DSpace at VNU: A study on developing aviation biofuel for the Tropics: Production process-Experimental and theoretical evaluation of their blends with fossil kerosene

Chemical Engineering and Processing 74 (2013) 124–130

Contents lists available at ScienceDirect

Chemical Engineering and Processing:
Process Intensification
journal homepage: www.elsevier.com/locate/cep

A study on developing aviation biofuel for the Tropics: Production
process—Experimental and theoretical evaluation of
their blends with fossil kerosene
Thong D. Hong a,e,∗ , Tatang H. Soerawidjaja b , Iman K. Reksowardojo a ,
Osamu Fujita c , Zarrah Duniani d , Mai X. Pham e
a
Combustion Engines and Propulsion Systems Laboratory, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Bandung 40132,
Indonesia
b
Chemical Engineering Department, Faculty of Industrial Technology, Institut Teknologi Bandung, Bandung 40132, Indonesia
c
Division of Mechanical and Space Engineering, Hokkaido University, Sapporo 060-8628, Japan
d
Research & Development Division, Pertamina Oil Company, Jakarta 13920, Indonesia
e
Department of Automotive Engineering, Faculty of Transportation Engineering, Ho Chi Minh City University of Technology, Ho Chi Minh City 70350,
Viet Nam

a r t i c l e

i n f o

Article history:

Received 31 May 2013
Received in revised form 29 August 2013
Accepted 30 September 2013
Available online 8 October 2013
Keywords:
Aviation biofuel
Bio-jet fuel
Kerosene
Bio-kerosene
Hydroprocessing

a b s t r a c t
In the present work, the production process of bio-jet paraffins is appropriately proposed according to
the conditions of the socioeconomic situations, the current technologies of biofuel production and the
available feedstock sources for the tropical countries. The blending process of bio-kerosene which is a
mixture of bio-jet paraffins and fossil kerosene is also displayed. The two prototypes of bio-paraffins
(Bio-P1 and Bio-JP2), which were manufactured in Indonesia following the proposed production process,
are used for making bio-kerosenes in current study. The theoretical and experimental investigations have
been carried out to evaluate and identify the critical properties of bio-kerosenes: distillations, freezing
point, lower heating value, density, flash point and viscosity to ensure ASTM criteria of jet fuel. The results
show it can be blended directly 5% volume of Bio-P1 or 10% volume of Bio-JP2 to commercial Jet A-1 for
powering aviation gas turbine engines without redesigning fuel system or fuel supply infrastructure. The
use of these bio-paraffins not only reduces CO2 lifecycle but also significantly decreases emissions of
sulfur compounds (SOx ). With preliminary achievements of this work, it is no doubt about the feasibility
of developing aviation alternative fuels according to the proposed production process for the tropical
countries.
© 2013 Elsevier B.V. All rights reserved.

1. Introduction
Fuel is one of the biggest operating costs for the air transport

hence the aviation industry is significantly affected by the oil prices.
While the crude oil and petroleum products price permanently
fluctuate according to the socio-political situation of the main oil
reserves’ countries and the world’s economy. In 10 years, the difference of jet fuel prices between the peak set in June 2008 (3.89
USD/gallon) and the lowest in May 2003 (0.71 USD/gallon) was
more than 5.4 times [1]. The changing fuel prices make airline operators very difficult to plan and budget for the long-term operating

∗ Corresponding author at: Faculty of Mechanical and Aerospace Engineering,
Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132,
Indonesia. Tel.: +62 85794345668; fax: +62 022 2534212.
E-mail addresses: ,
(T.D. Hong).
0255-2701/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
/>
expenses. Thus, they have tried to develop a diversified fuel market
to reduce risk in the fuel volatility that comes with having a single
source of energy.
On the other hand, today’s airline industry is 70% more fuel efficient than over the past 40 years [2] due to more aerodynamic
and lighter aircrafts; more efficient modern turbine engines; huge
improvements in the air traffic control efficiency, in flying the aircraft and in developing more environmentally-friendly operations
at airports. Aviation CO2 emission, however, is still kept growth
of 2–3% per year due to the steady increase in annual air transportation. To reduce the environmental impact of the worldwide
aircraft’s fleet, the European Commission approved the European
Union Emissions Trading Scheme (EU ETS) to include the civil aviation sector. Directive 2008/101/EC of the European Parliament and
Council [3] agreed that from 2012, all airlines flying within or into
Europe had to buy CO2 allowances on the open market or reduced
their GHG emissions to 97% of average annual emissions for the
year 2004–2006 and this is lower to 95% as from 2013. Under the

T.D. Hong et al. / Chemical Engineering and Processing 74 (2013) 124–130

Nomenclature
m
V
T
A, B
log

mass (kg)
volume (m3 )
temperature (K)
constants
logarithm to base 10

Greek letters
volume fraction (%)
mass fraction (%)
ω
density (kg/m3 )
kinematic viscosity (mm2 /s)
Subscripts
i
component of ith
mix
mixture

EU ETS, biofuels are considered CO2 neutral [4,5] and airline can
benefit from an exemption from the need to surrender allowances
and credits.

Sustainable biofuels may offer a solution to both problems
above. Recent years, many researchers, airline operators and energy
entrepreneurs have seriously prepared and more interested in aviation alternative fuel [6–23]. Applying renewable fuels will be
an inevitable trend of the future airline industry. It will bring
a great significance in mitigating aviation’s total dependence on
petroleum-based fuel, stimulating the national agricultural development, stabilizing the domestic socioeconomics and leading to a
cleaner industry image for the nation. Each country or each region,
however, has different natural conditions, resources and potentials, therefore, the identification of proper production process and
appropriate technology for aviation biofuels are really important
and necessary.
In present study, the production process of aviation bio-jet
paraffins was proposed consistent with the socioeconomic conditions, production technology and feedstock sources of the Tropics.
The route of blending bio-jet paraffins with fossil kerosene (commercial Jet A-1), which formed bio-kerosene using as alternative
fuel for aircraft, was also provided. Two prototypes of bio-paraffins,
which were manufactured in Indonesia, were used to make the
samples of bio-kerosenes for current work. The experimental and
theoretical investigations of these bio-kerosenes were performed
to ensure their common properties satisfying the ASTM D1655
requirements and to verify the feasibility of developing and applying renewable fuel for the Tropics’ aviation industry.
2. Production process of aviation biofuel for the Tropics
2.1. The current status of aviation biofuels
There are currently three main research strategies for alternative aviation fuels as following: fatty acid esters (FAEs),
hydroprocessed renewable jet – synthesis paraffin kerosene (HRJ –
SPK) and Fischer–Tropsch jet – synthesis paraffin kerosene (FTJ –
SPK).
FAEs, which are called as biodiesel, derived from the transesterification of the triglycerides and fatty acids in the vegetable, animal
or waste oils. Biodiesel had remarkable advantage as it was produced on an available and simple technology, with low cost and
high efficiency. Besides, biodiesel also had big challenges to become
aviation fuel for by its small lower heating value (LHV) and high
freezing point. Furthermore, the ester properties depend on the

starting material and there is a carry through of any contamination,

125

such as metals, from the raw material into the FAE. This can have
an adverse effect on the hot end materials in the engine [24]. The
typical studies in this direction are Cromarty et al. [6], Llamas et al.
[7,8] and Jenkins et al. [9]. To meet the specification requirements,
the biodiesels were blended with fossil jet fuel to improve their
properties of LHV and freezing point or/and adding anti-icing additives.
HRJ – SPK is produced by hydrogenative refining of the triglycerides and fatty acids in the vegetable, animal or waste oils.
HRJ production firstly requires deoxigenation of triglycerides and
faty acids to produce C8 –C22 normal paraffins. In a second step,
the resulting hydrocarbons are further cracked and isomerized to
reduce the carbon number of the paraffins into the boiling range
of the jet fuel (number of carbon C8 –C16 ). Honeywell’s UOP is currently the only large-scale producer of HRJ [5] with the major of
production used to support engine testing and qualification. This
HRJ – SPK is expected to be commercial in the not-too-far future.
FTJ – SPK is produced from coal, biomass or natural gas feedstock through gasification followed by Fischer–Tropsch synthesis
process. The synthesis gas (i.e. mixture of carbon monoxide and
hydrogen) produced in the gasification process are then catalytically reacted to form a mixture of long-chain paraffins in the
Fischer–Tropsch synthesis process. These products are further
undergone the hydroprocess like HRJ. The identification or development of sufficient biomass feedstock and the lower technological
readiness of the process, however, present significant hurdles to
overcome [25]. FTJ – SPK has been also used for testing flights.
2.2. The production process of aviation biofuel proposed for the
Tropics
The production process of aviation biofuel which is built for the
Tropics is shown in Fig. 1. It is based on the hydrotreating process
and there are some adjustments in order to fit with conditions of

the tropical countries.
The main different point of this proposed process is the feedstocks must be selected from medium chain and dominant lauric
(the number of carbon is 12) fatty acid. Thus, no cracking step is necessary, results in using the simple production technology, reducing
investment and production costs for aviation biofuel. Furthermore,
it can be taken, in part, full advantage of the existing production line
of biodiesel. This issue is considered as the key of the solution since
it is really useful and suitable for the socioeconomic situation of the
tropical areas, where are the majority of developing countries.
Table 1 shows the compositions of feedstocks that satisfy
medium chain and dominant lauric fatty acids. Of these, coconut
and palm kernel oils can be mass-produced in the tropical regions.
They, however, are from the nutritious food sources and the sustainable development of aviation biofuel can be affected if we use
these edible feedstocks. The solution to overcome this hurdle is
given as follows: the triglycerides and fatty acids are first selectively
fractionated to separate healthy fatty-oils composed of caprylic
(C8:0), capric (C10:0), oleic (C18:1), and linoleic (C18:2) acids for
food. The remainders, which are the saturated C12 –C16 fatty acids,
are hydrotreated to produced C11 –C16 straight chain bio-paraffins
containing undecane (n-C11 H24 ) and dodecane (n-C12 H26 ) as the
dominant components. The chemical reactions of lauric oil and
triglyceride to form undecane and dodecane are illustrated in Fig. 2.
This bio-paraffinic compound is then partially isomerized to produce branched chain isomers having very low freezing point which
are called as bio-jet paraffins.
In order to satisfy the freezing point, density requirements of
aviation fuel standards, these bio-jet paraffins are then blended
with appropriate proportion of aromatics (<25% by volume) to form
bio-jet fuel. Blend of bio-jet fuel with fossil kerosene is called as
bio-kerosene which could be used to power jet aircrafts without

126

T.D. Hong et al. / Chemical Engineering and Processing 74 (2013) 124–130

Fig. 1. The production process of aviation biofuel proposed for the tropical countries.

Table 1
Feedstocks have medium chain and dominant lauric fatty acids.
Oil/fat

Fatty acid compositions (% weight)
8:0

Coconut [26]
Palm kernel [26]
Babassu [26]
Coconut [27]
Babassu [27]

7–9
3–5
4–6
4.6–9.5
2.6–7.3

10:0
5–10
3–6
6–8
4.5–9.7

1.2–7.6

12:0

14:0

46–47
48–55
44–48
44–51
40–45

17–20
12–19
15–20
13–20.6
11–27

16:0
9–10
3–8
5–11
7.5–10.5
5.2–11

18:0
3
4–8
2.5–5.5
1–3.5

1.8–7.4

18:1

18:2

7–8
15–21
10–16
5–8.2
9–20

2
0.5
1–3
1–2.6
1.4–6.6

C18:3
–
–
–
0–0.2
–

manufactured in Indonesia by using the above production process without and with the step of isomerization, respectively. The
composition of Bio-P1, which is expected from manufacturer, is a
normal paraffinic compound while Bio-JP2 has the presence of isoparaffinic hydrocarbon in its composition. That is a reason why the
freezing point of Bio-JP2 is lower than that of Bio-P1. The common
properties of Bio-P1 and Bio-JP2 are presented in Table 2.

3.2. Experimental and theoretical investigations

Fig. 2. Molecular transformation steps of bio-paraffins production process.

redesigning or modifying engine and fuel supply infrastructure.
Bio-jet paraffins can also be directly blended with a certain proportion of conventional kerosene without adding aromatic to make
bio-kerosene.
3. Experimental
3.1. The two prototypes of aviation biofuel
The two prototypes of aviation biofuels, which are called as
bio-paraffins 1 (Bio-P1) and bio-jet paraffins 2 (Bio-JP2), were

The theoretical and experimental investigations have been
carried out to evaluate and identify the critical properties of
bio-kerosenes: distillations, freezing point, lower heating value,
density, flash point and viscosity to ensure ASTM D1655 criteria.
In current work, the feedstock was used to produce two prototypes of bio-paraffins was coconut oil, which was purchased
from the Home Industry, Indonesia. The commercial Jet A-1 and
propylbenzene, which are used for the investigations, are supplied respectively by the Pertamina Oil Company, Indonesia and
the Merck Millipore Company, Japan. The common properties of
Jet A-1 are revealed in Table 2. The blends of commercial Jet A-1
with Bio-P1 and Bio-JP2 as well as the blends of propylbenzene
with Bio-P1 are prepared by standard volumetric procedures. Various blending ratios of tested fuels are used depending on observed


T.D. Hong et al. / Chemical Engineering and Processing 74 (2013) 124–130

127

Table 2

The common properties of Bio-P1, Bio-JP2 and Jet A-1.
Property

ASTM D1655 [28]

Bio-P1

Bio-JP2

Jet A-1

Distillation temperature
Initial BP (◦ C)
10% rec (◦ C)
50% rec (◦ C)
90% rec (◦ C)
Final BP (◦ C)
Freezing point (◦ C)
Lower heating value (MJ/kg)
Density at 15 ◦ C (kg/m3 )
Flash point (◦ C)
Viscosity at 25 ◦ C (mm2 /s)
Viscosity at −20 ◦ C (mm2 /s)a
Sulfur, total (wt%)

Report
Max. 205
Report
Report
Max. 300

Max. −47.0
Min. 42.8
775–840
Min. 38
–
Max. 8.0
Max. 0.3

141
191
218
283
308
9.5
42.48
759
47
4.199
6.485
11 ppm

126
150
211
275
306
−18.5
44.97
758
45

2.074
6.940
10 ppm

146
164
187
214
247
−55
44.45
781
48
1.599
6.789
470 ppm

a

Data were extrapolated by using ASTM D341 method which presented in Section 4.6.

characteristics in order to achieve optimal results of the investigations.

4. Results and discussions
4.1. Experimental investigation of distillation property
As we can see in Table 2, amount of less than 10% volume of BioP1 exceeds the ASTM standard of the final boiling point of 300 ◦ C.
If we blend a small volume of Bio-P1 with commercial jet fuel,
the volume of distillation that exceeds standard is expected to be
negligible in blend.
The investigation of distillation temperatures is carried out for

Bio-P1 and blends of 2, 5 and 10 vol.% Bio-P1 in Jet A-1 which
are called as bio-kerosene mixtures of BK1-2, BK1-5 and BK1-10,
respectively. It can be seen from Table 3, which shows the details
of the distillation temperatures of tested bio-kerosene mixtures,
the distillation specifications of BK1-10 are in the limit of ASTM
requirement. We can conclude that the maximum blending ratio is
up to 10% volume of Bio-P1 in commercial Jet A-1.
The distillation temperatures of Bio-JP2 are lower than those of
Bio-P1 at all required points of ASTM such as: initial boiling point,
final boiling point, 10%, 50% and 90% recovered volumes that are
shown in Table 2, thus, the blend of 10 vol.% Bio-JP2 and 90 vol.% Jet
A-1 certainly meets ASTM standard of distillations.
Bio-P1 and Bio-JP2 have high distillation temperatures are
due to the presence of long chain hydrocarbon components and
byproducts of production process. In the long term, when a larger
proportion of bio-paraffins in blends will be required, the step of
separating the unexpected components should be added to the
process.

Fig. 3. Freezing point versus volume fraction of Bio-P1 in blend.

4.2. Experimental investigation of freezing point
The requirement for freezing point, which is −47 ◦ C, is perhaps
the most stringent and the hardest to meet it. This specification is
to ensure the fuel donot become wax and ice crystals cause clog
and block filters preventing fuel flow.
The first two experimental investigations are performed for
blends of Bio-P1 and Bio-JP2 with Jet A-1 which are called as biokerosene 1 and bio-kerosene 2 mixtures, respectively. Bio-P1 is
blended with volume fractions of 0%, 2%, 5% and 10% in Jet A-1
and the volume fractions of Bio-JP2 in Jet A-1 are 0%, 5%, 10% and

20%. Figs. 3 and 4 show respectively the variations of experimental
freezing points along with volume fractions of Bio-P1 and Bio-JP2
in their blends with Jet A-1. The freezing points of bio-kerosene

Table 3
The distillation temperatures of Bio-P1, BK1-2, BK1-5 and BK1-10.
%Vol. rec.

0.5-IBP
5
10
20
30
50
70
80
90
95
99.5-FBP

Distillation temperature (◦ C)
Bio-P1

BK1-10

BK1-5

BK1-2

141.3

182.6
190.6
201.6
207.5
218.4
244.4
262.0
283.2
298.9
308.2

144.8
160.1
165.5
173.9
179.9
190.0
200.1
208.0
222.8
238.0
259.1

145.2
159.8
165.1
173.3
179.1
188.6
198.7

206.0
217.4
227.3
249.1

145.3
159.6
164.7
172.4
178.2
187.9
197.8
204.9
215.1
223.1
248.6

Freezing point, FP (0C)

-40

-45

-50

ASTM standard ≤ - 470C

-55
FP = 263.636χ2 + 2.818χ - 55.082
R² = 0.999

-60
0.00

0.05
0.10
0.15
% volume of Bio-JP2, χ

0.20

Fig. 4. Freezing point versus volume fraction of Bio-JP2 in blend.


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T.D. Hong et al. / Chemical Engineering and Processing 74 (2013) 124–130

Fig. 5. Freezing point versus volume fraction of propylbenzene in blend.

mixtures increase with increasing volume fraction of Bio-paraffins.
The results reveal that blend of 5 vol.% Bio-P1 or 17 vol.% Bio-JP2 in
Jet A-1 meets ASTM requirement of freezing point.
To improve the freezing point specification we can add amount
of aromatic, which less than 25% volume, to bio-paraffins. The further experimental investigation are performed for the blends of
0, 10, 20, 25 vol.% propylbenzene (a typical surrogate of aromatic
class for jet fuel [29]) in Bio-P1, which are called as the bio-jet fuel
mixtures. Tested freezing point is plotted against the percentage
of propylbenzene in blend in Fig. 5 which reveals freezing point of
bio-jet fuel mixture decreases with increasing volume fraction of
propylbenzene.

Fig. 6. LHV versus (a) volume fraction and (b) mass fraction of Bio-P1 in blend.

4.3. Experimental examination of lower heating value (LHV)
The performance of turbine engine significantly depends on the
LHV. A reduction of this property brings about an increase of specific
fuel consumption of engine and a reduction of the flight distance.
According to the laws of conservation of mass and energy, the LHV
of the mixture can be expressed as:
LHVmix =

ωi × LHVi

(1)

i

However, the experimental LHV investigation is also performed
in this case. The bio-kerosene mixtures which are blends of 0, 20, 50
and 100 vol.% Bio-P1 in Jet A-1 are tested LHV. Fig. 6a and b respectively show LHV versus volume fraction and mass fraction of Bio-P1
in bio-kerosene mixtures. The LHV of the mixture decreases with
increasing the percentage of Bio-P1. To meet the ASTM net heat
of combustion criteria, the maximum volume of Bio-P1 in blend is
81%.
Bio-JP2 has larger LHV than commercial Jet A-1 and ASTM
requirement hence it can be blended with Jet A-1 for any volume
fraction to meet the ASTM standard and use of Bio-JP2 will gain in
fuel consumption.

775–840 kg/m3 . The density specification will be improved if BioP1 and Bio-JP2 are blended with Jet A-1, which has a density of
781 kg/m3 .

The experimental investigation is performed to compare with
the result of calculation by using predicted Eq. (2). The bio-kerosene
mixtures which are blends of 0, 25, 50, 75 and 100 vol.% BioP1 in Jet A-1 are used for tests. Fig. 7 shows predicted density
versus volume fraction of Bio-P1/Bio-JP2 in blend with Jet A-1 and
experimental density is plotted against the percentage of Bio-P1
in Fig. 8. The tested density of mixture decreases with increasing volume fraction of Bio-paraffins following a linear relationship
with the R2 = 0.988. To meet the ASTM requirement of density, the
maximum volumes of Bio-P1 in blend are 27.3% and 29.0% according to the results of calculation and experiment, respectively. The

4.4. Theoretical calculation and experimental investigation of
density
According to the law of conservation of mass and the assumption
that the volume of the mixture is the sum of the single component
volumes, the density of the mixture can be expressed as:
mix

=
i

mi
Vmix

=
i

mi Vi
Vi Vmix

=

(

i

i)

(2)

i

The density of Bio-P1 and Bio-JP2, which respectively are
759 and 758 kg/m3 , are under the ASTM standard of range

Fig. 7. Predicted linear relationship of density and volume fraction of Bio-P1/Bio-JP2
in blends.


T.D. Hong et al. / Chemical Engineering and Processing 74 (2013) 124–130

129

Table 4
Kinematic viscosities of Jet A-1, BK1-5 and BK2-10 at various temperatures.
Kinematic viscosity (mm2 /s)

Fuel

Jet A-1
BK1-5
BK2-10

25 ◦ C

30 ◦ C

35 ◦ C

40 ◦ C

1.599
1.651
1.644

1.450
1.537
1.465

1.326
1.342
1.374

1.190
1.241
1.209

The kinematic viscosities of Jet A-1, BK1-5 and BK2-10 at −20 ◦ C
are extrapolated by using ASTM D341 method [31], bases on the
relationship of kinematic viscosity – temperature of petroleum oils
and liquid hydrocarbons:
Log[log(Z)] = A − Blog T

Fig. 8. Density versus volume fraction of Bio-P1 in blend.

absolute error between predicted and experimental values of BioP1 volume fraction is 1.7%.
The predicted volume fraction of Bio-JP2 in blend with Jet A-1
that satisfies density criteria is up to 26.1%. Experimental investigation has not yet verified in this case, however, it really is not hard
to accept that the expected blend of 10 vol.% Bio-JP2 with 90 vol.%
Jet A-1 meets current density requirement of aviation fuel.
4.5. The analysis of flash point
The flash point of Bio-P1 and Bio-JP2 are respectively 47 and
45 ◦ C, which are in accordance with ASTM requirement.
The flash point is the temperature at which the saturated vapor
is equivalent to the lower flammability composition. Hence, the
flash point of mixture is always in the middle range of those of their
components. It was proved by experimental studies of Affens and
coworker [30] and Llamas et al. [7,8]. This means that any blending
ratio of Bio-P1 and Bio-JP2 with jet fuel also agrees with the ASTM
requirement of flash point.
4.6. Examination of viscosity
The kinematic viscosity of Jet A-1, the mixture of 95 vol.% Jet
A-1 and 5 vol.% Bio-P1 (BK1-5), the mixture of 90 vol.% Jet A-1 and
10 vol.% Bio-JP2 (BK2-10) are tested at temperature of 25, 30, 35
and 40 ◦ C. The results are revealed in Table 4.

Z=

+ 0.7 + exp(−1.47 − 1.84 − 0.51

(3a)
2

)

(3b)

= [Z − 0.7] − exp(−0.7487 − 3.295[Z − 0.7]
+ 0.6119[Z − 0.7]2 − 0.3193[Z − 0.7]3 )

(3c)

Substituting the values of the kinematic viscosity in Table 4
into Eqs. (3a) and (3b), we can find the constants A and B of the
best fit curves for each fuel sample. Fig. 9 shows the correlation of
kinematic viscosity along with temperature of Jet A-1, BK1-5 and
BK2-10.
The kinematic viscosity of fuels at −20 ◦ C can be determined by
solving for Z in the finding equation of Fig. 9 and then subsequently
deriving the kinematic viscosity from the value of Z by the use of Eq.
(3c). The viscosities at −20 ◦ C of Jet A-1, BK1-5, and BK2-10 respectively are 6.485, 6.940, and 6.789 mm2 /s which all fall within the
limit of ASTM standard. The result indicates kinematic viscosities
raise 7.02% for BK1-5 and 4.69% for BK2-10 as comparison with Jet
A-1.
4.7. The analysis of the environmental impact
Concentration of sulfur component in Bio-P1 and Bio-JP2 are
11 and 10 ppm, respectively. These values are much smaller than
the ASTM standard of 0.3% and 470 ppm of the commercial Jet A1. Thus the exhaust emissions of sulfur compounds (SOx ) will be
significantly reduced when using bio-paraffins.
The CO2 lifecycle of alternative jet fuels can be reduced by up
to 80% [5] depending on the production method. If we take into

Fig. 9. Relationship of kinematic viscosity–temperature of Jet A-1, BK1-5 and BK2-10.

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T.D. Hong et al. / Chemical Engineering and Processing 74 (2013) 124–130

consideration the change in specific fuel consumption due to the
difference of LHV between Bio-P1, Bio-JP2 and Jet A-1, the CO2 lifecycle can be reduced by up to 76% and 81% for Bio-P1 and Bio-JP2,
respectively. This means that each 1% blend of Bio-P1 or Bio-JP2
with fossil jet fuel will reduce up to 0.76% or 0.81% of overall aviation
CO2 emission.
Further measurements on the gas turbine engine are required to
assess the effects of gas exhausted emissions and soot formation.
However, due to Bio-P1 and Bio-JP2 are expected from the manufacturer are the paraffinic compounds and not aromatics, use of
these bio-paraffins is predicted that have remarkably less soot formation and have a similar CO, HC and NOx emissions in comparison
with conventional jet fuel.
5. Conclusions
The route of the production process proposed in this study is
appropriate to develop aviation biofuel in the Tropics since: (1)
the tropical countries have plenty of suitable feedstocks for the
proposed production process; (2) the technology and capital investment for the proposed production process are not too high to
implement; (3) besides, they can use, in part, the available infrastructures, production line of biofuel.
With preliminary achievements of this study, we have no doubt
about the feasibility of developing aviation alternative fuels according to the proposed production process for the tropical countries.
The results of the theoretical and experimental investigations
present that it can be made the “drop in” bio-kerosene by directly
blending Bio-P1 and Bio-JP2 with commercial Jet A-1 up to 5% and
10% by volume, respectively. The volume fractions of Bio-P1 and
Bio-JP2 in blends are able to reach higher if the distillations of the
bio-paraffinic compounds are improved by adding the step of unexpected component separation on production process and adding

aromatics or/and anti-icing additives to Bio-P1 and Bio-JP2 in order
to decrease their freezing point.
Use of Bio-P1 and Bio-JP2 is able to reduce respectively up to
0.76% and 0.81% of overall aviation CO2 emission for each 1% blending and significantly lessens the emissions of sulfur compounds
(SOx ). It is also predicted that has remarkably less soot formation
when using these bio-paraffins.
The future works need to do experimental studies on performances, gas exhaust emissions, soot formation of these aviation
biofuels to put them onto using in practice soon.
Acknowledgment
The operation funds for this work have been partly provided by
Japan International Cooperation Agency (JICA) under the project of
ASEAN University Network/Southeast Asia Engineering Education
Development Network (AUN/SEED-Net).
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