Effect of Ion-exchange Sequence of Copper and Cerium on the Performance of Y Zeolite for the Adsorption Removal of Thiophene from Benzene
WEN Zhihui;LI Lihong;WANG Jingjing;ZHAO Jinchuan;WEI Xinjie;LIAO Junjie;SHANGGUAN Ju;CHANG Liping
太原理工大学 省部共建煤基能源清洁高效利用国家重点实验室太原理工大学 化学工程与技术学院太原理工大学 煤科学与技术教育部重点实验室
【目的】利用双金属改性Y型分子筛对焦化苯中的噻吩进行深度脱除具有重要的意义。其中,金属离子交换顺序对分子筛脱硫性能的影响至关重要。【方法】采用Cu、Ce双金属,利用离子交换法制备出系列双金属改性吸附剂,采用静态吸附实验评价了吸附剂对苯中噻吩的脱除性能,并通过XRD、Py-FTIR、XPS、H2-TPR和N2吸脱附等手段表征了吸附剂的物化性质。【结果】结果表明,金属离子交换顺序会影响吸附剂的相对结晶度、离子交换度、金属含量以及L酸酸量。吸附剂的物化性质与脱硫性能进行关联发现,离子交换度越大,吸附剂的脱硫效率越高;同时吸附剂中Cu+和Ce4+含量越高,形成更多的L酸,其脱硫效率越高。利用双金属对Y型分子筛改性,先Ce后Cu进行交换时,金属Ce会对Cu的落位产生影响,Ce提高了Cu的还原性能。3种吸附剂脱硫效率由大到小为:CuCeY,CeCuY,Cu-CeY.CuCeY吸附剂的脱硫效率最高,可达97.3%,且其相对结晶度最高,离子交换度最大。此工作为高效脱硫吸附剂的制备起到了指导作用。
【Purposes】 The bimetallic modified Y zeolite is of great importance for the deep re- moval of thiophene in coking benzene. The influence of metal ion-exchange sequence on the des- ulfurization performance of zeolite is crucial. 【Methods】 A series of bimetallic modified sorbents were prepared by ion-exchange with Cu and Ce. The desulfurization performance of sorbents in thiophene-benzene solutions was evaluated by static adsorption experiments. The physical and chemical properties of sorbents were analyzed by XRD, Py-FTIR, XPS, H2-TPR, and N2 ad- sorption and desorption techniques. 【Findings】 The results show that metal ion-exchange se- quence affects the relative crystallinity, ion-exchange degree, metal content, and L acid amount of sorbent. The correlations between the physical, chemical properties and the desulfurization performance of sorbent indicate that the higher the ion-exchange degree, the higher the desulfu- rization efficiency of sorbent. Meanwhile, the more Cu and Ce in the sorbent, the more L acid sites formed and the higher its desulfurization efficiency. When Y zeolite is exchanged by Ce first and then Cu, the metal Ce affects the location of Cu and improves reduction performance of Cu. The desulfurization efficiency order of sorbents is CuCeY>CeCuY>Cu-CeY. The desulfurization efficiency of CuCeY is the highest, reaching 97.3%, and its relative crystallinity is the highest and ion-exchange degree is the largest. This work serves as a guide for the preparation of high ef- ficiency desulfurization sorbents.
Cu and Ce modified zeolite;ion-exchange sequence;thiophene;adsorption;desul-furization
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会