2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
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Biomass has complicated composition, which could be
presented as the sum of extractable organic compounds
(usually 1-10
%
wt.), lignin (15-30
%
wt.), cellulose (20-
40
%
wt.) and other polysaccharides (hemicelluloses) (15-
25
%
wt.). The main products of the biomass pyrolysis are
charcoal and tar. The pyrolysis conditions have an
important influence and the amount and composition of
tar product formed [6].
The liquid product from biomass pyrolysis is known as
biomass pyrolysis oil, and bio-oil, pyrolysis oil, or bio-
crude for short. Bio-oil from biomass fast pyrolysis is
mainly produced from biomass residues in the absence of
air at atmospheric pressure, a low temperature (450-550
q
C), high heating rate (10
3
-10
4
K/s) and short gas
residence time to crack into short chain molecules and be
cooled to liquid rapidly. Fast pyrolysis, an effective
biomass conversion with high liquid yield, as much as
70-80
%
and a high ratio of fuel to feed, is regarded as one
of the reasonable and promising technologies to compete
with and eventually replace non-renewable fossil fuel
resources [4].
The present paper describes analysis costs estimation
for a BtL production in Thailand. This allows the
pyrolysis plants and gasification plants to be optimally
sized and located independently of each other. In order to
investigate the merits of possible plant combinations it is
necessary to have an understanding of investment
dependent costs, personal costs, and material and energy
flow dependent costs.
II. M
ATERIAL AND
M
ETHOD
Biomass to liquid (BtL) production design:
On the
basis of the reference configuration and the results from
biomass potential analysis a BtL production network is
elaborated. Sources for feedstock, locations and structure
of the fast pyrolysis and the gasification plants are
determined as well as feedstock supply, transport
distances and costs [7].
Studies have been carried out on:
I. Analyze the amounts, chemical compositions, and
location of accruance of biogenic residues
II. Elaborate a possible configuration for a BtL
production in Thailand
III. Economic assessment of the possible BtL
production chain
:
the parameters used in this study to
calculate the production cost of BtL fuel in Thailand are
an interest rate of 5.875% and 20 years expected lifetime.
The average annual maintenance costs for the pyrolysis
plant and gasification and synthesis plant equal about 4%
of the BtL facilities [7]. And calculate the payback
period.
The payback period standard is known as the timeline
or timeframe, which is normally expressed in years, for
the full payback or all the investment costs (total invested
capital) are being pumped in the project. The term
investment costs or total invested funds means the total
invested costs in the project which include: total fixed
assets, preliminary expenses, working capital, and bank
interest. The capital or investment costs are financed by
the equity, in addition to the banking facilities. Hence, the
recovery period should be looked at as the recovery of all
capital investments regardless of their sources. Therefore,
The Payback Period equation is calculated as follows [8]:
Payback Period = Total Investment Costs
Net Cash flow in the year
III. R
ESULT AND
D
ISCUSSION
I. Analyze the amounts, chemical compositions, and
location of accruance of biogenic residues
Potential biomass availability in Thailand
A large population in Thailand is dependent on
agriculture as their livelihood. Therefore, the potential of
various kinds of biomass availability exists in Thailand
villages. Crops that have been used for energy include:
sugarcane, corn, sugar beets, palm oil, and many others.
There are several factors, which determine whether a crop
is suitable for energy use. The main material properties of
interest during subsequent processing as an energy
source, relate to-moisture content (intrinsic and extrinsic),
calorific value, proportions of fixed carbon and volatiles,
ash/residue content, alkali metal content, and
cellulose/lignin ratio. The first five properties are
significant for dry biomass conversion processes, while
first and last properties are important for wet biomass
conversion. Good energy crops have a very high yield of
dry material per unit of land (dry ton /ha). Table I
presents the national harvested areas of sugarcane, rice,
and oil palm.. It was found that available potential land
for biomass production in Thailand, which is increasing
every year.
Agriculture crop residues
A large amount of agriculture residues are produced in
agriculture based country like Thailand. These constitute
a potential biomass feedstock for energy conversion. The
term agricultural residue is used to describe all the
organic materials which are produced as the by-products
from harvesting and processing of agricultural crops.
These residues can be further categorized in to primary
residues and secondary residues. Agricultural residues,
which are generated in the field at the time of harvest, are
defined as primary or field based residues (e.g. rice straw,
sugarcane tops), whereas those co-produced during
processing are called secondary or processing based
residues (e.g. rice husk and sugarcane trash). Availability
of primary residues for energy application is usually low
since collection is difficult and they have other uses as
fertilizer, animal feed. However secondary residues are
usually available in relatively large quantities at the
processing plant involving no or little transportation and
handling cost. In order to assess the potential of primary
residues, the available data has been listed in Table II.
