Jatropha curcas (jatropha) produces oil that can be converted to biodiesel by transesterification. However, because of its high free fatty acid value (>2 %), acid catalysts are usually used in the process, rather than alkalis. Because of this, longer reaction times are required. Furthermore, jatropha oil contains phorbol ester, a carcinogen that can be exposed when the seeds are extracted for the oil. The application of reactive extraction as a method to produce biodiesel from jatropha, enables alkali based catalyst to be utilized, and shortens the reaction time without compromising on conversion and quality of biodiesel. Since seeds are used as raw material instead of oil, the phorbol ester exposure is greatly reduced. This study evaluates the parameters involved in reactive extraction of jatropha seeds. The molar ratio of alcohol to oil was found to be the most important parameter in this reaction. The yield in 1 hour was low at 100 molar ratio (2%) but then increased sharply when the ratio was increased to 200 (55%), 300 (75%) and 400 (82%). Only small increments were observed when the ratio was increased further to 500 (85%) and 600 (90%). Methyl ester yield was a strong function of seed particle size. Of 5 different sizes of particle size, the smallest (0.5 mm), produced the highest yield (86%) and the biggest (2.0-4.0 mm) produced the lowest (35%). On agitation speed parameter, low speed agitation (100 rpm) was unable to produce a high yield compared to high speed agitation (300, 400 rpm). The study on temperature meanwhile revealed that there was little change in yield when the reaction was performed at 30oc (90%), 40oc (89%), 50oc (91) and 60oc (98). Interestingly, it was shown that the process was complete relatively quickly, typically after 30 minutes. The methyl ester content of the samples demonstrate that high purity of methyl ester (<90%) can be obtained from this method. An implication of this is that reactive extraction could be a method of producing biodiesel from seeds with high free fatty acid contents.
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