Ag-based π-complexation adsorbent for paraffin/olefin separation

ABSTRACT

With the massive requisition of light olefins in dedicated areas of petrochemical industry, adsorption separation approaches are developed to meet the requirements. The literature studying long-chain olefins/alkanes is scarce, and the actual adsorption capacity of liquid-phase is rarely studied. In this paper, the adsorption process of Ag-10× zeolite for long-chain alkanes/olefins was systematically studied, the preparation conditions and operating conditions of the zeolite were investigated. The samples were characterized by XRD, BET and XPS. The results show that silver ions were uniformly dispersed on the surface of the zeolite. The actual adsorption capacity of the modified zeolite was determined in intermittent experiments by liquid phase concentration difference and pore volume correction. The experimental data were fitted and the results showed that the Langmuir isotherm equation was more appropriate for adsorption, indicating that the adsorbent surface was homogeneous. The quasi-secondary kinetic chemical equation was consistent with the adsorption of olefins by the modified 10× zeolite, indicating that the process was a chemisorption process. Experimental results shows that Ag-10× zeolite is an excellent adsorbent for separating long-chain olefins/alkanes mixed systems.

KEYWORDS:

• Adsorption
• zeolite
• separation

Acknowledgments

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Statement of novelty

This work further investigates the actual adsorption capacity of modified 10× molecular sieve for liquid-phase adsorption of long-chain olefins, which is important for the separation process of long-chain olefins/alkanes. It also systematically investigates the separation process of liquid-phase adsorption of long-chain olefins and examines the effect of operating conditions on the adsorption process. The adsorption process is known to be monolayer adsorption by the Langmuir isotherm equation, which is chemisorption. The adsorption characteristics of dynamic adsorption were obtained by penetration curves. These results show that the adsorption of modified 10× molecular sieve is more effective for the separation of olefins/alkanes.