PREPARATION OF ACTIVATED CARBON FROM RICE HUSK AND SYNTHESIS OF TiO2/ACTIVATED CARBON COMPOSITE
Project no. 1339 · Status: Kapanmış · 2017
Summary
In recent years, both environmental and economic factors have been considered and the number of studies to obtain high value-added products from natural resources has increased. Rice husk is one of the natural resources that can be used as raw material in the production of many silicon-based products due to its high silicon content. During the processing of rice, which is the second most produced grain in the world, approximately 20% of the rice is exposed to silicon-rich husk. The low density and high quantity of rice husk creates disposal problem. Rice husk ash is obtained by burning the husks in order to overcome this problem partially and also to benefit from the high thermal value of the husk. Silica and carbon-rich rice husk ash is obtained by burning away some elements from the structure. It is important to develop innovative methods for producing high value-added silicon and carbon-based products by making use of the rich silicon and carbon content of rice husk ash. Therefore, in this study, alkaline carbonates (K2CO3 and Na2CO3) were used as activating agents to produce activated carbon from rice husk. Activated carbon was prepared by the treatment of char that is obtained by the carbonization of rice husk under nitrogen atmosphere, using two different forms of activating agents. In the presence of the agents in powder form, the effect of the type of activating agent (K2CO3 and Na2CO3) and the weight ratio of char to activating agent (1:4 and 1:2) on the surface properties of activated carbon was investigated. In the presence of the agents in solution form, the effects of the type of the activating agent (K2CO3, Na2CO3 and NaOH), activation temperature (500 ° C and 600 ° C), activation time (1 hour, 2 hours and 3 hours) and the weight ratio of char to activating agent (1:4 and 1:5) on surface properties were investigated. It has been observed that the surface areas of the products obtained in the presence of the powder form of agent are lower than the surface areas of the product obtained in the presence of the agent in solution form. The most suitable activating agent, activation temperature, activation time and ratio of char to activating agent were found as K2CO3, 600°C, 2 hours, and 1: 4, respectively. TiO2/activated carbon composites were obtained by the thermal hydrolysis synthesis of TiO2 particles on the activated carbon prepared under the predetermined optimum conditions. Characterization studies indicated that TiO2 particles are in rutile crystal structure and spherical.