Jin-Ho Sung

The simultaneous capture of mercury and fine particles by hybrid filter with powder activated carbon injection

The hybrid filter (HF) was newly designed and operated with powder activated carbon (PAC) injection to capture mercury and fine particulate matter in the coal power plant. With PAC injection in HF operation, the capture efficiency of elemental mercury was clearly enhanced. When the injection rate of PAC increased from 0 to 20 mg/m3, the speciation fraction of elemental mercury significantly decreased from 85.19% to 3.76% at the inlet of the hybrid filter. The speciation fraction of oxidized mercury did not vary greatly, whereas the particulate mercury increased from 1.31% to 94.04%. It was clearly observed that the HF played a role in the capture of mercury and fine PM by leading the conversion of elemental mercury as particulate mercury and the growth of PM via electrode discharge in the HF operation with PAC injection.

Adsorption and kinetics of elemental mercury vapor on activated carbons impregnated with potassium iodide, hydrogen chloride, and sulfur

Coal combustion emits large amounts of elemental mercury that cannot be captured by air pollution control devices such as flue gas desulfurization because of its insolubility. Therefore, technological advances are necessary for capturing elemental mercury. We conducted various tests on adsorption of elemental mercury using KI-, HCl-, and S-impregnated activated carbons, which were compared with virgin activated carbon. Tests with virgin activated carbon revealed that the optimal adsorption temperature for capturing elemental mercury was 363 K. The adsorption efficiency for elemental mercury was nearly 100% using activated carbon impregnated with 1% and 5% KI and 1%, 5%, and 10% HCl. Through kinetic analyses of the impregnated activated carbons, the optimal equilibrium adsorption capacities of KI-, HCl-, and S-impregnated activated carbons for mercury were determined to be 333.3, 333.3, and 256.4mg/g, respectively, by using a pseudo second-order kinetic model.

Estimation of Mercury Emission from Major Sources in Annex D of Minamata Convention and Future Trend

Abstract This study discusses the present status of mercury emission and distribution from major anthropogenic sources in Korea and the future trend of mercury emission by activity changes and application of BATs. Atmospheric mercury emission from major anthropogenic sources based on Annex D of Minamata convention was estimated to around 4.89 tonne in 2012. Emission ratios of cement clinker production, coal-fired power plant, waste incineration and non-ferrous metal smelting were 68.68%, 24.75%, 6.29% and 0.28%, respectively. High mercury emission regions were characterized by the presence of cement clinker production facilities and coal-fired power plants. Prediction of future activities was carried out by linear regression of the previous year data. The (total) mercury emission was estimated to decrease up to 48% Under the scenario of BATs to be applied and the change of future activities. Emissions from coal-fired powerplants and cement clinkers were expected to decrease significantly.

Performance of Removal Efficiency for Mercury Compounds using Hybrid Filter System in a Coal-fired Power Plant

Abstract This study focused on the performance of the newly developed hybrid filter system to capture fine particulatematter and mercury compounds in a coal-fired power plant. The hybrid filter system combining bag-filter andelectrostatic precipitator had been developed to remove fine particulate matter. However, it would have a goodperformance to control mercury compounds as well. In Hybrid filter capture system, the total removal efficiency oftotal mercury compounds consisting of particulate mercury(Hg p ), oxidized mercury(Hg 2 + ), and elemental mercury(Hg 0 ) was 66.2%. The speciation of mercury compounds at inlet and outlet of Hybrid filter capture system were1.3% and 0% of Hg p , 85.2% and 68.1% of Hg 0 , and 13.5% and 31.9% of Hg 2 + , respectively. In hybrid filter capturesystem injected with 100% of flue-gas, the removal efficiency of total mercury was calculated to increase to 93.5%. Key words : Particulate matter, Particulate mercury, Oxidized mercury, Hybrid filter, Mercury removal efficiency

Application of powdered activated carbon coating to fabrics in a hybrid filter to enhance mercury removal

Elemental mercury (Hg0) is predominant constituent of flue gas emitted from coal-fired power plants. Adsorption has been considered the best available technology for removal of Hg0 from flue gas. However, adsorbent injection increases the amount of ash generated. In the present study, powdered activated carbon (PAC) was coated on polytetrafluoroethylene/glass fiber filters to increase Hg0 removal while concurrently reducing the amount of ash generated. The optimal PAC coating rate was determined in laboratory experiments to ensure better Hg0 removal with low pressure drop. When PAC of particle size less than 45 μm was used, and the areal density was 50 g/m2, the pressure drop remained under 30 Pa while the Hg0 removal efficiency increased to 15.8% from 4.3%. The Hg0 removal efficiency also increased with decrease in filtration velocity. The optimal PAC coating rate was applied on a hybrid filter (HF), which was combined with a bag filter and an electrostatic precipitator in a single chamber. Originally designed to remove fine particulates matter, it was retrofitted to the flue gas control device for simultaneous Hg0 removal. By employing the PAC coating, the Hg removal efficiency of the HF increased to 79.79% from 66.35%. Also, a temporary reduction in Hg removal was seen but this was resolved following a cleaning cycle in which the dust layer was removed.