Malaysia produces 15.9 million tonnes of palm oil, of which 90% is fully refi ned. Palm oil is refi ned by a physical process in three stages – degumming, bleaching and deodorization. There are a variety of clays suitable for bleaching, with montmorillonites the most commonly used. Palm oil, as other vegetable oils, contains many minor components, such as phospholipids and other phosphorus compounds, metals, such as copper and iron, pigments, such as carotenoids and chlorophylls, gummy substances and oxidative degradation products of lipids. As the minor components differ in their polarity, acidity and sizes of molecules, the clay would have to be optimized for good bleaching. In our earlier project on bleaching earths and other adsorbents in the palm oil industry, we characterized the most commonly used earths in the Malaysian palm oil industry. But new materials are being introduced all the time and using the best clay for refi ning different quality crude oils would allow considerable cost savings. Moreover, companies producing bleaching clays may want to produce different clays for different oils.

Main Research: Dr. Siew Wai Lin