Transesterification of Soybean Oil
Malcolm Hegeman
Varun Mangla
Sheng Zheng
Brown Industries, INC.
October 1, 2012
Transesterification of Soybean Oil:
Investigation on the operating limits and
reproducibility of transesterification reaction
Malcolm Hegeman, Team Leader
Varun Mangla, Process Engineer
Sheng Zheng, Process Engineer
Brown Industries, INC.
Test Laboratory
Final Report
Monday Section
October 1, 2012
We have neither given nor received
unauthorized help on this report, nor have
we concealed a violation to the honor
code.
________ ________ ________
Malcolm Hegeman Varun Mangla Sheng Zheng
ABSTRACT ..................................................................................................................................... 4
1. OVERVIEW ................................................................................................................................ 5
1.1 Objectives ........................................................................................................................... 5
1.2 Summary of key results ....................................................................................................... 5
2. BACKGROUND ......................................................................................................................... 7
2.1 Industrial Background ......................................................................................................... 7
2.2 Theoretical Background ...................................................................................................... 7
3. MATERIAL AND METHODS ................................................................................................ 10
3.1 Equipment ......................................................................................................................... 10
3.2 Materials ........................................................................................................................... 11
3.3 Experimental Procedure .................................................................................................... 11
4. RESULTS AND ANALYSIS ..................................................................................................... 13
4.1 Operating limits of the transesterification apparatus ......................................................... 13
4.2 Calculation of mass fraction of species in the reactor from GC analysis .......................... 18
4.3 Composition profiles ......................................................................................................... 20
4.4 Reproducibility of the FAMEs conversion profile ............................................................ 21
4.5 Preliminary study on the effect of catalyst on conversion profile ..................................... 24
3. DISCUSSION ............................................................................................................................ 25
3.1 Uncertainties analysis for the mass fraction calculation ................................................... 25
3.2 Experimental techniques ................................................................................................... 27
4. CONCLUSION AND RECOMMENDATION ....................................................................... 28
5. REFERENCE ............................................................................................................................ 30
6. LIST OF APPENDICES ........................................................................................................... 32
4
ABSTRACT
Brown Industries testing team conducted the tranesterification of soybean oil to
produce biodiesel (mainly consists of FAMEs) using the experimental apparatus at the
testing facility. We established the operating limits of the our experimental
apparatus in the following four aspects
∙ Reactor temperature
∙ Catalyst concentration
∙ Agitation speed
∙ Molar ratio of soybean oil to methanol
The operating limits were established based on both experimental and literature
studies.
We defined a set of reference run conditions under which 4 sets of reproducible data
in terms of the conversion rate were obtained. The conversion rate obtained in our
experiments is consistent with the reported conversion rate in literature under
identical operating conditions.
Additionally, we also performed a preliminary study on the effect of catalyst
concentration on the conversion rate. We observed that higher catalyst concentration
results in higher conversion rate.
5
1. OVERVIEW
The board of directors of G.G. Brown Industries has recently decided to extend the
focus of the company to incorporate biodiesel production. The use of biodiesel has the
potential to benefit the economy and environment, both on local and global scales. A
new plant with an annual output of 10 million gallons of first generation biodiesel has
been proposed to be built in Milan, Michigan. G.G. Brown also intends to eventually
branch out to the production of third generation biodiesel, using the microalgae strain
of Chlorella vulgaris as the feedstock. However, prior to the implementation of any
new facilities, we must assess the feasibility of unit operations essential to the process
at the pilot scale.
1.1 Objectives
On September 6, 2012, our team received a memo instructing us to execute a
feasibility study of the transesterification reaction to yield biodiesel using purified
soybean oil and methanol with sodium methoxide as the catalyst. The purpose of our
assessment is to provide information for the next rotation teams to obtain reproducible
data in Design of Experiments (DoE). Our assessment focuses on accomplishing the
following 3 objectives:
∙ Establish the operating limits of the experimental apparatus
∙ Generate reproducible data in terms of the conversion rate under a defined set
of reference run conditions.
∙ If time permits, conduct preliminary study on the effect of operating conditions
on the conversion rate
The purpose of this report is to present the results that our team produced to meet all
of the above objectives.
1.2 Summary of key results
We established the operating limits of our experimental apparatus based on both
experimentation and literature research. We defined a set reference run conditions
which allowed us to generate four sets of reproducible data in terms of the mass
fraction of FAMEs in the reactor as a function of time. We also conducted a
preliminary study on the effect of catalyst concentration on the conversion rate.
6
1.2.1 The operating limits
We propose that the reactor to be operated at a temperature within the range of 30oC ~
60 oC based on the temperature limits on the heating and cooling stream supplies. We
propose the agitation speed to vary within the range of 300 ~ 1000 rpm to achieve
proper turbulent mixing of the reactants without the occurrence of extensive
mechanical vibration and vortex formation. The operating limits on the molar ratio
(soybean oil:methanol) as well as the catalyst concentration are not fixed. However,
based on a screen of the conditions reported in literature, we proposed to operate the
reaction at a molar ratio between 3:1 and 20:1 and at a catalyst concentration between
0.1wt% and 2 wt%.
1.2.2 Reference run conditions and reproducibility of the conversion rate
We conducted four reference runs under the following conditions
Chemicals Amount Mole (mol) Notes
Soybean Oil 266 grams 0.288 Molar ratio 6:1
Methanol 54.4grams 1.734
Sodium Methoxide 0.532 grams 9.86×10-3
0.2wt% based on
the weight of
soybean oil
Operating Conditions Values
Temperature (oC) 50
Agitation Speed (rpm) 600
For each run, we obtained the conversion profile in the reactor as a function of time.
The conversion profiles we obtained are statistically equivalent. In addition, the
conversion profiles we obtained are consistent with the conversion profile reported in
the literature under similar operating conditions.
7
1.2.3 Preliminary investigation on the effect of catalyst concentration on the conversion
rate
We conducted one additional run to investigate the effect of catalyst concentration on
the conversion rate. We discovered that initial conversion rate increases for
approximately 20% when the catalyst concentration is increased from 0.1 wt% to 0.2
wt%. In addition, the conversion achieved after 30 minutes with 0.2 wt% catalyst
concentration is approximated 1.5 times the conversion rate achieved with 0.1 wt%
after the same amount of time.
2. BACKGROUND
We examined both industrial background and theoretical background of our process to
better understand the context of our experiment.
2.1 Industrial Background
In order to develop alternatives to fossil based fuels and establish national energy
independence, renewable fuels have increasingly been receiving attention, specifically
oil producing material such as soybean. The oil derived from these crops can be
converted to a biodiesel product by means of transesterification. Biodiesel is
advantageous over other renewable energy sources, such as wind or solar, because of
its ability to be utilized as a ‘drop in’ fuel, which can be used in internal combustion
diesel engines, but without compromising performance. While biodiesel derived from
terrestrial crops is an attractive solution for producing renewable fuel, there are many
negative externalities that must also be taken into consideration, such as direct and
indirect land use, irrigation water requirements, and using a crop for fuel versus food.
[1]
2.2 Theoretical Background
The overall reaction under consideration is sodium methoxide base-catalyzed
tranesterification of triglyceride (purified soybean oil) with methanol to produce
triglycerol and fatty acid methyl esters (FAMEs). Prior research of this reaction shows
intermediates of diglyceride and monoglyceride, with each reaction being reversible.
The figured displayed below outlines the separate reactions that take place.
8
1
3
6
5
2
42
3 1 3
3 3
3 33
k
k
k
k
k
k
TG CH COOCH
DG CH COOCH
MG CH COOC
OH DG R
OH MG R
OH G HL R
Yielding an overall reaction of:
7
83 33 3
k
kTG CH COOCO HH GL R
Due to the fact that each intermediate reaction and the overall reaction are reversible,
it is important to investigate the effect of operating conditions on the chemical
equilibrium as well as the reaction rates. Reaction under favorable operating
conditions should be able to achieve a maximum extent of reaction at the chemical
equilibrium. In addition, reaction under favorable operating conditions is expected to
occur at a relatively high reaction rate, which allows a higher conversion to be
achieved within limited amount of time.
Critical parameters that affect both the chemical equilibrium and the rate of reaction
include the reaction temperature and the molar ratio of soybean oil to methanol. It is
reported that the transesterification between methanol and triglyceride (the relevant
reactant in soybean oil) is endothermic. [2] Therefore the chemical equilibrium
towards product formation is favored at high temperature. In addition, it is also
reported that the reaction rate constant for transesterification can be described
according to Equation (1) [3]
/n E RTk AT e (1)
According to Equation (1), higher reaction rate constant and consequently higher
reaction rate is achieved at higher temperature. Based on the two reasonings
presented above, it is desired to conduct the tranesterification reaction at a relatively
high temperature.
It is expected that a large molar ratio of methanol to soybean oil drives the reaction
toward product formation. However, a large amount of methanol in the reaction
mixture would also significantly dilute the soybean oil and result in a decrease in the
reaction rate. Therefore, an optimal molar ratio should be determined to achieve
high conversion within relatively short period of time.
9
In contrary to the reactor temperature and the molar ratio, operating conditions
including the catalyst concentration and agitation speed only affect the reaction rate
without shifting the chemical equilibrium.
Due to the fact the tranesterification reaction occurs heterogeneously at the interface
between the two reactive phases, it is expected that high agitation speed will facilitate
the mixing of the two reactive phases and accelerates the reaction.
A high catalyst concentration commonly leads to higher reaction rate. However, in
the case of transesterification catalyzed by sodium methoxide, excess amount of
catatlyst allows the soap forming side reactions. [4] Side reaction will decrease the
purity of the biodiesel product and also cast further challenge in post-processing after
reaction. Therefore, an optimal amount of catalyst also needs to be determined.
10
3. MATERIAL AND METHODS
The following equipment, materials, and experimental procedures were used to
conduct our experiment.
3.1 Equipment
Figure 1 shows a layout of the experimental apparatus [5] for transesterification
reaction and the detailed description of each critical element of the apparatus are
summarized in Table 1.
Figure 1: Layout of the experimental apparatus
Table 1: Description of critial elements in the apparatus
Element Description
(a) A cylindrical jacketed Pyrex glass tank – Chemglass brank model
CG-1931-2 with inside dimensions approximately 97 mm diameter by
320 mm high
(b) A top-entry variable-speed agitator
(c) Thermal couple to measure the jacket temperature
(d) Thermal couple to measure the reactor temperature
(e) Two feed pumps to charge the reactor with methanol and soybean oil
(f),(g) Drain/sampling port to drain the reactor or withdraw sample from the
reactor
(a)
(b)
(f)
(g)
(e)
(d)
11
It should be noted that there is also a manual feed port on the top of the reactor (not
marked in Figure 1) which allows manual injection of catalyst solution into the
reactor.
In addition to the main experimental apparatus, the following equipment is required to
conduct the experimentation with the transerterification apparatus
∙ A rpm gun to measure the agitation speed
∙ Shimadzu GC-2010 Gas chromatography for the analysis of product
composition and monitor the extent of reaction
∙ LabView data acquisition software for reaction temperature monitoring
3.2 Materials
The following materials are required to conduct the experiments.
∙ Soybean oil (Reactant 1), Methanol (Reactant 2)
∙ 5.4 M Sodium methoxide (Catalyst)
∙ Vials and syringes with proper sizes (GC Analysis)
∙ Cooling water supply
∙ Steam supply
3.3 Experimental Procedure
We first performed the start-up procedures according to the SOP for
transesterification reactor [5] in order to provide cooling water and steam supply to
the apparatus.
Before we started to conduct the transesterification reaction, we first washed the
reactor according to the SOP for reactor washing [5] in order to eliminate the potential
remaining catalyst from the previous lab session. This was done by loading 200 mL of
isopropyl alcohol into the reactor, stirring for 30 seconds, and draining. The process
was repeated twice more.
After the reactor was washed, we first charged the reactor with 55.4 grams (mole) of
methanol and 266 grams (mole) of soybean. The molar ratio between the reactants is
methanol: soybean oil = 6:1. After the reactor was charged, we tuned the knob on
the stirred to achieve an agitation rate of 600 rpm. We then set the reactor
12
temperature to 50 oC through the LabView control panel. After the reactor
temperature reached 50 oC and remained at that level, we added 1.9 mL of the 5.4 M
sodium methoxide – methanol mixture (the amount of sodium methoxide in this
solution is equivalent to 0.2 wt% of the amount of soybean oil) to the reaction in order
to start the reaction. We sampled the reaction mixture after 0 minute, 1minute, 2
minutes, 4 minutes, 7 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and
30 minutes for composition analysis by GC. The GC samples were prepared from
the reaction mixture samples according to the SOP for GC analysis. [6] The
composition analysis of the reaction mixture at different times provided us with data
to investigate the rate of the transesterification reaction and consequently generate a
conversion profile with respect to time. Table 2 summarizes the feed and operating
conditions we tested.
Table 2: Proposed operating conditions for the reference run
Chemicals Amount Mole (mol) Notes
Soybean Oil 266 grams 0.288 Molar ratio 6:1
Methanol 54.4grams 1.734
Sodium Methoxide 0.532 grams 9.86×10-3
0.2wt% based on
the weight of
soybean oil
Operating Conditions Values
Temperature (oC) 50
Agitation Speed (rpm) 600
The conditions summarized in Table 2 are defined as the reference run conditions.
We repeated the experiments with the reference run conditions three more times.
In addition to the previous set of conditions as summarized in Table 2, we also
performed one experiment with 0.1 wt% of catalyst based on the weight of soybean
oil while keeping other conditions unchanged in order to qualitatively study the effect
of catalyst amount on the conversion profile. The second set of operating conditions
that we tested is summarized in Table 3.
13
Table 3: Operating conditoins to study the effect of catalyst concentration on the reaction
Chemicals Amount Mole (mol) Notes
Soybean Oil 266 grams 0.288 Molar ratio 6:1
Methanol 54.4grams 1.734
Sodium Methoxide 0.266 grams 4.93×10-3
0.1wt% based on
the weight of
soybean oil
Operating Conditions Values
Temperature (oC) 50
Agitation Speed (rpm) 600
4. RESULTS AND ANALYSIS
In this section, we will first present the analysis on operating limits based on both
experimentation and literature studies.
The critical indicator of the reaction rate is the mass fraction of FAMEs in the
reaction mixture at different times. In this section, we will present a comprehensive
data analysis procedure to obtain the mass fraction of FAMEs in the reaction mixture
from GC analysis. Secondly, we will analyze the reproducibility of the conversion
profile. Additionally, we will also present a preliminary study on the effect of
catalyst amount on the conversion profile.
4.1 Operating limits of the transesterification apparatus
According to the SOP for transesterification reaction [5], the reactor temperature
could not exceed 60oC. Therefore, 60
oC is defined as the upper operating limit for
temperature. In addition, the lowest temperature that the reactor can achieve is
governed by the temperature of the cooling water (~30 oC). Consequently, the
reactor temperature could be varied from 30 oC to 60
oC in the DoE studies. In
addition, as is stated in Section 2.2 that transesterification reaction is a reversible
endothermic reaction, therefore, high reaction temperature favors the chemical
equilibrium towards and product formation as well as a high reaction rate.
Since transesterification reaction occurs at the interface between the methanol phase
and the soybean oil phase, intensive mixing by the impeller is critical to facilitate the
reaction. The extent of turbulent mixing by the impeller can be characterized by the
Reynolds number as defined in Equation (2).
14
Re
nDaN
(2)
is the Reynolds number
is the rotation speed of the impeller
is the diame
is the density of the fluid
is
ter o
the viscosity of the
f the impel
flui
ler
d
ReN
n
Da
Assuming mass-averaged density and mass-averaged viscosity calculated from the
density and viscosity of methanol and soybean oil, we calculated the Re number for
the fluid mixing at different agitation speed. Table 4 shows Re for agitation speed
varying from 150 to 1200.
Table 4: Calculated mixing intensity, NRe for different agitation speed
The calculated Re for our system is comparable to the Re calculated and reported by
Noureddini and Zhu. [3] The Re number in Noureddini and Zhu’s study is
NRe(150 rpm) = 3100
NRe(300 rpm) = 6200
NRe(600 rpm) = 12400
Figure 2 shows the effect of mixing on the conversion of FAMEs according to
Noureddini and Zhu’s study.
n (/s) Da (m) ρ AV (kg/m3) μ AV(Pa s) N Re
300 0.05 892.79 0.07 5105.85
600 0.05 892.79 0.07 10211.71
900 0.05 892.79 0.07 15317.56
1200 0.05 892.79 0.07 20423.41
15
Figure 2: The effect of mixing on the conversion rate, reproduced from [3]
It is seen from Figure 2 that the conversion rate at NRe (150 rpm) = 3100 is
significantly lower than the conversion rate at NRe (300 rpm) = 6200 and NRe (600
rpm) =12400, indicating inadequate mixing at NRe = 3100. Consequently we
recommend operating the reactor at an agitation rate of at least 300 rpm.
The mechanic stirrer can provide a maximum agitation speed exceeding 1000 rpm.
However, the transesterification apparatus vibrates intensively at agitation speed
higher than 1000 rpm. The mechanical vibration might leads to uncontrollable
uncertainties in the experiments. Therefore, we don’t recommend operating the
reaction at agitation speed higher than 1000 rpm.
The experimental apparatus does not cast any operating limits upon the molar ratio
and catalyst concentration. Reaction with different molar ratios can be achieved by
charging the reactor with different amount of soybean oil and methanol. It is
expected that a high molar ratio of methanol to soybean oil would favor the chemical
equilibrium towards product formation. We conducted the following analysis to
quantitatively investigate the effect of molar ratio on the chemical equilibrium. In
order to quantitatively characterize the position of the chemical equilibrium, we
choose the conversion of the reactive species in soybean oil, namely the conversion of
triglyceride (XTG) as an indicator of the position of the chemical equilibrium. A
desired chemical equilibrium features a XTG value close to 1, indicating approximately
complete conversion of triglyceride to FAMEs. For a reaction with a molar ratio of x
moles of methanol to 1 mole of triglyceride, the following stoichiometric table can be
constructed.
NRe=3100NRe=6200
NRe=12400
16
Table 5: Stoichiometric table for the reaction with various molar ratio
According to Table 5, the equilibrium constant of the reaction can be expressed as
Equation (3).
33
3 3
[ ] [ ]
[ ] [ ] (1 )(
(3 )
3 )
TG TG
TG TG
XFAMEs GLK
MeOH TG X x
X
X (3)
It is reported that at 60oC, the equilibrium constant K = 0.220. [2] Therefore, for the
reaction with different molar ratios at 60oC, XTG can be expressed as a function of x
by plugging K = 0.220. Figure 1 shows XTG as a function of x
Figure 3: Effect of molar ratio on the conversion rate
It is seen that the conversion of triglyceride increases with increasing molar ratio.
The effect of molar ratio on the conversion is most significant in the region of 3<x<10.
The effect of molar ratio on the conversion is relatively minimal when the molar ratio
is above 15:1. In the meanwhile, excessive amount of methanol significantly dilutes
the triglyceride and thus reduces the reaction rate. Consequently we recommend
operating the reaction at the molar ratio between 3:1 and 15:1.
In order to obtain reproducible data, the impeller, the temperature sensor and also the
sampling tube should be completely submerged in the reaction mixture. Figure 4
shows two scenario with adequate and inadequate amount of reaction mixture.
33T FAG M ME GLeOH s
Start 1 x 0 0
Converted -X TG -3X TG 3X TG X TG
Final 1-X TG -3X TG 3X TG X TG
33T FAG M ME GLeOH s
0.2
0.4
0.6
0.8
1
0 5 10 15 20 25
Co
nve
rsio
n o
f s
oyb
ea
n o
il
Molar ratio of methanol to soybean oil
17
Figure 4: (a) adequate amount of reaction mixture (b) inadequate amount of reaction mixture
because the thermal couple is not submerged in the reaction liquid
Therefore, in addition to the molar ratio, we recommend operating the reaction with a
reaction mixture with total volume greater than 360 mL.
The catalyst concentration can adjusted by changing the volume of the sodium
methoxide solution that is used. It is expected that a higher catalyst concentration
results in a higher reaction rate. However, in the case of transesterification, excess
amount of catalyst allows soap forming side reactions. [4] The side reaction is
undesired because it reduces the purity of the biodiesel and cast further challenge in
separation and purification after reaction. In most previous researches, the catalyst
concentration was varied from 0.1 wt% to 2.0 wt%. Therefore, we recommend
operating the reaction catalyst concentration from 0.1 wt% to 2.0 wt% in the DoE
studies. The proposed range for operating conditions is summarized in Table 6.
Table 6: Proposed operating limits based on experimentation and literature studies
(a) (b)
molar ratio (MeOH:soybean oil) 3:1~15:1
agitation speed (rpm) 300~1000
reaction temperature (oC) 30~60
catalyst concentration (wt%) 0.1~2.0
18
4.2 Calculation of mass fraction of species in the reactor from GC analysis
It should be clarified that GC analysis provides the weight percentage of relevant
chemical species including FAMEs, mono-, di-, tri-glyceride, and glycerol in the GC
sample. However, the weight percentage of FAMEs in the GC sample does not
equal the weight percentage of FAMEs in the reaction mixture because reaction
mixture is diluted by pyridine, MSTFA and heptanes during the GC sample
preparation. The procedures for GC sample preparation together with important
mass measurements are shown in Figure 5.
Figure 5: The procedure for GC sample preparation with key measurements
It should be noted that only a portion of the reaction mixture – pyridine solution was
transferred into the MSTFA solution for further sample preparation. Therefore, the
mass of the GC sample accounts for the mass of MSTFA in the GC vial and a portion
of the mass of the reaction mixture – pyridine solution, namely p(mr+mp), where p is a
portion factor between 0 and 1.
For a particular species i in the reaction mixture with mass fraction xi, the mass of
species i in the reaction mixture and also in the reaction mixture-pyridine solution is
mrxi. Consequently, the mass of species i that is transported into the GC vial equals
pmrxi. Therefore, the mass fraction of species i in the GC sample, namely x’i can be
expressed according to Equation (4)
Reaction mixture,
xFAMEs, mr
Reaction mixture in
pyridine, mr+mp
Pyridine, mp
MSTFA, mm
A portion of Reaction mixture in pyridine
mixed with MSTFA, p(mr+mp)+mm
measured
Composition Analysis by GC, x’FAMEs
GC sample, p(mr+mp)+mm+mh
heptane, mh
19
'( )
r ii
r p m h
xp m m
pm x
m m
(4)
is the mass of reaction mixture withdrawn from the reactor
is the mass of the pyridine solution
is the mass of MSTFA
is the mass of heptane
is the mass fraction of species i in the reactor
r
p
m
h
i
m
m
m
m
x
' is the mass fracton of species i in the GC sample
is the portion factor that accounts for the partial transfer
ix
p
It should be noted that x’i is directly measured by GC analysis.
If we define
1
2
3
4
5
The 1st mass measurement
The 2nd mass measurement
The 3rd mass measurement
( ) The 4th mass measurement
( ) The 5th mass measurement
p
p r
m
p r m
p r m h
m m
m
m m
m p m m m
m p m m m m
m m
The mass fraction of species i in the reaction mixture, xi can be expressed as shown in
Equation (5)
5
2 1
'[ ( ) ] '/ ( )
( )
ii r p m h i r
m xp m m m m x pm
mx
p m
(5)
Furthermore, the portion factor p can be expressed as
4 3
2
m
mp
m (6)
Plugging Equation (6) into Equation (7) gives
2 5
4 3 2 1
'
( )( )
iix
m
m m x
m m m
(7)
20
Equation (7) allows us to calculate the mass fraction of species i in the reaction
mixture from directly measured mass (m1~4) or mass fraction (x’i). Table 7 shows a
sample data set of mass/mass fraction measurements with respect to FAMEs.
Table 7: A representative set of collected data for the calculation of mass fraction of FAMEs in
the reactor
Equation (8) shows a sample calculation for the mass fraction of FAMEs in the
reaction mixture
6100.105
0.256 0.165
3.135 1.061 549.57
( )(3.135 2.945)ix
(8)
We applied this approach to calculate the mass fraction of each species in the reaction
mixture based on the composition of species in the GC samples. The resulting data
of all 4 runs are attached in Appendix A.
4.3 Composition profiles
We plotted the mass fraction of all relevant chemical species as a function of time to
generate the composition profile within the reactor as a function of time. Figure 6
shows a representative composition profile we obtained from the reference run
conditions.
Definition Value
m 1(g) mass of pyridine 2.945
m 2(g) mass of the reaction mixture - pyridine solution 3.135
m 3(g) mass of MSTFA 0.165
m 4(g) mass of the reaction mixture - pyridine - MSTFA solution 0.256
m 5(g) mass of the GC sample 1.061
x 'FAMEs(ppm) mass fraction of FAMEs in the GC sample 549.57
21
Figure 6: Mass fraction profiles for relevant reacting species in the reactor
The composition profiles for other 3 runs are attached in Appendix B.
It is seen from Figure 6 that the mass fraction of FAMEs and glycerol constantly
increase over time, indicating the formation of the product. In the meanwhile, the
mass fraction of Mono-, Di-, and Tri-glyceride first increase and then decrease,
because these three species are the intermediate products which are first formed and
then consumed.
4.4 Reproducibility of the FAMEs conversion profile
A critical parameter that quantifies the extent of reaction is the conversion of the
reaction. One critical task that was assigned to our team is to generate the
conversion as a function time for the reaction under a defined reference condition.
However, the conversion of the reaction is not directly measured. Instead, the mass
fraction of FAMEs in the reactor is measured by GC and the conversion could be
calculated according to the mass fraction of FAMEs in the reactor. In order to
calculate the conversion from the measured mass fraction, we performed the
following analysis.
According to the reaction equation
33 3OH FAMEs GlycerolTriGlyceride CH
We choose 1 mole of Tri-glyceride as a basis. Under this basis, the number of moles
for methanol is 6 moles because the molar ratio of methanol to soybean oil is 6:1.
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 500 1000 1500 2000
Ma
ss F
ractio
n
Time (s)
MonoGlyceride
DiGlyceride
TriGlyceride
Glycerol
FAMEs
22
Suppose the conversion is X, the number of moles of each species can be calculated
according to Equation (9) to Equation (10).
1Triglyceride Xn (9)
6 3MeOHn X (10)
3FAMEs Xn (11)
Glyceroln X (12)
Consequently, the mass fraction of FAMEs in the reaction mixture can be expressed
as shown in Equation (11).
3093
3 309 924(1 ) 32(6 3 ) 92.1
FAMEsFAMEs
Total
m Xx
m X X X X
(11)
Therefore, the conversion X, can be expressed in terms of the mass fraction of FAMEs,
xFAMEs, according to Equation (12).
92
1116
0.97
FAMEs
FAMEs
Xx
x
(12)
Table 8 shows the calculated conversion at different times according to the measured
mass fraction of FAMEs in reactor.
Table 8: Calculation of conversion from the mass fraction of FAMEs
Time(s) x FAMEs X
52 0.10573 0.12727
118 0.18704 0.22514
173 0.28311 0.34074
250 0.35654 0.42908
461 0.45802 0.55115
635 0.49783 0.59904
900 0.56388 0.67848
1184 0.61807 0.74364
1522 0.59593 0.71702
23
The same calculation of conversion from measured mass fraction was also performed
for the other 3 runs under the reference condition. The resulting data is attached in
Appendix C.
Figure 7 shows the conversion profile of FAMEs obtained from four trials under the
reference conditions.
Figure 7: Conversion profile obtained from 4 trials under reference run conditions
It is seen that the conversion profiles obtained from the three trials are statistically
equivalent. Therefore, it is verified that the conversion profile for FAMEs can be
reproduced under the reference conditions.
We also compared the measured conversion profile of FAMEs with the conversion
profile obtained by Noureddini and Zhu[3] under identical operating conditions.
Figure 8 shows the comparison between the conversion profiles we obtained with the
published conversion profile.
-0.4
-0.1
0.2
0.5
0.8
1.1
1.4
0 500 1000 1500 2000
Co
nve
rsio
n
Time (s)
Trial 1
Trial 2
Trial 3
Trial 4
24
Figure 8: Comparison between the measured conversion profile with the reported conversion
profile
It is seen from Figure 8 that the conversion profile we obtained is consistent with the
conversion profile of the first 30 minutes obtained in the literature, which further
verifies the reproducibility of FAMEs conversion profile under the reference
conditions.
4.5 Preliminary study on the effect of catalyst on conversion profile
In order to provide insight for the effect of catalyst concentration on the conversion
profile, we conducted one experiment with half of the catalyst concentration, namely
0.1 wt%, as we used for the reference runs. We repeated the analysis to obtain the
mass fraction of each species as a function of time and also the conversion profile.
The relevant data is attached in Appendix D. Figure 9 shows the comparison of the
conversion profile of FAMEs between this run with 0.1wt% catalyst and the reference
run with 0.2 wt% catalyst.
LiteratureThis work
25
Figure 9: The effect of catalyst concentration on the conversion
It is seen that the initial conversion rate is higher for the run with 0.2 wt% catalyst,
which is consistent with the expectation that higher catalyst concentration increases
the reaction rate more significantly than lower catalyst concentration. In addition,
the final conversion achieved with 0.2 wt% catalyst concentration after 30 minutes is
approximately 1.5 times higher than the conversion achieved with 0.1 wt% catalyst
after the same amount of time.
3. DISCUSSION
3.1 Uncertainties analysis for the mass fraction calculation
According to Equation (7), the mass fraction of each chemical species is calculated
based on 5 weight measurements and the GC measurements. Therefore, the
uncertainties in the 6 measured variables will propagate into the uncertainty in the
calculated mass fraction. The uncertainty in the calculated mass fraction can be
calculated according to Equation (13).
2 2 2
~ '
2
1 5 ( ) ( )'i j i
i ix j m x
j i
x x
m x
(13)
By plugging in the expression for xi, we obtained the following equations
2 22 5
4 3 2
2
1 1
[ ]( )( )
( )i m
m
x m
m m mm
(14)
-0.6
-0.3
0
0.3
0.6
0.9
1.2
1.5
0 500 1000 1500 2000
Co
nvers
ion
Time (s)
0.2 wt%
0.1 wt%
26
2 25 4 3 2 1 2 5 4 3
2 2
2 4 3 2 1
( )[
(]
( ) ( )
) ( )( )ix m m m m mm
m m
m m m
m m m
(15)
2 22 5
4 3 2 1
2
3
[ ]( ) ( )
( )i m
m
m
m mm
x
m
(16)
2 22 5
4 3 2 1
2
4
[ ]( ) ( )
( )i m
m
m
m mm
x
m
(17)
2 22
4 3 25 1
[ ]( )( )
( )i m
m
x
m m mm
(18)
2 22 5
4 3 2 1
2 '[ ]
' ( )()
)( i i
i
m m x
x m m
x
m m
(19)
The uncertainty in the weight measurements is governed by the accuracy of the scale,
which is 0.0001g ( ( 1~ 5) 0.001jx j ). The uncertainty of the GC analysis is
within 10 ppm. According to Equation (14) to (19) and the uncertainties in each
measured variable, we performed the uncertainty analysis to determine the propagated
uncertainty in xFAMEs. We present a sample uncertainty analysis for the data set shown
in Table 9.
Table 9: A representative data set used for uncertainty calculation
The calculated uncertainty contribution from each measurement together with the
total uncertainty in the mass fraction of FAMEs is shown in Table 10.
m 1(g) 2.945
m 2(g) 3.135
m 3(g) 0.165
m 4(g) 0.256
m 5(g) 1.061
x 'FAMEs(ppm) 152.970
27
Table 10: Distribution of uncertainty by error propagation analysis
It is seen from Table 10 that the uncertainty contributed by m3 and m4 measurements
account for 90% of the uncertainty in xFAMEs. m3 and m4 measurements introduce
significant uncertainties into xFAMEs because the quantity “m4-m3” is a small number in
the denominator in Equation (16) and (17). The quantity m4-m3 represents the mass
for reaction mixture – pyridine solution transferred into the MSTFA-containing vial.
Therefore, introduce a larger amount of reaction mixture-pyridine solution in the
MSTFA-containing vial will reduce the propagated uncertainty in xFAMEs.
3.2 Experimental techniques
We provide the following tips on experimental techniques in order to help the team
engineers to obtain reproducible data in the following DoE studies.
3.2.1 Timing the reaction
It should be noted that the transesterification reaction continues to occur in the
sampling syringe and also in the pyridine-containing vial after the sample is
withdrawn from the reactor. Therefore, it is incorrect to record the reaction time
immediately after sampling from the reactor. The reaction is stopped once the
sample is mixed with MSTFA because the active hydroxyl groups in the reacting
species are substituted with trimethylsilyl groups from MSTFA. Consequently, the
reaction time for each data point should be recorded immediately after the reaction
mixture sample is injected to MSTFA.
3.2.2 Rinsing the syringe for sampling
It is stated in the SOP that the sampling syringe should be rinsed by the reaction
mixture circulating in the sampling/draining loop before sampling. The purpose of
rinsing the syringe is to remove the remaining fluid in the syringe from the previous
sampling. Because each sampling requires withdrawing 0.2 mL of the reaction
Absolute Relative
m 1 contribution 3.35E-05 0.0%
m 2 contribution 0.01 9.2%
m 3 contribution 0.04 45.2%
m 4 contribution 0.04 45.2%
m 5 contribution 0.00 0.3%
x 'FAMEs contribution 3.46E-13 0.0%
σ x FAMEs2
0.10 100.0%
σ x FAMEs 0.31
28
mixture from the reactor, it is likely that trace amount of the previous sample adheres
to the inner wall of the sampling syringe from 0 mL to 0.2 mL. Consequently, we
recommend rinsing the syringe with at least 0.4 mL of the reaction mixture in the
sampling/draining loop before sampling to assure that the region contaminated with
the previous sample is sufficiently rinsed.
3.2.3 Rinsing the syringe for catalyst inject
We also recommend rinsing the syringe for catalyst injection with the provided 5.4 M
sodium methoxide – methanol solution 3 times before catalyst injection. It is likely
that a fluid film remains in the syringe and also the needle after each catalyst injection.
As methanol evaporates, the sodium methoxide dissolved in the fluid film will
precipitate and remain in the syringe and needle. The remaining sodium methoxide
solids will contaminate the fresh catalyst solution by changing the concentration of
the catalyst solution. Therefore we recommend rinsing the syringe and needle with
the sodium methoxide – methanol solution before each catalyst injection.
4. CONCLUSION AND RECOMMENDATION
During our rotation, we tested the transesterification apparatus with a defined
reference condition. Based on the measured mass fraction of FAMEs in the GC
sample, we calculated the mass fraction of FAMEs in the reactor and consequently the
conversion of the reaction at different times. We plotted the conversion of the
reaction as a function time and compared it with the predicted conversion profile by
previous research. The measured conversion profile is consistent with the predicted
profile. We also compared the conversion profile obtained from different trials with
identical operating conditions to investigate the reproducibility of the conversion
profile. It is found that the conversion profiles from different trials are statistically
equivalent, indicating satisfactory reproducibility. In addition, we carried out a
preliminary study on the effect of catalyst concentration on the conversion rate. It is
found that the conversion rate is higher for the trial run with higher catalyst
concentration.
We also provided several pieces of advice regarding the experimental techniques in
order to help the next team to achieve satisfactory reproducibility in experimentation.
In addition to the advices on experimental techniques, we further recommend to
include the following two trouble-shooting techniques in the SOP.
29
∙ The main gas flow valve is usually at “OPEN” position (in parallel with the
pipeline). If the main gas flow valve is at “CLOSED” position as indicated in
Figure 10, a low flow alarm will appear on the main control panel.
Figure 10: The status of the main gas flow valve
Therefore, we recommend checking the status of the main gas flow valve at the
beginning of each lab section.
∙ The cavities in the piping system might prevent the cooling water from flowing
through the reactor jacket. If no cooling water flows through the reactor jacket
even the cooling water control is set at “OPEN” position, cavities might exist in
the piping. The cavity can be eliminated by directing the cooling water
through the PFR reactor first. The cooling water can be re-directed back to the
STR reactor after the cavities are eliminate
30
5. REFERENCE
[1] Hass, M. J.; McAloon, A. J. l.; Yee, W. C.; Foglia, T. A. Bioresource Technology,
97(2006), 671-678
[2] Xiao, Y.; Gao, L.; Xiao, G.; Lv, J., Energy and Fuels, 2010, 24(11), 5829-5833
[3] Noureddini, H.; Zhu, D., Journal of the American Oil Chemists’ Society,
11(1997), 1457-1463
[4] Vicente, G.; Martinez, A. C.; Aracil, J.; Industrial Crops and Products, 8(1998),
29-35
[5] LaValle Pablo, Transesterification of Soybean Oil for Producing Biodiesel Fuels,
Laboratory Standard Operating Procedure, March 9, 2012, ChE 460 Course
Package
[6] LaValle Pablo, Transesterification Products Analysis Using the Shimadzu
GC-2010 Gas Chromatograph, , Laboratory Standard Operating Procedure,
March 9, 2012, ChE 460 Course Package
[7] The average molecular weight of the soybean oil is 920 g/mol, Patzek, T. W.; “A
First Law Thermodynamic Analysis of Biodiesel Production From Soybean”,
April 13, 2009
31
6. NOMENCLATURE TABLE
Term Definition Units
n Number of moles Mol
A Frequency factor L/(mol*s)
E Activation energy J/mol
R Gas constant J/(mol*K)
T Temperature °C
k Reaction rate constant
n Rotation speed of the impeller s-1
Da Diameter of the impeller M
ρ Density of the fluid kg/m3
µ Viscosity of the fluid Pa*s
NRe Reynolds numbers
K Equilibrium constant
XTG Conversion of triglyceride
mr Mass of reaction solution drawn from reactor g
mp Mass of pyridine g
mm Mass of MSTFA g
mh Mass of heptane g
m1 Mass of pyridine g
m2 Mass of the reaction mixture- pyridine solution g
m3 Mass of MSTFA g
m4 Mass of the reaction mixture- pyridine- MSTFA solution g
m5 Mass of the GC sample g
x'FAMEs Mass fraction of FAMEs in the GC sample ppm
32
7. LIST OF APPENDICES
Appendix A Calculation of Mass fraction of reacting species in the reactor
Appendix B Composition profiles for reacting species in reactor
Appendix C Conversion from xFAMEs to X
Appendix D Supplementary data for the run with 0.1wt% catalyst
concentration
A-1
APPENDIX A CALCULATION OF MASS FRACTION OF REACTING SPECIES IN THE REACTOR
Table A-11: Mass fraction calculation for the reaction species – reference run trial -1
Time to stop reaction (s) 52.00 118.00 173.00 250.00 461.00 635.00 900.00 1184.00 1522.00 1800.00
m 1(g) 2.95 2.94 2.95 2.95 2.94 2.94 2.94 2.95 2.94 2.94
m 2(g) 3.14 3.14 3.13 3.14 3.14 3.13 3.13 3.13 3.12 4.13
m 3(g) 0.17 0.17 0.17 0.17 0.17 0.16 0.17 0.17 0.17 0.22
m 4(g) 0.26 0.26 0.26 0.26 0.26 0.26 0.26 0.26 0.26 0.32
m 5(g) 1.06 1.00 1.02 1.02 1.00 1.03 1.06 1.04 1.05 1.04
x' MonoG(ppm) 152.97 229.69 249.56 273.21 293.35 241.48 207.23 198.61 157.48 149.56
x' DiG(ppm) 347.04 848.37 672.26 617.40 539.52 456.55 402.69 397.72 334.63 320.37
x' TriG(ppm) 335.23 1641.41 1233.39 1188.00 848.19 693.93 586.77 563.65 450.09 514.17
x' Glycerol(ppm) 15.29 39.84 80.89 122.23 194.06 209.26 217.01 240.37 226.83 231.34
x' FAMEs(ppm) 549.57 1061.10 1508.20 1983.66 2683.09 2711.28 2798.57 3116.32 2910.66 2951.60
x MonoG 0.03 0.04 0.05 0.05 0.05 0.04 0.04 0.04 0.03 0.01
x DiG 0.07 0.15 0.13 0.11 0.09 0.08 0.08 0.08 0.07 0.01
x TriG 0.06 0.29 0.23 0.21 0.14 0.13 0.12 0.11 0.09 0.02
x Glycerol 0.00 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.05 0.01
x FAMEs 0.11 0.19 0.28 0.36 0.46 0.50 0.56 0.62 0.60 0.11
A-2
Table 12: Mass fraction calculation for the reaction species – reference run trial -2
Time to stop reaction (s) 62.00 115.00 181.00 238.00 424.00 604.00 898.00 1211.00 1484.00 1790.00
m 1(g) 2.95 2.95 2.95 2.94 2.94 2.94 2.95 2.94 2.94 2.94
m 2(g) 3.13 3.12 3.13 3.13 3.12 3.12 3.12 3.13 3.13 3.12
m 3(g) 0.16 0.16 0.17 0.18 0.17 0.17 0.17 0.17 0.17 0.17
m 4(g) 0.25 0.25 0.26 0.27 0.26 0.26 0.26 0.26 0.26 0.26
m 5(g) 1.06 1.06 1.06 1.07 1.06 1.05 1.06 1.07 1.03 1.06
x' MonoG(ppm) 188.63 184.89 258.81 275.60 272.57 241.36 213.09 214.44 143.18 149.56
x' DiG(ppm) 810.65 634.84 595.40 564.90 496.65 438.70 406.36 395.08 322.07 320.37
x' TriG(ppm) 1741.45 1602.29 1174.91 1055.53 792.07 648.57 585.97 525.97 427.66 514.17
x' Glycerol(ppm) 15.78 47.45 92.05 134.55 182.13 212.43 233.95 266.48 264.68 231.34
x' FAMEs(ppm) 829.24 1061.84 1607.26 2011.69 2486.27 2598.65 2841.07 3055.36 2960.52 2951.60
x MonoG 0.03 0.04 0.05 0.05 0.05 0.04 0.04 0.04 0.03 0.01
x DiG 0.07 0.15 0.13 0.11 0.09 0.08 0.08 0.08 0.07 0.01
x TriG 0.06 0.29 0.23 0.21 0.14 0.13 0.12 0.11 0.09 0.02
x Glycerol 0.00 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.05 0.01
x FAMEs 0.11 0.19 0.28 0.36 0.46 0.50 0.56 0.62 0.60 0.11
A-3
Table 13: Mass fraction calculation for the reaction species – reference run trial -3
Time to stop reaction (s) 60.00 123.00 200.00 268.00 418.00 619.00 880.00 1185.00 1500.00 1758.00
m 1(g) 2.49 2.94 2.97 2.95 2.95 2.95 2.95 2.95 2.95 2.95
m 2(g) 2.66 3.13 3.13 3.13 3.12 3.12 3.13 3.14 3.13 3.13
m 3(g) 0.19 0.17 0.16 0.16 0.16 0.17 0.16 0.16 0.16 0.16
m 4(g) 0.28 0.26 0.25 0.26 0.26 0.26 0.26 0.26 0.26 0.26
m 5(g) 1.08 1.07 1.06 1.06 1.06 1.06 1.05 1.07 1.04 1.07
x' MonoG(ppm) 330.73 199.22 263.83 275.77 242.17 218.29 185.48 169.20 147.39 138.54
x' DiG(ppm) 1064.30 742.27 658.54 600.22 503.22 462.53 79.84 366.41 324.58 315.76
x' TriG(ppm) 1793.08 2116.30 1353.77 1067.20 837.70 760.91 630.23 587.69 503.00 484.33
x' Glycerol(ppm) 18.79 58.17 118.00 152.99 200.58 247.21 267.70 309.66 312.92 327.62
x' FAMEs(ppm) 1258.36 1268.25 1920.92 2252.87 2621.05 3012.74 3114.00 3461.00 3402.00 3558.00
x MonoG 0.03 0.04 0.05 0.05 0.05 0.04 0.04 0.04 0.03 0.01
x DiG 0.07 0.15 0.13 0.11 0.09 0.08 0.08 0.08 0.07 0.01
x TriG 0.06 0.29 0.23 0.21 0.14 0.13 0.12 0.11 0.09 0.02
x Glycerol 0.00 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.05 0.01
x FAMEs 0.11 0.19 0.28 0.36 0.46 0.50 0.56 0.62 0.60 0.11
A-4
Table 14: Mass fraction calculation for the reaction species – reference run trial -4
Time to stop reaction (s) 51.00 110.00 170.00 225.00 437.00 613.00 901.00 1200.00 1477.00 1784.00
m 1(g) 2.94 2.95 2.96 2.95 2.96 2.96 2.95 2.95 2.95 2.95
m 2(g) 3.12 3.13 3.14 3.13 3.14 3.13 3.13 3.14 3.13 3.13
m 3(g) 0.15 0.16 0.16 0.17 0.16 0.17 0.16 0.16 0.16 0.17
m 4(g) 0.25 0.26 0.26 0.27 0.27 0.27 0.26 0.26 0.28 0.27
m 5(g) 1.05 1.07 1.07 1.07 1.06 1.07 1.06 1.04 1.09 1.07
x' MonoG(ppm) 307.02 258.24 319.24 289.20 265.13 236.13 194.82 160.35 183.13 142.14
x' DiG(ppm) 933.49 872.25 858.48 745.06 571.98 504.74 416.51 377.53 447.25 352.22
x' TriG(ppm) 1447.47 1817.53 1656.12 1592.99 1059.74 882.52 752.03 690.98 821.25 618.52
x' Glycerol(ppm) 18.81 34.09 68.24 132.34 203.62 236.09 265.58 289.77 374.02 330.13
x' FAMEs(ppm) 1172.14 1164.05 1614.49 2123.68 2750.04 2942.86 3128.17 3275.35 4197.17 3614.22
x MonoG 0.03 0.04 0.05 0.05 0.05 0.04 0.04 0.04 0.03 0.01
x DiG 0.07 0.15 0.13 0.11 0.09 0.08 0.08 0.08 0.07 0.01
x TriG 0.06 0.29 0.23 0.21 0.14 0.13 0.12 0.11 0.09 0.02
x Glycerol 0.00 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.05 0.01
x FAMEs 0.11 0.19 0.28 0.36 0.46 0.50 0.56 0.62 0.60 0.11
B-1
APPENDIX B COMPOSITION PROFILES FOR REACTING SPECIES IN
REACTOR
Figure 11: Mass fraction profile of reacting species in the reactor – reference run trial 2
Figure 12: Mass fraction profile of reacting species in the reactor – reference run trial 2
-0.5
0
0.5
1
1.5
0 500 1000 1500 2000
Ma
ss F
ractio
n
Time (s)
MonoGlyceride
Di-Glyceride
Tri-Glyceride
Glycerol
FAMEs
-0.5
0
0.5
1
1.5
0 500 1000 1500 2000
Ma
ss F
ractio
n
Time (s)
Mono-Glyceride
Di-Glyceride
Tri-Glyceride
Glycerol
FAMEs
B-2
Figure 13: Mass fraction profile of reacting species in the reactor – reference run trial 2
-0.5
0
0.5
1
1.5
0 500 1000 1500 2000
Ma
ss F
ractio
n
Time (s)
Mono-Glyceride
Di-Glyceride
Tri-Glyceride
Glycerol
FAMEs
C-1
APPENDIX C CONVERSION FROM XFAMES TO X
Table 151: Conversion from xFAMEs to X – reference run trial 2
Table 16: Conversion from xFAMEs to X – reference run trial 3
Table 17: Conversion from xFAMEs to X – reference run trial 4
Time (s) x FAMEs X
62.00 0.04 0.20
115.00 0.04 0.28
181.00 0.06 0.42
238.00 0.06 0.50
424.00 0.06 0.62
604.00 0.05 0.66
898.00 0.04 0.71
1211.00 0.04 0.72
1484.00 0.03 0.68
1790.00 0.03 0.77
Time (s) x FAMEs X
60.00 0.24 0.29
123.00 0.24 0.29
200.00 0.43 0.52
268.00 0.46 0.55
418.00 0.51 0.62
619.00 0.57 0.69
880.00 0.58 0.70
1185.00 0.64 0.77
1500.00 0.65 0.78
1758.00 0.66 0.79
Time (s) x FAMEs X
51.00 0.23 0.28
110.00 0.23 0.27
170.00 0.30 0.36
225.00 0.38 0.46
437.00 0.47 0.57
613.00 0.55 0.66
901.00 0.57 0.68
1200.00 0.61 0.73
1477.00 0.68 0.82
1784.00 0.64 0.77
D-1
APPENDIX D SUPPLEMENTARY DATA FOR THE RUN WITH 0.1WT% CATALYST CONCENTRATION
Table 18: Mass fraction calculation for the reaction species
Time to stop reaction (s) 48.00 92.00 138.00 224.00 439.00 582.00 878.00 1179.00 1512.00 1791.00
m 1(g) 2.95 2.95 2.95 2.95 2.95 2.95 2.95 2.96 2.96 2.95
m 2(g) 3.13 4.12 3.13 3.12 3.13 3.14 3.14 3.14 3.15 3.14
m 3(g) 0.17 0.17 0.17 0.17 0.17 0.21 0.17 0.17 0.17 0.17
m 4(g) 0.26 0.26 0.25 0.26 0.27 0.30 0.26 0.26 0.26 0.26
m 5(g) 1.06 1.06 1.06 1.07 1.06 1.11 1.06 1.04 1.06 1.07
x' MonoG(ppm) 98.65 127.67 129.52 110.42 157.33 162.48 180.01 173.54 156.53 149.03
x' DiG(ppm) 696.73 730.57 719.12 659.12 638.75 600.99 595.94 576.69 551.82 515.26
x' TriG(ppm) 2623.62 2097.58 2213.91 2909.21 2292.99 1998.23 1653.25 1558.12 1489.17 1304.68
x' Glycerol(ppm) 5.66 7.19 11.45 26.16 80.49 106.41 144.77 175.22 194.13 199.18
x' FAMEs(ppm) 545.92 628.96 647.13 702.70 1329.47 1590.12 1993.37 2265.69 2442.12 2416.07
x MonoG 0.03 0.04 0.05 0.05 0.05 0.04 0.04 0.04 0.03 0.01
x DiG 0.07 0.15 0.13 0.11 0.09 0.08 0.08 0.08 0.07 0.01
x TriG 0.06 0.29 0.23 0.21 0.14 0.13 0.12 0.11 0.09 0.02
x Glycerol 0.00 0.01 0.02 0.02 0.03 0.04 0.04 0.05 0.05 0.01
x FAMEs 0.11 0.19 0.28 0.36 0.46 0.50 0.56 0.62 0.60 0.11
D-2
Figure 14: Mass fraction profile of reacting species in the reactor
Table 192: Conversion from xFAMEs to X
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
0 500 1000 1500 2000
Ma
ss F
ractio
n
Time (s)
Mono-Glyceride
Di-Glyceride
Tri-Glyceride
Glycerol
FAMEs
Time (s) x FAMEs X
48.00 0.11 0.13
138.00 0.14 0.17
224.00 0.14 0.16
439.00 0.25 0.30
582.00 0.31 0.38
878.00 0.38 0.45
1179.00 0.45 0.54
1512.00 0.49 0.59
1791.00 0.49 0.59
E-1
APPENDIX E LAB NOTEBOOK
E-2
E-3
E-4