Effect of palladium dispersion on the capture of toxic components from fuel gas by palladium-alumina sorbents

Abstract

The dispersion and location of Pd in alumina-supported sorbents prepared by different methods was found to influence the performance of the sorbents in the removal of mercury, arsine, and hydrogen selenide from a simulated fuel gas. When Pd is well dispersed in the pores of the support, contact interaction with the support is maximized, Pd is less susceptible to poisoning by sulfur, and the sorbent has better long-term activity for adsorption of arsine and hydrogen selenide, but poorer adsorption capacity for Hg. As the contact interaction between Pd and the support is lessened the Pd becomes more susceptible to poisoning by sulfur, resulting in higher capacity for Hg, but poorer long-term performance for adsorption of arsenic and selenium.

Superior activity of Ce‐HZSM‐5 catalyst for catalytic oxidation of arsine at low oxygen

“…Considering the strong reducibility of AsH 3 , modified adsorbents have been widely applied because of their advantages of easy preparation, selective adsorption and absence of secondary pollution . Generally, in the removal mechanism, the active component on the adsorbent carrier can oxidize AsH 3 into As 2 O 3 and As 2 O 5 , which are captured and purified on the catalyst . Compared with the elemental As, the recovery of arsenic oxide is of lower value.…”

Mercury adsorption in the gas phase by regenerable Au-loaded activated carbon foams: a kinetic and reaction mechanism study

“…The sorbents studied so far for this purpose are mainly metal oxides and porous solids impregnated with noble metals such as gold, silver, palladium and platinum. [8][9][10][11][12][13][14][15][16] The sorbents based on metal oxides have the ability to capture mercury and other trace elements at high temperatures (200-400 1C), and have even been tested for the retention of toxic metals in gasification processes. 17,18 Studies carried out with regenerable sorbents based on manganese oxide showed a good capability for mercury capture up to 300 1C and were completely regenerated at 500 1C.…”

“…On the other hand, the regenerable materials loaded with noble metals (Au, Ag, Cu, Pd or Pt), 8,11,14,[19][20][21] are able to retain elemental mercury by amalgamation between the metal and the mercury, both in an elemental state. 9,10,22 Subsequently, the amalgam can be decomposed by heating at 450 1C to detach and recover the mercury, leaving the sorbent ready for the next adsorption cycle.…”

A New Approach for Retaining Mercury in Energy Generation Processes: Regenerable Carbonaceous Sorbents

“…The mechanism of Hg 0 retention by regenerable sorbents impregnated with noble metals, such as gold, silver, copper, palladium or platinum, is based on the formation of a metal-Hg amalgam [26][27][28]. For this to occur, both the metal and the mercury have to be in an elemental state.…”