Amino-modified molecular sieves for adsorptive removal of H2S from natural gas

Ultrasonic-assisted preparation of highly active Co3O4/MCM-41 adsorbent and its desulfurization performance for low H2S concentration gas

Co₃O₄/MCM-41 adsorbents were successfully prepared by ultrasonic assisted impregnation (UAI) and traditional mechanical stirring impregnation (TMI) technologies and characterized by X-ray diffraction (XRD), N₂ adsorption desorption, Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetry-differential thermal analysis (TG-DTA). The H₂S removal performances for a simulated low H₂S concentration gas were investigated in a fixed-bed. The effect of preparation and adsorption conditions on the H₂S removal over Co₃O₄/MCM-41 were systematically examined. The results showed that UAI promotes more and well defined highly dispersed active Co₃O₄ phase on MCM-41. As compared to the Co₃O₄/MCM-41-T prepared via TMI, the saturated H₂S capacity of Co₃O₄/MCM-41-U prepared via UAI improved by 33.2%. The desulfurization performance of adsorbents decreased in the order of Co₃O₄/MCM-41-U > Co₃O₄/MCM-41-T > MCM-41. The Co₃O₄/MCM-41-U prepared using Co(NO₃)₂ concentration of 10%, ultrasonic time of 2 h, calcination temperature of 550 °C and calcination time of 3 h exhibited the best H₂S removal efficiency. At adsorption temperature of 25 °C with model gas flowrate of 20 mL min⁻¹, the breakthrough time of Co₃O₄/MCM-41-U was 10 min, and the saturated H₂S capacity and H₂S removal rate was 52.6 mg g⁻¹ and 47.8%, respectively.

Co₃O₄/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.

Research advancements in sulfide scavengers for oil and gas sectors

Sulfide species (inorganic and organic sulfides) are well known for their toxicity and corrosiveness. Several industries, including oil and gas, are prone to corrosive damage due to sulfides that necessitate their timely removal using appropriate methods. Employing chemical scavengers is the most suitable method where the scavenger combine with dissolved sulfides in aqueous/hydrocarbon phase and convert them to a nontoxic and less corrosive form that can be easily removed from the stream. Instead of direct chemical scavenger addition, different approaches, including absorption and adsorption methods, are employed in eliminating sulfide species from gas streams in different industrial applications. This review provides a detailed account of various sulfide scavengers used in oil and gas sweetening. Most recent research advancements in this area are highlighted. A brief account of the latest reported works on novel adsorbents for the desulfurization process for refinery fuels is also provided. The review ends with a short discussion on catalytic hydrodesulfurization.