Three-Dimensionally Ordered Macroporous Iron Oxide for Removal of H₂S at Medium Temperatures

Abstract

A series of iron oxide sorbents with novel structures of three-dimensionally ordered macropores (3DOM), ranging in size from 60 to 550 nm, were fabricated and creatively used as sorbents for the removal of H2S at medium temperatures of 300-350 °C. Evaluation tests using thermogravimetric analysis (TGA) and a fixed-bed reactor showed that, in comparison to the iron oxide sorbent prepared by a conventional mixing method, the fabricated iron oxide sorbent with a 3DOM structure exhibited much higher reactivity and efficiency, as well as high sorbent utilization with low regeneration temperature. The excellent performance of 3DOM iron oxide as a sulfur sorbent is attributed to its special texture, i.e., the open and interconnected macroporous, large surface area, and nanoparticles of iron oxide, which are revealed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nitrogen adsorption techniques. The investigation results of the pore effect on the performance of the sorbent show that sorbents with pores size around 150 nm in diameter revealed the best performance. The reason is that pores of this size are large enough to allow gas to pass through even if the channel is partially blocked during the reaction process while remaining a large surface area that can provide more active sites for the reaction.

Design of a Sorbent to Enhance Reactive Adsorption of Hydrogen Sulfide

“…The synthesis of monodispersed polystyrene (PS) microspheres and assembly of PS colloidal crystal templates are described elsewhere in detail. 33 For preparation of 3DOM composites, the typical procedures are as mentioned below. First, silica sol was prepared by mixing tetraethylorthosilicate (TEOS), anhydrous ethanol (EtOH), hydrochloric acid and distilled water at a molar ratio of 1:3.9:0.3:1.8.…”

Role of Surface Chemistry and Morphology in the Reactive Adsorption of H2S on Iron (Hydr)Oxide/Graphite Oxide Composites

“…As indicated in the literature, the crystal structure of the metal oxyhydroxides has an influence on the uptake of the H 2 S. 23,27,40 The XRD patterns for the samples studied are presented in Figure 1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 13…”

Fabrication and Fractality of Fe2O3-CeO2/ZSM-5 Composites for High-Temperature Desulfurization

“…However, iron oxide is the most widely used sorbent for hot coal gas desulfurization in the field of the coal chemical industry owing to its good adsorption capacity, abundant resource, lower cost, and good physical strength [15][16][17][18][19]. Doping cerium ion (Ce 4+ ) into Fe 2 O 3 lattice can generate more oxygen vacancies which facilitate the activation and transport of the oxygen species.…”