Journal of Supercritical Fluids 20 (2001) 45 – 53
Supercritical CO
2
fractionation of crude palm oil
Masturah Markom, Harcharan Singh *, Masitah Hasan
Department of Chemical Engineering, Uniersity of Malaya, 50603 Kuala Lumpur, Malaysia
Received 12 February 2000; received in revised form 3 October 2000; accepted 4 November 2000
Abstract
Crude palm oil was fractionated using supercritical CO
2
(SC–CO
2
) in a semi batch apparatus. The fractionation
conditions studied were at 40, 50 and 60°C and at 110, 140 and 200 bars, respectively. System pressure was found to
be more significant rather than temperature for increasing the solubility of palm oil triglycerides in SC – CO
2
. The
solubility of crude palm in SC–CO
2
was generally low for triglycerides rich in the saturated and lower molecular
weight fatty acids, i.e. C12:0, C14:0 and C16:0. These fatty acids were fractionated first followed by the heavier and
mainly unsaturated fatty acids, i.e. C18:1, C18:3 and C20:0. The initial extracted fractions were white to yellow in
colour and solid like. The later fractions however were more intense in colour and semi-liquid. It was difficult to
extract -carotene from the palm oil in the fractions even at high pressures because it is concentrated in the raffinate.
The del Valle-Aguilera correlation was found to over estimated solubility of crude palm oil in supercritical CO
2
.
© 2001 Elsevier Science B.V. All rights reserved.
Keywords: Fatty acid methyl esters; Fractionation; Palm oil; Supercritical CO
2
; -carotene
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1. Introduction
Separation and fractionation of edible oil com-
ponents for the food and pharmaceutical indus-
tries using safe solvents have been growing. The
demand for high quality oils has led researchers to
find safer techniques for the extraction of desired
components while at the same time reducing ther-
mal degradation and solvent contamination to a
minimum. The strength of a separation process
also depends on achieving high solubility and
selectivity for triglycerides present. This is usually
difficult to achieve for vegetable oils because of
their low volatility and narrow differences be-
tween molecular weights and component
volatilities.
Considerable interest has been shown in the
development of supercritical fluid processing in
the oil and fat industry. Some examples are
deacidification of olive oil [1,2]; degumming and
bleaching of soybean oil [3]; refining of palm oil
[4–6]; extraction of guava seed oil [7] and frac-
tionation of butter oil [8]. One of the major edible
oils consumed worldwide is palm oil. Crude palm
oil is a semi solid material at a room temperature
and has a melting point of 36°C [9]. It is
* Corresponding author. Present address. Department of
Chemical and Process Engineering, National University of
Malaysia, 43600 UKM Bangi, Selangor, Malaysia..
E-mail address: k2harch@umcsd.um.edu.my (H. Singh).
0896-8446/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
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