变色硅胶对模拟燃料中几种碱性氮化物的吸附行为研究

Adsorption behavior of several basic nitrogen compounds from model fuel over allochroic silica gel

比较了氧化铝、硅藻土、硅胶及变色硅胶对模拟燃料中碱性氮化物(如喹啉、苯胺、吡啶)的吸附脱除效果,并对变色硅胶进行了表征。实验结果表明,变色硅胶的脱氮效果明显好于其他吸附剂;变色硅胶具有典型非晶态结构,平均孔径、比表面积、孔体积分别为1.80 nm,623 m^2/g,0.344 2 cm^3/g;变色硅胶的酸性较强,极大增强了它吸附脱除碱性氮化物的能力;变色硅胶吸附喹啉和苯胺为Langmuir-Freundlich混合模型,吸附吡啶可归为Freundlich或Langmuir-Freundlich混合模型。

The adsorption removal of basic nitrogen compound quinoline,aniline or pyridine in model fuel over alumina,diatomite,silica gel and allochroic silica gel was investigated at first in this paper.The experiment results indicated that the adsorption denitrification performance of the allochroic silica gel was superior to that of the other three adsorbents.The allochroic silica gel was confirmed by characterization with XRD,FTIR,Nitrogen adsorption and NH3-TPD.The results indicated that the sample was of amorphous structure.The average pore diameter,BET surface area and pore volume of the allochroic silica gel were 1.80 nm,623 m^2/g and 0.344 2 cm^3/g,respectively.The results of TPD showed that the allochroic silica gel had far stronger acidity than that of the silica gel,which greatly enhanced its adsorption denitrification performance.The allochroic silica gel had strong acidity which greatly enhanced its adsorption denitrification performance.Moreover,an experiment study of adsorption thermodynamics of quinoline,aniline or pyridine over the allochroic silica gel was performed.Experiment data was fitted Langmuir,Freundlich and Langmuir-Freundlich equations,and the results revealed that the adsorption of quinoline and aniline over the allochroic silica gel belonged to Langmuir-Freundlich adsorption model.But the adsorption of pyridine over the allochroic silica gel belonged to Freundlich or Langmuir-Freundlich adsorption model.