利用奈米銅觸媒去除二硫化碳及汽柴油含硫污染物之研究

Desulfurization of Gasoline/Diesel and Adsorption of Carbon Disulfide Using Copper Nanocatalysts

吳國傑(Kuo-Chieh Wu)

指導教授 ： 林錕松

元智大學/工程學院/化學工程與材料科學學系/碩士(2007年)

https://doi.org/10.6838/YZU.2007.00352

摘要

隨著工業與經濟的發展，不斷提昇國人的生活品質與環保意識，民眾對於空氣品質與廢氣排放的認知與重視，尤其是惡臭物質之逸散，更日趨嚴格。另外，汽柴油中含硫量過多會增加粒狀物及SOx排放量，造成引擎排氣系統之腐蝕及加速觸媒轉化器之毒化，故對汽柴油中含硫量之降低，亦是不容忽視之問題。
本研究係利用銅觸媒(10% Cu/γ-Al2O3)對於工業上常用且易造成惡臭之二硫化碳(carbon disulfide, CS2)進行吸附處理之研究，另外對於低硫汽柴油(濃度低於50 ppmw)分別以10% Cu/γ-Al2O3銅觸媒及10% Cu/Y-Zeolite進行含硫汙染物之吸附處理研究，分別以固相微量萃取(solid-phase microextraction, SPME) /氣相層析質譜儀、能量分散式X光螢光分析儀進行檢測分析，並以X-ray粉末繞射儀、場發射掃描電子顯微鏡、化學分析電子光譜儀、比表面積分析儀、程溫還原分析儀、X光吸收近邊緣結構分析及延伸X光吸收精細結構分析等進行銅觸媒表面分析之探討研究。
本研究所使用SPME檢測技術於carbon disulfide的方法偵測極限為1.9 ppbv，銅觸媒於空氣狀態下係以氧化銅狀態存在，在溫度523 K下，CS2吸附量約為15 mg/g，吸附後的銅觸媒經EXAFS分析顯示，不同吸附溫度(523及393 K)下第一層結構的Cu-S鍵距差異不大，分別為1.98及1.96 Å，配位數分別為3.51及2.26。另外， Cu/γ-Al2O3於低硫汽、柴油之除硫效率為0.36及0.23 mg/g、Cu/Y-Zeolite銅觸媒為0.23及0.19 mg/g。在溫度393 K下，CuO/γ-Al2O3吸附CS2前後之XANES分析結果顯示，吸附前後具有相近之吸收邊緣位置，均於8982 eV時開始躍升，可以確認吸附過程中CuO/γ-Al2O3氧化價數並未改變。

關鍵字

固相微量萃取 ； 奈米銅觸媒 ； 二硫化碳 ； 油品中硫污染物 ； 汽油 ； 柴油

並列摘要

Along with the industrial and economic development, people’s awareness of life quality and environmental consciousness are getting strong. People have better cognition and more attention to air quality and waste gas emission, moreover, the standard to the stench material distributes is getting higher nowadays. As we know, too much sulfur content in the gasoline and diesel oils may increase the particulates and SOx emission, which may also cause engine exhaust corrosion of the waste gas control system, and accelerate catalytic converter catalysts transform poison. Therefore, the reduction of sulfur content in the gasoline and diesel oils is a problem that can not be ignored.
Mainly, the objective of this study was to utilize the copper catalyst (10% Cu / γ- Al2O3) dealing with carbon disulfide that apt to cause the material of stench on industry. Besides, this study also focused on the research of low sulfur gasoline and diesel oils (concentration is lower than 50 ppmw) with 10% Cu /γ- Al2O3 and 10% Cu/Y-Zeolite separately. It is also measured by SPME, GCMS, and WDXRF respectively. The research on the surface of copper nanocatalyst was carried out with XPRD, FE-SEM, XPS, BET, TPR, and XANES/EXAFS techniques.
The detection limit of the SPME detection technique, adopted by this research institute, can reach to 1.9 ppbv in carbon disulfide method. The copper catalyst existed in the form of Cu(II) oxidized in the air. The estimated copper catalyst’s absorbing amount is nearly 15 mg/g (mg CS2/g Cu cat.) at 523 K. The copper catalyst after absorption through EXAFS analysis showed that the different absorbing temperatures, 523 K and 393 K, the bonding distances of first shell of Cu-S structure of the copper catalyst were 1.98 and 1.96 Å respectively from the difference. The coordination numbers were 3.51 and 2.26, respectively. The efficiency of cleaning low sulfur gasoline and low sulfur diesel, by CuO/γ-Al2O3 can reach to 0.36 and 0.23 mg/g. The efficiency of cleaning low sulfur gasoline and low sulfur diesel, by CuO/Y-zeolite can also reach to 0.23 and 0.19 mg/g. In addition, the XANES spectra showed that the CuO/γ-Al2O3, before and after CS2 absorption, has similar absorption edge positions, beginning to rise up on 8982 eV, and it can be confirmed that absorbing CuO/γ-Al2O3 in the course CuO/γ-Al2O3 oxidation number had not changed eventually.

並列關鍵字

Solid-phase microextraction ； Copper nanocatalyst ； Carbon disulfide ； Sulfur content in oil ； Gasoline ； Diesel

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