Central composite design approach towards optimization of super activated carbons from bamboo for hydrogen storage

Abstract

Super activated carbons (ACs) were prepared by KOH activation from the moso bamboo and central composite design (CCD) methods were chosen for the experimental design to determine optimum responses by investigating the influence of the activation condition parameters, weight ratio of KOH/precursor (W) and activation temperature (T). Quadratic models were developed to predict the maximum specific surface areas (S_BET) and micropore volume (V_DR), and then the hydrogen storage performance. The results showed that the developed AC had outstanding hydrogen storage capacity, being among the highest hydrogen storage capacities in ACs so far. The analysis of variance (ANOVA) showed that the developed models for S_BET and V_DR gave a good prediction at 95% confidence level. The chosen models and individual parameters are appropriate for the prediction of S_BET and V_DR. The maximum values of S_BET and V_DR prepared under optimum conditions (W = 4.6 and T = 824 °C) are 3250 m² g⁻¹ and 1.01 cm³ g⁻¹, corresponding to hydrogen storage capacities of 6.8 wt% at 5 Mpa and 2.8 wt% at 1 bar, both at 77 K.