Development of high porosity structures of activated carbon via microwave-assisted regeneration for H2S removal

In this study, commercial coconut shell activated carbon (CSAC) was utilized for H2S adsorption application. The regeneration of the CSAC adsorbent was implemented via microwave-assisted method in order to investigate the H2S regeneration efficiency. The H2S-saturated CSAC adsorbent was subjected to experience three different regeneration variables; microwave heating temperature (100-500 °C), N2 flow rate (100-500 ml/min) and microwave heating time (5-25 min). The effect of the variables on the CSAC's regeneration efficiency was analyzed and discussed. The results indicated that the regeneration of H2S-saturated CSAC adsorbent via microwave-assisted method could improve the porosity of the CSAC and resulted in high H2S regeneration efficiency (efficiency of H2S breakthrough capacity = 1000% and efficiency of total H2S adsorption capacity = 400%). The regenerated CSAC adsorbent was tested for a few regeneration cycles, which resulted in a decrease in the H2S regeneration efficiency. The regenerated CSAC adsorbent was characterized by using nitrogen adsorption/desorption analysis, elemental analysis and SEM analysis. This study emphasizes on the important key-factors in the employment of microwave-assisted method for CSAC regeneration in the H2S adsorption application.