Reaction Mechanism of Simultaneous Removal of H2S and PH3 Using Modified Manganese Slag Slurry

Anchoring Cu-N active sites on functionalized polyacrylonitrile fibers for highly selective H2S/CO2 separation

As an essential part of clean energy, natural gas is often mixed with varying degrees of H₂S and CO₂, which poses a serious environmental hazard and reduces the fuel's calorific value. However, technology for selective H₂S removal from CO₂-containing gas streams is still not fully established. Herein, we synthesized functional polyacrylonitrile fibers with Cu-N coordination structure (PANF_EDA-Cu) by an amination-ligand reaction. The results showed that PANF_EDA-Cu exhibited a remarkable adsorption capacity (143 mg/g) for H₂S at ambient temperature, even in the presence of water vapor, and showed a good separation of H₂S/CO₂. X-ray absorption spectroscopy results confirmed the Cu-N active sites in as-prepared PANF_EDA-Cu and the formed S-Cu-N coordination structures after H₂S adsorption. The active Cu-N sites on the fiber surface and the strong interaction between highly reactive Cu atoms and S are the main reasons for the selective removal of H₂S. Additionally, a possible mechanism for the selective adsorption/removal of H₂S is proposed based on experimental and characterization results. This work will pave the way for the design of highly efficient and low-cost materials for gas separation.

Cu/ACF adsorbent modified by non-thermal plasma for simultaneous adsorption-oxidation of H2S and PH3

Non-thermal plasma (NTP) surface modification technology is a new method to control the surface properties of materials, which has been widely used in the field of environmental protection because of its short action time, simple process and no pollution. In this study, Cu/ACF (activated carbon fiber loaded with copper) adsorbent was modified with NTP to remove H₂S and PH₃ simultaneously under low temperature and micro-oxygen condition. Meanwhile, the effects of different modified atmosphere (air, N₂ and NH₃), specific energy input (0-13 J/mL) and modification time (0-30 min) on the removal of H₂S and PH₃ were investigated. Performance test results indicated that under the same reaction conditions, the adsorbent modified by NH₃ plasma with 5 J/mL for 10 min had the best removal effect on H₂S and PH₃. CO₂ temperature-programmed desorption and X-ray photoelectron spectroscopy (XPS) analyzes showed that NH₃ plasma modification could introduce amino functional groups on the surface of the adsorbent, and increase the types and number of alkaline sites on the surface. Brunauer-Emmett-Teller and scanning electron microscopy showed that NH₃ plasma modification did not significantly change the pore size structure of the adsorbent, but more active components were evenly exposed to the surface, thus improving the adsorption performance. In addition, X-ray diffraction and XPS analysis indicated that the consumption of active components (Cu and Cu₂O) and the accumulation of sulfate and phosphate on the surface and inner pores of the adsorbent are the main reasons for the deactivation of the adsorbent.

Catalysts and Processes for H2S Conversion to Sulfur

Hydrogen sulfide is one of the main waste products of the petrochemical industry; it is produced by the catalytic hydrodesulfurization processes (HDS) of the hydrocarbon feedstocks, and it is a byproduct from the sweetening of sour natural gas and from the upgrading of heavy oils, bitumen, and coals [...]

Catalysts and Processes for H2S Conversion to Sulfur

The hydrogen sulfide (H2S) is one of the main byproducts in natural gas plants, refineries, heavy oil upgraders, and metallurgical processes [...]