廢離子交換樹脂低溫熱處理之動力學研究

Kinetic Studies on Low-Temperature Heat Treatment of Spent Ion Exchange Resins

李財興(Tsye-Shing Lee)

指導教授 ： 莊 瑞 鑫

元智大學/工程學院/化學工程與材料科學學系/碩士(2000年)

摘要

摘要
放射性廢料焚化處理時，溫度愈高，放射性核種尤其是Cs核種，愈容易隨氣體逸出，所以把處理溫度降低，可降低放射性之污染擴散。本研究之主要目的，在降低廢離子交換樹脂熱處理溫度，避免放射性核種在焚化處理過程擴散。本研究係以添加硫酸銅、硫酸亞鐵或氧化銅於離子交換樹脂，並以熱重量分析儀，觀察樹脂在空氣中加熱氧化之行為，研究降低焚化溫度之可能性。
實驗結果顯示添加硫酸銅、硫酸亞鐵及氧化銅於陽離子交換樹脂中，可降低其氧化分解溫度，但硫酸亞鐵降溫幅度有限，硫酸銅及氧化銅之效果較佳。當添加20wt﹪之CuSO4.5H2O或8wt﹪之CuO於樹脂中，樹脂完全氧化溫度在590 ℃左右，比未添加時下降130℃；另將陽離子交換樹脂先以銅離子交換後，亦可達到相同的效果。添加硫酸銅或氧化銅的方法對陰離子交換樹脂及陰、陽混合離子交換樹脂，同樣具有降低溫度的效果。
本研究並依據離子交換樹脂TGA實驗結果，利用Arrhenius速率式模擬其在空氣中熱處理的動態行為，並以四階之Runge-Kutta數值演算法，求得Arrhenius速率式之參數，如反應級數、頻率因子與活化能等。

關鍵字

放射性廢料 ； 放射性核種 ； 焚化 ； 離子交換樹脂

並列摘要

ABSTRACT
In the incineration of nuclear wastes, a higher incineration temperature would result in more nuclides, especially Cs-137 and Cs-134, to escape to the gas stream. This caused more dispersion of the radioactivity. This study aimed at lowering the incineration temperature of the radioactive spent ion exchange resins by incorporating resins with copper sulfate, ferro sulfate, copper oxide or silica in incineration, and their thermo-gravimetric phenomena were investigated.
Experimental results showed that the temperature for complete incineration of cationic exchange resins was significantly reduced by incorporating with the above mentioned inorganic compounds. It was shown that copper sulfate and copper oxide were more effective for this purpose. The cationic exchange resin incorporated with 20wt% CuSO4.5H2O or 8wt% CuO of the resin was completely incinerated at 590℃, which is 130 ℃ lower comparing to that in the absence of copper sulfate. Pre-loaded copper in the resins by cationic exchange also showed the same effect. The method is also effective for anionic exchange resins as well as mixed type ion exchange resins.
In this study,the dynamic behaviors of the heat treatment of the ion exchange resinswere also obsered. A dynamic behaviorwas developed in terms of the parameters of Arrhenius equation, and the parameters in Arrhenius equation for thereactions such as reaction order, pre-exponential factor and activation energy were determined by the 4th order Runge-Kutta algorithm.

並列關鍵字

nuclear waste ； nuclide ； incineration ； ion exchange resin

參考文獻

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