Comparison of Dimethyl Disulfide and Carbon Disulfide in Sulfurization of Activated Carbons for Producing Mercury Adsorbents

In this work, the use of dimethyl disulfide (DMDS) as a sulfurizing impregnator for producing mercury adsorbents for the first time has been investigated and compared with CS2, one of the materials commonly used in this field. Sulfurized adsorbents were characterized by CHNS/O elemental analysis, N-2 adsorption/desorption, XPS, and FT-IR spectroscopy. The sulfur contents of CS2 and DMDS modified activated carbons were about 3.2 and 9.6 wt %, respectively. The impregnated sulfur was found in two major organic and elemental forms in granular activated carbon modified with DMDS; however, elemental sulfur was not observed in the case modified with CS2. After comparing the equilibrium capacities and the rates of mercury adsorption, the occurrence of sulfur leaching from the sulfurized adsorbents during the adsorption processes was studied.