A sulfur removal and disposal process through H 2S adsorption and regeneration: Breakthrough behaviour investigation

Abstract

The breakthrough behaviours of H 2S adsorption in a fixed-bed reactor of iron oxide based adsorbent under elevated pressures were studied. The effects of variations in superficial gas velocity from 0.09 to 0.26 m/s, H 2S feed concentration from 0.5% to 6% (v/v), the operating pressure from 405 to 5070 kPa absolute, and the height of the fixed-bed from 11.7 to 24.5 cm on the breakthrough curves and sulfur loading capacity were investigated. It was found that the shape of the breakthrough curves depends on the superficial velocity and the inlet H 2S concentration in gas streams. Under both higher superficial velocity and higher inlet H 2S concentration, the shape of the breakthrough curve becomes steeper, and vice versa. The sulfur loading capacity decreases as the superficial velocity and the inlet H 2S concentration increase, but it increases as the bed height increases. The change of operating pressure does not have a significant effect on the shape of the breakthrough curve or sulfur loading of the adsorbent. The pressure drop across the bed follows the Ergun equation. The investigation was also extended to the use of the regenerated adsorbents. An empirical equation of exponential function can be used to describe the breakthrough curves. This work provides useful data for the adsorption tower design and process optimization.