Environmental Engineering Reference
In-Depth Information
becomes unfit for use in a gasifier (Singh et al. 2008). They prepared the briquettes from jatro-
pha shell powder in the improved metal cooking stove (Chullah) having a thermal efficiency of
approximately 24%. The time required for the complete combustion of 1-kg briquettes was found
to be 35 min, and the temperature in the range of 525-780°C was achieved during the combustion
period. Briquettes did not crumble, and their original shape was maintained during combustion.
14.6.3 u
SE
of
o
il
c
akE
for
B
iogaS
and
m
anurE
Jatropha cake can be used as a source of feedstock for biogas production. In a study conducted by
Singh et al. (2008), biogas produced from jatropha cake was measured and compared with that gen-
erated from cattle dung. The quantity of biogas produced from seed cake was observed to be 60%
higher than that produced from cattle dung. It was reported that the total biogas production after the
incubation period of 40 days was 348 L/kg total solids (TS) from the reactors having jatropha cake
at 10% TS, whereas it was 241 L/kg TS from the reactors having jatropha cake at 15% TS. Methane
in biogas was found to be 66 ± 2% in both of the cases.
14.6.4 p
roduction
of
S
ilvEr
n
anoparticlES
Present green synthesis shows that the environmentally benign and renewable latex of jatropha
can be used as an effective capping and reducing agent for the synthesis of silver nanoparticles.
Silver nanoparticles synthesized by the above method are quite stable and no visible changes were
observed, even after a month or so, when the nanoparticle solutions were kept in light-proof con-
ditions (Bar et al. 2009). Synthesis of metallic nanoparticles using green resources such as jatro-
pha latex is a challenging alternative to chemical synthesis because this novel green synthesis is a
pollutant-free and ecofriendly synthetic route for silver nanoparticles.
14.6.5 p
roduction
of
a
ctivatEd
c
arBon
Activated carbon, also known as porous carbon, has been widely used as an adsorbent in the separa-
tion and purification of gas or liquid. In addition, high-porosity carbons have recently been applied
in the manufacture of high-performance layer capacitors. Sricharoenchaikul et al. (2008) prepared
activated carbon from pyrolyzed jatropha waste char in a laboratory-scale facility. The carbon con-
tent of the activated carbon was found to be in the range of 80.4-90.3% depending on the activation
method. The activated carbon prepared by chemical activation of the pyrolyzed jatropha residue at
800°C with KOH attained a maximal Brunauer-Emmett-Teller (BET) surface area of 532.3 m
2
/g,
as compared with the surface area of those activated with phosphoric acid (H
3
PO
4
) and CO
2
. Pores
of activated carbon from the jatropha residue were found to be mainly mesopores. The adsorption
capacity of the prepared activated carbon confirmed the feasibility of the production of quality acti-
vated carbon from plant oil (JO) waste.
14.6.6 w
aStEwatEr
t
rEatmEnt
The jatropha seed coat powder can be used as an adsorbent for removal of Cu(II) from wastewater.
Jain et al. (2008) reported that the time required to reach adsorption equilibrium was 80 min, and
82-89% of Cu(II) was removed by the jatropha seed coat at initial Cu(II) concentrations of 20-50
mg/L. The most plausible mechanism of adsorption seemed to be the electrostatic attraction of
Cu(II) toward lignocellulosic polar groups of the jatropha seed coat.
14.7 conclusIons
The interest in using jatropha oil as feedstock for the production of biodiesel is rapidly growing
throughout the world. The properties of the jatropha plant and its oil have persuaded investors,
