Sodium Silicate Manufacturing Process Utilizing Rice Hull/Straw Wastes

In the production of rice crops, there is a considerable amount of biowaste generated in the forms of hulls and straw. Hundreds of millions of tons of rice hulls are generated annually. Rice hulls have been utilized as biofuels and as a supplement in animal feed. However, the market for hulls is a small portion of the hulls generated, and this results in landfilling the excess. Rice hull ash generated from biofuel operations is used to a limited degree in such markets as foundries, where it is used as ladish cover. However, the steady growth of rice production is resulting in ever-increasing solid wastes as hulls, hull ash, and straw. The process proposed herein is a method to utilize rice biowaste to produce liquid silicates. The ash content of the hulls and straw are high in silica content, and the form of this silica is desirable for the production of sodium silicates. Presently, sodium silicates are produced predominantly in high temperature reverberatory furnaces by fusion of silica sand and soda ash. The proposed process would require a fraction of the energy required in the furnaces process, and would result in significant reductions in air emissions and solid waste generation.