Properties and performance testing of biodiesel from a mixture of jatropha curcas and croton megalocarpus blends
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Date
2010Author
Kavunja, Herbert W
Type
ThesisLanguage
enMetadata
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The main objective of this project was to study biodiesel production from two local nonedible
plant feedstocks namely Jatropha curcas and Croton megalocarpus. The oil from
the above plant seeds were mechanically extracted using a screw pressing machine and
the oil yield determined. Preliminary test were done on the neat oil to ascertain their
quality, these included; viscosity, density, acid value, iodine and calorific value. The oils
were then converted into biodiesel through trans-esterification process using methanol
and potassium hydroxide as a catalyst. The factors governing the trans-esterification
process investigated included; reaction time, amount of base catalyst (potassium
hydroxide) per liter of oil, amount of methanol per liter of oil and reaction temperature,
, , ,
Biodiesel yield of 87.5 % CNIE and 71.3 % JME were obtained at methanol/oil ratio of
5:1, temperatures of 60°C, reaction time of one hour while KOHlliter oil was 0.75 wt%
croton oil and 1.5 wi% jatropha oil respectively.
Blends consisting of Jatropha curcas methyl esters (JME) and Croton megalocarpus
methyl esters (CNIE) were also prepared and tested in the proportions; 25%Ji\lIE and
75%C1vIE, 50%JME and 50%C1vIE and 75% JME and 25%CNfE. The above mixtures
were further separately blended with commercial diesel to obtain B5, B10 and B20
blends. The individual esters were separately blended with grade 2 diesel (DF2) to obtain
B5, B10 and B20. Both esters and their blends with DF2 were characterized with respect
to specific gravity, kinematic viscosity, iodine value, acid value and calorific value. The
kinematic viscosities of all blends of the esters were lower than those of J1vIE(B100) and
Cl\I1E(BlOO) at all temperatures. Blending the above fuel esters with commercial DF2
lowered the specific gravity and kinematic viscosity significantly.
The acid values for all the neat fuel esters and their blends were. found to be within the
allowed maximum limit of 0.8mgKOHlg. The calorific values decreased with increase in
percentage ofbiodiesel in the blends. The iodine values for both the SVO, neat fuel esters
and their blends were within the allowed maximum limits of 115ghll00g oil and
120ghll OOgoil except for SVO from Croton megalocarpus which gave a high iodine
value of 133ghllOOg oil. The fatty acid methyl ester composition from CNIE determined
usmg gas chromatography showed it to contain primarily the three fatty acid methy
esters of methyl palmitate, methyl stearate and methyl oleate. The engine performance
tests of neat esters and their blends as investigated included; brake specific fuel
consumption, thermal efficiency, brake horsepower and exhaust temperatures. The results
obtained were comparable to those of commercial DF2.
Citation
Masters of science in ChemistrySponsorhip
University of NairobiPublisher
University of Nairobi Chemistry