Ni-Pt bimetallic adsorbent for deep desulphurization of coked benzene

In the field of chemical engineering, achieving deep thiophene removal from coked benzene is a formidable challenge. This, coupled with the limitation of low sulfur capacity, has been major obstacle to the large-scale application of adsorption desulphurisation technology. In this study, Ni-Pt/Al₂O₃-CA adsorbent was prepared. The citric acid treated γ-Al₂O₃ was used as the carrier, and Ni-Pt bimetal as the active component. The relationship between the microstructure and adsorption performance of the adsorbent was investigated by BET, XRD, SEM, TEM, TPR, XPS and Py-FTIR. The results showed that the Ni-Pt/Al₂O₃-CA adsorbent could not only reduce the thiophene content in benzene to less than 10 ppb but also had sulfur capacity of 2.73 mg S/g compared with the monometallic adsorbent. The adsorption performance of the Ni-Pt/Al₂O₃-CA adsorbent was restored to 95% of the initial one after three repetitive experiments. Meanwhile, based on the kinetic modelling results, the quasi-secondary kinetic model fitted the adsorption data of thiophene on Ni-Pt/Al₂O₃-CA adsorbent better. And the process of thiophene adsorption was described in depth in the diffusion model.