5.2.4.1 Palm Fatty Acid Distillate

Palm fatty acid distillate (PFAD) is a highly odoriferous by-product (comprising mainly glycerol esters) obtained from the refining of CPO whose main processes include phosphoric acid treatment, bleaching earth treatment, deacidification and deodorisation of CPO (Ab Gapor 2010). At room temperature, its state is solid but becomes liquid on heating at elevated temperatures. Deacidification removes the free fatty acids, whilst deodorisation removes the odour by steam distillation under high vacuum. The distilled fatty acid is known as PFAD. In Malaysia, about 0.63 and 0.71 million tonnes of PFAD were produced in 2006 and 2008, respectively (Ab Gapor 2010).

PFAD has a moisture content of 0.03-0.24%, 80-90% free fatty acid in the form of palmitic acid, 1.1-2.3% unsaponifiable matter, density of 0.8640-0.8880 kg/l, iodine value of 46.3-57.6 I2/100 g and saponifiable value of 200.3-249.4 mg KOH/g PFAD (Bonnie and Mohtar 2009). Other constituents of PFAD include glycerides (14.4%), squalene (0.8%), vitamin E (0.5%), sterols (0.4%) and other extractives (2.2%) (Bonnie and Mohtar 2009; Hamirin 1983).

Figure 5.1 summarises the generation of OPW from the production of 5 tonnes of FFB and a tonne of CPO.