2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
- 149 -
IV. R
ESULT AND
D
ISCUSSION
The calculation of amount from a life cycle assessment
(LCA) method is divided into 3 processes: transportation,
briquette production and electricity production. These can
be calculated by analyzing the amount of environmental
impact from the Ecoinvent database and SimaPro
Program (EDIP 2003 Method).
A. Goal and Scope Definition
The purpose of this work is to determine the
environmental impact of the electricity production from
biomass gasification. The emissions per 1 kWh of
electricity was estimated.
The scope of this LCA study is divided into three
phases:
beginning
with
transportation,
briquette
production, and electricity production, by focusing on the
materials and energy consumption, as shown in Fig. 2.
Fig. 2. Life cycle diagram of biomass gasification power
plant.
B. Life Cycle Inventory
In the life cycle inventory analysis, we collected the
actual data in the transportation process, briquette
production process, and data in the electricity production
at Thanksin University (Phatthalung campus). The data
considered the input materials such as rice husk,
glycerine, water, and energy. Briquette in the form of
mixed rice husk and glycerine with a ratio of 3kg: 500ml
is applied at a rate of 700,800 kg for electricity
production per year. Watering required 83,703.80
liters
per year. The power generation consists of a small-scale
community industry gasifier of 1 m
3
reactor with a screw
pressed conveyor for fuel feeding, a cyclone, an ash
hopper, a wet scrubber, a gas filter, a gas engine of 1,425
cc and a generator of 100 kW. The life cycle inventory of
briquette gasification power generation in
a year was
shown in Table 6.
TABLE VI
T
HE LIFE CYCLE INVENTORY OF THE BIOMASS GASIFICATION POWER
PLANT OPERATION IN A YEAR
Rice Husk Transportation
Input
Machine
Truck
15 t
Energy
Diesel 6,115.23 l
Distance
40 km
Output
Emission/Waste
Emission from Combustion
Glycerine Transportation
Input
Machine
Truck
15 t
Energy
Diesel 3,738.81 l
Distance
216 km
Output
Emission/Waste
Emission from Combustion
Briquette Production
Input
Machine
MSB-0001
Material
Rice Husk
611,523.04 kg
Glycerine 128,521.76 kg
Energy
Electricity 322,801.09 kWh
Heat
1,212,529.66
MJ
Output
Emission/Waste
Emission from Combustion
Electricity Production
Input
Machine
Gasification
Material
Water
83,703.80
l
Briquettes
700,800 kg
Energy
Electricity 135,569.76 kWh
Output
Emission/Waste
Emission from Combustion
C. Life Cycle Impact Assessment
Characterization
The substances that contribute to an impact category
are multiplied with a characterisation factor that
expresses the relative contribution of the substance. The
result of characterization processes shown in Fig 3. All
results showed the impact category in different units. The
units are rather abstract, like: CO
2
equivalents, SO
2
equivalents and some sort of toxic potential. This process
is unable to compare the impact category each other.
Fig. 3. Result of characterization process.
Material
Enviromental
Impact
Transportation
Briquette Production
Electricity Production
Energy
