Performance and Characterization of Bi-Metal Compound on Activated Carbon for Hydrogen Sulfide Removal in Biogas.

This study reports on the synthesis of bi-metal compound (BMC) adsorbents based on commercial coconut activated carbon (CAC), surface-modified with metal acetate (ZnAc), metal oxide (ZnO), and the basic compounds potassium hydroxide (KOH) and sodium hydroxide (NaOH). The adsorbents were then characterized by scanning electron microscopy and elemental analysis, microporosity analysis through Brunauer-Emmett-Teller (BET) analysis, and thermal stability via thermogravimetric analysis. Adsorption-desorption test was conducted to determine the adsorption capacity of HS via 1 L adsorber and 1000 ppm HS balanced 49.95% for N and CO. Characterization results revealed that the impregnated solution homogeneously covered the adsorbent surface, morphology, and properties. The adsorption test result reveals that the ZnAc/ZnO/CAC_B had a higher HS breakthrough adsorption capacity and performed at larger than 90% capability compared with a single modified adsorbent (ZnAc/CAC). Therefore, the synthesized BMC adsorbents have a high HS loading, and the abundance and low cost of CAC may lead to favorable adsorbents in HS captured.