改性Y型分子筛吸附脱除模拟油品中氯辛烷

Adsorption of 1-Chloroctane in Model Oil Using Modified Y Zeolite

分别采用离子交换法和等体积浸渍法对Na-Y分子筛进行改性。利用低温氮气吸附-脱附、X射线衍射、X射线荧光光谱和氨气程序升温脱附等手段对改性分子筛进行表征。考察了改性方法、交换的离子类型、吸附时间、吸附温度和吸附剂与油品质量比等因素对改性分子筛吸附脱除模拟油品中氯辛烷性能的影响,并研究了其再生循环使用性能。结果表明:离子交换法制备的Cu-Y分子筛的吸附脱氯性能高于等体积浸渍法制备的CuO/Y分子筛。经Co 2+、Cu 2+、Ag+改性的Y型分子筛,其脱氯性能较Na-Y分子筛显著增加,其中Cu-Y分子筛的脱氯性能最好。当Cu-Y分子筛与油品质量比为1∶5、吸附温度为20℃、吸附时间为1 h时,脱氯率达到91.9%。NH 3-TPD表征显示,分子筛的表面酸性对其脱氯性能具有显著影响,分子筛表面总酸量越大,其脱氯性能越高。Cu-Y分子筛再生循环使用7次后,其比表面积及酸量有少量减小,导致其脱氯性能略微降低。

Na-Y zeolite was modified by ion exchange method and incipient impregnation method,respectively.The modified Y zeolites were characterized by N 2 adsorption,X-ray diffraction(XRD),X-ray fluorescence spectrometer(XRF)and NH 3 temperature programmed desorption(NH 3-TPD).Influences of modification methods,exchanged metal ions,adsorption time,adsorption temperature and the mass ratio of adsorbent to oil on the adsorptive capacity of Y zeolite for 1-chloroctane from model fuel were investigated,and the regeneration performance of Cu-Y was also studied.Experimental results show that Cu-Y modified by ion exchange shows higher adsorption capacity for 1-chloroctane than CuO/Y modified by incipient impregnation.Co 2+,Cu 2+,Ag+modified zeolites exhibit enhanced adsorption capacity than Na-Y,among which Cu-Y has the highest adsorption capacity.The chlorine removal reaches 91.9%when the mass ratio of Cu-Y to oil is 1∶5,the adsorptive temperature is 20℃and the adsorption time is 1 h.NH 3-TPD analysis shows that the total acid amount of modified zeolite plays a very important role on its adsorption capacity for 1-chloroctane,and high total acid amount of Y zeolite is in favor of increasing adsorption capacity.The surface area and total acid amount of Cu-Y become slightly decreased after seven regeneration cycles,leading to a slight decrease of adsorption capacity for 1-chloroctane.