title: Selectivity of layered double hydroxides and their derivative mixed metal oxides as sorbents of hydrogen sulfide.
abstract: In the context of finding high efficient sorbent materials for removing hydrogen sulfide (H2S) from air stream, a screening study was performed to find the best combination of metals for the synthesis of layered double hydroxides (LDHs) and their derivative mixed metal oxides. Based on selectivity of 998 natural mineral species of sulfur-containing compounds, Cu(2+), Ni(2+) and Zn(2+) were selected as divalent metals, and Fe(3+), Al(3+) and Cr(3+) as trivalent metals to synthesis the LDHs sorbents. 10 LDHs materials and their calcined mixed metal oxides, Ni(0.66)Al(0.34), Cu(0.35)Ni(0.32)Al(0.33), Zn(0.66)Al(0.34), Cu(0.36)Zn(0.32)Al(0.32), Ni(0.64)Fe(0.36), Cu(0.35)Ni(0.31)Fe(0.34), Ni(0.66)Cr(0.34), Cu(0.35)Ni(0.31)Cr(0.34), Zn(0.66)Cr(0.34), Cu(0.33)Zn(0.32)Cr(0.35) were synthesized, characterized chemically and physically, and then tested using breakthrough test to determine their sulfur uptake. Ni(0.64)Fe(0.36) mixed metal oxides was found to have the best uptake of hydrogen sulfide (136 mg H₂S/g). Regeneration of spent Ni(0.64)Fe(0.36) mixed metal oxides was studied using two different mixture solutions, NaCl/NaOH and acetate-buffer/NaCl/NaOH. The latter mixture successfully desorbed the sulfur from the Ni0.64Fe0.36 sorbent for 2 cycles of regeneration/sorption.
authors.affiliation: Department of Civil Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Othman
authors.affiliation: Department of Civil Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
authors.forename: Waleed M
authors.initials: WM
authors.lastname: Zahid
authors.affiliation: Department of Chemical Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia. Electronic address: abasaeed@ksu.edu.sa.
authors.forename: Ahmed E
authors.initials: AE
authors.lastname: Abasaeed
mesh_terms: D000327:Adsorption; D004785:Environmental Pollutants / Q000737:chemistry*; D006862:Hydrogen Sulfide / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*
chemical_list: D004785:Environmental Pollutants; D006878:Hydroxides; D008670:Metals; D010087:Oxides; D006862:Hydrogen Sulfide