银、铈双金属改性的微-介孔Y分子筛制备及其吸附脱硫性能

发布时间：2018-01-12 22:38

  本文关键词：银、铈双金属改性的微-介孔Y分子筛制备及其吸附脱硫性能　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 吸附脱硫 金属改性 孔道调变 动力学 热力学

【摘要】：采用连续脱铝脱硅过程和液相离子交换Ag、Ce离子成功制备了微-介孔meso-AgCeY吸附剂,并使用比表面积测定(BET)、X射线衍射(XRD)、吡啶红外(Py-IR)、傅立叶变换红外(FT-IR)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和透射电子显微镜(TEM)等手段对分子筛吸附剂进行了物化性质表征。以含有不同竞争组分(甲苯或环己烯)的模拟油为原料,通过静态吸附脱硫法考察了制备条件对吸附剂脱硫性能的影响,通过固定床吸附脱硫法探究了吸附剂选择性吸附脱硫的性能,考察了吸附剂的再生能力,并研究了微-介孔meso-AgCeY吸附噻吩的等温吸附和吸附动、热力学。结果表明:(1)微-介孔meso-NaY分子筛适宜的孔调变条件为EDTA处理浓度为0.2mol·L~(-1),EDTA处理时间为6 h,NaOH处理浓度为0.8 mol·L~(-1),NaOH处理时间为30 min;(2)适宜的液相离子交换条件为Ce/Ag摩尔比为7.5,Ce离子交换时间为24 h,焙烧温度为500℃;(3)吸附剂的最佳吸附条件为吸附时间为20 min,吸附温度为50℃;(4)随着原料油中甲苯浓度提高,未进行孔调变的AgCeY和孔调变后的微-介孔meso-AgCeY分子筛吸附剂的吸附选择性均有明显下降,但当甲苯浓度为16.6 vol.%时,AgCeY丧失了选择性脱硫能力,而微-介孔meso-AgCeY仍然保留了一定的吸附能力;与甲苯类似,以环己烯为竞争组分的一系列模拟油,随着环己烯浓度的提高,两种吸附剂的吸附选择性有明显下降,但当环己烯浓度为15.8 vol.%时,AgCeY丧失了选择性脱硫能力,而微-介孔meso-AgCeY仍然保留了一定的吸附能力。表明孔道调变能显著提高吸附剂的选择性吸附能力,微-介孔meso-AgCeY的介孔结构会削弱“微孔填充效应”,能够在高浓度竞争组分存在的模拟油中保持良好的吸附脱硫选择性;(5)微-介孔meso-AgCeY吸附剂具有良好的再生性能,经乙醇洗涤、烘干、焙烧5次再生后,脱硫性能仅下降了6.3%;(6)微-介孔meso-AgCe Y对噻吩的吸附符合Langmuir模型;微-介孔meso-AgCeY吸附噻吩的过程可以用准一级速率方程和Langmuir模型描述;吸附是自发的、放热的过程。
[Abstract]:Micromesoporous meso-AgCeY adsorbents were successfully prepared by continuous desilication and liquid-phase ion exchange. X-ray diffraction (XRD), pyridine infrared (Py-IR), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM). The physicochemical properties of molecular sieve adsorbents were characterized by means of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Different competitive components (toluene or cyclohexene) were used to characterize molecular sieve adsorbents. The simulated oil is used as raw material. The influence of preparation conditions on the desulfurization performance of adsorbent was investigated by static adsorption desulfurization method. The performance of selective adsorption desulfurization of adsorbent was investigated by fixed-bed adsorption desulfurization method, and the regeneration ability of adsorbent was investigated. The isothermal adsorption and adsorption of thiophene on micromesoporous meso-AgCeY were studied. Thermodynamics. The results show that the suitable pore modification conditions for micromesoporous meso-NaY molecular sieve are 0.2mol 路L ~ (-1) EDTA treatment concentration. The treatment time of EDTA was 0. 8 mol 路L ~ (-1) and NaOH was 0. 8 mol 路L ~ (-1). The suitable liquid phase ion exchange conditions are as follows: the molar ratio of Ce/Ag is 7.5%, the exchange time of ce is 24 h, and the calcination temperature is 500 鈩，

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