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ABSTRACT KEYWORDS
Journal of Energy & Environment
Journal homepage: www.uniten.edu.my/jee
Pre-treatment of Empty Fruit Bunch for Biofuel Production
N.A. Amin
1*
, N. Ya’aini
1
, M. Misson
1
, R. Haron
1
, M. Fadhzir
1
, A. Kamaroddin
1
1
Chemical Reaction Engineering Group (CREG), Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Johor,
Malaysia
1. INTRODUCTION
Recently, many research programs are devoted to the
development of renewable resources as a source for alternative
energy. Major types of renewable resources include wind,
solar and biomass. EFB is one type of biomass found abundant
in Malaysia due to the oil palm industry [1]. Pyrolysis of
biomass produces fuels in three phases; gas, liquid and char.
Biomass consists of three major components: cellulose,
hemicellulose and lignin. Lignin is the most complex structure
compared to hemicellulose and cellulose and requires high
temperature to be degraded. Therefore, biomass are pre-treated
using either chemical or enzymes prior to pyrolysis in order to
degrade the lignin structures for obtaining higher liquid yields
with improved properties [2,3].
Chemical pre-treatments using acid and alkaline pre-
treatment have been widely reported as a potential technique
for lignin degradation [3]. Effect of sodium hydroxide (NaOH)
and hydrogen peroxide (H
2
O
2
) in decomposing cotton stalks
lignin and pre-treatment with calcium hydroxide [Ca(OH)
2
]
are some examples [4]. Thus, chemical pre-treatment could
isolate the lignocellulosic components, disassemble the
biomass chains and increase the accessible surface area of
EFB to produce important chemicals during pyrolysis [5]. For
the enzymatic pre-treatments, two groups of peroxidases,
lignin peroxidase (LiP) and manganese peroxidase (MnP)
have been reported as having great potentials in biological
treatment for degrading lignin structures. LiP enzyme is a
more powerful oxidant compared to typical peroxidases, and
consequently oxidized not only the usual peroxidase substrates
but also a variety of non-phenolic lignin structures [6, 7].
Unlike LiP enzyme, MnP enzyme is not as strong and is
consequently unable to attack non-phenolic structures that
predominate in the lignin.
Pyrolysis process is best suited for conversion of biomass
to liquid fuel. It is a thermo-chemical conversion process in
the absence of air or oxygen [8]. Different conditions of the
pyrolysis process have led to the formation of products in
different proportions of useful liquid oil, gases and solid [9].
In this study, the pyrolysis experiment was performed by
using a semi-batch reactor under nitrogen gas condition and
HZSM-5 as the catalyst with the ratio of catalyst and EFB, 5
wt%. The application of bio-oil as a fuel in boiler systems,
stationary diesel engines, gas turbines, and sterling engines
had been widely reported [10,11]. However, poor volatility,
high viscosity, coking and corrosiveness of crude bio-oil have
limited the application mentioned above. Therefore, a number
of bio-oil upgrading technologies were proposed to improve
the product properties and to increase the range of possible
applications [10].
The main objective of this study is to investigate the
potential of chemical and enzymatic pre-treatments for EFB
conversion to biofuel. The EFB samples were then
catalytically pyrolyzed while the resulting bio-oils were
further upgraded by reactive distillation to improve the
properties of the oil including heating value, water content,
viscosity, and acid content.
© 2011 Universiti Tenaga Nasional. All rights reserved.
A new method to convert biomass to valuable chemicals and fuels has been investigated.
Empty fruit bunch (EFB) was chemically and biologically pre-treated to enhance the
quality of biofuel and reduce undesired components such as alcohols, ketones and
nitrogenated compounds. For chemical pre-treatment, product analysis indicated bio-oil
contained mixtures of esters at 21 wt% yield and acids at 42 wt% yield with minimal
phenolic compounds. Meanwhile in biological pre-treatment, lignin peroxidase (LiP)
enzyme was the powerful oxidant compared to MnP enzyme with 71.69% of lignin was
degraded by LiP enzyme and 67.94% from manganese peroxidase (MnP) enzyme. Treated
EFB produced higher conversion and liquid oil yield. Further oil up-grading has improved
the heating value and reduced water content, thus the bio-oil can be conveniently
processed for further use. This new method provides an alternative technique for
producing important chemicals and fuels from biomass.
Pre-treatment
EFB
Pyrolysis
Upgrading
*Corresponding author
E-mail address: N.A. Amin < noraishah@cheme.utm.my>.
Tel.: +607-553-5579; Fax: +607-558-1463