The presence of hydrogen sulfide (H 2 S) and ammonia (NH 3) in biogas pose serious human health and environmental challenges. In this study, H 2 S and NH 3 were successfully removed from biogas using water hyacinth-derived carbon (WHC) nanomaterials. Carbonization temperature, biogas flow rate, mass of the adsorbent and activating agent (KOH/water hyacinth (WH)) ratio were found to greatly influence the efficiency of the H 2 S and NH 3 removal. The adsorption capacity of both H 2 S and NH 3 was found to increase with the carbonization temperature as carbon materials prepared at 450, 550, and 650°C afforded removal efficiencies of 22, 30, and 51% for H 2 S and 42, 50, and 74% for NH 3 , respectively, after contact time of 2 h. Similarly, the KOH/WHC ratio showed huge impact on the adsorptive removal of the two species. WH materials carbonized at 650°C and activated at 700°C using 1:4, 1:2, and 1:1 KOH/WHC ratios showed removal efficiencies of 80, 84, and 93% for H 2 S and 100, 100, and 100% for NH 3 , correspondingly after 2 h contact time. The adsorption capacity of NH 3 increased with the decrease in flow rate from 83 to 100% at flow rates of 0.11 and 0.024 m 3 /h, respectively, while that of H 2 S increased from 22 to 93% with flow rate 0.11 and 0.024 m 3 /h, respectively. The removal of H 2 S and NH 3 increased with adsorbent mass loading. With the 0.05, 0.1, 0.2, and 0.3 g of the adsorbent, the adsorption of H 2 S after 1.5 h contact time was 63, 93, 93, and 95%, respectively while that of NH 3 was 100% for all the adsorbent masses.
Elizabeth, M., Cecil, K. K., & Talam, E. K. (2017). Hydrogen sulfide and ammonia removal from biogas using water hyacinth-derived carbon nanomaterials. African Journal of Environmental Science and Technology, 11(7), 375–383. https://doi.org/10.5897/ajest2016.2246