The possibility to produce methyl esters in a small scale unit
from sunflower oil was tested in the pilot scale transesterification
facility at CRIBE.Fig. 1shows theflowsheet of the system. The core
of the plant is a 200 L batch reactor equipped with a water heating
jacket to modulate the reaction temperature, a loading cell system,
alcohol and catalyst dosing devices and a settling tank. The reactor
is specifically designed for transesterification conditions and it can
be continuously purged with nitrogen to remove the vapor phase
alcohol from the reactor. The alcohol is recovered by means of a
condenser where the coolingfluid is cold water produced with a
chilling system. The transesterification reactor is equipped with a
loading cell, pressure and temperature indication systems.
The transesterification reaction was carried out on the oil obtained from H31 seeds. Methanol was used as alcohol and asolution of sodium methoxide in methanol was employed as
catalyst. Typical reaction conditions[33,34] of alkaline-catalyzed
transesterification processes were used. A 6:1 molar ratio of
methanol to oil and 1% of basic catalyst by weight of vegetable oil
were employed. The reaction was carried out in a batch of 100 L at
70
C for two hours. After this time glacial acetic acid was added to
the batch in order to neutralize the catalyst. The mixture was then
allowed to settle in order to separate the glycerol phase and the
methyl ester phase. Subsequently the methyl ester phase was
stripped in order to remove residual methanol.
Methanol (99.8% purity) and glacial acetic acid were supplied by
Carlo Erba Reagenti (Milan, Italy); the catalyst (sodium methoxide
solution, 25 wt.% in methanol) was purchased from SigmaeAldrich