Palm Ash as an Alternative Source for Silica Production

Agricultural wastes such as palm ash and rice husk have a possibility to be used as a useful renewable source for the production of silica (SiO2). Extensive researches have been carried out to extract silica from agricultural wastes such as rice husk, due to silica as a useful raw material for industrial application. In this study, the environmentally benign and economically effective process to produce SiO2 materials from palm ash has been established by using citric acid leaching, not the conventional strong acids. Results showed that silica can be extracted from palm ash using the citric acid leaching method under the optimum extracting conditions with 700 °C of solution temperature, 60 minutes of reaction time and concentration of citric acid of more than 2 %. The purity of silica extracted is more than 90 %.