Copper Ammonia Complex Ion Modified Y Zeolites And Its Adsorption Desulfurization Performance

Si-Al zeolites are usually used as adsorbents in adsorption desulfurization technology,because the microporous zeolites have excellent adsorption desulfurization performance by their acid content advantage.The previous research of our group found that complex catalytic reactions would occur at the B acid site generated during liquid phase hydration of the adsorbent,which would reduce the adsorption desulfurization performance of the adsorbents.In order to solve this problem,Na Y zeolites were modified by Cu（II）-（NH₃）₄Y complex ions,and ammonia coordination Cu（II）-（NH₃）₄Y zeolites was prepared.Cu（I）-NH₃Y adsorbents were obtained after reduction.This study also provides important basic data for the further improvement of the new desulfurization adsorbent from two aspects of adsorption capacity and selectivity,and lays an important foundation for the further improvement of the new desulfurization adsorbent from the aspect of coordination chemistry theory.In this study,Cu（I）-NH₃Y zeolite was prepared by Cu（I）-NH₃Y zeolites modified by Cu（ammonia）complex ions.The texture properties of the samples were characterized by N₂ adsorption,XRD and ICP techniques.The results show that the six groups of Cu-modified Na Y zeolites not only have irregular intercrystalline mesoporous structure,but also exhibit irregular mesoporous structure,due to the destruction of skeleton structure during the modification process.The change of pore structure leads to the change of pore volume,pore size and specific surface area.In addition,when the ion exchange time of Cu（II）-NH₃Y zeolites is long enough,some Cu species will migrate to the SOD cage of zeolites quickly,and with the increase of the ion exchange time,this trend is more obvious.The properties and transformation rules of the active sites in Y zeolite were analyzed by using catalytic cracking unit,in-situ infrared spectroscopy,H₂-TPR and other techniques,and the structure of adsorbed species on the surface of Cu（I）-NH₃Y adsorbent was systematically analyzed,so as to further explore the adsorption configuration and synergistic interaction between the active sites of thiophene sulfur.The results show that the adsorption of Cu（I）-NH₃Y adsorbent successfully avoids the formation of strong B acid site.The adsorption desulfurization capacity of the new Cu（I）-NH₃Y adsorbents can reach 29.53 mg（S）/g（thiophene simulation oil,300ppm W）,which is about 2 times higher than that of the literature.At the same time,the thiophene simulated oil containing 20 wt%1-hexene on Cu（I）-NH₃Y zeolites has a sulfur penetration adsorption capacity of about 5.06 mg（S）/g,which improves the thiophene adsorption selectivity.The improved preparation technology of Cu（I）-NH₃Y adsorbent and the capacity and selectivity of sulfur penetration adsorption obtained have achieved a great breakthrough,compared with those reported in previous literatures.By introducing Cu（ammonia）complex ions,the modified Y zeolites occupied the vacant orbits of copper species and avoided the formation of the active sites of strong B acid to the greatest extent.In addition,the reduction of[Cu（NH₃）₄]²⁺into effective[Cu（NH₃）₂]⁺species can avoid the production of Cu O particles in the calcination by controlling the calcination temperature（～200℃）.