| 摘要: | 臭氧(O3)具有強氧化能力，常被用於消毒、殺菌、廢水及空污處理等方面，然而生成臭氧之操作成本偏高，此為瓶頸所在。本研究擬發展觸媒結合電漿系統進行臭氧合成，研發低能耗高產率之臭氧生成技術。本研究選擇使用直徑同為3 mm的玻璃珠、氧化鋁球、矽膠顆粒及不規則形之二氧化鈦顆粒作為填充介電質進行比較，研究結果顯示填充TiO2有最佳性能，最高臭氧濃度為73 gO3/m3；最佳能效達140 gO3/kWh，因其優勢尚包括: (1)介電常數較高加上使用金紅石晶相，比起一般使用的銳鈦礦TiO2有更高的介電常數(達約110-117)，(2)較高的光強度吸收特性，(3)光催化作用，而實驗最佳參數為操作電壓18 kV、頻率15 kHz、放電長度200 mm及放電間隙6 mm；後續研究於相同的操作條件下，加裝冷卻系統降低系統溫度，進一步增加臭氧生成濃度。為探討進氣氣體組成不同之影響，將二氧化鈦顆粒改質之觸媒使可見光吸收增加以利較佳的光催化活性，結果顯示添加少量的氮氣及氬氣並未有效提升臭氧生成濃度。眾觸媒中以改質之觸媒填充於電漿反應系統中有最佳效能且有良好的穩定度，其最高能量效率為415 gO3/kWh，優於國際大部分的研究，此觸媒可有效提升電漿觸媒系統之效能以優化臭氧生成反應。;With an oxidation potential second only to fluorine, ozone is a strong oxidizing agent that has been applied in many areas such as water disinfection, flue gas treatment, food processing, indoor air cleaning, and so forth. However, the cost of ozone generators is still high. Combination of non-thermal plasma (NTP) with heterogeneous catalysis, referred to as plasma-catalysis, has gained much interest during the last 20 years. However, few works on O3 generation via plasma catalyst system have been reported. In this work, a novel catalyst-based plasma system for ozone generation was developed. Based on the analysis of different operating parameters and catalyst surface characteristics, the mechanism of ozone synthesis in plasma catalytic system is discussed. In this study, glass beads, alumina balls, silicone and titanium dioxide with the same diameter of 3 mm were used as filled dielectric materials for comparison. The results indicate that TiO2 has better performance and higher ozone concentration of 73 gO3 / m3. The highest energy efficiency is 140 gO3 / kWh. The advantages of TiO2-based compared to others include: (1) higher dielectric constant (up to about 110-117), (2)the higher light intensity absorption characteristics, (3)the photocatalytic mechanism. Factors that affect the ozone production efficiency and concentration are studied, and the best operating parameters of the experiment contain the applied voltage of 18 kV, the frequency of 15 kHz, the discharge length of 200 mm and the discharge gap of 6 mm. Subsequent research under the same operating conditions, the installation of a cooling system reduces system temperature, which increases ozone generation concentration. The follow-up experiment was to explore the influence of different feed gas composition, and further modify the titanium dioxide particles to form the modified TiO2 catalyst, which increase the absorption of visible light to facilitate photocatalytic activity. Nitrogen can slightly increase the ozone concentration, but a small amount of argon doesn’t increase the ozone concentration. Compared with the different catalysts, filling modified TiO2 in the plasma reaction system has the best performance and stability. The maximum energy efficiency of the plasma catalysis system is 415 gO3 / kWh, which has better energy efficiency than most studies. Therefore, it is believed that this catalyst can effectively improve the efficiency of the plasma catalysis system for ozone generation. |
