銅鹽含浸吸附劑去除煙道中低濃度氣相汞之探討

Influence of Copper Chloride on the Adsorbent for Low Concentration Mercury Removal from Coal Combustion Flue Gases

莊明維(Ming-Wei Chuang)

指導教授 ： 席行正

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2011年)

摘要

吸附法早已被視為控制電廠汞排放之最佳可行控制技術之一，吸附劑之吸附容量、反應動力及成本均為吸附法成功與否之關鍵。本研究利用椰殼活性碳做為起始原料，配合CuCl2含浸，開發出具有不同理化特性之汞吸附劑，以評估銅鹽含浸吸附劑之汞吸附與氧化能力，並進一步探討吸附劑表面理化特性與吸附容量、反應動力之相關性。結果顯示銅鹽含浸明顯影響活性碳之物理性質，且比表面積下降比例隨含浸量增加而提升。酸洗前處理對於椰殼活性碳之比表面積並無顯著影響，但可增加椰殼活性碳之微孔表面積比例。在N2環境與模擬煙氣環境下之Hg0吸附實驗結果顯示(1) HCl酸洗具有增進活性碳汞吸附之效能；(2)銅鹽含浸處理之活性碳之吸附量明顯提升。但無論於模擬煙道氣環境下或氮氣環境下，所得之Hg0吸附實驗結果顯示大於重量百分比8%的銅鹽含浸量對於活性碳吸附幾乎沒有顯著的幫助，顯示8%以上銅鹽含浸活性碳之吸附量不但與其物理性質無關，且與銅含浸量也無顯著關係。並且在Elovich equation的相關係數大部分均大於0.9以上，代表著Hg0吸附呈現的是化學吸附的現象。

關鍵字

汞 ； 含浸 ； 氯化銅 ； 煙氣 ； 吸附劑

並列摘要

Activated carbon adsorption has been referred to an effective mercury control technology for coal fired power plants. In this study, the Hg0 adsorption equilibrium and kinetics for commercial granular activated carbon impregnated with different percentage of copper chloride (2-16 wt% as Cu) were examined with respect to the resulting physical and chemical properties of carbons. According to the results of the X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), Scanning Electron Microscope (SEM) and Hg0 adsorption at N2 and simulated flue gases condition, it was found that (1) acid treatment using HCl enhanced Hg0 adsorption of carbon, and (2) copper chloride impregnation markedly increased the adsorption capacity of carbon. However, the Hg0 adsorption capacity decreased gradually when Cu loading exceeded 8 wt%. The declining adsorption may be attributed to a decrease in the degree of CuCl2 dispersion and in the accessibility of microspores. Results from kinetic analysis demonstrated that a pseudo-second-order equation can best describe the adsorption behaviors of all tested adsorbents under the two test conditions, indicating that Hg0 adsorbed on the adsorbent surface was in a bimolecular reaction form.

並列關鍵字

mercury ； impregnation ； copper chloride ； flue gases ； adsorbent

參考文獻

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