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AReview of Thermo-chemical Energy Conversion Process of Non-edible Seed Cakes
13
Gasification
Gasification was simple and commercially well
proven technology. Gasification processes converted
biomass into combustible gases that ideally contain all
the energy originally present in the biomass. In
practice, gasification could convert 60% to 90% of the
energy in the biomass into energy in the gas.
Gasification process involved conversion of various
feed stocks to clean producer gas which was a mixture
of hydrogen (H
2
) and carbon monoxide (CO) by
thermo chemical process.
The information available about the use of Jatropha
seed husks for energy purposes was limited. Analysis
of the husks by Singh et al. (2008) and Vyas and Singh
(2007) showed that the husks contained 4% ash, 71%
volatile matter and 25% fixed carbon. The calorific
value of the husks was 16 MJ/ kg. The Jatropha seed
husks had been converted to syngas in an open core
down draft gasifier. In that study, it was found that the
syngas calorific value and concentration of carbon
monoxide, along with gasification efficiency increased
with the increase in gas flow rate.
Table 8 and Table 9 highlighted the proximate and
ultimate analysis of the seed cake. These values were
the main data for predicting the gas gross calorific
value composition and temperature limits of the
gasifier through mass and energy balances.
Table 8 Proximate analysis
S.N.
Seed cake material
Moisture (%) Volatile matter (%)
Fixed carbon (%) Ash (%)
Source
1
Jatropha
8.71
70.92
16.06
4.30
Antony et al., 2010
2
Pongamia
8.12
70.00
17.48
4.40
Raja et al., 2011
Table 9 Carbon, hydrogen and nitrogen content of seed cake
S.N.
Seed cake material
C%
H%
N%
C/N
Source
1
Jatropha
48.80
6.20
3.85
12.70
Ram et al., 2006
2
Pongamia
47.80
6.50
5.50
8.70
Ram et al., 2006
The seed cakes had good volatile matter which gave
an attractive potential for energy exploitation through
gasification. A fuel with high volatile matter content
was more reactive, and therefore could be converted
more easily into gas while producing less char. The
presence of ash in seed cake was low (4.30 w/w %).
Hence this low ash would not create any major
problems such as slogging during gasification process.
Even though there was not enough information
available regarding gasification of seed cake, energy
production through gasification via was advisable.
The process of synfuels from biomass would lower
the energy cost, improve the waste management and
reduce harmful emissions. The syngas thus produced
could be used to produce electricity via integrated
gasification and combined cycle (IGCC) and auto
fuels (Petrol, diesel etc.) via Fischer-Tropsch method
(Mahajani, 2009). The following salient features also
support conversion of seed cake into combustible gas
through gasification.
1. Gasification floor area requirement was lowest per
unit output of energy in the form of heat/electricity.
2. High turndown ratio comparable to biogas and
higher than steam turbine systems.
3. Easy to operate gasifier, Reliable in operation and
Maintenance is easy.
Conclusion
From the literature review it was observed that some
of the energy conversion route analysis were done on
Jatropha and pongamia seed cake. But there was no
detailed study on seed cakes for energy recovery
through gasification process. Experiments on non
edible seed cake using gasification conversion route to
analyze its feasibility for effective energy recovery
and its utilization for thermal application and power
generation becomes indispensable. So it is necessary
to look at the parameters in detail to estimate the
constructive features of gasification conversion
process on seed cake over biogas generation
through bio methanation process and energy
generation via thermo chemical processes other than
Jouranal of Energy Bioscience