel [1].
2.2 TransesterificationTransesterification of vegetable oils with alcohol is the best method for biodiesel
production. There are two types of transesterifications, one is with catalyst and other one
is without catalyst. Transesterification is a reversible reaction and the excess of alcohol
shifts the equilibrium to the product side.
Base-catalysed transesterification is one process that converts waste cooking oil to
biodiesel fuel. Fats and oils are tri esters of glycerol (triglycerides), with three long chain
fatty acids that give the molecule a high molecular weight and low volatility. A base-
catalysed transesterification (using methanol as the alcohol and NaOH as the catalyst)
converts fats and oils to the methyl esters of the three individual fatty acids. It is to be
noted here that the reaction would still proceed without a catalyst but would be too slow
and may take days to complete, therefore the addition of catalyst becomes necessity.
With molecular weights about a third of the original triglyceride, these methyl esters are
more volatile and work well in diesel engines, the mixture of fatty acid methyl esters is
called biodiesel [2].
The purpose of using methanol is its low commercial price and the reason that it gives
better performance in engines. Methanol has both physical as well as chemical
advantages. Esters produced using methanol gave higher power and produced more
torque [3].
4
2.3 Pre-treatment Free fatty acids are known as to cause saponification during the transesterification
reaction. Soaps make biodiesel purification harder and hence it is necessary to limit the
FFA content. This is done by the esterification process in which acid along with methanol
is employed to convert the FFAs into esters (biodiesel). Glycerine washing is then
employed to purify the refined oil. After such a treatment, the oil phase, having a low
level of free fatty acids (less than 0.5 wt.%), was subjected to the alkali-catalysed
transesterification.
2.4 Standard Practices & Their FlowsheetsConventionally the alcoholysis or transesterification of virgin or used cooking oils is
done via base catalyst. This can be done in either batch mode or it can be a continual
process.
In most cases the catalyst is sodium hydroxide or sodium methylate. It is recovered after
the transesterification reaction as sodium glycerate, sodium methylate and sodium soaps
in the glycerol phase. An acidic neutralization step with, for example, aqueous
hydrochloric acid is required to neutralize these salts. In that case glycerol is obtained as
an aqueous solution containing sodium chloride. Depending on the process, the final
glycerol purity is about 80% to 95%.
When caustic is employed in the catalyst role it can react with the broken glycerides to
form soap. These soaps can dissolve in the glycerol produced during the reactions in the
reactors. They cause a major hurdle in the purification of glycerol. These soaps need to
be broken down into FFAs by employing HCl. We have done this in our process. The
loss of esters converted to fatty acids can reach as high as 1% of the biodiesel production.
5
2.5 Raw Materials
1
2
2.1
2.2
2.3
2.4
2.5
2.5.1 Choice of Oil
There are more than 350 oil bearing crops identified, among which only sunflower,
soybean, cottonseed, rapeseed and peanut oils are considered as potential alternative fuels
for diesel engines [4]. We will be considering soya oil because the biodiesel produced by
this type of waste shows similar properties as diesel. Another point that warrants its
6
Figure 2.4 Global Scheme for A Typical Biodiesel
Setup
selection is it’s cetane number which is closer to petroleum diesel. Also, it is abundantly
produced as waste.
2.5.2 Catalyst
Transesterification can also be catalysed by Lowry acids. These catalysts give very high
yields in alkyl esters but reactions are slow, requiring typically temperature above 100
degrees centigrade and hours to complete the conversion [5]. We therefore use base
catalysed reactions which are comparatively less time consuming as compared to the
before mentioned. For that purpose, we can use potassium or sodium hydroxide but
because of better solubility of KOH with methanol we would likely prefer methanol. As
we will come to know the topic of catalyst is a sensitive one and affect heavily on the
yield and reaction times of the process.
The biodiesel industry currently uses sodium methoxide, because methoxide cannot
form water upon reaction with alcohol such as with hydroxides, which influence the
reaction and the quality of the production biodiesel [6]. Furthermore, base-catalysed
reactions are performed at generally lower temperatures, pressures, and reaction times
and are less corrosive to industrial equipment than acid-catalysed methods [7]. Therefore,
fewer capital and operating costs are incurred by biodiesel production facilities in the
case of the base-catalysed transesterification method.
2.5.3 Alcohol
Studies have shown that methylated esters are more suitable for diesel engines as
compared to ethylated ones. Hence, we will want a source for a methyl group and not an
ethyl group. The obvious choice is methanol. Another advantage is the cost factor
because methanol is cheaper than ethanol and easier to source as compared to ethanol.
Ethanol could even be a banned item in a specific country due to various reasons.
2.5.4 Factors Affecting the Transesterification Process
Main factors affecting the transesterification process are.
1. Methanol/Oil Molar Ratio2. Temperature 3. Reaction Time4. Mixing
7
5. FFAs & Moisture6. Catalyst Conc.
8
Figure 2-5-Factors Effecting FAME
Chapter 3 PROCESS DESCRIPTION &
FLOWSHEET
3
3.1 Process Flow Diagram & Description
Figure 3.1.1-Process Flow Diagram
9
3
3.1
3.1.1 Filter
First of all, the waste cooking oil or WCO goes to a filter where solid chunks of
impurities in it are removed. These are chunks from the eatables that have been heated in
the oil. This filtered WCO is then pumped into the reactor R1. The oil is still high In
FFAs however hence and cannot be processed by regular base catalysed
transesterification method hence we first need to perform acid assisted esterification in
order to bring the FFAs to an acceptable level before we can pursue the traditional base
catalysed transesterification.
3.1.2 Heat Exchanger (HE-1)
Water is heated to 55 °C in HE-1. This water is used to wash the biodiesel further along
the process. According to [8] hot water washing is a good way to obtain high purity
biodiesel (FAME) product.
3.1.3 Pre-Treatment Reactor
In the pre-treatment reactor esterification reaction is carried out at 70 °C, 400 kPa and a
6:1 molar ratio of methanol to crude oil. This is necessary in order to bring the FFAs
downs to a level where they can be processed by the transesterification reactor i.e. R-1.
Otherwise the free fatty acids can react with the alkali catalyst to produce soaps causing
emulsions. Emulsions make the purification of biodiesel difficult.
3.1.4 Heat Exchanger (HE-2)
Mix of caustic and alcohol is heated to 60 °C in this heat exchanger. This stream is used
both in R-1 & R-2 and since our reaction takes place at 60 °C, hence this stream is heated
to 60 °C.
3.1.5 Heat Exchanger (HE-3)
The HE-3 heats the filtered waste cooking oil from ambient temperatures to 60 °C.
10
3.1.6 Pre-treatment Heat Exchanger (PT_HE-1)
Effluents of the pre-treatment reactor are cooled in this heat exchanger to 46 °C.
3.1.7 Pre-treatment Heat Exchanger (PT_HE-2)
The glycerine washing separates the oil and it is heated in this heat exchanger. This oil is
then routed to the R-1 for base catalysed transesterification. The purpose of this heat
exchanger is angina, to bring the temperature of oil to 60 °C. The FFAs by now have
been brought down to acceptable levels.
3.1.8 Pre-treatment Distillation (P_D)
The stream other than the majority oil stream emanating from the glycerine washing
column is treated in this distillation unit. In P_D, five theoretical stages and a reflux ratio
of 5 are used. At 28 °C and 20 kPa, 94% of the total methanol fed to the column is
recovered in the distillate (i.e., stream 111) at the rate of 188 kg/h. It contained 99.94%
methanol and 0.06% water and is recycled to pre-treatment esterification reactor. At 70
°C and 30 kPa, bottom stream 112 (147 kg/h) is composed of 75% glycerol, 8%
methanol, 7% sulfuric acid, 7% oil and 3% water.
3.1.9 Reactor1 (R1)
Filtered WCO then enters the reactor1 where a feed of caustic mixed with methanol is
already coming in. The oil is heated to approx. 55-60 degree centigrade at atmospheric
pressure. Under such condition 90% conversion is achieved in the first reactor. Effluent
of R1 contains biodiesel, un-reacted oil, soap, salts etc.
3.1.10 Heat Exchanger (HE-4)
Effluents of R-1 are heated to 60 °C.
3.1.11 Reactor2 (R2)
Stream originating from C1 goes to R2 along with remaining methanol + catalyst at
atmospheric pressure and residence time of 1 hour. Here our conversions levels touch the
99% mark.
11
3.1.12 Centrifuge1 (C1)
The effluent of R1 goes to the centrifuge where the un-reacted oil and the biodiesel
produced are separated from the glycerol. This glycerol is not pure and needs treatment
in terms of solvent recycles and impurity removal.
3.1.13 Centrifuge2 (C2)
The effluent of R2 is fed to the centrifugal separator where the un-reacted oil and the
biodiesel produced are separated from the glycerol. This glycerol is not pure and needs
treatment in terms of solvent recycles and impurity removal.
3.1.14 Mixing Tank1 (Wash Tank)
Now the biodiesel stream from the C2 is fed to the mixing tank and is washed with the
process wash water and HCL solution. This neutralizes the catalyst and converts any soap
to FFA.
3.1.15 Centrifuge 3 (C3)
The MT1 effluent is fed to the centrifuge where the biodiesel is recovered together with
small amounts of water.
3.1.16 Flash Tank (FT1)
Final purification of biodiesel is achieved in the flash drum that operates under vacuum.
(5 kPa).
3.1.17 Mixing Tank2 (MT2)
Streams originating from C1, C2, C3 and the stream from the head of the FT end up in
the MT2. These contain methanol, glycerol, water as well as FFA, soaps and salts. This
stream is first treated with HCl to convert soaps into FFAs.
3.1.18 Centrifuge4 (C4)
The effluent of MT2 then passes through the C4 and thus FFAs get removed. We get a
stream that is rich in methanol and glycerol.
12
3.1.19 Mixing Tank3 (MT3)
Glycerol and methanol rich stream is treated with NaOH to maintain pH. The resulting
stream is fed to the distillation columns D1.
3.1.20 Heat Exchanger (HE-5)
The purpose of this heat exchanger is to bring the feed of the first distillation column to
the required temperature.
3.1.21 Distillation Column 1 (D1)
D1 operates slightly above atmospheric pressure. We get glycerol and water from bottom
which is 80% wt. /wt. glycerol & water. The top product consists of water and methanol.
3.1.22 Distillation Column 2 (D2)
D2 is operated at high pressure (50 kPa). We get almost pure 99.99 % methanol which is
then recycled as input stream from the top. Water is obtained from the bottom which can
be recycled as washing water.
3.2 Products There are two main products of the transesterification process.
Glycerin Biodiesel
3.1.23 Glycerine
To make the biodiesel plant economically attractive we have to make sure that anything
coming out of a product line other than the main product itself is sellable. For the most
part only two products are produced in a continuous biodiesel plant, its biodiesel and
glycerol. Excess methanol is reused or sold. However, there is a catch, glycerol produced
during the process is impure since it contains some quantities of methanol which make it
highly unsafe for a large sector of human consumable producing industries. It also has
salts as well as FFAs. Its physical appearance is also very undesirable. Hence the
traditional markets are off limits. To make the glycerol pure we generally flash or distil it
but since it (glycerol) is a high boiling component it can cause a strain on our financials.
So, what ends up happening is that this bio glycerol is used as a cattle feed supplement as
it adds to the cattle’s feed to weight gain ratio. This is because certain animals can handle
13
toxic methanol and its breakdown products. Another use for the bio glycerol is the
cement industry. It is added to various parts of the process such as in clinkering, kilning
etc. to add to the cement strength.
However, in our project the simulation indicates that the bottom product is essentially
80% glycerol and 20% methanol. If this can be translated to reality, then the economic
viability of the process can surely be ever increased.
3.3 Testing of Used OilChemically used oils contain triglycerides. When they are used for cooking purposes
these go through changes and the oil ends up having abundance of free fatty acids. It is
these acids that cause the acidity of the used oil. The problem is that when we try to make
biodiesel out of such oil and add KOH and alcohol for the purpose along with alcohol, it
ends up making soap. Soap is not what we want, we want biodiesel.
So, for that we have to measure the extra amount of KOH that needs to go in our batch of
waste oil. For this very purpose, we do a titration of our oil sample.
Prepare titration solution by mixing 1 gram of KOH in 1 L distilled water.
Prepare 3 beakers. Take1 ml of waste cooking oil and pour in beaker no. 1. Pour 10 ml of
isopropyl alcohol. Take your titrating solution in a third beaker.
Mix oil and alcohol. Add some indicator drops into the oil and alcohol mixture.
Now begin titrating. Slowly pour the titrating solution till pink colour appears and
remains so for 30 seconds.
It is generally considered that oil using 0-3 ml of the above-mentioned titrating solution
indicates a “good” cooking oil. Oil that uses 3-5 ml of the titration solution is average oil
while anything above that is harmful for human health since it has been heavily used and
has a lot of fatty acids. It is to be noted here that the presence of FFA greatly affects the
transesterification process. It has been noted that our oil must have a FFA value lower
than 3% for the base catalysed reaction to produce favourable results. Ester yields are
greatly reduced in the presence of greater than three percent FFAs.
Since we are using a base catalysed process we have to debate on the Achilles heel of
base catalysed transesterification and that is be soap formation. The issue is not so
relevant as long as the FFAs are within the 3-4 % mark but waste or used cooking oils
14
can contain up to 15 % FFAs. Our catalyst NaOH doesn’t react well with triglycerides
but reacts with mono glycerides well and diglycerides to some extent. This results in soap
which again calls for even more purification. And with purification comes energy costs.
To counter this problem, we can use vacuum distillation to remove the FFAs from our
triglycerides beforehand and sell them off either as animal feed or a separate
esterification can be arranged where different conditions can be perhaps used to convert
these FFAs into biodiesel. For smaller values of FFAs we can simply add in more catalyst
and carry on with removing the soap [9].
Now that we’ve calculated the catalyst to be used we can now proceed with the normal
biodiesel production. This is because we have effectively counteracted the free fatty
acids. Coincidentally this test can also be used to gauge how good our oil is for cooking
purposes. Used oil having a significant amount of free fatty acids is not a good choice. It
is harmful for health. This is precisely the reason that used cooking oil should not be
reused rather it should be waster in accordance with the laws of the country.
15
Chapter 4 MATERIAL BALANCEMaterial balance is the backbone in the design and conceiving of a chemical plant along
with the energy balance. It helps us in conceiving the designs, in financial evaluation, in
process control and in optimizing the process. Let’s say for example a solvent is required
for the extraction of soya bean oil (which also happens to be our primary triolein) from
the its source. In order to calculate the arithmetic quantity of that solvent required we can
apply the material balance on that particular unit. But even better is that we can not only
use that information to calculate the amount of solvent required we can also use that
information for the design and development of the machines that extracts the soya bean
oil. Hence in every plant design we first go through the phase of the material balance.
We can use the processed information in the design of equipment or in the evaluation of
the economics of the process. Material balance can also help in deciding the raw material
that we can use to achieve the same end product. Quite a few different types of
processing can achieve the same end result, so that case studies (simulations) of the
processes can assist materially in the financial decisions that must be made. Material
balances also helps in the hourly and daily operating decisions of plant managers.
For the most part we’ve used stoichiometry for our balances especially in reactors. For
almost all separation processes in our process we were provided with figures.
4.1 Survey for Waste Cooking Oil CollectionWe carried out an online survey to assess the amount of waste oil we could gather.
According to eatoye.com Lahore has 1000 restaurants from which you can order a 16
delivery... but the website has mostly branded places listed so we can only get but a
rough estimate from the website. I am going with an estimate that Lahore has three times
the places eatoye.com has listed. Exotic food is limited so I am going with a very low
estimate. The average waste vegetable oil generation column has been sourced from
a study [10]. Units are litres/month as also indicated in the paper from where the figures
are sourced. Most establishments seem to favour canola oil, while unspecified vegetable
oil and liquid shortening bring up a distant second and third respectively. The survey
showed that vegetable oils like sunflower oil and corn-mixes were the least common
types of oils being used in the group. Low responses in the Sunflower Oil, Corn/Soy Oil
and Corn/Canola Oil categories produced exceptionally high averages, skewing the data
and producing a total average volume significantly higher than the total average volume
by restaurant type.
3.1.24 Capacity Selection
Waste Cooling Oil Flow 30068.9043 kg/day OR 30.06 ton/day
4
4.2 Material Balance (Filter)The composition of our crude oil after pre-treatment is as such.
17
ComponentFin
(Kg/hr.)
Calculatio
n
Fout1
(Kg/hr.)
Calculatio
n
Fout2(kg/
hr.)
Oil1220.296
31220.2963
1220.2963*
1~ ~
Palmitic. A 7.016 7.016*1 7.016 ~ ~
Moisture 3.13 3.13*1 3.13 ~ ~
Unsaponifie
d55.87 ~ ~ 55.87*1 56.25
Ash .37586 ~ ~ .37586*1 .37586Table 4.2-1 Material Balance (Filter)
18Figure 4.2.2 Material Balance (Filter)
4.3 Material Balance Reactor1 (R-1)The reaction is as:
1 trio lein+6methanol catalyst⇔
3 FAME+1g lycerol+3methanol
1 mole FFA consumes 1 mole of catalyst to produce 1 mole of soap + water. 1FFA+1 catalyst catalyst
⇔
1 soap+1water
Reactor conditions and parameters are as such.
Pressure Atmospheric
Temperature 60 °C
Conversion 90 %
Residence Time 1 hourTable 4.3-2 Reactor1 Parameters
Component Fin (Kmol/hr.)Calculation (90%
Conv.)Fout (Kmol/hr.)
Oil 1.35581.3558 -
(1.3558*.90).13558
Palmitic. A .025 .025 - .02255 .00250
Moisture (Water) .174 .174 + .0222 .1965
FAME ~ 3*(1.3558*.90) 3.660
Glycerol ~ 1.3558*.90 1.220
Methanol 7.32 3*(1.3558*.90) 3.6608
Catalyst .2929 .2929-(.0250-.0025) .2787
Soap ~ .0250*.90 .0225Table 4.3-3 Material Balance (R-1)
19
4.4 Material Balance (Reactor 2)Reactor 2 has similar conditions as reactor 1. Overall conversion is 99%.
Pressure Atmospheric
Temperature 60 °C
Conversion 90 %
Residence Time 1 hourTable 4.4-4 Reactor2 Parameters
Component Fin (Kmol/hr.)Calculation (90%
Conv.)Fout(Kmol/hr.)
Oil .13558 .13558*.01 .001358
Palmitic. A 8.94E-068.94E-06-(8.94E-
06*90%)8.94E-07
Moisture (Water) .001965 .0019 + .0002335 .00219
FAME 3.6603.660 +
(3*.13558*.90)4.0269
Glycerol ~ .13558*.90 .1220
Methanol 2.196 + .7321 = (.13558*90%*3) + 4.539
20
Figure 4.3.3 Material Balance (R-1)
2.9281 2.9281
Catalyst.0026 + .029
= .0316
.029-((8.94E-
06)-.0000137).0301
Soap .000225.000225 + (8.94E-
06*.90).0002335
Table 4.4-5 Material Balance (R-2)
4.5 Material Balance (Centrifuge1) Centrifuges are assumed to achieve 99% recovery of the components. In Centrifuge1 and Centrifuge2 methanol is assumed to be distributed by 60% in
the biodiesel phase and 40% in the glycerol phase.
In Centrifuge3 methanol is assumed to distribute by 10% in the biodiesel phase and in
Centrifuge4 by 100% in the glycerol phase.
Recovery 99 %
Methanol Distribution 60 % (With FAME)/40% (With
Glycerol)
21
Figure 4.4.4 Material Balance (R-2)
Table 4.5-6 Centrifuge1 Parameters
Componen
t
Fin(kg/
hr.)
Calculation
s
Fout1(kg/
hr.)
Calculation
s
Fout2(kg/
hr.)
FAME 1098.26 1098.26*1 1098.26 ~ ~
Glycerol 112.267 ~ ~ 112.267*1 112.267*1
Methanol 117.148 117.148*.60 70.28 117.148*.40 46.859
Palmitic. A .7016 0.7016*.01 0.00701 .7016*.99 .69
Catalyst 11.1502 11.1502*.01 0.108 11.1502*.99 11.03
Soap 6.76 6.76*.01 0.067 6.76*.99 6.69
Oil 122.02 122.02*1 122.02 ~ ~
Water 3.538 3.538*.01 0.035 3.538*.99 3.52Table 4.5-7 Material Balance (C-1)
22Figure 4.5.5 Material Balance (C-1)
4.6 Material Balance (Centrifuge 2)
Recovery 99 %
Methanol Distribution60 % (With FAME)/40% (With
Glycerol)Table 4.6-8 Centrifuge1 Parameters
Componen
t
Fin(kg/
hr.)
Calculation
s
Fout1(kg/
hr.)
Calculation
s
Fout2(kg/
hr.)
Palmitic.
A1208.0934
1208.0934*
11208.0934 ~ ~
Glycerol 11.22 ~ ~ 11.22*1 11.22
Methanol 145.2640145.2640*.6
087.1584
145.2640*.4
058.1056
FFA .0002505.0002505*.0
11.37E-07
.0002505*.9
9.0002480
Catalyst 1.2049 1.2049*.01 .011 1.2049*.99 1.160
Soap .07000 .07000*.01 .0007 .07000*.99 .06937
Oil 1.2202 1.2202*1 1.2202 ~ ~
Water .0395 .0395*.01 .000395 .0395*.99 .039
23
Table 4.6-9 Material Balance (C-2)
4.7 Material Balance (Mixing Tank 1)The stream is fed to a mixing tank together with process (wash) water and HCl solution
so as to neutralize the catalyst and convert any soap to FFA. The wash and pH adjustment
tank effluent is fed to a centrifuge (C3) where biodiesel is recovered with small amounts
of water.
There are two reactions occurring in this mixer…
SOAP + HCl FFA + NaCl HCl + NaOH H20 + NaCl
Wash Water Ratio (Wt.) 1:1 (For Every kg FAME)
HCl (Molar) 1:1 (For Every Mole Catalyst + Soap)Table 4.7-10 Mixing Tank Parameters
24
Figure 4.6.6 Material Balance (C-2)
Compone
nt
Fin1(kmol/
hr.)
Calculatio
ns
Fin2(kg/
hr.)Calculation
Fout1(kmol/
hr.)
FAME 4.0269 ~ ~ ~ 4.0269
Methanol 2.7237 ~ ~ ~ 2.7237
Palmitic.
A3.196E-11 ~ ~
(3.19E-
11+293E-03)
*90%
2.10E-06
Catalyst .012049 ~ ~.012049-
(.000293*90%)3.0122E-05
Soap 2.33E-06 ~ ~2.33E-06-
2.10E-062.33E-07
Oil .0013 ~ ~ ~ .0013
Salt ~ ~ ~(.00029*.90+2.3
3E-6).0002656
HCl ~ ~ .000300.00029+2.335E-
06~
Water 2.199E-05 ~ 65.25(1208.09/18)
+2.19E-0567.11
Table 4.7-11 Material Balance (MT-1)
25
Figure 4.7.7 Material Balance (MT-1)
4.8 Material Balance (Centrifuge 3)
Recovery 99 %
Methanol Distribution 10 % (FAME) / 90% (Glycerol)Table 4.8-12 Centrifuge3 Parameters
Compone
nt
Fin(kg/
hr.)Calculations
Fout1(kg/
hr.)Calculations
Fout2(kg/
hr.)
FAME 1208.0934 1208.0934*1 1208.0934 ~ ~
Methanol 87.15 87.15*.10 8.715 87.15*.90 78.435
Palmitic.
A.0005 .0005*.01 5.8E-06 .0005*.99 .0005
Catalyst .0012 .0012*.01 .000012 .0012*.99 .00188
Soap 9.314E-069.314E-
06*.019.24E-08
9.314E-
06*.999.34E-08
Oil 1.220 1.220*1 1.220 ~ ~
Salt .015 .015*.01 .00015 .015*.99 .015
Water 1208.09921208.0992*.0
112.08
1208.0992*.9
91196.9020
26
Table 4.8-13 Material Balance (C-3)
4.9 Material Balance (Flash Tank)Final purification of biodiesel is achieved in the flash drum that operates under vacuum.
(5 kPa)
ComponentFin
(Kg/hr.)Calculation
Fout1
(Kg/hr.)Calculation
Fout2(kg/
hr.)
FAME 1208.0934 ~ ~ 1208.0934*1 1208.0934
27
Figure 4.8.8 Material Balance (C-3)
Methanol 8.7158 8.7158*1 8.7158 ~ ~
Oil 1.186 ~ ~ 1.186*1 1.186
Water 12.08 12.08*1 12.08 ~ ~Table 4.9-14 Material Balance (FT)
4.10 Material Balance (Mixing Tank 2)
Compo
nent
Fin1(kg/
hr.)
Fin2(kg/
hr.)
Fin3(kg/
hr.)
Fin4(kg/
hr.)Calculations
Fout(kg/
hr.)
Glycero
l109.155 10.91 ~ ~ 109.155+10.91 120
Methan 45.56 56.49 76.2 8.47 45.56+56.49+76.2 186
28
Figure 4.9.9 Material Balance (FT)
ol +8.47
Palmiti
c. A.6945 .00029 .0005 ~
.6945+.00029+.00
05.6983
Catalys
t10.70 1.16 .0116 ~ 10.70+1.16+.0116 11.8798
Soap 6.69 .0699.24E-
06~
6.69+.069+9.24E-
066.76
Water 3.502 .0391162.86
311.74
3.502+.039+1162.
8+11.741178.15
Table 4.10-15 Material Balance (MT-2)
4.11 Material Balance (Centrifuge 4)
Recovery 99 %
Methanol Distribution 100 % In Glycerol PhaseTable 4.11-16 Centrifuge4 Parameters
29
Figure 4.10.10 Material Balance (MT-2)
Compone
nt
Fin(kmol/
hr.)
Calculatio
ns
Fout1(kmol/
hr.)
Calculatio
ns
Fout2(kmol/
hr.)
Glycerol 1.30 1.30*1 1.30 ~ ~
Methanol 5.8 5.8*1 5.8 ~ ~
Palmitic.
A.0024 ~ ~
.0024+.022
55.0250
Catalyst .2933 ~ ~ ~ ~
Soap .02255 ~ ~ ~ ~
Water 64.800 64.8+.315 65.11 ~ ~
HCl .315 .003*1 .003
NaCl ~ ~ ~.2933+.022
55.31588
Table 4.11-17 Material Balance (C-4)
30
4.12 Material Balance (Mixing Tank 3) Reaction taking place in the mixer 3 is as under…
NaOH + HCl H2O + NaCl
Compone
nt
Fin1(kmol/
hr.)
Calculatio
ns
Fin2(kmol/
hr.)
Calculati
on
Fout1(kmol/
hr.)
Glycerol 1.342 ~ ~ 1.342*1 1.342
Methanol 6.0038 ~ ~ 6.0038*1 6.0038
Water 66.96 ~ ~ 66.96*1 66.96
HCl .003 ~ ~ ~ ~
NaOH ~ .003*1 .003 ~ ~
31
Figure 4.11.11 Material Balance (C-4)
NaCl ~ ~ ~ .003*1 .003Table 4.12-18 Material Balance (MT-3)
4.13 Material Balance (Distillation Column 1) All glycerol is removed in the bottom product of D1 which is 80% w/w in glycerol and
the remaining is predominantly water.
ComponentFin
(Kg/hr.)Calculation
Fout
1(Kg/hr.)Calculation
Fout2(kg/
hr.)
Glycerol 123.49 ~ ~ 123.49*1 123.49
Methanol 192.123 192.123*1 192.123 ~ ~
Water 1205.40 1205.40*.90 1175.40 1205-1175 30
NaCl .1095 ~ ~ ~ ~Table 4.13-19 Material Balance (D-1)
32
Figure 4.12.12 Material Balance (MT-3)
4.14 Material Balance (Distillation Column 2)
ComponentFin
(Kg/hr.)Calculation
Fout
1(Kg/hr.)Calculation
Fout2(kg/
hr.)
Methanol 192.123 192.123*1 192.123 ~ ~
Water 1175.40 ~ ~ 1175.40*1 1175.40Table 4.14-20 Material Balance (D-2)
33
Figure 4.13.13 Material Balance (D-1)
34
Figure 4.14.14 Material Balance (D-2)
Chapter 5 ENERGY BALANCETo properly utilize the energy that is consumed or produced within a chemical producing
industry the engineer must be familiar with the fundamentals of the energy balance. This
includes the know-how of the basic terminology associated with the subject. An
engineer’s main attention ought to be devoted to heat, work, enthalpy, and internal
energy. Next, the energy balance must be applied to the project. This can help in
calculating the amount of steam that our heater needs for heating purposes or the cooling
water required for cooling a stream to a required temperature.
In our project, we have used the standard enthalpy calculation formula that goes as.
5
5.1 Cp CalculationWe know that value of Cp and specific enthalpy is a function of temperature and that
function can be written as an empirical power series equation. Now if we take this
equation and put in the above equation and integrate it, we’ll get something like below
which we can then use to calculate our enthalpy.
35
C p=a+b∗T +c∗T2+d∗T3
H=m∗(a∗(T−Td )+ b2 (T 2−T d2 )+ c3 (T 3−T d
3 )+ d4 (T 4−T d4 ))
Wherem=molar flow rate∈kmolhr
WhereC p=heat capacity∈J
kmol . K
T d=DatumTemperature∈K
T=Specified Temeprature∈Kelvin
H=m∫T d
T
C pdT
Wherem=molar flow rate∈kmolhr
WhereC p=heat capacity∈J
kmol . K
T d=DatumTemperature∈K
T=Specified Temeprature∈Kelvin
The values of heat constants were used from the book “Perry’s Chemical Engineers’
Handbook”. However, some values were also obtained from other sources such as
Coulson Vol. 6 and internet. Some static Cp values were also used after appropriate unit
conversion.
Energy balance Calculation
Steady state Law of conservation of energy applied on each equipment is applied by
using the following equation.
H ¿−H out+Consumption+Heat Addition=0
5.2 EquipmentWe are applying our energy balance on the following equipment…
Heat Exchangers Reactors R1 and R2 Distillation Column D1 and D2 Flash Tank
36Figure 5.2.15 Steam Properties
5.3 Energy Balance Heater (HE-1)The heater is used for heating water that washes the FAME. For every kg biodiesel, we
use 1 kg water, since hot water provides better washing we heat it to about 55 °C. Our
reference or datum temperature is 25 °C.
So, as stated above we calculate the specific enthalpy of our feed and product stream
using the heat equation constants from the Perry’s. We then put it into the formula to
calculate our enthalpy.
Component a b c D T1 T2Flow
(kmol/h)H ¿−Hout=Q( J
hr .)
Water 276370 -2090 8.125 -
0.0141
298 333 79.11 1.72E+08
Table 5.3-21 Energy Balance (HE-1)
Required SteamFlow Rate (m¿¿ steam)=Qλ=79.11 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
37
Figure 5.3.16 Energy Balance (HE-1)
5.4 Energy Balance Heater (HE-2)This heater is used to heat the entering methanol and caustic to 60 °C. this is because our
reaction in the reactor takes place at 60 °C.
Componen
ta b c d e T1 T2
Flow
(kmol/h)
Heat
In
Heat
OutH ¿−Hout=Q( J
hr .)
Catalyst 883.47 -
2.49
-3.01 -.86
2
.0422 298 333 .071
0E+00 2.3E+7 2.3E+7Methanol 105800 -
362.
.937
9
0 0 298 333 8.053
Table 5.4-22 Energy Balance (HE-2)
Required SteamFlow Rate (m¿¿ steam)=Qλ=11.01 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
38
Figure 5.4.17 Energy Balance (HE-2)
5.5 Energy Balance Heater (HE-3)
Componen
t
a b c d e T1 T2 Flow
(kmol/h)
Heat
In
Heat
Out H ¿−H out=Q( J
hr .)
Oil .45 .0007 .99 0 0 298 333 1120.64
6
1124.5 9.1E+7 9.13E+07FFA .43 0 0 0 0 298 333 7.01
Water 276370 -
2090
8.12
5
-.01
4
9e-
6
298 333 .174
Table 5.5-23 Energy Balance (HE-3)
Required SteamFlow Rate (m¿¿ steam)=Qλ=42.02 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
39
Figure 5.5.18 Energy Balance (HE-3)
5.6 Energy Balance Heater (HE-4)
Componen
ta b c d e T1 T2
Flow
(kmol/h)Heat In
Heat
OutH ¿−Hout=Q( J
hr .)
FAME 30060 206 6 0 032
8333 3.9153
9.25E+7 1.10E+8 1.73E+07
Glycerol 8.24244E-
01
3.E-
04
9E-
080
32
8333 0.11864
Methanol 105800-
362.3.9379 0 0
32
8333 4.413
FFA .43 0 0 0 032
8333 8.95E-07
Catalyst 883.47-
2.495
-
3.013
-.862
1.0422
32
8333 0.02928
Soap .56 0 0 0 032
8333 0.000233
Water 276370 -
2090
8.125 -
0.014
9E-
06
32
8
333 0.002199
40
Figure 5.5.19 Energy Balance (HE-4)
Oil .45 .0007 .99 0 032
8333 0.11864
Table 5.6-24 Energy Balance (HE-4)
Required SteamFlow Rate (m¿¿ steam)=Qλ=7.98 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
5.7 Energy Balance (Reactor 1)Conditions of our reactor are given below.
Pressure Atmospheric
Temperature 60 °C
Conversion 90 %
Residence Time 1 hourTable 5.7-25 Reactor1 Parameters
Feed goes in at our datum temperature i.e. 25 °C and in the reactor, we maintain a
temperature of 60 °C in the reactor as per the kinetics study. We do this by cooling the
reactor with water. Supposing that the temperature of our water rises by a 30 °C when
cooling the reactor, we can calculate how much cooling water is required.
41
Figure 5.7.20 Energy Balance (R-1)
The values of our constants have been obtained from Perry’s Handbook.
Componen
ta b c d e T1 T2
Flow
(kmol/h
)
Heat InHeat
OutH ¿−H out=Q( J
hr .)
FAME 30060 206 6 0 0 298 333 3.5594
1.12E+8 1.10E+8 5.25E+07
Glycerol 8.242 44E-
01
3.E-
04
9E-
08
0 298 333 1.1864
Methanol 105800 -
362.3
.9379 0 0 298 333 3.559
FFA .43 0 0 0 0 298 333 .0701
Catalyst 883.47 -
2.495
-
3.013
-.862
1
.042
2
298 333 .2704
Soap .56 0 0 0 0 298 333 6.7655
Water 276370 -
2090
8.125 -
0.014
9E-
06
298 333 .1965
Oil .45 .0007 .99 0 0 298 333 118.646
Table 5.7-26 Energy Balance (R-1)
∆T=30 °C
C p=4120 jouleskg°C
CoolingWater Flow= Q∆T C p
=417.96 kghr .
5.8 Energy Balance (Reactor 2)Conditions of our reactor are given below. Feed goes in at our datum temperature i.e. 25
°C and in the reactor, we maintain a temperature of 60 °C to maintain the optimal
conditions for our first reactor.
Pressure Atmospheric
Temperature 60 °C
42
Conversion 90 %
Residence Time 1 hourTable 5.8-27 Reactor2 Parameters
The values of our constants have been obtained from Perry’s.
Componen
ta b c d e T1 T2
Flow
(kmol/h)Heat In
Heat
OutH ¿−H out=Q( J
hr .)
FAME 30060 206 6 0 0 328 33
3
3.9153 1.07E+8 1.11E+8 1.02E+07
Glycerol 8.242 44E-
01
3.E-
04
9E-
08
0 328 33
3
0.11864
Methanol 105800 -
362.3
.9379 0 0 328 33
3
4.413
FFA .43 0 0 0 0 328 33
3
8.95E-07
Catalyst 883.47 -
2.495
-
3.013
-.862
1
.0422 328 33
3
0.02928
43
Figure 5.8.21 Energy Balance (R-2)
Soap .56 0 0 0 0 328 33
3
0.000233
Water 276370 -
2090
8.125 -
0.014
9E-
06
328 33
3
0.002199
Oil .45 .0007 .99 0 0 328 33
3
0.11864
Table 5.8-28 Energy Balance (R-2)
∆T=30 °C
C p=4120 jouleskg°C
CoolingWater Flow= Q∆T C p
=81.54 kghr .
5.9 Energy Balance (Flash Tank)Flash tank is used for the purification of our biodiesel (FAME). The feed essentially
contains methanol, water and biodiesel. It operates at 5 kPa. A valve is used to reduce the
pressure while heat is provided to flash our mixture so that methanol goes into the
upwards stream while biodiesel is obtained from the bottom.
44
Figure 5.9.22 Energy Balance (FT)
Componen
ta b c d e T1 T2
Flow
(kmol/h)Heat In
Heat
OutH ¿−H out=Q( J
hr .)
Water 276370 -
2090
8.125 -
0.01
4
9E-
06
312.9 357.
7
.67116
4.03E+8 1.84E+8 1.43E+08Methanol 105800 -
362.3
.9379 0 0 312.9 357.
7
.27237
FAME 30060 206 6 0 0 312.9 357.
7
4.02
Table 5.9-29 Energy Balance (FT)
Required SteamFlow Rate (m¿¿ steam)=Qλ=65.88 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
5.10 Energy Balance Condenser
45
Figure 5.10.23 Energy Balance (Condenser)
Componen
ta b c d e T1 T2
Flow
(kmol/h
)
Heat InHeat
OutH ¿−Hout=Q( J
hr .)
Water27637
0
-
2090
8.12
5
-
0.01
4
9E
-06
357.
7
32
8.6526
4.32E+
6
2.31E+
8
-
2.1E+0
6Methanol
10580
0
-
362.
3
.937
90 0
357.
7
32
8.2648
Table 5.10-30 Energy Balance (Condenser)
∆T=30 °C
C p=4120 jouleskg°C
CoolingWater Flow= Q∆T C p
=17.37 kghr .
5.11 Energy Balance Heater (HE-5)The purpose of this heat exchanger is to bring the feed of the first distillation column to
the required temperature i.e. 100 °C.
46
Figure 5.11.24 Energy Balance (HE-5)
So, as stated above we calculate the specific enthalpy of our feed and product stream
using the heat equation constants from the Perry’s. We then put it into the formula to
calculate our enthalpy.
Component a b c d e T1 T2Flow
(kmol/h)Heat In
Heat
OutH ¿−Hout=Q( J
hr .)
Glycerol 8.242 44E-
01
3.E-
04
9E-
08
0 328 333 1.3015
1.51E+83.82E+
82.31E+8
Methanol 10580
0
-
362.3
.9379 0 0 328 333 5.8374
Water 27637
0
-
2090
8.125 -
0.014
9E-
06
328 333 65.1159
Table 5.11-31 Energy Balance (HE-5)
Required SteamFlow Rate (m¿¿ steam)=Qλ=106.18 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
47
5.12 Energy Balance Distillation Column (DC-1)Feed going into the distillation column contains glycerol, water and methanol. Since
glycerol has a very high boiling point as compared to the other two, it is separated out
first. The following column separates the methanol from water. The first distillation
column operates at a bit higher pressure than atmospheric pressure. (101.3 kPa)
48
Figure 5.12.25 Energy Balance (DC-1)
Component a b c d e T1 T2Flow
(kmol/h)Qb
Glycerol 8.242 44E-
01
3.E-
04
9E-
08
0 328 333 1.305
1.18E+09Methanol 10580
0
-
362.3
.9379 0 0 328 333 0
Water 27637
0
-
2090
8.125 -
0.014
9E-
06
328 333 1.66
Table 5.12-32 Energy Balance for Boiler of DC-1
Required SteamFlow Rate (m¿¿ steam)=Qb
λ=542.93 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
Component a b c d e T1 T2Flow
(kmol/h)Qc
Glycerol 8.242 44E-
01
3.E-
04
9E-
08
0 328 333 0
1.55E+09Methanol 10580
0
-
362.3
.9379 0 0 328 333 5.8374
Water 27637
0
-
2090
8.125 -
0.014
9E-
06
328 333 63.4492
Table 5.12-33 Energy Balance for Condenser of DC-1
∆T=30 °C
C p=4120 jouleskg°C
CoolingWater Flow=Q c
∆T C p=12352.67 kg
hr .
49
5.13 Energy Balance Distillation Column (DC-2)The second distillation column operates at 50 kPa and separates methanol from water.
99.9 mole % methanol is obtained as the distillate.
50
Figure 5.13.26 Energy Balance (DC-2)
Component a b c d e T1 T2Flow
(kmol/h)Qb
Water 27637
0
-
2090
8.125 -
0.014
9E-
06
328 333 63.44
4.04E+08Methanol 10580
0
-
362.3
.9379 0 0 328 333 0
Table 5.13-34 Energy Balance for Boiler of DC-2
Required SteamFlow Rate (m¿¿ steam)=Qb
λ=185.87 kg
hr .¿
λ=Latent Heat Of VaporizationOf Steam=2174000 jouleskg
Component a b c d e T1 T2Flow
(kmol/h)Qc
Water 27637
0
-
2090
8.125 -
0.014
9E-
06
328 333 0
6.16E+07Methanol 10580
0
-
362.3
.9379 0 0 328 333 5.83
Table 5.13-35 Energy Balance for Condenser of DC-2
∆T=30 °C
C p=4120 jouleskg°C
CoolingWater Flow=Q c
∆T C p=490.34 kg
hr .
51
Chapter 6 EQUIPMENT DESIGNAFTER ALL the preliminary work, has been completed, the detailed design work can
begin. Equipment can be designed in its final form and full specification sheets prepared
for each item. Process flowsheet and equipment list can be checked and amended. Cost
estimates can also be revised to account for any significant changes from the preliminary
design specifications.
6
6.1 Reactor Design
Parameter Value Units
Reactor Type CSTR Dimensionless
Temperature 60 / 333 °C/°K
Total Conversion 99 %
Residence Time 1 hour
Number of Reactors 2 Dimensionless
Configuration Series Dimensionless
Molar Flow of Oil (Fao) 1.355 kmol /hour
Volumetric Flow Rate of Oil (vao) 1.35 m3/hour
Cao 1.0 kmol /m3
Material of Construction SS Type 304 Dimensionless
Reactor volume can be calculated by the study of kinetics in our process. The study of
kinetics can lead us to the volume by algorithms specifically designed to calculate reactor
volume, conversion etc. kinetics for the transesterification reaction have been thoroughly
studied albeit with some confusion and contradiction. Despite this we were able to find a
paper that specifically studied the soya bean oil transesterification under our specified
conditions i.e. 6:1 methanol oil ratio. And 1 % of catalyst w.r.t the weight of our oil. The
temperature however was 50 °C [10]. the reactions are as such.
52TG+MeOH k1 /k2
⇔
DG+FAME
DG+MeOH k 3/k 4⇔
MG+FAME
MG+MeOH k 5/k 6⇔
GL+FAME
TG+3MeOH k 7 /k 8⇔
GL+3 FAME
The rate equations used for volume calculation are given below.
The mole balance equation for a CSTR is as under…
53
V=FTG−FTGo
−rTG
V=FTG∗X−rTG
where→−rTG=d [TG ]dt
d [TG ]dt
=−k 1∗[TG ] [ A ]+k 2 [DG ] [A ]−k 7 [TG ] [A ]3+k 8[A ] [GL ]3
d [DG ]dt
=−k1∗[TG ] [A ]−k 2 [DG ] [E ]−k 3 [DG ] [A ]+k 4 [MG][E]
d [MG ]dt
=k 3∗[DG ] [A ]−k 4 [MG ] [E ]−k 5 [MG ] [A ]+k 6 [GL ][E]
d [E ]dt
=k 1∗[TG ] [A ]−k 2 [DG ] [E ]+k 3 [DG ] [A ]−k 4 [MG ] [E ]+k 5 [MG ] [ A ]−k 6¿
d [GL ]dt
=k 5∗[MG ] [ A ]−k 6 [GL ] [E ]+k 7 [TG ] [ A ]3−k 8[GL] [E ]3
TG+MeOH k1 /k2⇔
DG+FAME
DG+MeOH k 3/k 4⇔
MG+FAME
MG+MeOH k 5/k 6⇔
GL+FAME
TG+3MeOH k 7 /k 8⇔
GL+3 FAME
We solved the differential equations in matlab for both the reactors. The program is
provided in Appendix A. Upon solving the equations, we got two volumes each. Reactor
1 has a volume of 6.3m3 while the second reactor has a volume of 1.42m3.
Similarly, for the R-2 we can calculate the diameter and height.
V=π∗d4
2
∗h
1.06∗4π
=d2∗h
.8∗4π∗1.5
=d3
.7= d3
d ≈1.06mh≈1.6m
6.1.1 Reactor SelectionFollowing are the reasons for choosing CSTR for our project.
Liquid phase reaction. Provides optimal mixing. The reactors can be operated at temperatures between -6.66 and 232 °C and at
pressures up to 7 atm. Relatively cheap to construct. Also, relatively easy to clean and maintain.
54
V=π∗d4
2
∗h
5.3∗4π
=d2∗h
6.3∗4π∗1.5
=d3
4.5= d3
d ≈1.7mh≈2.6m
Ease of control of temperature in each stage, since each operates in a stationary state; heat transfer surface for this can be easily provided hence it is relatively easy to maintain good temperature control with a CSTR.
Can be readily adapted for automatic control in general, allowing fast response to changes in operating conditions (e.g., feed rate and concentration).
With efficient stirring and viscosity that is not too high, the model behavior can be closely approached in practice to obtain predictable performance.
6.1.2 Rate Constants Sourced from [10] the rate constants are as such.
Rate Constants (mole/dm^3*seconds) Value
k1 .049
k2 .102
k3 .218
k4 1.280
k5 .239k6 .007
k7 7.84e-05
k8 1.58e-05
55
Since ours is a well-mixed vessel as stated per our primary source. We need to have a
stirrer involved which basically means that there is an impeller that needs be designed.
56
6.1.3 Reactor ImpellerIt is quite common practice to have vessels with some form of mixing apparatus, it I
commonly referred to as an agitator. Especially in the case of a CSTR mixing plays an
important role as the constituents are considered to be well mixed. The basis of this
assumption is that the mixing is strong enough to provide enough mass transfer. Agitators
are chosen predominantly on the basis of reactor volumes and fluid properties mainly the
viscosity.
For the selection of the reactor impeller we need to know about the reactor volume and
the viscosity of the fluid. To calculate the volume of the reactor we simply need to use
the provided ratio of impeller diameter to the rector diameter. This ratio is given in the
volume 6. [11]
6.1.4 Specifications SheetParameter Value Units
R-1 Volume 6.3 m3
R-2 Volume 1.4 m3
R-1 Diameter 1.7 m
57
R-1 Height 2.6 m
R-2 Diameter 1 m
R-2 Height 1.6 m
Impeller Type Turbine Dimensionless
R-1 Impeller Dia. 1.06 m
R-2 Impeller Dia. .6 m
6.1.5 Pressure DropIn liquid-phase reactions, the concentration of reactants is insignificantly affected by even
relatively large changes in the total pressure. Consequently, we can totally ignore the
effect of pressure drop on the rate of reaction when sizing liquid phase chemical reactors.
However, in gas-phase reactions, the concentration of the reacting species is proportional
to the total pressure and consequently, proper accounting for the effects of pressure drop
on the reaction system can, in many instances, be a key factor in the success or failure of
the reactor operation.
6.2 Heat Exchanger Design A heat exchanger is a device built for efficient heat transfer from one fluid to another,
whether a physical barrier separates the fluids so that they never mix, or the fluids are
directly contacted. It is used for heating of one fluid while cooling the other. Heat transfer
equipment is defined by the function it fulfils in a process. Exchangers recover heat
between two process streams.
58
4
5
6
6.1
6.2
6.2.1 Types with respect to Structure
Some major types are:
Double pipe heat exchanger. Shell and tube heat exchanger. Compact heat exchanger.
Double pipe consists of two concentrically arranged pipes or tubes, with one fluid
flowing in the inner pipe and the other in the annulus between the pipes. The term double
pipe refers to a heat exchanger consisting of a pipe within a pipe, usually of a straight-leg
construction with no bends. Hairpin heat exchangers consist of two shell assemblies
housing a common set of tubes and interconnected by a return-bend cover referred to as
the bonnet.
59
6.2.2 Principal Parts
Two sets of concentric pipes which constitutes;
i. Inner pipe.
ii. Outer pipe.
iii. Annulus.
Connecting tees.
Return head.
Return bend.
Packing glands.
6.2.3 Working Principle of Double Pipe Heat Exchanger
The basic working principle of the heat exchanger is based on the law of conservation of
heat i.e.
As by law of nature heat tends to flow from higher potential to lower potential. It tends to
equalize the temperature of both streams. But physical barrier of good conductor prevents
the both streams from physical mixing and allows only heat to flow from one to other.
6.2.4 HEAT TRANSFER MODES
Conduction Convection Radiation
6.2.5 Types of Double Pipe Heat Exchanger
Double pipe exchangers are divided into two major types:
Single-tube
The Single-tube type consists of a single tube or pipe, either finned or bare, inside a
60
Annulu
s
Inner pipe
shell.
Multi-tube
The Multi-tube type consists of several tubes, either finned or bare, inside a shell.
6.2.6 Double Pipe Heat Exchangers
Advantages
The use of longitudinal finned tubes will result in a compact heat exchanger
for shell side fluids having a low heat transfer coefficient.
Counter current flow will result in lower surface area requirements for
services having a temperature cross.
Potential need for expansion joint is eliminated due to U-tube construction.
Shortened delivery times can result from the use of stock components that can
be assembled into standard sections.
Modular design allows for the addition of sections at a later time or the
rearrangement of sections for new services.
Simple construction leads to ease of cleaning inspection and tube element.
Disadvantages
Hairpin sections are specially designed units which are normally not built to
any industry standard other than ASME Code. However, TEMA tolerances are
normally incorporated wherever applicable.
Multiple hairpin sections are not always economically competitive with a
single shell and tube heat exchanger.
Proprietary closure design requires special gaskets.
61
6.2.7 Operation of Double Pipe Heat Exchanger
Double pipe exchangers are usually assembled in 12-, 15-, or 20-ft effective lengths
(the distance in each leg over which heat transfer occurs).
When hairpins are employed in excess of 20ft, the inner pipe tends to sag and touch the
outer pipe causing a poor flow distribution in the annulus.
The best-known use of the hairpin is its operation in true counter current flow
which yields the most efficient design for processes that have a close
temperature approach or temperature cross. However, maintaining counter
current flow in a tubular heat exchanger usually implies one tube pass for each
shell pass.
The double-pipe exchanger is very flexible: vaporization, condensation, or
single-phase convection can be carried out in either channel.
The exchanger can be designed for very high pressures or temperatures if
required.
By proper selection of diameters and flow arrangements, a wide variety of
flow rates can be handled.
Design Calculation
The purpose of this equipment is to heat the waste vegetable oil to the required
temperature.
6.2.8 Heat Exchanger Design
Assumed Calculations:
A= QU∗∆T
By Assuming U = 300 W/m2 OC
Q = 90481300 J/Kg (25133 Watt)
A = 3.055 m2
As our area is not much big so we will use Double Pipe Heat Exchanger.
62
m= QCp∗∆T
m = 429.95 Kg/hr
Pipe Side (Hot Water)
Inlet temp = 90 oC
Outlet temp = 50 oC
Mass flow rate of hot water = 947.899 lb/hr
Annulus side (WVO)
Inlet temp = 25oC
Outlet tem = 60oC
Mass flow rate of oil = 1217.44 Kg/hr
Pipe Dimensions
We are using 20ft length of the pipe. If the length of the pipe will be greater than 20-feet,
the inner pipe tends to sag and it will touch the outer pipe and causes a poor flow
distribution in the annulus.
D2 = 0.0525 m
D1 = 0.0420 m
D = 0.0350 m
Calculation of LMTD
LMTD= ∆T 1−∆T 2
ln ( ∆T 1∆T 2
)
63
LMTD=11.18 °C
PHYSICAL PROPERTIES
PHYSICAL PROPRTIES INNER PIPE ANNULUS
Hot Water WVO
Viscosity µ (Cp) 0.014 0.357
Thermal Conductivity (k)
(W/m.K) 0.636 0.243
Heat capacity(Cp) (KJ/Kg.°C) 0.221 3.818
Density ρ(kg/m3) 965 908
Annulus Side (WVO)
D2 = 0.0525 m
D1 = 0.0420 m
aa = 3.14(D22- D1
2)/4
aa = 0.00076 m2
Equivalent Diameter
Deq = (D22- D1
2)/ D1
Deq = 0.023 m
Mass Velocity
Ga = W/ aa
Ga = 1586494.5 Kg/hr.m2
Reynolds Number
64
Re = DeGa/ µ
Re = 28657.8558
L/D = 262.4
Jh = 100
Pr = Cp µ/k
Pr = 5.593063265
ho = 1853.26 W/m2.OC
Inner pipe (Hot Water)
D = 0.0350 m
ap = 0.00096 m2
Gp = W/ ap
Gp = 445005.07 Kg/hr.m2
Rep = DGp/ µ
Rep = 11706.02989
L/D = 175
Jh = 60
Pr = Cp µ/k
Pr = 0.129183469
hi = 97.72362084 W/m2.OC
hio = 81.24011853
Uc = hio*ho/hio+ho
Uc = 369.12 W/m2.OC
1/UD = 1/Uc + Rd (Rd is assume as 0.002 hr.ft2.OF/Btu)
UD = 326.62 W/m2.OC
65
Required Area
A = Q/UD∆T
A = 2.80 m2
Required Length
Required Length = Surface Area/0.435Ft2
L = 21.14 m
Actual Length
L = 24.38 m
Hairpin = 2
Actual Area will be:
Form table for 1.25- in we have 0.435 Ft2 of external surface per foot length.
Actual Length * 0.435
Actual Area (A) 3.23 m2
This area is close to the assumed calculation area (3.05 m2)
The surface apply will actually be
UD = 328.771447 W/m2 OC
The overall heat transfer coefficient is close to the assumed calculation
Rd = 0.001897 m2.OC/W
Pressure Drop (Annulus)
1) De’ = (D2 – D1)
De’ = 0.01 m
Re’a = De’ Ga/µ
66
Re’a = 12520.00405
f = 0.0035 + 0.246 /( Re’a)0.42
f = 0.0085
ρ = 56.75
2) ∆Fa = 4f Ga2L/2g ρ2 De’
∆Fa = 0.94 m.
V = G/3600 ρ
V = 1.590 FPS
3) Ft = 3(V2/2g’)
Ft = 0.117
4) ∆Pa = 1.2676 Psi
Inner Pipe
1) Rep = 35030
f = 0.0035 + 0.246 /( Rep)0.42
f = 0.00675791
ρ = 60.31
2) ∆Fp = 4f Ga2L/2g ρ2 De’
∆Fp 0.015 m.
∆Pp = 1.052 Psi
6.2.9 Mechanical Design
Selection of material
Inner pipe material : Carbon steel (approximately 0.30–0.59% carbon content)
67
Whose density is = 7877.61 kg/m3 (table 2-118 Perry chemical Engineering 8th edition)
The permissible stress is ft = 0.788 kg/m2
% Elongation = 28
Characteristics of material
available in a wide range of standard forms and sizes
good tensile strength and ductility
not resistant to corrosion
6.3 Flash Tank1. Final purification of biodiesel is achieved in the flash drum that operates under
vacuum (5 kPa).
2. Modelling of the flash tank was performed on Aspen Hysys. Material balance &
construction sheet is given in Appendix B.
3. The feed rates were taken from the material balance.
4. Pressure was provided in our primary source.
5. Temperature was set around the boiling point of water.
6. Components present in too low an amount were neglected for the ease.
7. Multiple fluid packages were used which gave similar results. These include
NRTL Ideal.
68Figure 6.3.27 Flash Tank
Operating Conditions of the flash tank are given as under.
Flash Tank Conditions
Liquid Residence Time 720 seconds
Operating Pressure 5 Kilo Pascals
Package Used NRTL Ideal Dimensionless
Valve IN Conditions
Temperature 55 °C
Operating Pressure 101.3 kPa
Total Feed (Molar Flow) 5 kmol/h
Mole Fraction (Triolein) .003 Dimensionless
Mole Fraction (Methanol) .0548 Dimensionless
Mole Fraction (H2O) .1350 Dimensionless
Mole Fraction (FAME) .1350 Dimensionless
Flash IN Conditions
Temperature 53.32 °C
Operating Pressure 5 kPa
Total Feed (Molar Flow) 5 kmol/h
Mole Fraction (Triolein) .003 Dimensionless
Mole Fraction (Methanol) .0548 Dimensionless
Mole Fraction (H2O) .1350 Dimensionless
Mole Fraction (FAME) .1350 Dimensionless
Flash UP Conditions
Temperature 110 °C
Operating Pressure 5 kPa
Total Feed (Molar Flow) .8359 kmol/h
Mole Fraction (Triolein) 0 Dimensionless
Mole Fraction (Methanol) .3118 Dimensionless
Mole Fraction (H2O) .6881 Dimensionless
Mole Fraction (FAME) 0 Dimensionless
69
Flash DOWN Conditions
Temperature 110 °C
Operating Pressure 5 kPa
Total Feed (Molar Flow) .4.164 kmol/h
Mole Fraction (Triolein) 0.0004 Dimensionless
Mole Fraction (Methanol) .0032 Dimensionless
Mole Fraction (H2O) .0240 Dimensionless
Mole Fraction (FAME) .9725 Dimensionless
Table 6.3-36 Streams from Flash Tank
6.3Design Specifications of the flash tank are given as under.
Parameter Value Units
Diameter .609 m
Total Length (Height) 3.353 m
L/D Ratio 5 Dimensionless
Material Type Carbon Steel Dimensionless
Shell Thickness 6.350 mm
Corrosion Thickness 3.175 mm
Table 6.3-37 Design Specifications of Flash Tank
6.4 Distillation Column Design (D-1)In industry, it is common practice to separate a liquid mixture by distillation of the
components, which have lower boiling points when they are in pure condition from those
having higher boiling points. This process is accomplished by partial vaporization and
subsequent condensation
70
6.4
6.4.1 Choice between Plate and Packed Column
Vapor liquid mass transfer operation may be carried out either in plate column or packed
column. These two types of operations are quite different. A selection scheme
considering the factors under four headings.
Factors that depend upon the system i.e. scale, foaming, fouling factors, corrosive
systems, heat evolution, pressure drop, liquid holdup.
Factors that depend upon the fluid flow moment.
Factors that depends upon the physical characteristics of the column and its
internals i.e. maintenance, weight, side stream, size and cost.
Factors that depend upon mode of operation i.e. batch distillation, continuous
distillation, turndown, and intermittent distillation.
The relative merits of plate over packed column are as follows:
Plate column are designed to handle wide range of liquid flow rates without
flooding.
If a system contains solid contents, it will be handled in plate column, because solid
will accumulate in the voids, coating the packing materials and making it ineffective.
Dispersion difficulties are handled in plate column when flow rate of liquid are low
as compared to gases.
For large column heights, weight of the packed column is more than plate column.
If periodic cleaning is required, man holes will be provided for cleaning. In packed
columns packing must be removed before cleaning.
For non-foaming systems, the plate column is preferred.
Design information for plate column are more readily available and more reliable
than that for packed column.
Inter stage cooling can be provide to remove heat of reaction or solution in plate
column.
When temperature change is involved, packing may be damaged.
Plates are mostly used for large diameter more than 0.6 m
71
For this particular process, “Methanol, DME, Water” plate column is selected
because:
System is non-foaming.
Temperature is high.
Diameter is greater than 0.6 meter.
6.4.2 Choice of Plate TypeThere are three main plate types, the bubble cap, sieve plates, ballast or valve plates.
Sieve plate is selected because:
They are lighter in weight and less expensive. It is easier and cheaper to install.
Pressure drop is low as compared to bubble cap trays.
Peak efficiency is generally high.
Maintenance cost is reduced due to the ease of cleaning.
6.4.3 Design Steps for A Distillation ColumnCalculation of Minimum number of plates
Calculation of optimum reflux ratio
Calculation of theoretical number of stages
Calculation of actual number of stages
Calculation of diameter of the column
Calculation of the height of the column
Design Calculations:
Components mass %
Feed Top Bottom
Glycerol 0.08319 0.00 0.4401
Methanol 0.102 0.08416 0.00
Water 0.814 0.9158 0.5598
Stream Temperature Flow rate Pressure
72
℃ Kg/hr psi
Feed 100 1485.35 49.3128 (3.35 atm)
Top 98.1 1334.78 14.6488 (1atm)
Bottom 250.3 150.71 15.95 (1.019atm)
Pressure of feed = P = 49.31
psia
Temperature of feed = T = 100 oC = 373K
Boiling point of water = Tw = 101.1 °C = 374.1 K
Boiling point of Methanol= Tm = 64.8 °C = 337.8 K
Heat of Vaporization of methanol = ΔHvap = 35200 J/mol
Relative Volatility Calculation
α =exp [−ΔH vapLR ( 1T w
− 1T m )]
“integratedClausius-Clapeyron equation”
α =exp [−352008.314 ( 1
374.1− 1
337.8 )]α = 3.37
6.4.3.1.1.1.1.1.1 Reflux Ratio (RD)
Colburn’s method for minimum reflux
RM = 1
α−1 [ xdAx fA −α (1−xdb1−x fb )]
73
RM = 1
3.37−1 [0.084160.102
−3.37( 1−0.001−0.08319 )]
RM = 1.5
R = 1.2 RM
R = 1.2 x 1.5
R = 1.8
Minimum Number of Stages
Minimum number of Stages can be found Fenske relation.
6.4.3.1.1.1.1.1.2 where:
N is the minimum number of theoretical plates required at total reflux (of which the
reboiler is one),
Xd is the mole fraction of more volatile component in the overhead distillate,
Xb is the mole fraction of more volatile component in the bottoms,
α avg is the average relative volatility of the more volatile component to the less volatile component
Nmin = 4 (reboiler is excluded)
Plate Efficiency
Using O’Connell relation
74
Eo = 51−32.5 log10(μaαa)
µa = Molar average liquid viscosity mNs/m2 = 0.1553 mNs/m2
αa = average relative volatility = 3.37
Eo = 50.3 ¿αa µa)-0.226
Eo = 68.226 %
Theoretical no. of Plates:
Gilliland related the number of equilibrium stages and the minimum reflux ratio and the
no. of equilibrium stages with a plot that was transformed by Eduljee into the relation:
N−Nmin
N+1=0.75¿
6.4.4 From which the theoretical no. of stages to be 7
(calculated by aspen see appendix C)
6.4.5 Feed plate location
Using Kirkbride’s relation
logNR
N S=0.206 log [( 0.0831
0.102 )(0.000750.00662 )
2 1328.75151 ]
N R
N S=0.611
R = 1.8, N = 7
75
Nr+¿NS = 6
NS = 6 - Nr
Ns = 7 - 0.61Ns Ns = 4.3
Feed plate = 4
6.4.6 Column Diameter
uV=(−0.171lt2+0.27 lt−0.047)[ ρL−ρvρv ]1⁄2
Where uv = maximum allowable vapour velocity based on the gross total column cross-
sectional area.
Lt = plate spacing, m, (range 0.5 to 1.5)
The column diameter, Dc can be calculated by
Dc=√ 4 vwπρ vuv
Where as Vw = is maximum vapour rate, m3/s
Dc=0.9144m
Provisional Plate Design
Column diameter = 0.914 m
Column Area A
= π4d2
Side DC Top Width = 120.7mm
Side DC Btm Width =120.7mm
Side DC Top Length = 0.6189m
Side DC Btm Length = 0.6189m
Net area An = Ac – Ad
= 0.6567m2
Active area Aa = Ac – 2Ad
76
= 0.5542m2
Hole area Ah take 10% Aa = 5.584 × 10-2m2
Pressure drop per plate
Assume 100 mm water pressure drop per plate,
Columnpressuredrop=100∗10−3∗1000∗9.81∗18
¿17658 Pa
TopPressure=14 Psia
Estimatedbottompressure=15.5 psia
Total Pressure Drop
ht = hd + (hw + how) + hr
Max delta P( ht of liq) = 3.871kpa ( aspen, see appendix)
Height of Column
No. of plates = 7
Tray spacing = 0.609 m
Distance between 15 plates = 0.609¿ 7 = 3.9 m
Top clearance = 0.5 m
Bottom clearance = 0.5 m
Tray thickness = 3.175mm/plate
Total height of column = 4.267m (aspen, see appendix)
77
SPECIFICATION SHEET OF DISTILLATION COLUMN
Identification
Item Distillation Column
Item # T-102
Type Sieve Tray
Function
The separation of methanol from glycerol
Design data
No. of trays 7
Operating Pressure Slightly above than atm
Operating Temperature 101 °C
Tray spacing 0.6096m
Tray thickness 3.175 mm
Height 4.267 m
Diameter
Max Flooding
Total Weir Length
Max weir load
DC Clearance
0.9144 m
59%
618.9mm
12.63m3/h.m
38.10mm
Reflux ratio 1.8
Sieve hole Diameter 6.350mm
78
Sieve hole Area
No. of Holes(estimated)
5.58 ×10-2m2
1763
Liquid density 959.119Kg/m3
Vapor density 0.5881 Kg/m3
Material of Construction Stainless steel 18Cr/8Ni Ti stabilized
(aspen, see appendix )
6.5 DISTILLATION COLUMN DESIGNFeed = 1367.5263 Kg/hr = 71.3039 K.mole/hr
Components wt
%
Kg/hr Mol. Wt K.mole Mole%
CH3OH 192.1234601 32 6.0038 8.42001
H2O 1175.402976 18 65.10036 91.2998
About (8.42001+ 91.2998) = 99.71%) of the feed consists of methanol and water. Thus binary distillation can be assumed.
Distillate = 192.1234601 Kg/hr = 6.0038 K.mole/hr
Component wt
%
Kg/hr Mol. Wt k.mole Mol. Wt
CH3OH 192.1234601 32 5.854 99.99
H2O 0.26964 18 0.1498 0.01
Bottom = 1175.402976 Kg/hr = 65.10036 K.mole
Component wt
%
Kg/hr Mol. Wt k.mole Mol. Wt
79
CH3OH 0.02688 32 0.00084 0.01
H2O 1175.402976 18 65.10036 99.9
We getXf = 0.084Xd = 0.9999 Xw = 0.01
(Equlibrium data from the compilation by Gmehling, J. and Onken, U. 1977. Vapor-Liquid Equilibrium Data Collection, Dechema, Frankfurt, Germany, vol. 1, p. 60.)from Chemical Engineering Design and Analysis: An IntroductionT. M. Duncan and J. A. Reimer, Cambridge University Press, 1998.
Equilibrium Data for Methanol – Water is given as follows
Temp (oF)
Temp (oC)
x (mole f)
y (mole f)
y_calc Diagonal
212 100 0 0 0 0209.12 98.4 0.012 0.068 0.164522 0.012206.42 96.9 0.02 0.121 0.203265 0.02204.44 95.8 0.026 0.159 0.226586 0.026203.18 95.1 0.033 0.188 0.250089 0.033201.38 94.1 0.036 0.215 0.259262 0.036197.96 92.2 0.053 0.275 0.304281 0.053194 90 0.074 0.356 0.349368 0.074191.48 88.6 0.087 0.395 0.373577 0.087188.42 86.9 0.108 0.44 0.408558 0.108185.72 85.4 0.129 0.488 0.439742 0.129182.12 83.4 0.164 0.537 0.485687 0.164179.6 82 0.191 0.572 0.517318 0.191174.38 79.1 0.268 0.648 0.595187 0.268172.58 78.1 0.294 0.666 0.618443 0.294169.7 76.5 0.352 0.704 0.666301 0.352167.54 75.3 0.402 0.734 0.703963 0.402165.56 74.2 0.454 0.76 0.740321 0.454163.76 73.2 0.502 0.785 0.771772 0.502161.6 72 0.563 0.812 0.809295 0.563159.62 70.9 0.624 0.835 0.844504 0.624156.56 69.2 0.717 0.877 0.894496 0.717
80
154.58 68.1 0.79 0.91 0.931129 0.79152.96 67.2 0.843 0.93 0.956498 0.843152.42 66.9 0.857 0.939 0.963042 0.857150.26 65.7 0.938 0.971 0.999729 0.938149 65 1 1 1.026572 1
Where X = Mole fracti
on of M.V.C in Liquid phase
Y = Mole fraction of M.V.C in Vapor phase
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
VLE for MeOH/H2O system
Equilibrium Diagonal
x (mole frac MeOH)
y (m
ole
frac
MeO
H)
Now after drawing equilibrium curve
(11.49) Coulson and Richardson Vol.2
Minimum Reflux Ratio = Rm = xd− y f
y f−x f
= (0.9999 – 0.391)/(0.391 – 0.084)= 1.98
Reflux Ratio = R = 1.5* Rm= 1.5 * 1.98=2.97
6.5
6.5.1 Top Operating Line
F = 71.23kmol/hr D = 5.854 kmol/hr
81
W = 71.05 kmol/hr
D = 5.854Kmol/hr, XD = 0.99, xf =0.084
Ln = 17.79 Kmol/hr Vn = 23.456 Kmol/hr
yn = LnV nxn+1+
DV n
xD
yn =17.79
23.456xn+1+
5.864×0.99923.456
yn = 0.75 xn+1+¿ 0.249
6.5.2 Bottom Operating Line
F = 71.23 Kmol/hr, xw = 0.001,
Lm = 89.09 Kmol/hr Vm = 23.655 Kmol/hr
Ym = LmV m
xm+1−BV m
xW
yn =89.0923.65
xn+1−65.435×0.001
23.655
ym = 3.8012xm+1−¿0.00276
The Points Of Top Operating Line
(0 , DV nxD)) ; (Xf , Xd)
(0 , 0.249) ; (0.084 , 0.999)
The Bottom Operating Line Points
(0 , BV m
xw) ; (Xf , Xw)
(0 ,0.00276) ; (0.084 , 0.01)
82
6.5.3 Ideal no of trays is 8
6.5.4 Efficiency And Total Number Of Real Stages
Coulson and Richardson’s volume 6( page549)Eo = 51 – 32.5 Log μa, aa
Where Eo = Overall column efficiency percent.
Average temperature of column = 87.5 oC = 189.5 oF
(Kaye & Laby, Engineers Edge, RoyMech and Dynesonline) Viscosity of Methanol = 0.257 cp
Viscosity of Water = 0.325 cp μ = (0.7108 * 0.257) + (0.2843 * 0.325) = 0.257 cpEo = 51 – 32.5 Log (0.257)
= 70 %
83
Actual number of trays in column = 8 / 0.7
= 12Feed should be entered on plate # 6
Maximum vapor flow rate in rectifying section =Vn=23.456kgmole/hr
Maximum liquid flow rate in rectifying section =Ln=17.592 kg mole/hr
Maximum vapor flow rate in stripping section =Vm=23.655kg mole/hr
Maximum liquid flow rate in stripping section =Lm=89.09kg mole/hr
Plate spacing initial estimate = T_S= 0.5m = 18in
Calculation of column diameter based on flooding velocity
Calculate FLV= liquid vapor flow factor
FW=LWVW √ δVδL
LW= liquid mass flow rate kg/s
VW= vapor mass flow rate, kg/s
FWTOP=17.59223.655 √ 1.15
750=0.039
FWbotom= 89.0923.655 √ .5
962=0.022
From figure 11.27 Coulson and Richardson vol.6)
t1= a constant obtained from fig 11.27
84
K1Top= 0.08 K1Bottom= 0.085
Flooding Velocity:
Uf= flooding velocity
U f=K1√ δL−δVδV ( σ20 )0. 2
U f bottom=0 .085√962−0 .50.5 (58
20 )0. 2
= 4.3 m/s
U f Top=0 .08√750−1.151 .15 (19
20 )0 .2
= 2.17 m/s
Based on 85% flooding velocity
6.5.5 Superficial Vapor Velocity
Ubase=4 . 3×0. 85=3 .57 m/s
U v , top=2 .17×0 . 85=1 . 9 m/s
Maximum volumetric Flow rate = V/δV
Top = 0.573 m3/sec
Bottom = 1.147 m3/sec
6.5.6 Net Area Required
Maximum volume metric flow rate / superficial velocity
Top = 0.5735/1.9 = 0.30m2
85
Bottom = - 1.471/3.57 = 0.41m2
As first trial take down comer area as 12% of the total.
Column cross sectional area
Base = 0.41/0.88 = 0.46 m2
Top = 0.30/0.88 = 0.34 m2
6.5.7 Column Diameter
Diameter =√ (4 × Area /0.88π )
Area = = π
4d2
Top=3.14 ¿¿, = 0.090 m Bottom =3.14¿¿= 0.166m
Diameter top =0.362m diameter bottom = 0.490 m
6.5.8 Height of the column :
Hc=1.2 *T_S*(N-1) taken from paper
1.2(0.5)(16-1)=9 m
Provisional Plate Design
Column diameter (base) = 0.4827 m
Column Area Ac = π
4d2
Ac = 0.182 m2
Downcomer area Ad = 0.12(0.182)
= 0.021m2
Net area An = Ac–Ad
= 0.182– 0.021
= 0.161m2
Active area Aa = Ac–2Ad86
= 0.182 – 2(0.021)
= 0.14 m2
Hole area Ah take 10% Aa = 0.1 × 14 = 0.014m2
Weir length
Ad / Ac = 0.021 / 0.182 = 0.115
(From figure 11.31 vol.6)
lw / dc = 0.76
lw =1 .6×0.76
lw = 1.22 m
Take weir height , hw = 50 mm
Hole diameter, dh = 5 mm
Plate thickness = 5 mm
Maximum liquid rate Lm’ = 89.09× 18 / 3600 = 0.4454 kg/sec
Minimum liquid rate at 70% turn down 0.7*0.4454
= 0.31178s kg/sec
Maximum h0w =750(o .4454
962∗1.22 )2/3 =3.9313 mm liquid
Minimum how =750(o .31174
962∗1.22 )2/3 =3.096 mm liquid
At minimum hw+how= 50 + 3.096
= 53.096 mm liquid
87
From fig 11.30, Coulson and Richardson Vol.6
K2= 30.4
U ( min )=K2−0 . 9 (25. 4−dh)
(ℓv )1/2
U (min )=30 .4−0 . 9 (25. 4−5 )
(0 .5 )1/2
= 14.2 m/s
Actual minimum vapour velocity =min . vapour rate
Ah
=0 . 70×6 . 50 .155
= 28.1 m/s
So minimum vapor rate will be well above the weep point.
6.5.9 Plate Pressure Drop
Dry Plate Drop
Max. Vapour velocity through holes
Uh = Volumetric Flow Rate / Hole Area
Uh=1.4170.155=9.14 m/s
Fom fig. 11.43 Coulson and Richardson Vol.6
for plate thickness/hole dia = 5/5 = 1
and
AhA p
≃AhAa
=. 1551. 55
=0 .1
88
Co= 0.84
From Eq.11.88 Coulson vol.6
hd=51[ U h
Co ]2δVδL
hd=51[9.140.84 ]2 0.5
962=3.13 mm liquid
6.5.10 Residual Head
hr=12. 5×103
962=12. 9mm liquid
mm liquid
Total Pressure Drop
ht = hd + (hw + how) + hr
Total pressure drop = 3.12+ (50 + 3.096) + 12.9
ht = 69.116 mm liquid
6.5.11 Check Residence Time
t r=Ad×hbc×ℓL
Lwd
t r=
0.23×0 .218×9622. 48
= 12.8 sec
> 3 sec. so, result is satisfactory
6.5.12 Check Entrainment
Uv = Maximum Volumetric Flow Rate of vapors/Net Area
UV = 1.147/ 1.78 = 0.644 m/s
89
No of Holes
Area of one hole =1 .964×10−5
Number of Holes = Hole Area / Area of one hole
No. of holes = 0 .155
1 .964×10−5 = 6620
Specification Sheet
Equipment Distillation Column
Actual No.of Trays 12
Efficiency 70 %
R 2.97
Diameter top 0.362 m
Bottom diameter 0.49 m
Height 9 m
No. of holes 6620
90
Superficial velocity 80 % of flooding velocity
Pressure Drop 69.116 mm liquid
Tray Thickness 5mm
Tray spacing 0.5 m
6.6 Mixing Tank Design
6.6
6.6.1 Volume Calculation
we can calculate volume of tank by this formula
v= τR Q
0.8
residence time= τR = 1 hr., volumetric flow rate
Q=2.86862 m3
v = 3.582 m3
now we have
V = π4 D2L (1)
D= internal diameter
L=height or length
suppose
LD=3 0r L=3D
putting values of L in equation…. (1)
v=π4 D2(3D)
3.582 = 3.14
4 3D3
91
3.582(4)=9.42 D3
D=1.521 m
L=3(1.521)
L = 4.563 m
6.6.2 Thickness
Pressure in tank =1 atm
Pressure in guage = 1-1=0
Design pressure=Pi=0+10% =0.1 Nm2= 0.01
Nmm2
Material of construction= strainless steel 18cr/8Ni
Design temperature = 55 °C
Typical design stress at this temperature =f =160 Nmm2 (from table 13.2)
Joint factor = 1 , diameter of tank Di = 1.521 m
Thickness for cylindrical shell ‘e’
e= PiDi2J f−Pi
e=0.0000475 mm
Corrosion allowance = 2mm
e=2.0000475 mm
2.2 Thickness for head section
Most standard ellipsoidal heads are manufactured with a major and minor axis ratio of 2 :
1. For this ratio, the following equation can be used to calculate the minimum thickness
required:
e = Pi Di2J f−0.2 Pi
e=o . o1(1.521)
2 (1 ) (160 )−0.2(0.01)¿
= 0.0000475 m
Add corrosion allowance = 2mm
92
e = 2.0000475 mm
6.6.3 choice of closure :-
torispherical heads are used when internal pressure 0-15 bar
e = Pi RcCs
2 fJ+Pi(Cs−0.2)
where Cs = stress concentration factor for torispherical head
cs= 14 (3+√ R c
R k )
Rc =crown radius
Rk = knuckle radius
(The ratio of the knuckle to crown radii should not be less than 0.06, to avoid buckling; and the crown radius should not be greater than the diameter of the cylindrical section. For formed heads (no joints in the head) the joint factor J is taken as 1.0)
Rc =Rk (0.06) equal to dia of vessel
RC= (1.52)(0.06) =0.0912
Cs=0.8075
Now put the values in the main equation ..
e = 0.01(0.0912)(0.8075)2 (160 ) (1 )+0.01(0.0912−0.2) =0.0000023
add corrosion allowance =2 mm
e = 2.0000023 mm
6.6.4 Impeller design
Type = pitched-blade turbine impeller
93
It is used when fluid is low viscous it gives radial as well as axial mixing .
Standard properties for impeller
Da = impeller diameter
Dt = tank diameter =1.521 m
Impeller dia
Da
D t =1
3
Da =1.521
3 =0.507 m
94
Depth of liquid
HDt
=1
H=1.521
Width of impeller blades
wDa
=15
W=Da
5= 0.104 m
Length of impeller
LDa
=14
L=Da
4 =0.507
4 =0.1267 m
Clearance EDt
=13
1.5213 =0.507 m
Power calculation :-
In impeller design rpm is taken as 20-150.For low viscous fluid it will be 90rpm.
Reynold's number¿ D2Npμ
Reynold's number >10,000 so Np=KT
Np=Power number, KT=Constant for turbulent flow
For pitched blade
KT=1.27
P = 0.04-0.10 k wm3
D=0.507 ,N=90 rpm 0r 1.5 rps ,
ρ= 1060.8 kgm3
Np=P
D5N3 ρ
95
Power for impeller is given by,
P=kT N3Da5
P=152W=0.152kW
6.6.5 Design Data
Parameter Value Units
Volume 3.582 m3
Internal diameter 1.512 m
Height 4.563 m
Total pressure .01Nmm2
Operating temperature 55 °C
Wall Thickness 2 mm
Closure Torri Spherical Dimensionless
Impeller Type Pitch Blade Turbine Dimensionless
Power for Impeller .152 kW
96
Chapter 7 INSTRUMENTATION & PROCESS
CONTROL
7
7.1 IntroductionProcess control is an inherent requirement for any process industry in one way or the
other. Instrumentation implement in the form of actual hardware. In our project, we are to
propose the elements of instrumentation that will render control to our process. We have
done that by applying process control on the common types of equipment in our process
such as the reactor, heat exchanger and the distillation column.
7
7.1
7.1.1 Requirements of Control
During the operation of chemical plant, the control system must satisfy several
requirements and it must accomplish certain objectives, these are as following.
7.1.2 Safety
The safe operation of chemical process is a primary requirement for the wellbeing of the
people in the plant, thus the operating pressure, temperature and concentration of
chemical should always be within allowable limits.
7.1.3 Product Specification
To achieve the desired quantity and quality of our product we must put in place some
appropriate instrumentation. This will ensure proper production.
7.1.4 Environmental Regulation
Various laws may specify that temperatures, concentration of chemicals and flowrates of
the effluents from a plant must be within certain limits.
97
7.1.5 Operational Constraints
The various types of equipment’s used in a chemical plant have constraints inherent to
their operations.
7.1.6 Economics
The operation of a plant must conform with the market conditions, that is the availability
of raw material and the demand of the final product. Furthermore, it should be as
economical as possible in its utilization of raw materials, energy, capital and human
labour. Thus, it is required that the operating conditions are controlled at given optimum
levels of minimum operating costs and maximum profit. All the requirements above
dictate the need for continuous monitoring of the operation of a chemical plant and
external control to ensure the satisfaction of operational objectives.
Generally, a control system satisfies the following
1. Suppressing the influence of external disturbances.2. Ensuring the stability of chemical process.3. Optimizing the performance of chemical process.
7.2 Reactors
Measured Variable(s) Foil ,F NaOMe , T R−1
Manipulated Variable FNaOMe ,FCoolingWater
Controlled Variable T R−1 ,Foil /FNaOMe
Name of Control System Applied for
Flow ControlRatio Control
Name of Control System Applied for
Temperature ControlCascade Control System
Table 7.2-38 Measured, Control & Manipulated Variables for R-1
98
For the control of feeds into the CSTRs we use ratio control which divides the feed
according to flowrate of the oil input into the CSTR. While for temperature control we
use a cascade feedback control system. A cascade control system is one which uses
temperature as a secondary measurement. We have to supply cooling water to the
reactors in order to keep the reaction temperature around the optimum (60 °C).
7.3 Heat Exchanger The objective of this heat exchanger with this instrumentation is to keep the exit
temperature of waste vegetable oil constant by manipulating the hot water flow. There are
two principal disturbances (loads) that are measured for feed forward control: WVO flow
rate and WVO inlet temperature.
99
Figure 7.2.28 Reactor Control
7.4 Distillation Column
100
Figure 7.3.29 Heat Exchanger Control
Chapter 8 COST ESTIMATION
8
8.1 IntroductionBefore the plant is put into production we must together some rough estimates of
financials. The capital needed to supply the necessary plant facilities is called fixed
capital investment while that for the operation of the plant is called the working principal
and sum of two capitals is called total capital investment.
An acceptable plant design must present a process that is capable of operating
under conditions which will yield a profit. Since, Net profit total income-all expenses it is
essential that chemical engineer be aware of the many different types of cost involved in
manufacturing processes. Capital must be allocated for direct plant expenses; such as
those for raw materials, labour, and equipment. Besides direct expenses, many other
indirect expenses are incurred, and these must be included if a complete analysis of the
total cost is to be obtained. Some examples of these indirect expenses are administrative
salaries, product distribution costs and cost for interplant communication.
Source for cost indices used is provided in Appendix F.
101
8.2 Equipment Cost Estimation
8
8.1
8.1.1 Reactor Cost Estimation
For A CSTR Cylindrical Vessel We Have:
C=Fmexp (2.631+1.3673 ( lnV )−.06309 ( lnV 2))
Parameter Value Units
Fm 2.4 Dimensionless
Volume 1644.06 USGallons
Purchase Cost 26155 $
C installed(¿1.6) 41848 $
Where Index∈1985=333.3
Where Index∈2016=668.1
102
Cost∈2016=26155∗668.1333.3
=52427.7$
8.1.2 Flash Tank Cost Estimation
For A CSTR Cylindrical Vessel We Have:
C=FmCb+C a
Parameter Value Units
Fm 1.7 Dimensionless
Volume 34.55 f t 3
Purchase Cost 4562.86 $
C installed(¿1.5) 6844.30 $
Where Index∈1985=333.3
Where Index∈2016=668.1
Cost∈2016=4562.86∗668.1333.3
=9146.2549$
8.1.3 Heat Exchanger Cost Estimation
For Double Pipe Heat Exchanger: [12]
C=900∗fm∗fp∗A.18
103
Parameter Value Units
f m 1 Dimensionless
f p 1 Dimensionless
Area 34.8 ft2
Purchase Cost 1705 $
C installed(¿2.0) 3410 $
Where Index∈1985=333.3
Where Index∈2016=650.9
Cost∈2016=1705∗650.9333.3
=3329.68$
8.1.4 Centrifuge Cost Estimation
For Centrifuge:
C=a+b∗W
Parameter Value Units
a 98 Dimensionless
b 5.06 Dimensionless
104
W 1.344 tons /hr
Purchase Cost 104804.78 $
C installed(¿1.2) 125765.74 $
Where Index∈1985=333.3
Where Index∈2016=668.1
Cost∈2016=104804.78∗668.1333.3
=210081.228$
8.1.5 Distillation Column Cost Estimation (D-1)
For Distillation Column:
C t=f 1∗C b+N f 2 f 3 f 4Ct∗C p1
Cb=exp ¿
9020<W <2470000 ,2<D<16 ft .tray diameter
N=Number Of Trays
C p1=204.9D .6332L.8016
2<D<24
57<L<170 ft
Material F1 F2
Stainless steel, 304 1.7 1.189+.05770D
Stainless steel, 316 2.1 1.401+.07240D
105
Carpenter (20CB-3) 3.2 1.525+.07880D
Nickel-200 5.4
Monel-400 3.6 2.306+.1120D
Inconel-600 3.9
lncoloy-825 3.7
Titanium 7.7
Tray Types F3
Valve 1.00
Grid .80
Bubble Cap 1.59
Sieve .85
Parameter Value Units
F1 1.7 Dimensionless
Cb 11540 $
F2 1.27 Dimensionless
F3 .85 Dimensionless
F4 1.693 Dimensionless
106
C t 285.4 $
C p1 4170.6 $
C purchased 67732.96 $
Where Index∈1985=333.3
Where Index∈2016=668.1
Cost∈2016=67732.96∗668.1333.3
=135770.74 $
8.1.6 Distillation Column Cost Estimation (D-2)
For Distillation Column:
C t=f 1∗C b+N f 2 f 3 f 4Ct∗C p1
Cb=exp ¿
9020<W <2470000 ,2<D<16 ft .tray diameter
N=Number Of Trays
C p1=204.9D .6332L.8016
2<D<24
57<L<170 ft
Material F1 F2
Stainless steel, 304 1.7 1.189+.05770D
Stainless steel, 316 2.1 1.401+.07240D
107
Carpenter (20CB-3) 3.2 1.525+.07880D
Nickel-200 5.4
Monel-400 3.6 2.306+.1120D
Inconel-600 3.9
lncoloy-825 3.7
Titanium 7.7
Tray Types F3
Valve 1.00
Grid .80
Bubble Cap 1.59
Sieve .85
Parameter Value Units
F1 1.7 Dimensionless
Cb 11540 $
F2 1.9 Dimensionless
F3 .85 Dimensionless
F4 1.224 Dimensionless
108
C t 285.4 $
C p1 4170.6 $
C purchased 32253.96 $
Where Index∈1985=333.3
Where Index∈2016=668.1
Cost∈2016=32253.96∗668.1333.3
=64653.077$
8.3 Total Equipment Cost
Serial No. Equipment Cost ($)
1 Reactor (*2) 17869
2 Heat Exchanger (*5) 17869
3 Distillation Column (*2) 69176.95
4 Centrifuge (*4) 419219
5 Flash Tank 6844
7 Mixing Tank (*3) 97140
Total 536984
109
8.4 Total Physical Plant Cost (PPC)
1 f1 Equipment Erection .4
2 f2 Piping .7
3 f3 Instrumentation .2
4 f4 Electrical .1
5 f5 Utilities .5
6 f6 Storage .15
PPC=PCE∗(1+f 1+ f 2+ f 3+ f 4+ f 5+f 6)
Where PCE=Purchased Equipment Cost
Where PPC=Total PhysicalPlant Cost=1637801.19$
Fixed Capital
1 f7 Designing & Eng. .3
2 f8 Contingencies .1
¿Capital=PPC∗(1+ f 7+ f 8)
Where PPC=Physical Plant Cost=1637801.19$
¿Capital=Equipment Cost=2292921.66 $
110
8.5 Total InvestmentWorkingCapital (5%of ¿capital)=114646.08$
Total Investment Required For Project=¿Capital+WorkingCapital
Total Investment Required For Project=2407567.75$
8.6 Annual Operating Cost
Annual Fixed Cost
1 Maintenance Cost 7% of Fixed Capital 2272983.43 $
2 Operating Labour Depend on Market 159108.84 $
3 Laboratory Cost20 % of Operating
Labour1820437.50 $
4 Supervision20 % of Operating
Labour364087.50 $
5 Plants Overheads 50% of Operating Labour 910218.75 $
6 Capital Charges 10% of Fixed Capital 227298.34 $
7 Insurance 1% of Fixed Capital 45459.67.67 $
8 Local Taxes 2% of Fixed Capital 3913427.94 $
Total Fixed Cost 3917415.58 $
Annual Variable Cost
1 Raw Materials Depends on Market Rate 9385819.61 $
111
2 Miscellaneous 10 % of Maintenance Cost 15910.88 $
Total Variable Cost 9401870.06 $
8.7 Direct Production CostsDirect ProductionCost=Total ¿Cost+TotalVariableCost=13319285.65 $
8.8 Annual Production CostR∧DCost=25 % of Direct productionCost
Annual ProductionCost=Direct ProductionCost+R∧D=16,6,49,107.06 $
Annual ProductionCost (¿ Rs .)=1,744,410,192.21Rs .
8.9 Production Cost
Operating hours of plant per annum = 8000/ year
Product Rate=X kghr
=10512000 kgyear
ProductionCost= Annual ProductionCostAnnual Production Rate
=166491079654336
=1.72 $kg
ProductionCost (¿ Rs . )=180.21 $kg
112
Chapter 9 SITE & MATERIAL SELECTION
9
9.1 The ProjectOur project deals with the production of waste cooking oils (preferably soybean oil) via
the method of base catalysed transesterification. We are to design a viable continuous
method of production of our product using the cheapest resources possible while
maintaining little to no compromise on quality.
9.2 Proposal for Site LocationThe criteria most important for the selection of our site location are as listed.
1. Raw Materials
2. Market
3. Energy Availability
4. Climate
5. Transport
6. Water Supply
7. Waste Disposal
8. Labor Supply
113
9
9.1
9.2
9.2.1 Raw Materials
The raw materials for our project are as follows.
1. Waste Cooking Oil
2. KOH
3. Methanol
Possible route for the cheapest waste oil for our product is perhaps through food markets
or at ports near Karachi where waste oil from abroad is dumped. A setup near edible
markets would be really profitable if their presence is limited to a smaller area. In this
way, our transportation cost would be massively cut down which will eventually cheapen
our fuel making it more viable for the masses. Hence it is recommended that the plant be
set near an area which deals with food items on regular basis and in large volumes.
9.2.2 Climate
FAMEs have an approximate pour pt. between -10 to -20 degree centigrade. It is
therefore essential that our site not be located in an area with temperatures lower than 0
degree centigrade. This will cause the biodiesel flow to hinder and in turn the energy
consumption will increase.
9.2.3 Market
Our end product may be sold at conventional fuel pumps in the form of mixing of the
diesel reservoir with manufactured biodiesel in proportionate amount. However, the
government must enforce stricter laws regarding air pollution prior to that. An example
would be the environmental protection laws of Europe and the United States.
9.2.4 Waste Disposal
1. Salts
2. Filter Residue
114
Main wastes from our production unit would be salts and filter residue. Both of these are
not that harmful for human health. Filter residue, since it is organic waste can be sold as
manure for crops. The salt can also be sourced to the preferable industries. Hence, waste
disposal is not the most critical of issues.
9.2.5 Transport
It is essential for any industry to have a sound means for both transferal of its raw
materials and its products. It is highly recommended that our project be located near a
busy route. It will also ensure the quick availability of our product to the masses. Since
we’ve already established that our project needs to be in the vicinity of a cluster of food
outlets, the issue has been resolved to a greater extent.
9.2.6 Water Supply
In biodiesel production, it is quite necessary that we have a reasonable water supply
means. This is because it is often required by the biodiesel manufacturers to wash their
fuel. This is done in order to remove the impurities. Hence a sustained water supply is
necessary for a biodiesel plant.
9.2.7 Labour Supply
In a country like Pakistan labour is not really an issue especially since our project is to be
located in a populous city.
9.3 ConclusionSo, a few points’ important tips for the site selection for our project are.
1. Plant should be near a mass food market.
2. Should have adequate storage facilities for waste oil collected from the above-
mentioned outlets.
3. Should be near a main road for easy transportation of raw materials and finished
goods.
4. It is necessary that the plant be installed in a place with a weather that is not too
cold. Else we will have to invest a lot of resources on the pumping of our finished
product.
115
5. Also, provision of energy is a key factor to our project since we will be using
steam for the removal of methanol from our (ester + methanol) mixture. We can
use natural gas for this purpose or wood which is locally sourced for winters when
there is a shortage of gas utility.
Chapter 10 HAZOP STUDYA hazard and operability study is a procedure for the systematic, critical,
examination of the operability of a process. When applied to a process design or an
operating plant, it indicates potential hazards that may arise from deviations from the
intended design conditions. HAZOP is basically for safety and hazards are the main
concern. Operability problems degrade plant performance (product quality, production
rate, profit). For HAZOP, considerable engineering insight is required - engineers
working independently could develop different results.
10
10.1 HAZOP On Double Pipe Heat Exchanger
116
Guide Word Deviation Causes Consequences Action
LessLess flow of
heating waterPipe blockage
Temperature of
oil remains
constant
Low
temperature
alarm
MoreMore flow of
heating water
Failure of hot
water valve
Temperature of
oil increase from
set point
High
temperature
alarm
10.2 HAZOP On Distillation Column (Parameter Pressure)
Guide Word Deviation Causes Consequences Action
NODeviation
Inlet Pipe
Rupture/Inlet
Valve Closed
No Separation
Check Inlet
Pipeline &
Valve
117
LESSNo Pressure
Leakage in
Column
Less Separation,
Off Specified
Product
Check Inlet
Pipe Condition,
Check Tower
Walls
MORELow Pressure
Temperature
Too High
Inside the
Column
Both
Components
Methanol &
Water Vaporize
Install PIC at
Inlet & TIC in
Column
10.3 HAZOP On Distillation Column (Parameter Temperature)
Guide Word Deviation Causes Consequences Action
MORE Temperature
Higher Than
Required
Reboiler Not
Working
Properly
No Separation of
The Components
Both Vaporize
Install Flow
Control Valves
at Steam Inlet
118
to The Reboiler
10.4 Hazard Analysis
The Process of Hazard Identification is the procedure to assess all the hazards that could
directly and indirectly affect the safe operation of that plant and or system, and is referred
to as the Hazard Identification procedure or HAZAD. The Plant of fame having different
hazards which could cause an Event (release of toxic, flammable or explosive chemicals,
or any action) that could result in injury to personnel or harm to the environment. That
Hazards are listed in the table below:
Hazard/Threat Causes Consequence Possible
Safeguards
Exposure of
glycerol
Possible leak in
glycerol storage
May cause eye
irritation. May
Flush eyes with
plenty of water for 119
tank or line. cause skin irritation.
Can cause
gastrointestinal
irritation.
at least 15 minutes.
Flush skin with
plenty of water for
at least 15 minutes
while removing
contaminated
clothing and shoes.
Never give
anything by mouth
to an unconscious
person. Do NOT
induce vomiting
Exposure of FAME Possible leak in
biodiesel storage
tank or line.
Severely irritation
to skin and eyes,
Inhalation cause
irritation of
respiratory tract.
May cause central
nervous system
depression with
symptoms of
dizziness, headache,
nausea, vomiting,
and drowsiness.
Irrigate eyes with a
heavy stream of
water for at least 15
to 20 minutes.
Wash exposed
areas of the body
with soap and
water. Remove
from area of
exposure; seek
medical attention if
symptoms persist.
Give one or two
glasses of water to
drink. If gastro-
intestinal symptoms
develop, consult
medical personnel.
120
(Never give
anything by mouth
to an unconscious
person.)
Fire/Explosion due
to biodiesel
Heating or any
ignition source in
storage or auto
ignition due to
high temperature
Flash Point
(Method Used):
130.0 C or 266.0
F min (ASTM 93)
May result in loss of
human lives and
material and
equipment loss
Storage should be
designed according
to internationally
recognized
guidance and
requirements. Use
water spray to cool
drums exposed to
fire. Dry chemical,
foam, halon (may
not be permissible
in some countries),
CO2, water spray
(fog). Water stream
may splash the
burning liquid and
spread fire.
Exposure of
biodiesel
Possible leak in
biodiesel tank
High concentrations
in air causes frost
burns to eyes
irritating, to
respiratory system.
Causes burns. May
cause cancer.
Harmful to aquatic
If vapours or mists
are generated, wear
a NIOSH approved
organic vapor/mist
respirator. Safety
glasses, goggles, or
face shield
recommended to
121
organisms. protect eyes from
mists or splashing.
PVC coated gloves
recommended to
prevent skin
contact. Employees
must practice good
personal hygiene,
washing exposed
areas of skin
several times daily
and laundering
contaminated
clothing before re-
use
Exposure of
methanol
Possible leak of
methanol from
cylinders or pipe
lines
Hazardous in case
of skin contact
(irritant), of eye
contact (irritant), of
ingestion, of
inhalation. Slightly
hazardous in case of
skin contact
(permeator). Severe
over-exposure can
result in death.
Check for and
remove any contact
lenses. Immediately
flush eyes with
running water for at
least 15 minutes,
keeping eyelids
open. Cold water
may be used. Get
medical attention,
Cold water may be
used. Get medical
attention if inhaled,
remove to fresh air.
If not breathing,
122
give artificial
respiration. If
breathing is
difficult, give
oxygen. Get
medical attention
immediately
123
124
Appendix A Matlab Program
125
126
127
128
Appendix B Flash Tank Data
129
130
Appendix C D-1 Data
131
132
133
134
135
136
Appendix D D-2 Data
137
138
139
140
Appendix E Heat Exchanger Charts & Graphs
141
142
143
Appendix F Costing Indices
144
145
146
References
[1] M. A. H. b. Fangrui Ma, “Biodiesel production: a review,” Nebraska, 1999.
[2] L. W. JR., Orgainc Chemistry, Pearson.
[3] G. Knothe, Dependence of biodiesel fuel properties on the structure of fatty acid alkyl esters, 2005.
[4] M. S. C. HUNG, “PROSPECT OF BIODIESEL PRODUCTION FROM WASTE OIL AND FAT IN MALAYSIA,” 2010.
[5] C. M. T. S. M. L. L. &. S. Garcia, Transesterfication of soybean oil catalyzed by sulfated zirconia, 2008.
[6] W. Y. &. B. Zhou, “Phase behavior of the base-catalyzed transesterification of soybean oil,” Journal of the American Oil Chemists Society, 2006.
[7] Moser, “Biodiesel production, properties, and feedstocks,” In Vitro Cellular & Developmental Biology-Plant, 2009.
[8] Y. Zhang, “Biodiesel production from waste cooking oil: 1. Process design and technological assessment,” Elsevier, 2002.
[9] M. J. V. G. H. M. W. G. Canakci, “Used and Waste Oil and Grease for Biodiesel,” 16 December 2015. [Online]. Available: http://articles.extension.org/pages/28000/used-and-waste-oil-and-grease-for-biodiesel. [Accessed 22 February 2016].
[10] D. Z. H.Noureddini, “Kinteic of Transesterification of Soyabean Oil,” Nebraska, 1997.
[11] R. K. Sinnot, Chemical Engineering Design, Coulson & Richardson’s Volume 6, 2005.
[12] S. M. Walas, Chemical Process Equipment (Selection & Design).
[13] J. H. Marco Aurélio, BIOFUEL PRODUCTION RECENT DEVELOPMENTS AND PROSPECTS, Petra Zobic, 2011.
[14] D. Kern, Process Heat Transfer, McGraw Hill, 1950.
147