MODELING AND OPTIMIZATION OF SILICA PRODUCTION FROM MAIZE HUSK

Maize Cob has been used for silica production but no research had been reported on the optimization of maize husk for silica production. This study is aimed at developing an approach for the optimization of silica production from Maize Husk (MH) using Response Surface Methodology (RSM). The MH was analyzed for crude fiber (CF), crude protein (CP) and ash constituents using standard method. The MH (30kg) was run using Box Behnken Design to determine the experimental combinations of the predictor variables: Temperature (400-700 ºC), Time (2-6 h) and MH (5-7 g). Optimal process variables predicted were validated by confirmatory experiments. The silica produced was characterized using Fourier Transform Infrared Spectroscopy (FTIR). The CF, CP and ash content were 1.52, 10 and 1.5 % respectively. The optimal values of the variables from the RSM, namely: temperature, time and MH were 528 ºC, 5.31 hr and 5.85g. There was no significant difference between the values obtained from RSM and that of the validation. FTIR showed noticeable absorption peaks attributed to O-Si-O stretching. It can be concluded that maize husk which is an agricultural waste is a viable product for silica production.