Rice Husk Ash Silica: Agricultural Byproduct to Silica Filler

Rice has the second highest production of any crop in the world (7.0 x 10⁸ metric tons/year) and for every five tons of rice one ton of rice husk is produced .^1,2 Rice husk ash (RHA) silica is predominately high purity silica generated as a waste by-product from burning rice husks for fuel value. Until recently, RHA silica has only been utilized in low value added products, such as: fertilizer additives, fuels and paving materials, but in the last decade Mayaterials, Inc. has developed a simple low energy chemical method to produce a number of chemicals including silsesquioxanes and high surface area silica fillers from RHA. In this study we have investigated a traditional silica filler, HiSil 190, in comparison to two different RHA silicas produced by Mayaterials, Inc. to elucidate similarities and differences between these silica fillers. The RHA silicas discussed have the potential to be used within tires for reinforcement.

1.           Liu, N., Huo, K., McDowell, M. T., Zhao, J. & Cui, Y. Rice Husks as a Sustainable Source of Nanostructured Silicon for High Performance Li-ion Battery Anodes. Sci. Rep. 3, 1–6 (2013).

2.           Tuck, C. O., Perez, E., Horvath, I. T., Sheldon, R. A. & Poliakoff, M. Valorization of biomass: deriving more value from waste. Science 337, 695–699 (2012).