Reactive Extraction Technology - Process Intensification for Green Chemistry - page 275

analysed using GC (PerkinElmer, claurus 500) equipped with a flamed ionized detector
(FID) and Nukol capillary column (15m 0.53mm; 0.5 m m film). N-hexane was used as

the solvent, while helium was used as the carrier gas. The oven temperature was set at
110 C and then increased to 220 C at a rate of 10 C/minute. The temperatures of the
detector and injector were set at 220 and 250 C, respectively. The yields of FAME were
then calculated using the formula in Equation 10.1:

Þ
Weight of oil in 20g of seeds

Weight of FAME ð g

FAME yield ð wt %Þ¼

Þ

100 ð%Þ (10.1)

ð g

'Oil extraction efficiency' is defined as the quantity of oil that can be extracted from the
blended and sieved jatropha seeds during reactive extraction. The volume of the upper
layer, formed after evaporation of the reaction filtrate, was measured and recorded to
calculate oil extraction efficiency, as shown in Equation 10.2. The densities of the jatropha
oil and jatropha methyl esters were considered to be equal because the difference was less
than 5% at room temperature.

Final volume of collected sample
Total volume of oil in original sample

Extraction efficiency ð%Þ¼ 100 ð%Þ (10.2)

10.2.1.2 Result and Discussion

The average moisture content of Jatropha curcas L. seeds was found to be 5.39%. This was
in agreement with those reported in the literature, with values ranging from 4.75 to 19.57%
[16]. The average oil content for jatropha seeds was 54.4%, and this value also falls within
the range reported in the literature [17], which states that jatropha seeds normally contain
40-60% oil, depending on variety and species.

Effect of Different Seed Sizes. For solid-liquid reactive extraction, seed size is an
important factor that must be investigated in order to show that mass transfer is not a
problem for FAME production using this method. The reaction was performed using 20 g
of blended and dry jatropha seeds in different sizes:

0.250mm, 0.250mm

< 1mm. The reaction was performed under

the following reaction conditions: reaction temperature of 60 C, methanol to seed ratio
of 7.5ml/g, H 2 SO 4 as catalyst at 15wt% and different reaction periods of 0, 4, 8, 12 and
24 hours. The amounts of chemicals used in this study were based on numbers reported
in the literature [14,15]. Figure 10.2 shows the extraction efficiency of the reactive
extraction process at different reaction periods and for different ranges of seed particle
size, while Figure 10.3 shows the yield of FAME. As shown in Figure 10.2, it was
observed that the oil extraction efficiency gradually increased with increasing reaction
period, and within 8 hours almost 50% of the oil content in the seeds had already been
extracted, even for seeds with larger particle sizes. Initially, all ranges of particle size
exhibited similar trends for extraction efficiency up to a reaction period of 8 hours.
Beyond that, for particles with a size of either 0.355mm

x 0.355mm, 0.355mm < x 1mmand >

1mm, the
extraction efficiency remained almost constant, while for particles of less than

x 1mm or

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