| Facing the problems of SO2 pollution and sulfur resource scarcity,it is particularly important to develop renewable desulfurization technology with the characteristics of efficient desulfurization and sulfur resource recycling.In view of the good comprehensive performance of desulfurization method of basic aluminum sulfate（aluminum base）,such as high desulfurization efficiency,recyclable sulfur resources,renewable and recycled desulfurizer,non-toxic and not easy to block the equipment under acidic conditions,this method has been paid more and more attention.The recovery of SO2 and regeneration of desulfurizer become the key technical problems.In order to study a new method for regeneration of desulfurizer,the desorption performance of basic aluminum desulfurization rich solution was studied under the environment of ultrasound,microwave and their synergistic fields compared with that of thermal desorption at the same temperature.The single ultrasonic experiments under the conditions of different desorption temperature,ultrasonic frequency and power were carried out by the single ultrasonic desorption system.The results showed that ultrasound could effectively improve the desorption ratio,desorption rate and shorten the desorption time.Under the condition of the ultrasonic frequency of 20 k Hz,when the desorption temperature was 60℃,70℃and80℃,the desorption ratio under the condition of optimal ultrasonic power was 19.08%,25.35%and 22.67%higher than that of thermal desorption at the same temperature respectively and the desorption time under the condition of optimal ultrasonic power was44.5 min,47.5 min and 42 min shorter than that of thermal desorption respectively when the desorption ratio of the optimal ultrasonic power reached the terminal desorption ratio of thermal desorption.Under the condition of the ultrasonic frequency of 30 k Hz,when the desorption temperature was 60℃,70℃and 80℃,the desorption ratio under the condition of optimal ultrasonic power was 21.03%,35.21%and 27.29%higher than that of thermal desorption at the same temperature respectively and the desorption time under the condition of optimal ultrasonic power was 45.5 min,51 min and 44 min shorter than that of thermal desorption respectively when the desorption ratio of the optimal ultrasonic power reached the terminal desorption ratio of thermal desorption.When the steady-state cavitation was utilized in the ultrasonic desorption,the effect of ultrasonic enhancement on the thermal desorption performance was the largest and the best steady-state cavitation power existed in the process of ultrasonic desorption.At the same desorption time,when the desorption power was less than the optimal steady-state cavitation power,the desorption performance increased with the increasement of ultrasonic power,otherwise,the increasement decreased.Based on the comparison and comprehensive analysis of the evaluation indexes under different frequencies,the optimal and worst combination of ultrasonic parameters were 80℃30 k Hz 540 W and 70℃20 k Hz 360 W,respectively.The single microwave experiments under the conditions of different desorption temperature and microwave power were carried out by the single microwave desorption system.The results showed that microwave had advantages in improving desorption ratio and desorption rate.When the desorption temperature was 60℃,70℃and 80℃,the terminal desorption ratio were 6.96%,16.91%,12.41%and the maximum desorption rate were 1.99×10-4 mol·L-1·min-1,5.32×10-4 mol·L-1·min-1 and 4.81×10-4 mol·L-1·min-1higher than that of thermal desorption at the same temperature,respectively.The desorption ratio and desorption rate increased with the increasement of desorption temperature and microwave power level.The synergistic experiments of ultrasound and microwave under the conditions of the worst and best combination of ultrasonic parameters cooperating with different microwave powers respectively were carried out by the synergistic desorption system.The results showed that the synergistic field could improve the desorption ratio,desorption rate and shorten the desorption time,but the extent of promotion were different.The increasement of the desorption ratio,desorption rate and the extent of shortening time by synergistic desorption of the worst ultrasound compared with by single ultrasound was greater than that by synergistic desorption compared with by single microwave.The improvement of synergistic desorption performance was reflected in the enhancement of ultrasonic desorption performance.The increasement of the desorption ratio,desorption rate and the extent of shortening time by synergistic desorption of the best ultrasound compared with by single microwave was greater than that by synergistic desorption compared with by single ultrasound.The improvement of synergistic desorption performance was reflected in the enhancement of microwave desorption performance.Based on the comparison of desorption performance and the increasement of desorption ratio caused by synergetic unit energy consumption increasing,the optimal and worst synergetic desorption scheme were when the ultrasonic parameters of 30 k Hz 80℃540 W cooperating with the microwave parameters of 720 W and when the ultrasonic parameters of 20 k Hz 70℃360 W cooperating with the microwave parameters of 360 W,respectively. |
