Optimizing the Neutralization Effect on the Yield and Quality of Corn
Oil Methyl Ester
Abstract
The conversion of corn oil into quality methyl ester through the
transesterification process is an age-old concept. Because of its higher
degree of unsaturation, similar to soybean oil, transesterified corn oil
can be used to produce bio-based resin. Replicating published methods
did not result in the desired quantity and quality of corn methyl ester
needed for bio-resin production, which requires further investigation.
This research investigated the effect of neutralization on the yield and
quality of methyl ester produced from corn oil. The reaction was
conducted at 60 ºC with a methanol-oil ratio of 6:1 and NaOH as a
catalyst. After stopping the reaction with HCl, a hypothesized recovered
yield (>70%) of corn methyl ester was achieved. The
process was conducted at different reaction times (0.5, 1, and 1.5 h)
and acid amounts in neutralization (0, 25, 50, 75, and 100%). The
methyl ester yield ranged from 45-79%. A statistical model was obtained
with linear and quadratic terms, and the recovered yield varied
significantly with the acid amount, reaction time, and their
interactions. Stopping the reaction with 25% neutralization resulted in
around 20% yield increase compared to no acid treatment. On the other
hand, the yield was reduced by 18-24% with increasing time when no acid
was added. All the measured characteristics of the produced corn methyl
ester sample were found within the limits of ASTM D6751 pure methyl
ester. Overall, the optimization of the neutralization process showed
promise in increasing the yield of quality methyl ester from corn oil.