利用超重力旋轉填充床去除於模擬廢印刷電路板銅回收製程中所排放氮氧化物之研究

Abstract

近幾年，隨著電子科技產品的快速發展，「都市礦山」成了最新穎的名詞，意謂著從產生的電子廢棄物中回收其中的貴重金屬。本研究和優勝奈米公司合作，優勝奈米公司發展高銅回收率之技術，然而其中的溶銅製程會產生大量的氮氧化物，造成人體和環境的危害。因此本計畫引入超重力旋轉床，藉由離心力所產生之高質傳特性，並搭配適當之氧化劑和吸收劑將氮氧化物去除。對於平均濃度1127 ppm之入口氮氧化物濃度，本研究之最高去除效率可達91.4%，對應之條件為使用臭氧為氧化劑和氫氧化鈉為吸收劑，超重力因子152、氣液比0.83和pOH 1.22。經反應曲面法可得到一更好之操作條件: 超重力因子131、氣液比0.837和pOH 1.22，此條件應用至實際廢印刷電路板溶銅試驗所產生平均濃度349.3 ppm之氮氧化物亦可達95.54%之去除效率。本研究也發展理論和經驗模式來和實際實驗數值比較其誤差。最後，本研究提出Pcap針對能源消耗和去除效率做鏈結，也針對成本效益分析，並提出最佳之操作條件，期盼能提供未來做利用超重力旋轉床去除氮氧化物之研究進行優化、實廠化和全面性分析之實際案例。

Over the past several decades, significant developments have taken place in the field of urban mining, namely recovering invaluable metal from electronic waste. U-win company developed latest technology to effectively and efficiently screw out the precious copper within them. A copper dissolution process is inevitable, and a large amount of nitrogen oxides would be produced and therefore a state-of-art equipment, rotating packed bed, which could largely enhance the gas-liquid mass transfer through centrifugal force was applied and appropriate oxidants and absorbents were added to grade down NOx emission. The highest removal efficiency achieved in this study was 91.4%, when using ozone as oxidants, high gravity factor of 152, gas-to-liquid ratio of 0.83, and pOH of 1.22 dealing with average NOx concentration 1127 ppm. In addition, theoretical as well as empirical models were advanced to compare with experimental results. A motivational approach to examine a clean production technology with the integration of NOx removal efficiency and energy consumption as NOx capture capacity was also established and cost benefit analysis was also accomplished, providing a reference for optimizing, scaling up and comprehensively evaluating for NOx emission control via rotating packed bed.