台灣地區燃煤發電廠含汞物質流布與管理之研究

A Study on the Flow and Management of Mercury-Contained Material in Coal-Fired Power Plants in Taiwan

李淑莉(Su-Li Lee)

指導教授 ： 張添晉教授

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00487

摘要

煤為現今石化燃料中便宜且存量大之物質，亦是台灣主要發電之燃料來源，而燃煤事業所排放之空氣污染物除了SOX、NOX、CO2及重金屬對環境危害及人類健康一直受人類所關注，其中汞為全球性第一級之污染物質，更是不容忽視，亦被美國環保署列為129種優先管制之毒性污染物之一，因具有持久性生物累積物質，即使微量也可能對人體健康產生高度危害，而燃煤發電更是汞排放至大氣之主要來源，因此，調查國內燃煤發電程序含汞物質之流布實為刻不容緩之議題。
為了解燃煤發電廠含汞物質之流布，本研究採用物質流分析方法，將汞投入來源以燃煤量與煤之汞含量計算，產出之底灰、飛灰、石膏、污泥及煙道排氣等含汞物質，以質量守恆原理進行估算。並依實地訪視之中部燃煤A廠、B廠及南部燃煤C廠之權重比例，做為估算台灣地區燃煤產業含汞物質之流布依據。所求得2006年煤投入之汞量為5,464.6 kg，產出之底灰及飛灰最終掩埋之汞量分別為285.3 kg及871.6 kg，底灰、飛灰及石膏再利用所排出汞量分別為22.4 kg、2,788.6 kg及201.1 kg，隨著煙道排入大氣中之汞量為1,239.4 kg。
假使國內燃煤產業所產出之含汞物質經再利用後若未做任何清除處理，每年則會有3,012.1 kg進入環境中，加上直接掩埋1,213.2 kg，最終將會有4,225.3 kg掩埋於地底，長期來說，對環境及人民健康將造成累積性影響，因此，為更進一步瞭解因燃煤發電對台灣所造成之總負荷量，故採取汞使用量與國土面積之比較，依內政部內政統計月報得知2006年台灣土地面積為36,000 km2，與燃煤發電汞使用量5,464.6公斤，計算得知汞總負荷量為151.8 g/km2-yr，故藉由汞排放控制措施有效管理燃煤發電廠含汞物質，勢必為未來降低汞負荷量之趨勢。

關鍵字

物質流分析 ； 燃煤電廠 ； 含汞物質 ； 煤 ； 汞

並列摘要

Coal is cheap and massively available fossile fuel currently, and is the main fuel material of electric power generation in Taiwan. But airborne polution such as SOX, NOX, CO2 and heavy material generated by coal-fired industry will harm the environment and human health, is being concerned. Among them, mercury is the grade-1 polution material worldwide, and is also listed in the 129 priority control toxicity polutions list by U.S.EPA, cannot be neglected. Because the permant bio-accumulation effect of Hg, even trace amount of mercury may cause highly harm of human body. Coal-firing power generator is the main source which discharges Hg into the air. Thus, the research of mass-flow of coal-firing power generator in Taiwan is an urgent issue.
To understand the mercury mass flow of coal-firing power plants, this research adopts mass-flow analysis methodology. This study calculates the consumption of coal which conatins Hg, using law of mass conservation to figure out the quantity of mercury-contained material such as bottom ash, fly ash, gypsum, sludge and flue gas. And this study visited coal-firing power plants A and B in middle of Taiwan, and power plants C in south of Taiwan. The average of the estimated ratios of the three plants was used as the basis for the mass flow of mercury-contrained material of coal-fired power plants in Taiwan. The result shows that the amount of mercury conatined in coal which was consumed in 2006 was 5,464.6 kg, and the amounts of mercury in bottom ash and fly ash discharged were 285.3 kg and 871.6 kg respectively. Mercury discharged by reusing of bottom ash, fly ash and gypsum is 22.4 kg, 2,788.6 kg and 201.1 kg respectively. Mercury discharged into air through stack is 1,239.4 kg.
If the mercury-contained material generated by coal-firing industry is not treated after reusing, 3,012.1 kg mercury will be discharged into environment. When direct disposal of mercury of which the amount is 1213.2 kg is considered, there will be 4225.3kg mercury to be landfilled. In long term, this will cause accumulation effect to environment and human health. Thus, in order to further realize the total loading which is caused by coal-firing power plants to Taiwan, this study compared the mercury usage and area of Tawian. According to Monthly Bulletin of Interior Statistics, the area of Taiwan is 36,000 km2 in 2006, so the total loading of mercury is 151.8 g/km2-yr. Controling the mercury discharge and managing the mercury-contained material from coal-firing power plants effectively will be a tendency towards the decrease in mercury loading.

並列關鍵字

Material Flow Analysis (MFA) ； Coal-Fired Power Plants ； Coal, Mercury-Contained Material, Mercury (Hg)

參考文獻

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