Characteristics of the removal of mercury vapor in coal derived fuel gas over iron oxide sorbents

• Published in: Fuel (Guildford) Vol. 85; no. 2; pp. 213 - 218
• Main Authors: Wu, Shengji, Azhar Uddin, Md, Sasaoka, Eiji
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 2006; Elsevier
• Subjects: Air pollution caused by fuel industries; Applied sciences; Coal derived fuel Gas; Energy; Energy. Thermal use of fuels; Exact sciences and technology; H 2S; Iron oxide; Pollution reduction; Removal of mercury vapor; H 2S; Removal of mercury vapor; Iron oxide; Coal derived fuel Gas; Hydrogen Sulfides; Reaction mechanism; H2S; Coal gas; Sorbent; Flue gas purification; Mercury
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2005.01.020

The characteristics of a novel method for Hg removal using H 2S and sorbents containing iron oxide were studied. Previously, we have suggested that this method is based on the reaction of Hg and H 2S over the sorbents to form HgS. However, the reaction mechanism is not well understood. In this work, the characteristics of the Hg removal were studied to clarify the reaction mechanism. In laboratory made sorbents containing iron oxide were used as the sorbent to remove mercury vapor from simulated coal derived fuel gases having a composition of Hg (4.8 ppb), H 2S (400 ppm), CO (30%), H 2 (20%), H 2O (8%), and N 2 (balance gas). The following results were obtained: (1) The presence of H 2S was indispensable for the removal of Hg from coal derived fuel gas; (2) Hg was removed effectively by the sorbents containing iron oxide in the temperature range of 60–100 °C; (3) The presence of H 2O suppressed the Hg removal activity; (4) The presence of oxygen may play very important role in the Hg removal and; (5) Formation of elemental sulfur was observed upon heating of the used sample.