Coal-derived Fuel-gases Research Articles

Effects of Supports on Pd–Fe Bimetallic Sorbents for Hg0 Removal Activity and Regeneration Performance from Coal-Derived Fuel Gas

Pd–Fe bimetallic sorbents were shown to be a great potential sorbent for Hg0 removal from coal-derived fuel gas. In this work, activated carbon (AC), Al2O3, and Beta molecular sieve were chosen as supports to disperse Pd–Fe bimetallic components. The effects of the supports on Hg0 removal of Pd–Fe bimetallic sorbents were evaluated using a fixed-bed reactor at 200 °C. The regeneration performance of sorbents was also investigated. The results showed that Hg0 removal activity and regeneration performance over Pd–Fe/AC was the best, followed by Pd–Fe/Beta, and Pd–Fe/Al2O3. The Hg0 removal efficiency of Pd–Fe/AC bimetallic sorbents remained above 80% within 400 min after regeneration 4 times. The Pd–Fe bimetallic sorbents were characterized by N2 adsorption–desorption, Fourier transform infrared spectroscopy, X-ray diffraction, CO pulse adsorption, Hg temperature-programmed thermal desorption, and X-ray photoelectron spectroscopy. The analysis results revealed that three sorbents had a similar Hg0 removal me...

A Magnetically Recoverable Fe3O4\u2013NH2\u2013Pd Sorbent for Capture of Mercury from Coal Derived Fuel Gas

A sort of magnetical material named Fe3O4–NH2–Pd was prepared by loading varying amounts of immobilizing Pd on the surface of the magnetic Fe3O4–NH2 microspheres. This magnetical material was used firstly for capturing Hg° from coal derived fuel gas based on its recoverability. The experimental results showed that the loading Pd on the amine-functionalized magnetite nanoparticles can greatly improve the efficiency of removing Hg° at a high temperature range between 200 and 300 °C. The magnetic Fe3O4–NH2–Pd sorbent with 5% Pd loaded exhibited significantly high activity and stability in capturing Hg°, affording over 93% capture efficiency at 200 °C for more than 8 hrs. Compared to the Fe3O4–NH2 sorbent that converted the Hg° as HgS, this Fe3O4–NH2–Pd sorbent can remove the Hg° by forming Pd-Hg amalgam and HgS. In addition, the experimental tests indicated that the as-synthesized Fe3O4–NH2–Pd sorbent still showed stable magnetic properties after two regeneration cycles in removing Hg°, which provided the opportunity for preparing a recyclable sorbent which can be easily separated and recovered for Hg° removal.

Catalytic Oxidation and Stabilized Adsorption of Elemental Mercury from Coal-Derived Fuel Gas

The aim of this study is to develop an efficient process for the stabilized removal of elemental mercury (Hg0) from coal-derived fuel gas by the aid of the catalytic oxidation of Hg0 over activated carbon (AC). The experiments were performed in the temperature range of 120–240 °C with simulated coal-derived gases containing varying concentrations of CO, H2, CO2, H2O, and H2S. O2 was introduced to promote the oxidation reaction between H2S and Hg0 over the AC sorbent to form mercury sulfide (HgS). The results indicated that the Hg0 removal capacity of AC could be dramatically improved in the presence of both H2S and O2. The presence of O2 was indispensable for the efficient and stable removal of Hg0 from H2S-containing fuel gas. The high temperature and high content of reducing gases, such as CO and H2, may inhibit the oxidation reaction and decrease the Hg0 removal efficiency, whereas the high content of H2O can promote Hg0 removal. On the basis of thermodynamic analysis, as well as the temperature-programmed decomposition (TPD) and X-ray photoelectron spectroscopy (XPS) characterization of the sorbents, it is suggested that the partial oxidation of H2S with O2 to active sulfur may contribute to the stabilized removal of Hg0 by the reaction of active sulfur with Hg0 to form HgS.

Temperature-Programmed Decomposition Desorption of Mercury Species over Activated Carbon Sorbents for Mercury Removal from Coal-Derived Fuel Gas†

The mercury (Hg0) removal process for coal-derived fuel gas in the integrated gasification combined cycle (IGCC) process will be one of the important issues for the development of a clean and highly efficient coal power generation system. Recently, iron-based sorbents, such as iron oxide (Fe2O3), supported iron oxides on TiO2, and iron sulfides, were proposed as active mercury sorbents. The H2S is one of the main impurity compounds in coal-derived fuel gas; therefore, H2S injection is not necessary in this system. HCl is also another impurity in coal-derived fuel gas. In this study, the contribution of HCl to the mercury removal from coal-derived fuel gas by a commercial activated carbon (AC) was studied using a temperature-programmed decomposition desorption (TPDD) technique. The TPDD technique was applied to understand the decomposition characteristics of the mercury species on the sorbents. The Hg0-removal experiments were carried out in a laboratory-scale fixed-bed reactor at 80−300 °C using simulated...

Desulfurization of Hot Coal-Derived Fuel Gases with Manganese-Based Regenerable Sorbents. 3. Fixed-Bed Testing

In recent studies, the thermodynamic feasibility of using manganese-based sorbent pellets for the removal of H 2 S from hot coal-derived fuel gases, and the subsequent regeneration of loaded (sulfided) pellets with air was established. Screening sulfidation tests on a number of formulations, consisting of a manganese-containing compound (ore or MnCO 3 ), alundum (Al 2 O 3 ), and organic or inorganic binders, were carried out using H 2 S-H 2 gas mixtures in a thermogravimetric apparatus (TGA) at temperatures ranging from 700-1000 °C. A formulation, designated FORM4-A, was found to possess the best combination of sulfur capacity, reactivity, and strength. Regeneration tests determined that for T ≥ 900 °C, loaded pellets can be fully regenerated with air in 10-15 min, without sulfate formation. This paper reports on fixed-bed testing of the leading Mn-based sorbent pellet formulation (i.e., FORM4-A). Experiments are carried out to test the long-term durability and regenerability of the sorbent using a simulated Tampella-U fuel gas for sulfidation and air for regeneration. In addition, the effect of temperature on sulfidation reaction equilibrium is determined in the range 800-1000 °C. A reassessment of the equilibrium states of reactions involving solid MnO, MnS, Mn 3 O 4 , and MnSO 4 is then presented based on the results obtained and a recent study by Turkdogan.

Desulfurization of Hot Coal-Derived Fuel Gases with Manganese-Based Regenerable Sorbents. 1. Loading (Sulfidation) Tests

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesulfurization of Hot Coal-Derived Fuel Gases with Manganese-Based Regenerable Sorbents. 1. Loading (Sulfidation) TestsR. Ben-Slimane and M. T. HepworthCite this: Energy Fuels 1994, 8, 6, 1175–1183Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994https://doi.org/10.1021/ef00048a003RIGHTS & PERMISSIONSArticle Views373Altmetric-Citations54LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts

Desulfurization of Hot Coal-Derived Fuel Gases with Manganese-Based Regenerable Sorbents. 2. Regeneration and Multicycle Tests

In a previous paper, the reduction and sulfidation thermodynamic and kinetic characteristics of four manganese-based high-temperature desulfurization sorbents were investigated. A formulation, FORM4-A, which consisted of manganese carbonate, alundum, and bentonite exhibited the best combination of capacity and reactivity; whereas, FORM1-A, which consisted of Mn ore, alundum, and dextrin exhibited the best combination of strength, capacity, and reactivity. In this paper the thermodynamic feasibility of regeneration is discussed. The kinetics of regeneration of sulfided (loaded) pellets with air is studied in the 800-1000°C temperature range. Repeated cycling of the leading sorbent formulation (FORM4-A) was then conducted in a thermogravimetric apparatus (TGA), up to five consecutive cycles

Thermodynamic comparison of several sorbent systems for hot coal-derived fuel-gas desulfurization

A systematic approach toward the evaluation of the behavior of single-metal sorbents for removing sulfur from hot coal-derived fuel gases is developed from thermodynamic considerations. A procedure is developed (and represented in graphical form) to compare a range of metal-based sorbents (Fe, Ni, Mg, Ca, Mn, Cu, and Zn) with respect to their ability to remove sulfur from fuel gases produced over a range of equivalence ratios. The examples which are given are for a specific Illinois No. 6 coal; however, the calculation method can readily be extended for any coal and other sorbent, such as mixed-metal systems using referenced standard computer programs