旋轉填充床中水吸收高濃度氨氣

Abstract

氨氣是半導體制程中常用的氣體，同時也是一種高污染氣體，因此，含有氨氣的廢氣，尤其是高濃度氨氣的廢氣之處理非常重要。旋轉填充床利用離心力所造成之高重力場，達到提升質傳效果之目的。本研究採用逆流式旋轉填充床，以水為吸收劑吸收氨氣。氨氣溶在水會釋放大量溶解熱，導致旋轉填充床內溫度劇烈變化。本研究利用溫度記錄器iButton，分別置於填充床的內外徑處，記錄不同實驗條件下，溫度的變化。實驗結果顯示，吸收效率隨液體流量，轉速的增大而增大，隨著氣體流量，濃度和pH值的增大而減小，受溫度(35℃-40℃)影響不明顯。用旋轉填充床處理高濃度氨氣，吸收效率可以達到96%。

Ammonia is commonly used semiconductor process, but it is also a kind of highly polluting gases. Therefore, dealing with waste gases which contain ammonia, especially high concentration ammonia, is very important. Rotating packed bed (RPB) which substitutes the centrifugal force for gravitational force plays an important role in the field of process intensification. With the help of centrifugal force, a better mass transfer efficiency could be expected. In this study, ammonia was absorbed by water in an RPB. Ammonia dissolving in water could release a lot of heat, that could cause temperature in RPB change sharply. In this study, two temperature loggers were placed at the inner and outer diameter of the packed bed to record the temperature profile under different experimental conditions. It is found that absorption efficiency increased with increasing liquid flow rate and rotation speed, decreased with increasing gas flow rate, concentration and pH, but was not affected obviously by temperature(35℃-44℃). By using RPB the absorption efficiency could be up to 96%.