Investigation To Adsorption Desulfurization Of Model Gasoline Over Modified Y Molecular Seive

In recent years, Sulfur content in transportation fuels (gasoline and diesel) was an important source of atmospheric pollution, so, it was important to research the way of wiping off sulfur compounds and produce standard of sulfur content.Modified Y molecular seive and were carried out investigation in the model gasoline. As follows:(1) single adsorbentsNaY molecular sieve was used as the starting material for preparation for the adsorbents. Single adsorbents were prepared by liquid ion-exchage and were carried out investigation on the progress of removal sulfur in the model gasoline.The suitable adsorption condition: temperature was 75℃, LHSVwas 8.4 ml.h"1. It was seen that from the breakthrongh curves:the best adsorbents were AgY adsorbents, it handled 72 ml/g adsorbents and made the sulfur content descending below 1 ppm.(2) double adsorbents①AgKY/AgMgY/AgCaYAgY,AgKY,AgMgY and AgCaY adsorbents were prepared by liquid ion-exchange method. They were carried out investigation on the progress of removal Thiophene,Thiophene and toluene in the model gasoline. The maximun adsorption content of AgKY,AgMgY and AgCaY were 120,120 and 120 ml/g adsorbents and could descend below 1 ppm. It emphasised on the effect of K+. Mg2+ and Ca2+ as a cocatalyst that increasing the content of Lewis acidity and enhancing dispersion, it was good at adsorption. Adsorption amount of the used adsorbents were not descended comparing with new adsorbents.②AgCeY/AgLaY double adsorbentsAs AgY adsorbents, Optional the best adsorption condition by batch reactor:temperature was 20℃, time was 1 h. making an investigation about the taking off sulfur capacity of the thiophene,Tetrahydrothiophene,thiophene and toluene in the model solution. The saturation sulfur content of AgY,CeY,LaY,AgCeYand AgLaY adsorbents were 1.12,0.54,0.51,1.28 and 1.70 mmol/g respectively. The results showed that AgCeY and AgLaY adsorbents were more effective on the performance of adsorption desulfurization which exhibited higher removal sulfur capacity than AgY adsorbents and had better selectivity than CeY,LaY adsorbents. It emphasised on the effect of Ce3+,La3+ as a cocatalyst that increasing dispersion. Adsorption capacity of AgLaY adsorbents kept consisting with the new adsorbent after first regeneration and then decreased slightly after continues 20 times. Adsorption amount related to electron density of sulfur.③AgTiY/AgZrYTiY and ZrY adsorbents were prepared by impregnation method with tetrabutyl titanate as a titanium source and zirconium oxychloride as a zirconium source and then AgTiY and AgZrY double metal adsorbents were prepared by liquid ion-exchange. It was characterized by XRD,XRF,H2-TPR and XPS. It was seen that adsorption content of double metal adsorbents were bigger than single adsorbents. Adsorption content did not descend after too many times.