SAS APPLICATION: BIODIESEL & VEGETABLE OILS
SAS silica hydrogel is a free flowing, sustainable powder used in biodiesel and edible oil refinery processes, a trusted method to remove unwanted contaminants such as fats, soaps, metals, FFAs, triglyceride oils and fats during processing. SAS silica hydrogel assists biodiesel and vegetable oil producers to reduce costs while increasing overall performance.
During typical vegetable oil processing, adsorbents are used to remove components that have been reduced substantially, but have not yet been reduced to an acceptable concentration. Traditionally, the step of adsorbent treatment in edible oil processing is referred to as ‘bleaching’ since one of the main objectives is to decolorize oil. Currently, either a form of bleaching earth or clay (bentonite based clay, with both activated and acid-activated forms), activated carbon or amorphous silica is used, based on adsorbent cost, the overall refining process and the crude oil composition. There is published evidence that rice husk ash, if produced correctly, has the appropriate absorption characteristics that make it useful for the vegetable oil and biodiesel processing industry.
Biodiesel feedstocks require a similar process 1) degumming (phosphatide removal), 2) deodorization or vacuum distillation to remove volatile compounds, such as short and medium chain length aldehydes, ketones, even pesticides, fungicides and herbicides, etc., 3) free fatty acid (FFA) reduction by various methods, including steam and caustic stripping, solvent extraction and esterification, etc., and finally, 4) bleaching, which is normally used to remove remaining impurities such as pigments, soaps, insoluble, peroxides, phospholipids and metals. The production of biodiesel from vegetable oil requires an adsorbent based clean-up step for its manufacture if the FFA content is relatively low (~1%).
