Surface characterization of palladium–alumina sorbents for high-temperature capture of mercury and arsenic from fuel gas

Baltrus, John P.; Granite, Evan J.; Pennline, Henry W.; Stanko, Dennis C.; Hamilton, Hugh; Rowsell, Liz; Poulston, Stephen; Smith, A. W.; Chu, Wilson

doi:10.1016/j.fuel.2009.09.030

Cited by 57 publications

(35 citation statements)

References 7 publications

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“…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.…”

Section: Introductionmentioning

confidence: 99%

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

Xie

Wang

Ning

et al. 2019

Applied Organom Chemis

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A series of Ce modified catalysts were prepared using equivalent‐volumetric ultrasonic impregnation method for AsH3 removal. The performance of catalytic oxidation of AsH3 under dynamic conditions was studied under different synthesis and reaction conditions. Through screening tests, the optimum catalyst was impregnated by 10 wt.% Ce (CH3COO)3 precursor and subsequently calcinated at 550 °C. When the reaction temperature reached 170 °C, the Ce‐HZSM‐5 catalyst could maintain an oxidation efficiency of over 90% in 82 hrs. Furthermore, the chemical structure and properties of the catalyst and its catalytic oxidation mechanism with AsH3 were analyzed using SEM‐EDS, BET, XRD, XPS, H2‐TPR and FT‐IR. The results showed that Ce mainly existed on the catalyst surface in the forms of Ce4+ and Ce3+. In the reaction process, the chemisorbed oxygen played a key role in the transformation between the two valence states. AsH3 was firstly oxidized to elemental As with the participation of lattice oxygen. Then, the elemental As was partially blown into the rear part of the adsorption column along with the air flow and subsequently, de‐sublimed on the column wall. Herein, the elemental As remained on the surface of Ce‐HZSM‐5 catalyst, which would further oxidize to As2O3. For the recovery of As, Ce‐HZSM‐5 proved to be a promising catalyst in AsH3 removal. Highlights The CeOx modified HZSM‐5 catalyst was used to catalytic oxidation of AsH3. The Ce‐HZSM‐5 catalyst could maintain over 90% oxidation efficiency in 82 hrs. AsH3 was catalytic oxidized to elemental As and H2O on the catalyst surface and the As can be collected. The As adsorbed on the catalyst surface can be oxidized to As2O3 but cannot be further oxidized to As2O5.

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Section: Introductionmentioning

confidence: 99%

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

Xie

Wang

Ning

et al. 2019

Applied Organom Chemis

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“…and their oxides and sulfides, calcium species (lime) and zeolites [5][6][7][8][9][10][11][12]. However most of these sorbents are less effective at higher temperature, have low capacities, cannot be regenerated and are easily deactivated by flue gas components such as sulfur oxides (SOx) [13][14], which means that the search for the ideal mercury sorbent is far from over [15].…”

Section: Introductionmentioning

confidence: 99%

Experimental study of mercury removal from exhaust gases

Wdowin

Wiatros-Motyka

Panek

et al. 2014

Fuel

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An initial study has been made of the use of synthetic zeolites for mercury capture from exhaust gases. Synthetic zeolites (Na-X and Na-P1), and for comparison a natural zeolite (clinoptilolite) and activated carbon with bromine (AC/Br) were tested for mercury uptake from a gaseous stream. The materials were subjected to mercury adsorption tests and their thermal stability was evaluated. The untreated synthetic zeolites had negligible mercury uptake, but after impregnation with silver, the adsorption of mercury was markedly improved.The synthetic zeolite Na-X impregnated with silver adsorbed significantly more mercury before breakthrough than the activated carbon impregnated with bromine, indicating the potential of zeolite derived from coal fly ash as a new sorbent for capture of mercury from flue gases.

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“…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.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2017

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Abstract:The energy production processes from fossil fuels represent the first anthropogenic source of mercury emissions in Europe and the second in the world. Among the different possibilities that can be posed to reduce these emissions, this work focuses on the use of regenerable sorbents based on gold nanoparticles dispersed on activated carbon foam. The use of regenerable sorbents would not only allow the objective of reducing mercury emissions, but also avoiding the generation of new toxic wastes. The results showed a retention efficiency of 100% and a retention capacity close to 600 µg·g −1 over several cycles of regeneration. Moreover, acid gases did not poison the support. It was observed that mercury capture in this simulated oxy-combustion atmosphere was a consequence of two mechanisms: (1) the amalgamation of elemental mercury and elemental gold and (2) the oxidation of elemental mercury in the presence of HCl, with the subsequent retention of the oxidized mercury on the surface of the activated carbon foam. The nanodispersion of gold on such supports involves a high initial investment. However, this would be counterbalanced by the remarkable regeneration capacity of the sorbent and the possibility of recovering all the materials used.

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Surface characterization of palladium–alumina sorbents for high-temperature capture of mercury and arsenic from fuel gas

Cited by 57 publications

References 7 publications

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

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

Experimental study of mercury removal from exhaust gases

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

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