Elemental Mercury Removal from Flue Gas over TiO₂ Catalyst in an Internal-Illuminated Honeycomb Photoreactor

Abstract

TiO 2 catalyst in an internal-illuminated honeycomb photoreactor was prepared for Hg 0 removal from flue gas. The Hg 0 removal efficiency was above 95% under the optimal operation condition. With the increasing TiO 2 coating value, the Hg 0 removal efficiency significantly increased. The catalyst calcined at 400 °C presented optimal Hg 0 removal performance, while higher calcination temperature weakened the Hg 0 photocatalytic removal activity. Similar Hg 0 removal performances were obtained under UV irradiation when the reaction temperature was in the range 25−90 °C, and 1.5 mW/cm 2 of UV light irradiation was competent for Hg 0 photocatalytic removal. With the same quantity utilization of TiO 2 catalyst, the internal-illuminated honeycomb photoreactor presented better Hg 0 removal performance than the fixed-bed reactor. Finally, the procedure of Hg removal from flue gas over TiO 2 catalyst in internal-illuminated honeycomb photoreactor was proposed, and the product in the Hg 0 photocatalytic removal process was analyzed as well.

Magnetic γ-Fe2O3-Loaded Attapulgite Sorbent for Hg0 Removal in Coal-Fired Flue Gas

“…The addition of 500 ppm SO2 to the pure N2 atmosphere resulted in a significant decrease in the Hg 0 removal efficiency, η, from 28% to 12.2%. According to the previous studies 37,61 , SO2 could inhibit Hg 0 oxidation via the following three routes: (1) The reaction between SO2 and the oxygen species on the surface of sorbent; (2) The competitive adsorption between SO2 and Hg 0 for the same active sites on the sorbent surface; (3) The sulfation of metal oxide under the atmosphere of SO2. Without the presence of O2 in the reaction environment, SO2 inhibited Hg 0 oxidation over 0.5Fe1ATT sorbent by consuming the surface oxygen species and hence significantly suppressed Hg 0 removal.…”

“…Mercury pollution has attracted worldwide attention due to the properties of extreme toxicity, high volatility and strong bioaccumulation of mercury compounds in the environment 1,2 . Coal-fired power plants have been regarded as the main anthropogenic source of mercury emissions 3 and almost account for one third of the total mercury emission caused by human activities 4 .…”

Research on the Mechanism of Elemental Mercury Removal over Mn-Based SCR Catalysts by a Developed Hg-TPD Method

“…[1][2][3] Hg p can be easily removed by particle control devices such as electrostatic precipitators or fabric filters while Hg 2+ is soluble in water and can be easily captured by wet flue gas desulfurization (WFGD) scrubbers. [3][4][5] However, Hg 0 is very volatile and insoluble in water so that it is difficult to be controlled by the existing air pollution control devices (APCDs) of the power plants. 6,7 The effect of mercury control that can be achieved with each of these approaches is extremely variable, which ranges from 43.8% to 94.9%, and it is affected by such factors as coal chemistry or operational conditions.…”

Investigation of Elemental Mercury Removal from Coal-Fired Boiler Flue Gas over MIL101-Cr

“…This confirms that NO2 was produced by the reaction of the NO containing flue gases with the sorbent, and subsequently participated in the Hg 0 oxidation process to form Hg(NO3)2. The reactions involved in these processes can be described as follows (5)(6)(7)(8)(9)(10)(11).…”

“…However, Hg 0 is hard to be captured by the existing air pollution control devices (APCDs) due to its high volatility and insolubility 10 . Therefore, the key challenge to control mercury emissions from coal-fired power plants is how to effectively remove Hg 0 from the coal-fired boiler flue gas 11 .…”