title: New method for H(2)S removal in acid solutions.
abstract: Several different technologies are available for H(2)S removal from the gas stream of medium capacity. Among them, the most widely used is Locat with more than 120 plants worldwide. In the last decade, many new processes, such as Sulfatreat-DO, Crystasulf, Caltech, and UCSR, were proposed to overcome the drawbacks of the state-of-the-art processes (low sulfur purity, chemical degradation, thiosulfate formation). We have developed a new H(2)S conversion method based on acid ferric nitrate solution, co-catalyzed by a heteropolyacid. H(2)S was converted to pure sulfur (>99.9 %), with no traces of organic compounds. Due to the acid pH of the solution, no chelant or surfactant was needed and iron content in the solution could reach very high levels. Keggin heteropolyacid (H(6)PW(9)V(3)O(40)) catalyzed the reoxidation of reduced ferrous solution with air at mild temperature and at very high reaction rate. The undesired side reaction (NO(x) formation) could be avoided by simply increasing the oxygen partial pressure.
authors.affiliation: Eni Refining & Marketing Division via F. Maritano26, S. Donato, Italy. alberto.de.angelis@eni.it
authors.forename: Alberto
authors.initials: A
authors.lastname: de Angelis
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellussi
authors.forename: Paolo
authors.initials: P
authors.lastname: Pollesel
authors.forename: Carlo
authors.initials: C
authors.lastname: Perego
mesh_terms: D002384:Catalysis; D005296:Ferrous Compounds / Q000737:chemistry; D006862:Hydrogen Sulfide / Q000737:chemistry* / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012996:Solutions
chemical_list: D005296:Ferrous Compounds; D012996:Solutions; D006862:Hydrogen Sulfide