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采用溴化铵对钠基膨润土进行改性制得脱汞吸附剂,在固定床实验装置上对所制备的吸附剂进行脱汞性能测试。脱汞实验结果表明,钠基膨润土较钙基膨润土在脱汞性能上提高不大,而溴化铵改性的钠基膨润土(Br-Ben/Na)脱汞性能得到明显提高,脱汞效率达到97.7%。吸附温度的升高有利于对Hg0的脱除,在140℃下,10%Br-Ben/Na吸附剂的脱汞率能长时间保持在90%以上,说明在此吸附过程中化学吸附占主导性作用。通过N2吸附/脱附、X射线衍射(XRD)、元素分析仪和傅里叶变换红外光谱(FT-IR)分析等结果表明,改性后的膨润土比表面积下降,平均孔径增大;铵根离子进入到膨润土的层间置换出层间钠离子,煅烧活化过程中层间的铵根离子并未分解,而在层间与膨润土结合为某吸附活性组分协助Br-与Hg0反应,提高了膨润土的脱汞性能。
Ammonia - bentonite was modified with ammonium bromide to get mercury - removing adsorbent. The mercury removal performance of the prepared adsorbent was tested on a fixed bed experimental apparatus. The results of mercury removal showed that sodium bentonite showed little improvement in mercury removal performance compared with calcium bentonite, while the mercury removal performance of Bromine-modified sodium bentonite (Br-Ben / Na) was significantly improved and the mercury removal efficiency reached 97.7%. Adsorption of Hg0 was beneficial to the removal of Hg0. The desorption rate of 10% Br-Ben / Na adsorbent at 90 ℃ for more than 90% of the time showed that the chemisorption was dominant during the adsorption process Sexual function. The results of N2 adsorption / desorption, X-ray diffraction (XRD), elemental analysis and Fourier transform infrared spectroscopy (FT-IR) showed that the specific surface area of modified bentonite decreased and the average pore diameter increased. Ions into the interlayer of bentonite exchange interstitial sodium ions during the calcination activation of the ammonium ion between the layers did not break down in the interlayer with bentonite as an adsorptive active component to help Br- and Hg0 reaction increased Bentonite mercury removal performance.