Design of a Sorbent to Enhance Reactive Adsorption of Hydrogen Sulfide

Abstract

A series of novel zinc oxide-silica composites with three-dimensionally ordered macropores (3DOM) structure were synthesized via colloidal crystal template method and used as sorbents for hydrogen sulfide (H2S) removal at room temperature for the first time. The performances of the prepared sorbents were evaluated by dynamic breakthrough testing. The materials were characterized before and after adsorption using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the composite with 3DOM structure exhibited remarkable desulfurization performance at room temperature and the enhancement of reactive adsorption of hydrogen sulfide was attributed to the unique structure features of 3DOM composites; high surface areas, nanocrystalline ZnO and the well-ordered interconnected macroporous with abundant mesopores. The introduction of silica could be conducive to support the 3DOM structure and the high dispersion of zinc oxide. Moisture in the H2S stream plays a crucial role in the removal process. The effects of Zn/Si ratio and the calcination temperature of 3DOM composites on H2S removal were studied. It demonstrated that the highest content of ZnO could reach up to 73 wt % and the optimum calcination temperature was 500 °C. The multiple adsorption/regeneration cycles showed that the 3DOM ZnO-SiO2 sorbent is stable and the sulfur capacity can still reach 67.4% of that of the fresh sorbent at the fifth cycle. These results indicate that 3DOM ZnO-SiO2 composites will be a promising sorbent for H2S removal at room temperature.

Manganese Oxide Nanoarchitectures as Broad-Spectrum Sorbents for Toxic Gases

“…Wang et al recently reported on templated macroporous zinc oxide–silica composites that provide H 2 S capacities of up to 170 mg g –1 under humid conditions, but only 16 mg g –1 under dry challenge . Bandosz has studied multiple metal oxides and metal oxide, reporting iron oxide dispersed with graphite oxide that showed a maximum of 116 mg g –1 for H 2 S .…”

Highly esthetic, deodorant, and antibacterial tile with natural zeolite set via a blast furnace slag-based geopolymer

“…Furthermore, both the rate and total amount of H 2 S adsorption were much larger than those of NH 3 . This was probably due to high alkalinity of the tile surface, so that H 32) iron oxide/graphite (114 mg H 2 S•g ¹1 ). 33) Nonetheless, the tiles developed in this study may be enough applied to interior building products providing us with comfortable lifestyle.…”

Synthesis of ZnO-CuO and ZnO-Co3O4 Materials with Three-Dimensionally Ordered Macroporous Structure and Its H2S Removal Performance at Low-Temperature

“…As demonstrated in the characteristic results of XRD, HRTEM and nitrogen adsorption, the inter-connected macropores, large specific area, and well-dispersed nanoparticles were beneficial to improve desulfurization performance due to excellent mass transfer inside the adsorbents and easy access to the active phase. Pore structure plays an important role in gas-solid non-catalytic reactions, especially reactions which produce large amounts of products, such as the reaction of metal oxide and H 2 S [27]. However, the difference of specific area between 3DOM-Zn x Co 1-x and 3DOM-Zn x Cu 1-x (such as 3DOM-Zn 0.33 Co 0.66 and 3DOM-Zn 0.33 Cu 0.66 , 237.1 vs 213.2 m 2 /g) might illustrate that the specific area was not the major cause of the improvement of adsorption ability (72.7 vs. 102.5 mg/g).…”

“…The materials have some advantages including high surface area, excellent internal diffusion, large porosity, and large pore volume due to their unique structure, making them attractive as catalysts, especially for diffusion-controlling processes. In earlier studies, ZnO- [27], Fe 2 O 3 - [28], CuO- [29], Co 3 O 4 - [30] based 3DOM have been prepared and their desulfurization abilities were investigated. The results showed that the structure provided open and interconnected pores and improved metal oxides dispersion, resulting in better reaction kinetics and higher H 2 S breakthrough capacity.…”