Regenerative Adsorption and Removal of H ₂ S from Hot Fuel Gas Streams by Rare Earth Oxides

Abstract

Sorbent materials that allow for high-temperature, regenerative desulfurization of fuel gas streams for the anode of a solid oxide fuel cell have been developed. Reversible adsorption of H2S on cerium and lanthanum oxide surfaces is demonstrated over many cycles at temperatures as high as 800 degrees C, on both fresh or presulfided sorbents, and at very high space velocities. The adsorption and desorption processes are very fast, and removal of H2S to sub-parts per million levels is achieved at very short (millisecond) contact times. Any type of sulfur-free gas, including water vapor, can be used to regenerate the sorbent surface. Preferably, the anode off-gas stream is used to sweep the desorbed H(2)S to a burner.

Investigation of Impregnated Activated Carbon Properties Used in Hydrogen Sulfide Fine Removal

“…It is seen that water presence enhanced the adsorption of H 2 S. Previous results stated that water is very important in H 2 S removal (Primavera et al, 1998;Bandosz et al, 2000;Yang et al, 1998;Yan et al, 2004;Flytzani-Stephanopoulos et al, 2006;Li et al, 2008;Klein and Henning, 1984;Mikhalovsky and Zaitsev, 1997). According to Primavera et al (1998), water presence may affect the removal reaction path in two ways: (a) H 2 S dissolution to HS -ions occurs in the water film inside the adsorbent pores; thus, the removal reaction proceeds faster in water than on the catalyst surface; (b) water continuously removes sulfur from the active sites and promotes sulfur adsorption on different carbon sections (Xiao et al, 2008, Primavera et al, 1998, Klein and Henning, 1984).…”

Applications and Preparation Methods of Copper Chromite Catalysts: A Review

“…This improvement in efficiency would represent a significant decrease in the cost of electricity along with a reduction in emissions of sulphur compounds [296]. In addition, the method offers potential improvements for hydrogen fuelled solid oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC) technologies [297].…”

A lamellar ceria structure with encapsulated platinum nanoparticles

“…The non-toxic and inexpensive CeO 2 is widely used in the water gas shift (WGS) reaction [1], H 2 S removal [2], three-way catalytic (TWC) conversion [3], fuel cell electrodes [4], oxygen storage [5], and chemical-mechanical planarization [6].…”