Experimental Study on Mercury Adsorption and Adsorbent Regeneration of Sulfur-Loaded Activated Carbon

A kind of commercial sulfur-loaded activated carbon (SAC) was experimentally studied on the mercury adsorption and adsorbent regeneration performance. Mercury adsorption experiments were carried out on a bench-scale fixed-bed experimental device. The physicochemical properties of the original and used SAC were characterized and discussed on the basis of the surface area and porosity (Brunauer-Emmett-Teller measurements) and X-ray photoelectron spectroscopy analysis. The results showed that the specific surface areas and the content of oxygen functional groups as well as non-oxidized sulfur on the surface decreased after mercury adsorption. The used samples were regenerated via the co-pyrolysis with elemental sulfur. The regenerated adsorbent showed an average mercury removal efficiency up to 95% in 2 h under the conditions of the co-pyrolysis temperature at 600 degrees C, 1 h heating time, and sulfur-carbon ratio of 1:1. The regenerated sample was found to be structurally stable and sustainably reactive on the Hg-0 capture within 5 cycles. The mercury adsorption capacity still maintained 291.22 mu g/g after 5 cycles. SAC with the adsorbent regeneration method will provide a database for developing the renewable mercury adsorbent applied in the injecting demercuration technology in flue gas of coal-fired power plants.