摘要
制备Cr^(3+)和Ni^(2+)双离子改性NaY分子筛Cr-Ni-Y,采用FT-IR和XRD对其进行了详细表征。FT-IR谱图分析表明,Cr-Ni-Y分子筛在波数为1 147cm^(-1)处的吸收峰随改性温度、改性浓度增加而逐渐变宽,1 024cm^(-1)处吸收峰与标准NaY分子筛相比发生了蓝移现象,Cr-Ni-Y分子筛的XRD谱图与标准NaY分子筛特征峰基本一致,说明改性并没有改变分子筛结构,确定较适宜的改性条件为温度70℃、溶液中Cr^(3+)和Ni^(2+)浓度均为0.25mol/L。吸附时间对NaY,CrY,Cr-Ni-Y分子筛吸附脱除模拟燃料中喹啉氮的影响结果表明,Cr-Ni-Y分子筛吸附效果略低于CrY分子筛,优于NaY分子筛。Cr-Ni-Y分子筛对模拟燃料中苯胺、吡啶或喹啉的吸附结果表明,苯胺、吡啶和喹啉分别在40,60,50℃时吸附基本趋于平衡,且吸附效果由好到差的顺序为苯胺>吡啶>喹啉。分子模拟计算结果表明,苯胺、吡啶和喹啉分子中N的电荷数分别为-0.361,-0.233,-0.252,结合晶体场理论,苯胺与Cr-Ni-Y分子筛上Cr^(3+)和Ni^(2+)的静电作用强于喹啉和吡啶,又因为喹啉的位阻大于吡啶,吡啶吸附效果优于喹啉。
The NaY molecular sieves modified by Cr 3+and Ni 2+ion were characterized by XRD and FT-IR.Compared with standard NaY molecular sieve,FT-IR spectra results showed that the 1 147 cm-1 peak of Cr-Ni-Y sieve becomes wider with increase of modification temperature and concentration of modified ions,and a blue shift appears at 1 024 cm-1 which demonstrates that Cr 3+and Ni 2+exchange occurs on the NaY molecular sieve skeleton.The XRD results of Cr-Ni-Y molecular sieve are mainly the same as NaY,indicating no changes in the structure of NaY.The suitable modification conditions are:modification temperature of 70℃,ion concentration 0.25 mol L for Cr 3+and Ni 2+each in solution.The effect of adsorption time on the removal of quinoline from the model fuels over NaY,CrY and Cr-Ni-Y molecular sieve were investigated.The results showed that the adsorption effect of Cr-Ni-Y molecular sieve is lower than CrY molecular sieve,but better than NaY.The adsorption tests indicated that the adsorption equilibrium temperature are 40℃,50℃and 60℃for aniline,pyridine and quinoline,respectively.The charge number of aniline,pyridine and qinoline from molecular simulation is-0.361,-0.233,-0.252,respectively.Combined with the crystal field theory and charge numbers calculated,it is recognized that the absorption efficiency for aniline is better than pyridine and quinoline is due to the stronger electrostatic interaction of aniline and Cr 3+,Ni 2+on Cr-Ni-Y molecular sieve,while the steric hindrance of quinoline is larger than pyridine,resulting in higher absorption efficiency for the later.
作者
洪新
李云赫
赵永华
唐克
Hong Xin;Li Yunhe;Zhao Yionghua;Tang Ke(School of Chemical and Environmental Engineering,Liaoning University of Technology,Jinzhou,Liaoning 121001)
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2018年第2期18-22,共5页
Petroleum Processing and Petrochemicals
基金
辽宁省自然科学基金项目(2014020113)
广西高校北部湾石油天然气资源有效利用重点实验室2016年度开放课题(2016KLOG04)
关键词
NAY分子筛
铬
镍
离子交换
吸附脱氮
NaY molecular sieve
chromium
nickel
ion-exchange
adsorptive denitrogenation
