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TOLEDO (SPAIN)COMPOSITION OF PRODUCTS OBTAINED VIA FLASH PYROLYSIS OF DIFFERENT
LIGNOCELLULOSIC BIOMASS. EFFECT OF PYROLYSIS TEMPERATURE
A. Marcilla1, A. N. Garcia1, M.V. Pastor1, A.J. Sanchez2 and D.M. Gomez2
1Chemical Engineering Department, University of Alicante, 03080 Alicante, P. Box 99, Spain
2 Acciona Infraestructuras. Technological Center I+D+I, Valportillo II, nº 8, 28080 Alcobendas, Madrid, Spainemail2:e-mail1: antonio.marcilla@ua.esdianamaria.gomez.lozano@acciona.esAbstractFlash pyrolysis experiments were carried out with six different lignocellulosic biomass (almond shell, olive stone,
conglomerate wood, eucalyptus leaves, eucalyptus branches and eucalyptus wood) in a fluidized bed reactor. Low
temperatures were selected in order to maximize the liquid yields obtained. So, pyrolysis experiments were conducted at
500 and 600 ºC under a nitrogen atmosphere with the aim to study the effect of temperature on the proportion of gas,liquid and solid fraction, which were analyzed to identify and quantify the compounds detected. A total of 29 and 96
chemical species were positively identified and quantified in the gas and liquid phase respectively. Note the large numberof phenolic compounds detected in the liquid phase as well as compounds that only were part of eucalyptus biomass(eucalyptol, calarene, alloaromadendrene, etc.). Respect to the gas phase, CO 2 and CO were the major compounds, thesum of these increasing with temperature as solid and liquid fractions decreased, in a more or less pronounced way,depending on the material being pyrolyzed.

Keywords: flash pyrolysis, almond shell, olive stone, conglomerate wood, eucalyptus

1. Introduction
Renewable energy is of growing importance in satisfying
environmental concerns over fossil fuel usage. Wood andother forms of biomass including energy crops andagricultural and forestry wastes are some of the main
renewable energy resources available. These canprovide the only source of renewable liquid, gaseous andsolid fuels [1]. In this way, thermochemical methods suchas pyrolysis are the most appropriate to provide a liquid
fuel that can substitute for fuel oil in any static heating orelectricity generation application.
The overall objective of this work was to study the use of
biomass pyrolysis as a means of characterization of thesamples and to obtain molecules of interest, especiallythose from the lignin fraction (mainly phenoliccompounds) from the liquid phase.

2. Materials and Methods
Six lignocellulosic biomass samples, almond shell (AS),olive stone (OS), conglomerate wood (CW), eucalyptus
leaves (EL), eucalyptus branches (EB) and eucalyptus
wood (EW) were studied. Almond shell and olive stone
were supplied by region manufacturers, conglomerate
wood by the carpentry of the University of Alicante andeucalyptus biomass were supplied by Acciona
Infraestructuras. The samples were dried before
performing the experiments.

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Flash pyrolysis experiments were carried out in a
fluidized bed reactor which consisted of a 71 x 5.2 cm
cylindrical stainless steal reactor surrounded by arefractory furnace with a controller to select thetemperature of pyrolysis. Moreover, it had a side exit to
the volatile compounds generated during pyrolysis.
Furthermore, the furnace and the reactor could berotated on its horizontal axis to facilitate removal of solids
inside at the end of the experiment. As a feeding system
was used a hopper where about 2 g of sample wasloaded. Experiments were carried out at low
temperatures (500 and 600 ºC).
In this case, the fluidized bed was silica sand with aparticle size between 70-210 Pm. The particle size of thesample selected was between 710-1000 Pm in order tofacilitate, after the experiment, the separation of theresidue from the sand by sieving. The gas used to carryout and drag the gaseous products generated wasnitrogen, which flow was controlled through a previously
calibrated rotameter.
Condensable volatiles generated in the pyrolysis process
were collected through a series of glass traps submergedin ice-water bath, filled with stainless steel Dixon rings.
This liquid fraction was extracted with ethanol andanalysed by gas chromatography/mass spectroscopy.
Non-condensed volatile products were collected in Tedlarbags of 5 and 25 liters for further analysis in TCD and26/9/11 13:12:57

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6th International Symposium on Feedstock Recycling of Polymeric Materials

FID chromatographs. Finally, the solid fraction wasobtained after sand bed sieving and weighting.
Response factors of some patterns were determined toquantify obtained compounds in gas and liquid fractions.

Table 2. Major compounds detected in liquid fraction ofolive stone
Compound

3. Results and Discussion

Acetic Acid
FurfuralFurfuryl alcohol
Phenol
3-Metilhidantoin
CorilonGuaiacolMaltol
Pyrocatechol
3-Methoxycatechol
p-Ethylguaicol
Siringol
Levoglucosan
Methoxyeugenol
Coniferyl alcohol
Others phenolic derivatives
Other compounds

The percentages of gas and liquid fractions obtained ineach pyrolysis experiment carried out are shown in Table
1. The gas percentage increases with temperature, inmore or less extent as a function of the biomass, as canbe seen in Table 1.
Table 1. Gases and Liquids yields (% wt)
Biomass
OSAS
CW
ELEB
EW

T (ºC)
500
600
500
600
500
600
500
600
500
600
500
600

Gases (% wt)
20.4
23.7
21.8
29.9
13.1
24.4
15.3
31.8
19.7
34.4
18.6
26.7

Liquids (% wt)
37.2
28.8
34.5
40.6
30.2
39.4
39.1
21.837.0
35.7
39.4
30.2

In the gas fraction, CO2 and CO were the compoundswith higher yield obtained, summing up between 12 and
31% as a function of temperature and biomass. Almondshell and eucalyptus branches were the biomasses
which produced higher yield of these compounds whileconglomerate wood was the biomass which produced alower amount of them. Other compounds detected in thisfraction were light hydrocarbons such as methane,ethane, propane, n-butane, pentane, n-hexane, nheptane, toluene etc, being methane the major
compound after CO2 and CO. The sum of all of thesehydrocarbons obtained was in the range 0.6 and 3.5 %.
About the liquid fraction, a large number of compounds
were identified and quantified. As an example, Table 2
shows the major yields obtained from the olive stone. As
can be seen in this Table, the major compound detected
was Acetic Acid. In addition to this, most of thecompounds decreased their yield with temperature.
However, compounds as Maltol, Pyrocatechol, 3Methoxycatechol and Levoglucosan increased their yield
when temperature increased. Note that this behavior wasdifferent as a function of the biomass under study.

OS500 ºC
7.8
1.1
0.17
0.21
0.50
0.30
0.58
0.037
0.35
0.14
0.062
0.56
0.22
0.063
0.12
2.6
4.1600 ºC
5.1
0.68
0.12
0.18
0.20
0.22
0.26
0.063
0.52
0.20
0.036
0.15
0.44
0.012
0.048
1.6
2.9

4. Conclusions
The experiments carried out at 500-600 ºC lead to thefollowing conclusions:--The percentage of hydrocarbons on the gas fraction
obtained was in the range 0.6-3.5 %. The calorificvalue of this fraction was around 2000 kcal/kg
Respect to the liquid fraction, the major compound
obtained was acetic acid (1.2-7.8%). The
percentage of phenolic compounds were in therange 0.5-6.7%, and other compounds (such asaldehydes, ketones and other acids) in the range
0.8-5.8 %.

Acknowledgements
Finnancial support for this investigation has been
provided by CDTI (Project Ingenio 2010-CDTI-BioSosCEN-2009-1040) and by Ministry of Science andInnovation. Local investment fund for employment.
Government of Spain.

References[1] A.V. Bridgwater, S. Czernik, J. Piskorz. In: A.V.
Bridgwater Ed. The status of biomass fast pyrolysis. Fastpyrolysis of biomass: A handbook. Vol. 2, pp. 1-22, UK,April 2002. CPL Press Liberty House

Moreover, it is worth mentioning the different compounds
detected in eucalyptus biomass, such as Allo-ocimene,
Aromadendrene, Gurjunene, Calarene, Selinene, etc.,
being the most notable Eucalyptol which higher yieldobtained was around 1% from leaves of eucalyptus.

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