高级检索

    工业炉窑VOCs废气吸附-脱附-催化一体化净化技术研究

    Study on adsorption-desorption-catalytic integrated purification technology for the abatement of VOCs waste gas from industrial furnaces

    • 摘要: 针对小型企业工业炉窑VOCs低浓度、不连续的排放特点,以商用活性炭为吸附材料,采用自制Pd-Ce/Al2O3双元催化剂开展工业炉窑VOCs废气吸附-脱附-催化一体化净化技术研究,通过BET、SEM和TG表征手段对吸脱附再生前后的活性炭进行表征测试。以甲苯为探针分子,考察不同脱附时间、烟气稀释倍数、催化温度及烟气循环次数对该工艺净化甲苯废气性能的影响。研究表明100 ℃下热脱附1 h即可将吸附物质基本脱除,催化温度为320 ℃时,甲苯即可完全催化氧化;系统循环操作10~15次后,活性炭材料在100 ℃下焙烧6 h进行彻底再生,具有最好的经济效益。表征结果表明,经多次热再生后,活性炭孔道存在部分坍塌,比表面积由889 m2/g降至688 m2/g,孔容由0.50 mL/g降至0.37 mL/g,孔径无明显变化,均在2.2 nm左右;这与SEM观察到的活性炭表面褶皱减少相吻合,说明多次热再生后活性炭孔道存在一定程度的坍塌,但依然保持介孔特性;TG曲线中再生后活性炭失重曲线略低于新鲜活性炭,进一步证明多次热再生对活性炭孔道结构存在一定的破坏性。

       

      Abstract: In view of the characteristics of low concentration and discontinuous emission of VOCs from industrial furnaces in small enterprises,the commercial activated carbon was chosen as adsorption material and the home-made Pd-Ce/Al_2O_3 binary catalyst was used as catalytic material to study the integrated purification technology of VOCs waste gas from industrial furnaces. BET,SEM and TG were used to characterize and test the adsorption performance of the activated carbon. Toluene was chosen as target pollutants to investigate the effects of the desorption time,the flue gas dilution ratio,the catalytic temperature and the flue gas cycle times on the purification performance of toluene exhaust gas. The results show that the adsorbed toluene in the active carbon can be removed with the thermal generation at 100 ℃ for 1 hour,and toluene be completely oxidized when the catalytic temperature is 320 ℃ .After 10-15 cycles of operation,the activated carbon material can be completely regenerated at 100 ℃ for 6 h,which has the best economic benefit. The characterization results show that after many times of thermal regeneration,the pore channel of activated carbon partially collapses,the specific surface area decreases from889 m~2/g to 688 m~2/g,and the pore volume decreases from 0.50 mL/g to 0.37 mL/g. But the pore diameter is still about 2.2 nm,which is consistent with the reduction of wrinkles on the surface of activated carbon observed by SEM,indicating that the pore of activated carbon collapses to a certain extent after thermal regeneration,but can maintained the mesoporous characteristics. The weight loss curve of activated carbon after regeneration in TG curve is slightly lower than that of fresh activated carbon,which further proves that multiple thermal regeneration has a certain destructive effect on the pore structure of activated carbon.

       

    /

    返回文章
    返回