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314 Advances in Eco-Fuels for a Sustainable Environment

0.1N of an aqueous solution of potassium hydroxide (KOH). The acid value of the
sample was calculated using the following equation:

M W N V KOH
Acid value ¼ (11.1)
W s
where, M W , molecular weight of KOH, g/mol; V KOH , volume of KOH, mL; N, nor-
mality of KOH, mol/mL; W S , Weight of sample, g.

11.2.7.2 Saponification value

The saponification value of oil and biodiesel were estimated by the ASTM D1962
titration method. The fat sample of 1g was taken in the beaker and dissolved in
10mL of ethanol solvent. Further, 25mL of ethanolic 0.5 normality of KOH was quan-
titatively transferred to the fat-solvent mixture and named as a test sample. The same
procedure was followed to prepare the blank sample without the fat sample. Then,
both the samples were attached to the reflux condenser and heated up to the boiling
point of the water for about 30min. After that, the samples were allowed to attain room
temperature. Finally, 2–3 drops of phenolphthalein indicator were added to samples
and titrated against 0.5 normality of hydrochloric acid. The saponification was esti-
mated using the following equation.

M W N V Blank V Test Þ
ð
Saponification value ¼ (11.2)
W s
where M W , Molecular weight of KOH, g/mol; V Blank , volume of HCl for Blank sam-
ple, mL; V Test, volume of HCl for the Test sample, mL; N, normality of KOH, mol/mL;
W S , weight of sample, g.

11.2.7.3 Iodine value

The iodine value of raw oil and biodiesel were determined as per the titration method
described by the EN 14111 standard. In a tared beaker, 1g of fat sample was taken and
dissolved in 10mL of chloroform solvent, which is labeled as “test.” Then, 20mL of
iodine monochloride reagent was thoroughly mixed into it. In the same way, another
sample labeled as “blank” was prepared, except the fat sample. Then, both samples
were kept in a dark place for incubation about 30min. After that, 10mL of potassium
iodine solution was added to the sample and the side of the beaker was rinsed with
50mL of distilled water. The samples were titrated against 0.1 normality of aqueous
solution of sodium thiosulfate (Na 2 S 2 O 3 ) until the color changed to pale straw. Then,
1mL of the starch indicator was added to the solution, and the color of the solution
changed to purple. The titration process was continued until the solution color chan-
ged to colorless. The following formula was used to estimate the iodine value of the fat
sample.