The genus Cinnamomum

138 K.R. Dayananda, U.M. Senanayake and R.O.B. Wijesekera
Figure 5.7 Modern cinnamon bark still.
Hydro-distillation units are heated by direct firing. Bark or other parts of the inner
bark are placed in the still and direct fire is introduced. The distillate produced from
the still body is first passed through a pre-cooler and then through a large static
water condenser. In Sri Lanka a large number of existing cinnamon oil distillation
units are still of traditional design. Although present day distillers introduced
several modifications to modernise the design (Fig. 5.7), they have not made any
significant differences to the system. These old stills are still adequate to distill the
oil from the bark. They are made out of copper or tin lined copper or steel and hold
around 50kg of bark. The still body is built over a brick or mortar hearth and direct
fire is introduced from the bottom. Cinnamon bark is placed in the still, which is
partly filled with water. The condenser is a static copper tubing immersed in a large
water tank. Recently a precooler has been introduced in between the still body and
static condenser. The precooler cools the distillate to about 70 °C when it is sent into
the main condenser. All the time the precooler is kept cold by cold water. Certain
distillers have a battery of still bodies with a common static water condenser. Five
to six copper, aluminium or stainless steel Florentine vessels in a cascade arrangement
are placed to collect the distillate. As cinnamon oils are heavier than water,
condensed oils collect at the bottom of vessels. Loading and unloading of the bark
is done manually. The time taken to distill a batch of 40–50 kg of bark is around
four to five hours and a yield of 0.5–0.7% of oil on dry weight basis is obtained
(Anon, 1993).
Cinnamon bark oil is graded according to its cinnamic aldehyde content (CS 185,
1972).