透過您的圖書館登入
IP:18.209.63.120
  • 學位論文

海水煙氣脫硫吸收效率研究

The Efficiency of Flue Gas Desulfurization by Absorption in Seawater

指導教授 : 李嘉塗

摘要


台電目前電廠燃煤機組之煙氣除硫系統(Flue Gas Desulfurization,簡稱FGD)均為濕式石灰石/石膏法,需使用大量淡水及石灰石,雖可製備石膏副產品,唯近年來石膏產量有日益過剩及價格下跌等情形,大量石膏之處理需有長久之規劃及考量,否則又形成另一廢棄物問題。而海水法煙氣除硫系統,相關資料顯示除硫效率均可達90%以上。國際上已有大型燃煤機組採用海水法煙氣除硫系統,且國內台塑麥寮電廠也已率先使用。 利用海水本身的鹼性脫除煙氣中的二氧化硫 本研究主要目標是利用電廠之煙氣進行系列之模擬試驗,預期探討海水法FGD實際運轉時之優缺點及相關參數,提供未來台電電廠之海水法FGD之設計及運轉之參考。 海水法FGD原理,主要是利用海水中所含之天然鹼度去中和煙氣中之SO2,首先煙氣被引入吸收塔與海水以逆向流(counter-current)方式進行接觸,煙氣中SO2與海水在吸收區內進行反應。吸收煙氣SO2之海水(吸收塔底部)含HCO31-及SO32-兩種離子,此兩種離子會造成海水中之化學需氧量(Chemical Oxygen Demand,簡稱COD)上升,因此注入空氣,利用空氣中之氧氣將HSO31- 及SO32-兩種離子氧化成SO42-離子,以減少排放海水之COD值。除硫後之酸性海水再進入一水池,與原海水混合並同時通入空氣,海水脫硫中之海水SO32-必須與其他循環海水混合曝氣成SO42-再排放大海;通入空氣之目的有三:可繼續降低海水之COD值;增加海水之溶氧量;吹除CO2 (g)增加海水pH。 本研究實驗設備,在電廠選擇孔板式海水煙氣除硫程式作為研究評估之模擬系統,本系統之主要設備為除硫塔槽,區分為除霧區、SO2吸收區(噴水區)及廢水氧化區。 本研究實驗方法,選擇三種試驗條件: 1.批式海水除硫試驗:為減少海水之使用量(可節省泵能源及廢水量),部份海水可循環使用。 2.連續式海水除硫試驗:連續操作時可利用迴流比【迴流比R=(回收海水流量/原海水流量)】表示海水迴流使用情形,控制循環量時之試驗結果 。 3.貫流式海水除硫試驗:原海水直接通過除硫塔而不再循環使用。 本研究試驗結果: 1. 海水除硫程式之選釋 依據試驗結果,孔板式除硫系統運轉極為順暢,未有因積灰產生結塊(clogging)之現象,且除硫效果佳,所需之除硫塔比填充塔式小,設備簡單,具經濟優勢,可符合大林電廠佔地較小之限制,燃煤電廠選用海水除硫程式應以孔板式為佳。 2. 孔板式系統除硫條件之選擇 採用貫流式(one-through)操作,除硫效率較高、設計容易且裝置成本低,液氣比(L/G)可根據除硫效率而設定之,L/G設定為10除硫效率可達95%,若L/G設定為20除硫效率可達99%以上。

關鍵字

海水脫硫 液氣比 迴流比 貫流式

並列摘要


In Taiwan power company,there were coal-fired boiler units utilizing wet limestone-gypsum FGD units for flue gas desulphurization. Recently ,the price of gypsum by-product is getting down because the production is getting more. It is time to reevaluate what kind of FGD is suitable for Taipower to set new coal-fired boiler units in the near future. Seawater contains natural alkalinity, in terms of carbonate ions(CO32-) and bicarbonate ions(HCO3-)can be employed to remove sulfur dioxide from flue gas. Seawater FGD offers a number of remarkable abvanages, such as the simplicity of the process, less process water and no additional chemical is needed, and no solid wastes are produced, and high sulfur dioxide removal can be achieved. In the study,we were to evaluate the feasibility of Seawater FGD to be utilized in large coal-fired boiler units of Taipower. For this purpose,the study had been finished ,and the conclusions were as follows : 1. We have designed and constructed a little packing tower and a little perforated plate tower seawater FGD to test in Tai-Chung and Da-Lin power pant. Both of the two systems can remove more than 90% of the sulfur dioxde from flus gas exited from EP of large coal-fired boiler units in the two power plants. 2. In addition to recognize high sulfur dioxide removal of seawater FGD in our tests ,we also built the abilities to design it. 3. Both of packing toewe and a little perforated plate tower seawater FGD are in commercial operating in the world and have the advantages and disadvantages of itself, but perforated plate type is less easy to cause clogging than packing tower,therefore it is more easy to handle.

參考文獻


13. Hermine N Soud(1994), Mitsuru Takeshita〝FGD Handbook〞,IEA Coal Research.
14. Katsuo Olikawa(2003), Chaturong Yongsiri, Kazuo Takeda, Tayoshi Harimoto, 〝Seawater Flue Gas Desulfurization: It’s Technical Implications and Performance Results〞, Environmental Progress, Vol.22,No.1.
16. Fujikasui Engineering Co(2002). LTD. 〝Moretana Flue Gas Desulfurization System〞.
17. G.Bearman(1989), 〝Seawater its composition, properties and behavior〞Pergamon press,87-88.
1. 林慶山(1992)燃煤電廠濕式煙氣除硫之廢水處理,台電工程月刊第。526期。

被引用紀錄


吳欣儒(2014)。利用活性碳捕捉模擬脫硫廢水中之氧化態汞研究〔碩士論文,國立臺北科技大學〕。華藝線上圖書館。https://doi.org/10.6841%2fNTUT.2014.00004
張孝全(2016)。垃圾焚化底渣全資源化應用作為CLSM粒料之可行性研究〔碩士論文,中原大學〕。華藝線上圖書館。https://doi.org/10.6840%2fcycu201600888

延伸閱讀