本研究基於美國EPA公告之汞採樣參考方法US EPA Method 30B建立汞採樣方法，內容包含採樣流程、採樣儀器設備操作、採樣紀錄表建立、採樣及分析之QA/QC等，並於國內某一燃煤電廠進行測試並調查其汞排放及分布，此外亦針對US EPA Method 30B與汞CEMS之採樣數據進行比較並評估US EPA Method 30B作為汞CEMS的RATA參考方法之可行性，研究結果顯示US EPA Method 30B之採樣與分析方法及其QA/QC已完整建立，實廠之汞排放及流布調查部分，三季煙囪煙道氣之汞排放濃度為0.04 ~ 0.346 µg/Nm3之間，皆遠低於電力設施空氣污染物排放標準中新設汽力機組規範的2 µg/Nm3，符合國家排放標準之規定，此外US EPA Method 30B與汞CEMS之數據絕對值差不超過1.0 µg/scm，結果為可接受，驗證US EPA Method 30B作為汞CEMS的RATA之參考方法為可行的，本研究亦針對空氣污染防制設備之固體與液體樣品進行分析，固體樣品部分，三季之燃煤汞濃度範圍為0.031 ~ 0.057 mg/kg；底灰除了第Ⅲ季2號機為0.01 mg/kg外，其餘皆低於方法偵測極限（ND）；飛灰之汞濃度介於0.075 ~ 0.712 mg/kg，相對富集因子則是飛灰遠高於底灰。液體樣品部分，各季之脫硫海水汞濃度範圍為0.057 ~ 1.190 µg/L，而第Ⅲ季之進流海水之汞濃度為0.029 µg/L，各季煙囪之排放係數為0.37 ~ 3.37 mg Hg/t coal並符合美國MATS燃煤電廠汞排放之規範，此外由於煙道氣中氯化氫(HCl)對汞氧化影響亦是重要關鍵，因此本研究亦針對商用SCR觸媒之汞氧化效率與HCl之影響進行實驗並探討，結果顯示於370℃且低汞濃度環境下(5.5 ~ 6.0 µg/Nm3)商用SCR觸媒之汞吸附現象仍然明顯，而加入20 ppm與30 ppm HCl則明顯提升汞之氧化效率(80% ~ 90%)。;In this study, a mercury sampling method based on US EPA Method 30B, including the sampling process, the operation of sampling equipment and the QA/QC of sampling and analysis is developed. A survey of mercury emissions and distribution in the flue gas of stacks a coal-fired power plant in Taiwan is conducted in three seasons. In addition, the results obtained by US EPA Method 30B were compared with that obtained with the Continuous Emissions Monitoring Systems (CEMS). The results show that the sampling and analysis method of US EPA Method 30B and its QA/QC have been fully established and the difference between US EPA Method 30B and mercury CEMS data does not exceed 1.0 µg/scm. Mercury concentrations emitted from a large-scale coal fired power plant ranged from 0.04 to 0.346 µg/Nm3, which are lower than the emission standards enacted by Taiwan EPA (2 µg/Nm3). To verify that US EPA Method 30B is feasible as a reference method for Relative Accuracy Test Audits (RATA) of mercury CEMS, this research also analyzes the solid and liquid samples discharged by air pollution control devices. For solid samples, the mercury concentrations of coals in three seasons range from 0.031 to 0.057 mg/kg; the bottom ashes are below the method detection limit (MDL) except for the boiler No. 2 in season Ⅲ (0.01 mg/kg). The mercury concentrations of fly ashes are between 0.075 ~ 0.712 mg/kg. The relative enrichment factor of fly ash is much higher than that of bottom ash. For liquid samples, the mercury concentrations of desulfurized seawater in each season range from 0.057 to 1.190 µg/L, and the mercury concentration of influent seawater in season Ⅲ is 0.029 µg/L. The emission factors of the stacks in each season range from 0.37 to 3.37 mg Hg/t coal, which meets the mercury emission standards for coal-fired power plants in the US MATS. Moreover, the influence of hydrogen chloride (HCl) in the flue gas on the oxidation of mercury is also an important key. Thus, this research also conducts experiments and discusses the mercury oxidation efficiency of commercial SCR catalysts and the influence of HCl. The results show that at low concentrations (5.5 to 6.0 µg/Nm3), mercury is strongly adsorbed on commercial SCR catalyst even at 370oC. The addition of HCl, especially at 20 ppm and 30 ppm, can effectively increase mercury oxidation efficiency (80% to 90%).
