Preparation and evaluation of active Cu-Zn-Al mixed oxides to CS2 removal for CO2 ultra-purification

Abstract

A simple synthesis route for the formation of Cu-Zn-Al-oxide with high surface area and porosity has been presented, tuned, and evaluated for CS₂ removal from CO₂ stream. Saturation of aqueous suspension of raw Cu, Zn, Al oxides with a stream of CO₂ at mild conditions and subsequent thermal treatment was used for preparation of a series of materials with the same (Cu + Zn/Al) molar ratio but differentiated carbonate content. They were characterized by techniques: X-ray diffraction (XRD), differential thermal gravimetry with evolved gas analysis (DTG/EGA), N₂ sorption, scanning electron microscopy and energy dispersive spectroscopy SEM-EDS and were subjected to tests for CS₂ sorption from the CO₂ stream at 90 °C. It was shown that Cu-Zn-Al sorbents can effectively remove CS₂ if the specific surface area exceeds 40 m²/g and the mean CuO and ZnO crystallites size is not greater than 15 nm. Obtaining active sorbents of sulphur compounds by CO₂ saturation of raw Cu, Zn, Al oxides can be an effective route for preparation of active traps for CS₂ removal from CO₂ at low temperature.

Keywords: CO(2) ultrapurification; CS(2) removal; CuO-ZnO-Al(2)O(3); Sorbent.