制备方法对AgCeY吸附剂脱硫性能的影响

以硅铝比为5.3的NaY分子筛为母体,分别采用微波辅助离子交换法(AgCeY-1)、水热离子交换法(AgCeY-2)和液相离子交换法(AgCeY-3)制备了AgCeY-n吸附剂,并利用XRD、BET、XPS和Py-FTIR对吸附剂进行了表征。以噻吩和苯并噻吩为模型硫化物,甲苯和环己烯为竞争吸附组分,考察了制备方法对制备得到的吸附剂脱硫性能的影响。结果表明,AgCeY-n吸附剂上Ag、Ce元素分别以Ag~+、Ce~(4+)形式存在。经微波辅助离子交换法制备得到的AgCeY-1吸附剂表面Ag~+、Ce~(4+)含量均最高,且具有最高的L酸和B酸量。AgCeY-n吸附剂对硫化物的吸附选择大小顺序为:BTTP,竞争吸附组分对AgCeY-n吸附脱硫性能的影响顺序为:环己烯甲苯。在所研究的制备方法中,微波辅助离子交换法所需时间最短(20 min),合成的AgCeY-1对所研究的模拟油的吸附效果均最好,且具有较好的重复使用性能。各吸附剂对TP和BT的脱除能力大小顺序为:AgCeY-1AgCeY-2AgCeY-3。

Effect of preparation method on desulfurization performance of AgCeY adsorbents

The AgCeY-n adsorbents were successfully synthesized by microwave-assisted liquid ion exchange (AgCeY-1), hydrothermal ion exchange (AgCeY-2) and liquid phase ion exchange (AgCeY-3) methods with NaY (Si/Al ration=5.3) molecular sieve parent and characterized by XRD, BET, XPS and Py-FTIR analysis. With thiophene (TP) and benzothiophene (BT) as the model sulfides, and toluene and cyclohexene as the competition components, the effects of the preparation method on the adsorptive desulfurization properties of the as-prepared adsorbents were evaluated. The results show that the Ag and Ce species in AgCeY-n zeolites exist as Ag⁺ and Ce⁴⁺. The AgCeY-1 prepared via microwave-assisted liquid ion exchange method possesses the highest Ag⁺ and Ce⁴⁺ contents. In addition, it possesses the highest amounts of L and B acid. The adsorption selectivity to sulfur compounds follows the order:BT>TP. The effects of competition components on the sulfur removal with AgCeY-n zeolites follow the order:cyclohexene>toluene. Among the preparation methods tested,the microwave-assisted liquid ion exchange method takes the shortest time (20 min). The as-prepared AgCeY-1 adsorbent exhibits most satisfied performance of adsorption for all the model oils and a wonderful regeneration property. The removal ability for TP and BT of various adsorbents follows the order:AgCeY-1 >AgCeY-2 >AgCeY-3.