Production of activated carbon from rice husk Vietnam

This work is dedicated to the production of activated carbon from rice husk from Delta of the Red River in Viet Nam. At the first stage, carbonization of a rice husk was carried out to obtain material containing 43.1% carbon and 25 % silica with a specific surface area of 51.5 m(2)/g. After separating of silica (the second stage), the specific surface area of the product increased to 204 m(2)/g and the silica content decreased to 1.23% by weight as well. The most important stage in the formation of the porous structure of the material is the activation. The products with the high specific surface area in the range of 800-1345 m(2)/g were obtained by activation of carbonized product with water vapour or carbon dioxide at temperatures of 700 degrees C and 850 degrees C, with varying the flow rate of the activating agent and activation time. The best results were achieved by activation of carbon material with water vapour at the flow rate of 0.08 dm(3)/min per 500 g of material and the temperature of 850 degrees C.