1 Contents Heat Exchanger 1 balance
.............................................................................................................................
2 Reactor Sizing
..............................................................................................................................................
13 Reactor 1
.................................................................................................................................................
19 Reactor 2
.................................................................................................................................................
21 Agitation
......................................................................................................................................................
22 Tank 1 Dimension
....................................................................................................................................
23 Reactor/tank 2 Dimensions
....................................................................................................................
25 Energy Balance
............................................................................................................................................
27 Reactor 1
.................................................................................................................................................
27 Reactor 2
.................................................................................................................................................
32 References
.....................................................................................................
Error! Bookmark not defined. 2 Heat Exchanger balance The most
commonly used type of heat-transfer equipment is the ubiquitous
shell and tube heat exchanger due to the following reasons (SINNOT,
R K, 2005); 1.The configuration gives a large surface area in a
small volume. 2.Good mechanical layout: a good shape for pressure
operation. 3.Uses well-established fabrication techniques. 4.Can be
constructed from a wide range of materials. 5.Easily cleaned.
6.Well-established design procedures. There are two heat exchangers
that are being used in heating up the feed to reactor 1 because the
feed to reactor 1 is needed to be at 60OC for the reaction
(FREEDMAN, Bernard et al., 1984). According to the heat of reaction
calculated later in this document, this reaction is said to be
exothermic and a material balance on the second reactor without a
jacket indicated that the temperature exiting the reactor is
actually higher than 60 OC therefore a jacket around reactor 2 is
needed to keep the reaction temperature at 60 OC. The general
equation for heat transfer across a surface is:
Where Q = heat transferred per unit time, W U = the overall heat
transfer coefficient, W/m2 K A = heat-transfer area, m2 Tm = the
mean temperature difference, the temperature driving force Table 1:
Thermal Conductivities of the fluids Thermal Conductivity W/Om.K
Reference Triolein0.184 (PRZYBYLSKI, Dr. Roman) Methanol0.201
(Engineering Toolbox) Biodiesel0.17 (MCCRADY, Jonathon P. et al.,
2007) Glycerol0.29 (KNOTHE, Gerhard et al., 2005) Catalyst0.703
(Engineering Toolbox) Water0.8 (Engineering Toolbox) Heat Exchanger
1 2514 Kg/h of oil has to be heating up from room temperature 25 OC
to 60 OC at the beginning of the operation to allow an easier
process. Two general types of heat exchangers problems are commonly
encountered, specifying the specific heat exchanger type for a
required duty, and the sizing, which 3 refers to the heat transfer
surface area. Designing or predicting the performance of the heat
exchanger requires major parameters such as, the overall heat
transfer coefficient U; the total heat surface area A, and the
inlet and outlet temperature of the working fluid. The present
report uses the value of U given in the referenced document
(APOSTOLAKOU, A.A. et al., 2009) which is assumed U = 0.5 kW/m2.K.
Assumption:1.U is constant 2.The flows conditions are steady3.The
specific heats and mass flow rates of both fluids are constant
4.There is no loss of heat to the surroundings, due to the heat
exchanger beingperfectly insulated.5.No change of phase either of
the fluid during the heat transfer6.The changes in potential and
kinetic energies are negligible7.Axial conduction along the tube of
the heat exchanger is negligible.8.The shell and tube heat
exchanger is used.9.The flow is counter current arrangement. As the
LMTD is always greater than that for a parallel flow unit (SINNOT,
R K, 2005). Figure 1: Flow Arrangement for Counter-Current Fluid
allocation: shell or tubes Since there was no phase change, the
following factors determined the allocation of the fluid streams to
the shell or tubes. 1.Corrosion: The more corrosive fluid should be
allocated to the tube-side this will reduce the cost of expensive
alloy or clad components (SINNOT, R K, 2005). In this case steam is
more corrosive 2.Fluid temperatures: If the temperatures are high
enough to require the use of special alloys placing the higher
temperature fluid in the tubes will reduce the overall cost. At
moderate temperatures, placing the hotter fluid in the tubes will
reduce the shell surface temperatures, and hence the need for
lagging to reduce heat loss, or for safety reasons (SINNOT, R K,
2005). In this case steam has the highest temperature therefore it
should be allocated on the tube-side. 3.Operating pressures: The
higher pressure stream should be allocated to the tube-side.
High-pressure tubes will be cheaper than a high-pressure shell
(SINNOT, R K, 2005). Steam will be having the highest pressure
therefore it should be on the tube-side. 4.Pressure drop:For the
same pressure drop, higher heat-transfer coefficients will be
obtained on the tube-side than the shell-side, and fluid with the
lowest allowable pressure drop should be allocated to the tube-side
(SINNOT, R K, 2005). 4 5.Viscosity: Generally, a higher
heat-transfer coefficient will be obtained by allocating the more
viscous material to the shell-side (in this case is oil), providing
the flow is turbulent. The critical Reynolds number for turbulent
flow in the shell is in the region of 200. If turbulent flow cannot
be achieved in the shell it is better to place the fluid in the
tubes, as the tube-side heat-transfer coefficient can be predicted
with more certainty (SINNOT, R K, 2005).6.Stream flow-rates:
Allocating the fluids with the lowest flow-rate to the shell-side
will normally give the most economical design (SINNOT, R K, 2005).
The pressures were obtained using the heuristics. Total mass
balance Total mass of oil entering pre heater = Total mass of oil
leaving pre-heater Composition = 1 Min = Mout = 2510 kg/hr Energy
Balance Specific heat of Triolein = 2.083 J/kg.K (MORAD, Noor Azian
et al., 2000) The amount of heat needed to raise the temperature of
oil from ambient temperature to 60 oC is (heat load: Temperature
(K)298 Pressure (kPa)102 Flow rate (kg/hr)2510 Composition (mass
frac: -BA1 Cp,m,t2 (kJ/kg.K)2.083 Steam In Temperature (K)413
Pressure (kPa)370 (kJ/kg)2 147.35Flow rate (kg/hr) Steam out
Temperature (K)413 Pressure (kPa)360 Flow rate (kg/hr) Temperature
(K)333 Pressure (kPa)101 Flow rate (kg/hr)2510 Composition (mass
frac: -BA1 Cp,m,t2 (kJ/kg.K)2.083 5 kWhr JT T c m Qp8 . 50/ 10 83 .
1) 25 60 ( 083 . 2 2510) (51 2= = = =- Heat of vaporisation of
steam = 2145 J/kg (ELLIOT, V, 1998) Therefore, the amount of steam
requirement is: C TTT T mcT mc QQ Qpp oilsteam oil04454 33 . 142) 1
. 143 ( 2738 3 . 85 10 83 . 1) (= = =A == Figure 2: Temperature
Profile s kg hr kgQm/ 0237 . 0 / 3 . 85214510 83 . 15= ===-6 ( ) (
)( )( )5 . 99333 416298 416ln333 416 298 416ln121 2= A = AAA A A=
AlmlmlmTTTTT TT Use one shell pass with two tube passes in order to
increase the exchanger overall effectiveness. An even number of
tubes was chosen to simplify the pipe-working; two passes were
chosen because large number of tube passes increases the tube side
fluid velocity which could result to significantly increase in
pressure drop ( )( )( )( )0298 333416 4161 22 1===Rt tT TR (
)(
) 3 . 0298 416298 333== S The temperature correction factor: Ft
= 0.74 (SINNOT, R K, 2005)Tm =
The overall heat transfer heat coeffient, U must be assumed to
find the provisional area. (APOSTOLAKOU, A.A. et al., 2009) of
which this design is based on suggested that the overall transfer
coefficient for all heat exchangers be assumed to be 0.5 KW/m2.k.
Provisional area:
7 A = 1.38 m2 Choosing: outer diameter38 mm Inner diameter34 mm
Length6.1 m 273 . 0 1 . 6 038 . 0 m DL Area = = = t t tubestube one
of Areaarea ovisionaltubes of Number 2 9 . 173 . 038 . 1 Pr= = = =
A Triangular pitch was chosen because Triolein is not a heavily
fouling fluid. K1 = 0.249 and n1= 2.207 mm DKNd D diameter
Bundlebnto b7 . 97249 . 0238,207 . 21111=((
=((
= A Pull-through floating head was chosen because its very easy
to clean and can even be used at higher temperatures (SINNOT, R K,
2005). Bundle diametrical clearance = 50 mm (SINNOT, R K, 2005)
Shell diameter, Ds = Bundle diameter + Bundle diameter Clearance =
(97.7 +50) = 147.7 mm Tube-side coefficient Table 2: Physical
properties of steam (Engineering Toolbox) Properties of steam
Viscosity (mPa.s)0.014 Thermal conductivity (W/m.oC)0.016 Specific
heat (kJ/kg)2.38 Density of steam (kg/m3)0.8 ( )Ke temperatur
outlet steam e temperatur Steame temperatur steam Mean4162416
4162=+=+= Tube Cross Sectional Area: 2 292 . 907 3444mm Ad Ati t= =
=tt Number of tubes per pass 122= = pass per tubes of NumberTotal
flow Area1907.92
m2 0.000908 m2 Steam mass velocity: s m kgarea flow
Totalflowrate mass SteamGS2/ 1 . 26 = = Steam linear velocity: s
mGuSSS/ 6 . 328 . 01 . 26= = = 3310 4 . 6310 014 . 06 . 32 034 . 0
8 . 0Re = = =t iu d Heat transfer factor JH = 0.003 9 012 . 2016 .
010 014 . 0 10 3 . 2Pr3 3= = = kCp
Choose baffle spacing of 0.5 so that higher transfer
coefficients can be achieved
mm Tube pitch = 1.2538 = 47.5 mm Cross flow area:A()
Mass velocity: Gs
kg/s m2 For an equivalent triangular pitch arrangement
(
) (
)=0.027m Where de = equivalent diameter, m. oil linear velocity:
s mGuSSS/ 9 . 043 . 8857 . 798= = = Acceptable because it does not
exceed the maximum allowable shell-side velocity of 1.5 m/s Mean
shell side temperature
Pr =
10 25% baffle cut was chosen as an optimum to avoid excessive
pressure drop. jh0.0045
W/m2.K Overall coefficient Nickel; will be used as the material
of construction since this is not a high pressure operation
(SINNOT, R K, 2005) Thermal conductivity of nickel59 W/m2 oC
(SINNOT, R K, 2005) Table 3: Fouling coefficients of the fluids
(SINNOT, R K, 2005) Fouling coefficients 2-butanol (heavy
organic)2000W/m2 oC steam (oil free)10000W/m2 oC
(
)
ln (
)
85.44 W/m2 oC The calculated U is assumed to have exceeded the
acceptable 30% error from the assumption therefore a correct real
area will be calculated.
A = 8.08 m2 11 Table 4: Table of Heat Capacities (SINNOT, R K,
2005) Specific heat of Methanol
( ) (
) (
)
KJ/kg Specific heat of water
() (
) (
) 12
KJ/kg Specific heat of Sodium Methoxide = 2.302 KJ/kg
The amount of heat needed to raise the temperature of the stream
from ambient temperature to 60 oC is: kWhr JT T c m Qp71 . 6/ 31 .
24166) 25 60 ( 49 . 1 4 . 463) (1 2== = =- Heat of vaporisation of
steam = 2145 J/kg (ELLIOT, V, 1998) Therefore, the steam
requirement is: C TTT T mcT mc QQ Qpp oilsteam oil0444 33 . 142) 1
. 143 ( 2738 3 . 11 121200) (= = =A == ( ) ( )( )( )5 . 99333
416298 416ln333 416 298 416ln121 2= A = AAA A A= AlmlmlmTTTTT TT hr
kgQm/ 3 . 11214524200= ==-13 U = 0.5 W/m2 oC (APOSTOLAKOU, A.A. et
al., 2009) Provisional area:
A = 0.13 m2 Reactor Sizing Since the primary purpose of a
reactor is to provide desirable conditions for reaction, the
reaction rate
perunitvolumeofreactorisimportantinanalysingorsizingareactor.Foragivenproductionrate,it
determines the reactor volume required to effect the desired the
transformation.
Thesizingofachemicalreactorfortheproductionofbiodieselrequiredthe
modellingofthecomplex
seriesofreversiblereactionswhichhavebeenreportedbyFreedmanet.al.
Poljanseket.al.reported
ontheproductionofbiodieselbytransesterificationoflargebranchedtriglycerides(TG)intosmaller,
generallystraight-chainmoleculesofalkyl(mostoftenmethyl)estersinthepresenceofacatalyst.
Di-
andmonoglycerides(DGandMG)areintermediatesandglycerol(G)isthesideproduct.Thethree
reactions are consecutive and reversible and these reactions are
shown below in figure 1. 14 Figure 3: Reaction scheme of
triglyceride transesterification to glycerol and alkyl ester
(POLJANEK, Ida and Likozar, Bla)
Reactorsizingfocusesonfindingthevolumeofthereactoratacertainconversionandvolumetric
flowrate.Ithasbeenreportedinliteraturethatforcontiniousflowsystems,theconversionusually
increases with increasing volume therefore conversion is a function
of reactor
volume.Fromtheaboveknowledgeofsizingachemicalreactorfromtherateofreactionasafunctionof
conversion, the chemical reactors in the biodiesel production were
sized.
Tofullyunderstandtheprocessreactionofbiodiesel,thekineticsofthereactionsisthereforevery
significanttostudyfirst.Workonchemicalkineticsspecifictobiodieselproductionbeganwith
Freedman and colleagues at USDA in the early 1980s (FREEDMAN,
Bernard et al., 1984). In Freedmans model, the overall reaction: 15
Freedmaninvestigatedtransesterificationofsoyoilusingbutanolandmethanol,withmolarratiosof
alcoholtooilof30:1and6:1,attemperaturesrangingfrom20oCto60oC.Withbutanol,hefoundthe
forward reactions to be second order at 6:1 and pseudo-first order
at 30:1. With methanol, he found the forward reactions to be fourth
order at 6:1, implying the shunt reaction, and pseudo-first order
at 30:1. All reverse reactions were found to be second order.
In(NOUREDDINI,H.andZhu,D.,1997)againstudiedthekineticsoftransesterificationofsoybeanoil.
They used the same reaction model proposed by (FREEDMAN, Bernard et
al., 1984). However, they took
measurementsatdifferingmixingintensities,asmeasuredbytheReynoldsnumberofthestirrer.
(NOUREDDINI, H. and Zhu, D., 1997) reported that the shunt reaction
reported by (FREEDMAN, Bernard
etal.,1984)isnotnecessary,thereforeinthispaper,thereactionconstantswillbetakenfrom
(NOUREDDINI, H. and Zhu, D., 1997). Below are the activation
energies as well as reaction rate constants as reported by
(NOUREDDINI, H. and Zhu, D., 1997). The reaction rate constants at
60 OC were estimated using the activation energies from the
equation: ()(
)
(
)
Table 5: Rate Constants and Activation Energies (NOUREDDINI, H.
and Zhu, D., 1997) 16 Triglyceride can be shown below to react with
methanol to produce diglycerides, the diglycerides react with
another methanol molecule to produce monoglycerides and then these
react with a third methanol molecule to produce glycerol. At each
of these three stages, a molecule of Biodiesel is produced so that,
overall, three molecules of methanol are needed to produce three
molecules of ester and one molecule
ofglycerol.Eachofthesereactionsisreversiblewithadifferentrateconstant(kn)denotingthatthe
forwardandreversereactionstakeplaceatdifferentrates.Thereactionsareallknowntobesecond
order(orpseudo-secondorder)sothatwecanexpresstherateofdisappearance/appearanceofthe
various components in a series of differential equations
(Noureddini et. al. (1997). Figure 4: Reactions and Rate equations
controlling the transesterification reaction (NOUREDDINI, H. and
Zhu, D., 1997)
Reactorsizingfocusesonfindingthevolumeofthereactoratacertainconversionandvolumetric
flowrate.Ithasbeenreportedinliteraturethatforcontiniousflowsystems,theconversionusually
increaseswithincreasingvolumethereforeconversionisafunctionofreactorvolume.Fromfirst
principles, the reactor volume equation has been derived to be:
17
(
) Where:FA0 is the molar flow rate of species A fed to the
reactor operated at steady state (mol/h) X is the conversion of the
reactor rA is the rate of reaction in terms of component A
Fromtheaboveknowledgeofsizingachemicalreactorfromtherateofreactionasafunctionof
conversion, the chemical reactors in the biodiesel production were
sized. FA0 and X are known except rA therefore calculations are
needed. Since there are a number of reactions in series both giving
biodiesel,
bothhavingdifferentrates,thereforethereisaneedtoassumetheratelimitingstepwhichisthe
slowest reaction and that will be the reaction that control the
overall reaction. From the reactions above, the rate of reactions
are given below
[][]
[][]
([][] [][]
) Where
[][]
[][]
[][]
[][]
([][] [][]
)
([][] [][]
) Where
[][]
[][]
[][]
[][] 18
([][] [][]
)
([][] [][]
)
Global reactions are not usually well represented by mass action
kinetics because the rate results from the combined effect of
several simultaneus elementary reactions that underline the global
reaction. The
elementarystepsincludeshort-livedandunstableintermidiatecomponentssuchasfreeradicals,ions,
molecules, transition complex e.t.c (Perry 7-14, 2008).
Thereasonmanyglobalreactionsbetweenstablereactantsandproductshavecomplexmechanismis
that these unstable reactants intermidiates have to be produced in
order for the reaction to proceed at
reasonablerates.Oftensimplifyingassumptionsarevalidoverlimitedrangesofcompositions,
temperatureandpressure.Theseassumptionscanfailcompletely-inthatcasethefullelementary
reactionnetworkhastobeconsidered,andnoclosed-formkineticscanbederivedtorepresentthe
complex system as a complex reaction (Perry 7-14, 2008).
Assumingthethirdreactiontoberatelimitingstepbecausethethirdreactionwasreportedby
Nouriddini to be the slowest and reduces as the temperature
increase. Therefore this means that rTG/k1 andrDG/k3arerelatively
verysmall(approximatelyzero)whilerMG/k5islarge.Nowweneedtoexpress
the third rate law interms of measurable concentration. [] [][]
[] [] [][]
[]
[][]
[]
([][]
[]
[][]
[])
([][]
[]
[][]
) 19 Reactor 1 Figure 5: Reactor 1 20
Substituingvaluesinthepreviouslyderivedequationtofindr,itwasthensubstitutedin
(
) And a volume of 0.1m3 was found. Since the entire design of
the whole process is based on a design illustrated in(APOSTOLAKOU,
A.A. et
al.,2009)asthebasecase.(APOSTOLAKOU,A.A.etal.,2009)suggestedareactorvolumetobe
calculatedusinganequation:
with
theresidancetime,Qasthevolumetricflowrateofall streams and V as
the reactor volume.
Anothermethodtofindthevolumeofthereactorwasusingthemethodillustratedin(FOGLER,H.S,
2006) where volume of the reactor is calculated from the space time
equation shown below:
WereVisthereactorvolume,andv0
istheinputvolumetricflowrateandTasthespacetime.Space time is the
the time it takes for the fluid to enter the reactor completely
(FOGLER, H.S, 2006), it is also called the holding up time or mean
residance time. In absence of dispersion, space time is the time
the molecules spends in the reactor. In this design, the residance
time is 1 hour therefore the volume of the reactor is 3.29 m3. 21
Reactor 2 22 Using the equation
The volume was found to be 3m3 while using the equation
below:
Using the rate laws, the volume calculated as illustrated in
reactor 1 sizing is 4.8m3.Agitation The reason why the reactor has
an agitator is because of the following reasons:
1.Therateoftransesterificationdependsontheagitationrateordirectlyproportionaltothe
Reynolds number (NOUREDDINI, H. and Zhu, D., 1997) 2.Blending the
two miscible liquids3.Increase the heat transfer between
Thetworeactorshavethesamevolumethatmeansthetwotanksareidentical.Thereforethe
calculationsaremadeforonereactor.Generally,liquidsareagitatedinacylindricalvesselwhichcan
either be closed or open to the air. There are different types of
agitators listed below and their descriptions (WELTY, James R. et
al., 2008).23 1.There-blade propeller agitator -Turns at high
speeds of 400 to 1750 rpm (Revolution per minute) -Used for low
viscosities liquids below about 3 Pa.s (3000 cp) 2.Paddle agitators
-Used for low speeds between 20 to 200 rpm -Two-bladed and
four-bladed flat puddles are often used -Total length of the paddle
impeller is usually 60 80% of the tank diameter -Width of the blade
is 1/6 to 1/10 of the tank length-Used for viscous liquids where
deposits on walls occur and to improve heat transfer to the walls
-It sweeps and scraps the tank walls and sometimes the tank bottom
-It is a poor mixer -Used for viscosities of the fluid of about
below 100Pa.s (100 000cp) 3.Turbine agitators-Used at high speeds
for liquids with a very wide range of viscosities -Diameter of the
turbine is normally between 30-50% of the tank diameter -Useful in
suspending solids since the currents flow downward and then sweep
up the solids. -Used for viscosities below about 100 000 cp
4.Helical Ribon agitators -Used in highly viscous solutions
-Operates at low rpm in laminar region
Sincethetwotanksareidentical,thedimensionsaregoingtobethesameexceptthepower
consumption. It has been calculated that the reactions require a
volume of about 4 m3. Tank 1 Dimension:Choosing the allowance of
20% The tank volume will therefore be ()
The liquid depth is approximately equal the diameter of the tank
(MCCABE, L.W. et al., 2005)
24
The viscosity of the mixture was calculated using the equation
below (SINNOT, R K, 2005).
25
Fromtheviscosityandthedescriptionofimpellersdescribedearlier,thetypeofimpellerschosenare
Propellers due to the low viscosity. The density of the mixture was
calculated to be 904 kg/m3. Assumingthethespeedoftheimpeller
Using the curve shown in (MCCABE, L.W. et al., 2005), on page
260, Figure 9.14 which shows the Power number NP versus Reynolds
number Re for propellers, the NP was found to be 0.91. Calculating
the power:
The amount of workdone to the fluid is:
Reactor/tank 2 Dimensions Choosing the allowance of 20% The tank
volume will therefore be ()
The liquid depth is approximately equal the diameter of the tank
(MCCABE, L.W. et al., 2005)
26
The viscosity of the mixture was calculated using the equation
below (SINNOT, R K, 2005)
Fromtheviscosityandthedescriptionofimpellersdescribedearlier,thetypeofimpellerschosenare
Propellers due to the low viscosity. The density of the mixture was
calculated to be 880 kg/m3. Assumingthethespeedoftheimpeller
27 Using the curve shown in (MCCABE, L.W. et al., 2005), on page
260, Figure 9.14 which shows the Power number NP versus Reynolds
number Re for propellers, the NP was found to be 0.8 Calculating
the power:
The amount of workdone to the fluid is:
Energy Balance Reactor 1 A + + + + =((
+ +R soutleto o o o oinleti i i i iH W Q V v gz H V v gz H V v
gz Udtd )21( )21( )21(2 2 2 Simplifying Assumptions The change in
Potential Energy Ep is insignificant since there is no change in
height. The change in Kinetic Energy Ek is insignificant. 28 Since
the liquid is already heated to the reaction temperature, there is
no more heating required therefore it is assumed that Q = 0 ( )R
sOutleto oinleti i iH W V H V H V HdtdA + + = 0 ) (dtPdVdtdP
VdtdHdtdUPV H UPV U HR RRR+ = = + = Volume of the Reactor is
constant Assume that the reactor is isobaric Since T C HdtdHdtdUPA
== R s in in in P out out out PR s out out out P in in in P PH W V
T C V T CdtdVceH W V T C V T C V T CdtdA + + A = A=A + + A A = A )
( ) (0 sin) ( ) ( ) ( Table 6: Heat Capacities (SINNOT, R K, 2005)
Sample calculationSpecific heat of methanol
( ) (
) (
) 29
kJ/kg Group contribution method was used to estimate the Cp of
biodiesel and triolein Table 7: Specific Heat Capacities for
Elements (SINNOT, R K, 2005) Biodiesel ElementsMolecular massCp
C228222.3 H36648 O3250.2 Total296920.5 Biodiesel Cp3.109797297
Triolein Elements Molecular Cp HCL 0.938404131water
1.884515154Methanol 1.453953383Glycerol 1.354743066Cp at
60OCElements Cp for liquidsC 11.7H 18B 19.7Si 24.3O 25.1F 29.3P 31S
31Other 33.5Group contibution method30 mass C684666.9 H1041872
O96150.6 Total8842689.5 Triolein Cp3.042421 Sodium Methoxide
ElementsMolecular massCp C1211.7 H354 Na2333.5 O1625.1 Total54124.3
Sodium methoxide Cp2.301851852 Heat of Formations -Heat of
formation of Triolein is -2193.7 kJ/mol (AMANDA, C.O. et al.,
2011)-Heat of formation of Methanol is -238.4 kJ/mol (AMANDA, C.O.
et al., 2011) -Heat of formation of Glycerol is -669.6 kJ/mol
(AMANDA, C.O. et al., 2011) -Heat of formation of Biodiesel is -429
kJ/mol (SORGUVEN, Esra and Ozilgen, Mustafa, 2010) 31 The overall
heat of reaction for the production of biodiesel is calculated
below:
()
()
(
) (
)
Heat capacity for the inlet mixture = 2.26 Kj/Kg Heat capacity
for the outlet mixture = 2.8 KJ/Kg.k R s in in in P out out out PH
W V T C V T C A + + A = A ) ( ) (
OC 32 Reactor 2 Heat capacity for the inlet mixture = 2.91 Kj/Kg
Heat capacity for the outlet mixture = 2.96 KJ/Kg.k R s in in in P
out out out PH W V T C V T C A + + A = A ) ( ) (
OC 33 References AMANDA, C.O., Luiz, F.M. , and C. DILSON. 2011.
Method of contribution of groups to estimate thermodynamic
properties of components of biodiesel formation in liquid phase.
Fluid Phase Equilibria., pp.59-64. APOSTOLAKOU, A.A., I.K. KOOKOS,
C. MARAZIOTI, and K.C. ANGELOPOULOS. 2009. Techno-economic analysis
of a biodiesel production process from vegetable oils. Fuel
Processing Technology. ELLIOT, V. 1998. Introductory applied
thermodynamics. Cape Town: Metric Publications. Engineering
Toolbox. [online]. Available from World Wide Web: FOGLER, H.S.
2006. Elements of Chemical Reaction Engineering. New Jersey:
Prentice-Hall, Inc. FREEDMAN, Bernard, Royden O. BUTTERFIELD, and
Everett H. PRYDE. 1984. Transesterification Kinetics of Soybean
DiP. Peoria. KNOTHE, Gerhard, GERPEN, Jon Van, and KRAHL, Jrgen
(eds). 2005. The Biodiesel Handbook. Champaign, Illinois: AOCS
Press. MCCABE, L.W., C.J. SMITH, and P. HARRIOTT. 2005. Unit
Operations of Chemical Engineering. New York: McGraw-Hill. MCCRADY,
Jonathon P., Stringer L VALERIE, Alan C HANSEN, and Chia-fon F LEE.
2007. Computational Analysis of Biodiesel Combustion in a
Low-Temperature Combustion Engine using Well-Defined Fuel
Properties. SAE International. MORAD, Noor Azian, A.A. Mustafa
KAMAL, F. PANAU, and T.W. YEW. 2000. Liquid Specific Heat Capacity
Estimation for Fatty Acids,Triacylglycerols, and Vegetable Oils
Based on Their Fatty Acid Composition. Kuala Lumpur. NOUREDDINI, H.
and D. ZHU. 1997. Kinetics of Transesterification of Soybean.
Lincoln, Nebraska: AOCS Press. POLJANEK, Ida and Bla LIKOZAR.
Influence of Mass Transfer and Kinetics on Biodiesel Production
Process. In: Mass Transfer in Multiphase Systems and its
Applications, Slovenia, pp.533-458. PRZYBYLSKI, Dr. Roman.
http://www.canolacouncil.org/uploads/technical/chemical1-6/chemical1-6_1.html.
[online]. SINNOT, R K. 2005. Coulson & Richardson Chemical
Engineering Volume 6: Chemical Engineering Design. Jordan Hill,
Oxford: Elsevier Butterworth-Heinemann. SORGUVEN, Esra and Mustafa
OZILGEN. 2010. Thermodynamic assessment of algal biodiesel
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