title: Development of Nano-Sulfide Sorbent for Efficient Removal of Elemental Mercury from Coal Combustion Fuel Gas.
abstract: The surface area of zinc sulfide (ZnS) was successfully enlarged using nanostructure particles synthesized by a liquid-phase precipitation method. The ZnS with the highest surface area (named Nano-ZnS) of 196.1 m(2)·g(-1) was then used to remove gas-phase elemental mercury (Hg(0)) from simulated coal combustion fuel gas at relatively high temperatures (140 to 260 °C). The Nano-ZnS exhibited far greater Hg(0) adsorption capacity than the conventional bulk ZnS sorbent due to the abundance of surface sulfur sites, which have a high binding affinity for Hg(0). Hg(0) was first physically adsorbed on the sorbent surface and then reacted with the adjacent surface sulfur to form the most stable mercury compound, HgS, which was confirmed by X-ray photoelectron spectroscopy analysis and a temperature-programmed desorption test. At the optimal temperature of 180 °C, the equilibrium Hg(0) adsorption capacity of the Nano-ZnS (inlet Hg(0) concentration of 65.0 μg·m(-3)) was greater than 497.84 μg·g(-1). Compared with several commercial activated carbons used exclusively for gas-phase mercury removal, the Nano-ZnS was superior in both Hg(0) adsorption capacity and adsorption rate. With this excellent Hg(0) removal performance, noncarbon Nano-ZnS may prove to be an advantageous alternative to activated carbon for Hg(0) removal in power plants equipped with particulate matter control devices, while also offering a means of reusing fly ash as a valuable resource, for example as a concrete additive.
authors: School of Energy Science and Engineering, Central South University , Changsha, China 410083.|Department of Civil Engineering, The University of Hong Kong , Hong Kong SAR, China.
authors: Hailong
authors: H
authors: Li
authors: School of Energy Science and Engineering, Central South University , Changsha, China 410083.
authors: Lei
authors: L
authors: Zhu
authors: Department of Occupational and Environmental Health, College of Public Health, University of Oklahoma Health Sciences Center , Oklahoma City, Oklahoma 73126, United States.
authors: Jun
authors: J
authors: Wang
authors: School of Energy Science and Engineering, Central South University , Changsha, China 410083.
authors: Liqing
authors: L
authors: Li
authors: Department of Civil Engineering, The University of Hong Kong , Hong Kong SAR, China.
authors: Kaimin
authors: K
authors: Shih
mesh_terms: D000327:Adsorption; D000393:Air Pollutants; D003031:Coal; D060729:Coal Ash / Q000737:chemistry; D008628:Mercury; D011210:Power Plants; D013440:Sulfides / Q000737:chemistry
chemical_list: D000393:Air Pollutants; D003031:Coal; D060729:Coal Ash; D013440:Sulfides; D008628:Mercury