Study On The Adsorption Desulfurization Of Thiophene And Its Derivatives In The Oils

The systematic research about the modified Y zeolites and UiO-66s adsorbents prepared by liquid-phase ion exchange and hydrothermal synthesis has been investigated.The adsorption performances of thiophene and dibenzothiophene were studied by the dynamic and static tests.The physical and chemical properties of the adsorbents are characterized by XRD,XRF,BET,SEM,TG-DTG,FT-IR,In-situ FT-IR,TPD and NH3-TPD.The results of charaterization were also linked with the adsorption desulfurization mechanism of the adsorbents.It was found that CsY adsorbents exhibited high selectivity for thiophene even when a large amount of olefins exist.In-situ FTIR spectra of thiophene and 1-hexene adsorption indicated that both thiophene and 1-hexene were mainly adsorbed on CsY via?-complexation.The higher desorption activated energy and higher adsorption heat of thiophene than 1-hexene obtained by thiophene-TPD and hexene-TPD has revealed that thiophene is adsorbed more strongly in CsY adsorbents than 1-hexene.The results showed that UiO-66 samples with different amounts of defects could be successfully prepared by varying the amount of acetic acid used in the synthesis system.The specific surface area and pore volumes increased with the increase of the amounts of defects.For porous material,higher porosity is generally preferred and beneficial for most applications,thus UiO-66-30 was favorable adsorbent for DBT removal.The pseudo-second-order model fits better for the adsorption data.It was assumed that physical interactions are mainly involved in the adsorption processes and the whole adsorption rate is also controlled by the chemical adsorption.At the same time,the Langmuir and Freundlich models were used to simulate the isothermal adsorption of dibenzothiophene.The result showed that chemical adsorption of single molecular occupies the dominant position.While the amount of the AcOH increases,the acid amount with the medium strength in the samples decreased,and the acid amounts with weak acid increased correspondingly.The increased weak acid improved the adsorption desulfurization performance.