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Used Felhasznált quantity mennyiség, 10 6 t/year 10
EFFECTS OF BLENDING BIOPARAFFINS TO JET FUEL PRODUCTS
Zoltán Eller 1 , Jenő Hancsók
1 MOL Department of Hydrocarbon- and Coal Processing, University of Pannonia,
Egyetem street 10., Veszprém, Hungary (ellerz@almos.uni-pannon.hu)
Key words: Jet fuel, bioparaffin, aromatic content
Abstract: Presently the growing demand for the jet fuels is increasing even more and the
severe quality specifications are getting more and more severe. The reasons of these are the
growing aviation and the more conscious environmental requirements.
In this context we studied the changing of the properties of products produced at different
process parameters (temperature: 200-360°C, pressure: 20-50 bar, liquid hourly space
velocity: 1.0 – 3.0 cm 3 /cm 3 h and hydrogen/hydrocarbon volume ratio: 200-400 Nm 3 /m 3 ) from
the catalytic experiments as a function of blending bioparaffins. Based on the quality
parameters of the liquid products we found that by blending bioparaffins in to the products the
aromatic content decreased successfully more (< 5%), moreover the application technology
properties improved, too – smoke point: 33 mm, crystallization point -51°C.
I. Introduction
Recent demands for low aromatic content jet fuels have shown significant increase
in the past 20 years. (Figure 1.) [1]. This is caused by the constant growing of
aviation. Besides, the quality requirements for jet fuel quality have got more severe,
too. This is caused partially by the increasing environmental regulations and the
growing performance properties. Nowadays the production of jet fuels with good
burning properties is expedient from reduced aromatic hydrocarbon fractions [1,2, 3].
The expansion of aviation featured the last two decades, especially the 2% of the
front of the reviewed session approaches 15%, if we calculate in the point of
passenger kilometers the driven passages with vehicles, buses, railroad and jets.
6 t/év
250
200
JET Motorbenzin Gasoline Dízelgázolaj
Diesel gasoil
150
100
50
0
1990 1995 2000 2005 2010 2015 2020
Year Év
Figure 1.: Quantity demands of fuels (EU-27) [1]
It can not be left from focus that aviation generates only 2% of the CO 2 emission of
the world. This value can grow only to 3% to 2050. Moreover it generates only 12%
of the CO 2 emission of the full transportation section. For comparison the road
transport generates 76% of the CO 2 emission [4, 7, 8, 9].

One of the greatest problems are the jets that fly at one time more than 1500
kilometers, because aviation produces the 80% of greenhouse gases, because at the
end of the passage they let the emergency fuel out, so they increase the forming of the
greenhouse effect. But there are no alternative solutions to bridge these distances in
the transport section [10, 11].
In the near past the properties of gasolines and diesel gas oils continuously got
more severe, and the properties of jet fuels are expected to become stricter, too. So the
possibilities to produce low aromatic and low sulphur content jet fuels in a
heterogeneous catalytic way is now being studied all over the world. [2, 7, 8, 12].
Presently the jet fuels are produced from different feedstocks. Due to the growing
demand more feedstock sources must be taken into account. With their application
environmental friendly (low sulphur and aromatic content) fuel can be produced with
favourable application-technical properties. (Figure 2.) [1, 2, 3, 4, 5, 6].
POSSIBILITIES OF PRODUCTION
OF JET FUEL
FROM RENEWABLE
FEEDSTOCK
FOSSILIC BASED
FEEDSTOCK
HYDROGENATION OF
TRIGLYCERIDES
HYDROGENATION OF
LIGNOCELLULOIDES
FROM
SYNTHESIS GAS
PRODUCTION WITH
CONVERSION PROCESS
WITHOUT CARBON
NUMBER CHANGING
Hydrogenation, desulphurization and/or
aromatic saturation of petroleum fractions
WITH CARBON
NUMBER CHANGING
Hydrocracking of heavy distillates,
oligomerization + hydrogenation
PRODUCTION
WITH SYNTHESIS
Based on synthesis gas (CH 4, coal, crude oil products) Fischer-
Tropsch synthesis, products and hydrocracking isomerization
Figure 2.: Classification of the possibilities of producing jet fuels
The role of producing jet fuels from triglycerides in a catalytic way will be more
important in the near future (Figure 3.). During the hydrogenation, the formed
normal- and iso-paraffin hydrocarbons have suitable energetical and low temperature
properties [7].
Figure 3.: Jet fuel production from triglycerides

In the future, beside the hydrogenation of triglycerides, two other processes
operating with renewable source feedstock can get a role; one produces motor fuels
with transformation and hydrogenation of lignocelluloids, while the other is the
Fischer-Tropsch synthesis, which processes synthesis gas from biomass, and which is
applied in our present days (Figure 4. and 5.) [8].
Carbonhydrates
Lignocelluloids
Acid catalyzed
condensation
Aldol
condensation
Solid basic catalyst
Hogh molecular weight organic compounds
Hydrogenation
Bifunctional catalyst
Jet fuel
Figure 4.: Jet fuel from lignocelluloids
BIOMASS
OILSAND, CRUDE OIL, WASTES,
NATURAL GAS, COAL
From other sources
2 H 2
+ CO 2
SYNTHESIS GAS
(CO+H 2
)
FISCHER-TROPSCH
SYNTHESIS
SYNTHETIC
CRUDE OIL
z (-CH 2
-CH 2
) X
-
SYNTHETIC
GASOLINE, JET,
GAS OIL, BASE OIL
ISOMERIZER
HYDROCRACKING
CH 2
CH
CH 2
n
m
Figure 5.: Jet fuel production with Fischer-Tropsch synthesis during
isomerizer hydrocracking

II. Experimental
The aim of our experimental work was to study the production possibilities of reduced
sulphur and aromatic content jet fuel with the catalytic hydrogenation of a petroleum
fraction. We studied the effect of the process parameters on the liquid product yield
and quality. Our further aim was to study the availability of a paraffin mixture that is
produced by catalytic hydrogenation of triglycerides, as a jet fuel blending
component.
2.1. Experimental apparatus
The heterogeneous catalytic hydrogenation experiments for aromatic saturation
were carried out in a reactor system which contained all of the important apparatus
and units that can be found in a reactor loop of an industrial desulphurizer and
aromatic hydrogenation plant. The simplified process flow diagram of the apparatus is
shown in Figure 6. The effective volume of the reactor was 100 cm 3 .
7.
14.
6.
15.
20.
5.
16.
I-3
Purge gas
Hydrogen
2.
4.
17.
I-2
19.
3.
18.
1.
13.
8.
12.
Feedstock
10. 11.
9.
21.
22.
23.
Liquid product
Figure 6.: The applied experimental apparatus
Legend: 1.: bottle-storage; 2., 4., 6 non-return valves; 3., 5.: gasreductors; 7.:
gasflow controller; 8.: feedstock vessel; 10.: filter; 11.: feedstock pump; 12.:
throttle valve, 13.: flowmeter; 14.: reactor; 15., 16., 17.: thermometers; 18.:
separator; 19.: pneumatic valve; 20.: gas-meter; 21.: magnetic valve;
22.: product receiver; 23.: liquid product outlet
2.2 Materials
During the experiments we used a NiMo/Al 2 O 3 catalyst, which is suitable for the
desulphurization of gas oils. Before the starting of the experiments we loaded 60 cm 3
(56.79 g) catalyst in to the middle section of the reactor. After the load, we carried out
the activation of the new, unactivated catalyst by the activation (curing and
presulphidation) program that was worked out by the Department.
The quality properties of the applied feedstock, which we used during the
experiments, are given in Table I. It was produced from Russian crude oil at the MOL
Plc. with distillation.

Appearance
Aromatic content, %
Monoaromatic
Diaromatic
Merchaptane sulphur
content, %
Total sulphur content,
Clear, transparent and
sediment free
17.9
3.8
0.01
1800
mg/kg
Density on 15°C, g/cm 3 0.8083
Crystallization point, °C -43
Heating value, MJ/kg 42.37
Smoke point, mm 23.4
Table I.: Quality properties of the used petroleum fraction
The main quality properties of the alternative origin blending component (paraffin
mixture), which was used for the blending of jet fuel, are shown in Table II.
2.3 Methods
Property
Value
Sulphur content, mg/kg < 1
Aromatic content, % < 0.1
Heating value, MJ/kg 43.3
Crystallization point, °C -53
Smoke point, mm 44
Table II.: The main properties of the alternative origin jet fuel blending
components
Appearance MSZ 10870:1995
Density EN 12185:1998
Sulphur content EN 14596:2007
EN 20846:2004
Aromatic content EN 12916:2000
Smoke point EN 3014:1993
Heating value EN 19954:1971
Crystallization point EN 2047:1986
Distillation properties EN 3405:2000
Table III.: Standard methods for the quality properties of the feedstocks and
the liquid products
The main quality properties of the petroleum fraction that was used as feedstock
and the liquid products were determined according to the standards with the
prescribed tolerance given in Table III.

Aromatic content, %
III. Results and discussion
In the following we discuss the effects of the bioparaffin mixture that was blended
to the products hydrogenated in a catalytic way, so its effect on the total aromatic
content, sulphur content, heating value, moreover on the crystallization point and
smoke point.
The aromatic content of the feedstock petroleum fraction was 21.7% based on
HPLC results, which we reduced to 14% at 300°C and 40 bar pressure and 1.0 h -1
liquid hourly space velocity. With the aggravation of the process parameters, this
value decreased further. The aromatic content of the products decreased further with
the blending of bioparaffins. In case of product produced at 340°C (P= 50 bar,
LHSV= 1.0 h -1 ) this value was the lowest, it was 4% (Figure 7.).
16
14
12
0% Bioparaffin, P=40 bar 10% Bioparaffin, P=40 bar
20% Bioparaffin, P=40 bar 30% Bioparaffin, P=40 bar
0% Bioparaffin, P=50 bar 10% Bioparaffin, P=50 bar
20% Bioparaffin, P=50 bar 30% Bioparaffin, P=50 bar
10
8
6
4
2
0
290 300 310 320 330 340 350 360 370
Temperature, °C
Figure 7.: Changing of the aromatic content as a function of the temperature
and share of bioparaffins
(LHSV: 1.0 h -1 , H 2 /HC volume ratio: 400 Nm 3 /m 3 )
The changing of the aromatic content affects the crystallization point and smoke
point of the products. The crystallization point decreased well during the catalytic
experiments, the reason is the hydrogenation of the aromatic content of the feedstock
to cycloparaffins. The reason of this is that the crystallization points of cycloparaffins
are lower than the crystallization points of aromatics. Due to the -53°C crystallization
point of the bioparaffin mixture after the blending the crystallization points of the
products from the catalytic experiments decreased by 2-3°C, so we produced a
product that has a crystallization point of -51°C (Figure 8.).

Smoke point, mm
Crystallization point, °C
-43
-44
-45
-46
-47
0% Bioparaffin, P=40 bar
10% Bioparaffin, P=40 bar
20% Bioparaffin, P=40 bar
30% Bioparaffin, P=40 bar
0% Bioparaffin, P=50 bar
10% Bioparaffin, P=50 bar
20% Bioparaffin, P=50 bar
30% Bioparaffin, P=50 bar
-48
-49
-50
-51
-52
290 300 310 320 330 340 350 360 370
Temperature, °C
Figure 8.: Changing of the crystallization point as a function of the
temperature and share of bioparaffins
(LHSV: 1.0 h -1 , H 2 /HC volume ratio: 400 Nm 3 /m 3 )
The smoke point is determined by the aromatic content of the product, too. During
the hydrogenation the value of this property increased with decreasing the aromatic
content. The smoke point of the applied bioparaffin mixture was 44 mm. At 300°C
and 40 bar pressure the 10% blended bioparaffin mixture improved the smoke point,
so this blend performed the 25 mm prescription of the standard. The smoke point
values of the products produced at 360°C can be explained by the declined
hydrogenation (saturation) of the aromatics caused by the thermodynamic inhibition
(Figure 9.).
35
32
29
26
23
0% Bioparaffin, P=40 bar 10% Bioparaffin, P=40 bar
20% Bioparaffin, P=40 bar 30% Bioparaffin, P=40 bar
0% Bioparaffin, P=50 bar 10% Bioparaffin, P=50 bar
20% Bioparaffin, P=50 bar 30% Bioparaffin, P=50 bar
20
290 300 310 320 330 340 350 360 370
Temperature, °C
Figure 9.: Changing of the smoke point as a function of the temperature and
share of bioparaffins (LHSV: 1.0 h -1 , H 2 /HC volume ratio: 400 Nm 3 /m 3 )

The heating value of the products increased in a small amount with the blending of
the bioparaffins. At the same time this increase has high importance, considering the
quantity loadable into the fuel tank of jets, because a product with higher energy
content can be loaded in the same volume (Table IV.).
Properties
Heating value, MJ/kg
Bioparaffin content, % 0 10 20 30
Pressure, bar
Temp.,°C
40 50 40 50 40 50 40 50
300 41.94 42.81 42.08 42.86 42.21 42.91 42.35 42.96
320 42.07 42.94 42.19 42.98 42.32 43.01 42.44 43.05
340 42.16 43.03 42.27 43.06 42.39 43.08 42.50 43.11
360 42.10 42.97 42.22 43.00 42.34 43.04 42.46 43.07
Table IV.: Changing of the heating value of the products caused by the
bioparaffin mixture
Summary
There are a lot of possibilities to produce modern jet fuel. Our aim was to improve
further the quality of catalytic hydrogenated jet fuels with blending bioparaffins to
them.
We studied the changing of the aromatic content of the products caused by the
attenuative effect of the bioparaffin mixture. We produced products that have 4%
aromatic content. We studied the effect of the bioparaffin mixture on the applicationtechnical
properties (crystallization point and smoke point). We determined that the
values of both of the studied properties improved, and by the blending of the
bioparaffin mixture, in case of 30% bioparaffin content the crystallization point was -
51°C, while the smoke point was 33 mm when the bioparaffin mixture was blended to
the product which was produced at 340°C, 50 bar and liquid hourly space velocity 1.0
h -1 .
References
[1] Dastillung, M.: “Oil Refining in the EU in 2015”, CONCAWE Report, no.
1/07, 2007
[2] . J. Hancsók.: “Fuels for Engines and JET Engines Part II: Diesel Fuels”,
Publisher of University of Veszprém, Veszprém, 1999,ISBN:963 9220 27 2
[3] J. Hancsók, G. Gárdos, E. Szatmári, Zs. Keresztessy: “Catalytic hydrogenation
of petroleum fractions” 7 th International Symposium of Heterogenous
Catalysis, Bourgas , Proceeding, 1991., 827-832.
[4] Nagy, G., Hancsók J., Varga, Z.: “Investigation of the Hydrodearomatization
of Diesel Fuels”, 5th International Colloquium on Fuels 2005, Esslingen,
Németország, 12-13 January 2005 (ISBN 3-924813-59-0) 385-392.
[5] L. Vradman, M. V. Landau, M. Herskowitz: “Hydrodearomatization of
petroleum fuel fractions on silica supported Ni-W sulphide with increased
stacking number of the WS 2 phase” Fuel, 633-639., 2003.

[6] R. H. Natelson, M. S. Kurman, N. P. Cernansky, D. L. Miller: “Experimental
investigation of surrogates for jet and diesel fuels”, Fuel, 2339-2342., 2008.
[7] Hancsók, J., Krár, M., Magyar, Sz., Boda, L., Holló, A., Kalló, D.,
Microporous and Mesoporous Materials, 2007, 101(1-2), 148-152.
[8] Hancsók, J., Kasza, T.: “The Importance of Isoparaffins at the Modern Engine
Fuel Production”, 8th International Colloquium Fuels 2011, Germany,
Stuttgart/Ostfildern, 19-20 January 2011, In Proceedings (ISBN 3-924813-75-
2), 361-373.
[9] Varga, Z., Hancsók, J., Nagy, G., Stumpf, Á., Kalló, D.: “Investigation of
hydrotreating of gas oil fractions of different crude oils”, 7th World Congress
of Chemical Engineering Incorporationg the 5th European Congress of
Chemical Engineering, SECC, Glasgow, Scotland, 10-14 July 2005.
[10] C. Song: “An overview of new approaches to deep desulfurization for ultraclean
gasoline, diesel fuel and jet fuel” Catalysis Today, 211-263., 2003.