Optimization of Silicon Selective Leaching with Glycerol Using Response Surface Methodology (RSM)

Selective removal of silicon might open-up the possibility of reusing silicon-contaminated spent catalyst. Unfortunately, study regarding this topic is still scarce. The effect of important parameters such as leaching treatment time and temperature was investigated, and the process conditions were optimized using response surface methodology (RSM) based on central composite design (CCD). Based on analysis of variance (ANOVA) results, leaching treatment time was found to be the most significant parameter, followed by temperature. Higher temperature and longer treatment time were satisfactorily enough for efficient silicon leaching from spent catalyst. The obtained quadratic model (R2 = 0.995) shows a good correlation between the predicted values and experimental data. The optimum condition for silicon leaching was identified to be a temperature of 213.3oC and a treatment time of 5.83 hours.