活性炭改性及其对噻吩吸附性能的研究

Modification of activated carbon and its adsorption property of thiophene

吸附是一种极具应用前景的汽油深度脱硫分离技术。采用硝酸氧化、焙烧、负载金属等方法对活性炭进行改性,利用静态实验研究了改性活性炭对模拟汽油中噻吩的吸附脱除性能。结果表明硝酸氧化可以增加活性炭表面酸性基团的量,提高脱硫性能;N2气氛下焙烧后吸附剂脱硫效果明显优于未处理活性炭;活性炭表面负载Fe、Zn、Cu、Ni金属离子改性中,Fe离子改性活性炭脱硫效果最好。根据上述实验结果,进行了活性炭复合改性实验,得出68%硝酸氧化后再进行Fe离子负载,吸附剂脱硫率最高,噻吩的脱硫率可达到85%。

Adsorption is one of the most promising methods in deep desulfurization of gasoline. The activated carbon was modified by HNO3 oxidation, calcinations and loading with metallic ions. the desulfurization performance of the activated carbons was evaluated by adsorptive removal of thiophene from thiophene-cyclohexane binary solution with equilibrium adsorption capacity as the criterion for evaluation. The experimental results show that the surface acidity groups of activated carbon increase considerably bv HNO3 treatment and imoroveits desulfurization performance; The desulfurization rate of modified activated carbon increased through calcina- tions under N2 atmosphere;loading of Fe,Zn,Cu, Ni ion on the activated carbon improved its adsorption of thio- phene, while modified by Fe ion gave the higher desulfurization rate than by other metal ions. Then, the effect of different modification method combination on the activated carbon are studied. The complex modification of active carbon, oxidized firstly by HNOa before loading active component, its desulfurization efficiency greatly enhanced, and then impregnated by Fe ion, gave the highest desulfurization rate, which could reach 85 %for the thiophene.