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M T Hepworth - One of the best experts on this subject based on the ideXlab platform.

  • desulfurization of hot coal Derived Fuel gases with manganese based regenerable sorbents 3 fixed bed testing
    Energy & Fuels, 1995
    Co-Authors: R Benslimane, M T Hepworth
    Abstract:

    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
    Energy & Fuels, 1994
    Co-Authors: R Benslimane, M T Hepworth
    Abstract:

    In earlier studies, zinc ferrite and zinc titanate were developed as regenerable sorbents capable of removing hydrogen sulfide from hot coal-Derived Fuel gases. Manganese ore as well as manganese carbonate, precipitated from aqueous solutions, combined with alumina to form indurated pellets is shown to hold promise of being a highly-effective, inexpensive, regenerable sulfur sorbent for hot Fuel gases. Although the thermodynamics for sulfur removal by manganese predicts somewhat higher hydrogen sulfide overpressures than can be accomplished with zincbased sorbents, zinc tends to be reduced to the metallic state under coal gasification conditions resulting in loss of capacity and activity by volatilization of reactive surfaces. This volatilization phenomenon limits the temperatures to which desulfurization can be effectively accomplished to less than 550°C for zinc ferrite and 700°C for zinc titanate, whereas, manganese-based sorbents can be utilized at temperatures well in excess of 700°C

R Benslimane - One of the best experts on this subject based on the ideXlab platform.

  • desulfurization of hot coal Derived Fuel gases with manganese based regenerable sorbents 3 fixed bed testing
    Energy & Fuels, 1995
    Co-Authors: R Benslimane, M T Hepworth
    Abstract:

    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
    Energy & Fuels, 1994
    Co-Authors: R Benslimane, M T Hepworth
    Abstract:

    In earlier studies, zinc ferrite and zinc titanate were developed as regenerable sorbents capable of removing hydrogen sulfide from hot coal-Derived Fuel gases. Manganese ore as well as manganese carbonate, precipitated from aqueous solutions, combined with alumina to form indurated pellets is shown to hold promise of being a highly-effective, inexpensive, regenerable sulfur sorbent for hot Fuel gases. Although the thermodynamics for sulfur removal by manganese predicts somewhat higher hydrogen sulfide overpressures than can be accomplished with zincbased sorbents, zinc tends to be reduced to the metallic state under coal gasification conditions resulting in loss of capacity and activity by volatilization of reactive surfaces. This volatilization phenomenon limits the temperatures to which desulfurization can be effectively accomplished to less than 550°C for zinc ferrite and 700°C for zinc titanate, whereas, manganese-based sorbents can be utilized at temperatures well in excess of 700°C

Eiji Sasaoka - One of the best experts on this subject based on the ideXlab platform.

  • development of iron based sorbents for hg0 removal from coal Derived Fuel gas effect of hydrogen chloride
    Fuel, 2008
    Co-Authors: Masaki Ozaki, Md Azhar Uddin, Eiji Sasaoka
    Abstract:

    Laboratory studies were conducted to develop an elemental mercury (Hg°) removal process based on the reaction of H 2 S and Hg° using iron-based sorbents for coal Derived Fuel gas. It is well known that hydrogen chloride (HCl) is present in Fuel gases Derived from some types of coal, but the effect of HCl on the Hg° removal performance of iron-based sorbents in coal Derived Fuel gas is not yet well understood. In this study, the effects of HCl on the removal of Hg° from coal Derived Fuel gases over iron-based sorbents such as iron oxide (Fe 2 O 3 ), supported iron oxides on TiO 2 , iron oxide-Ca(OH) 2 , and iron sulfides were investigated. The Hg° removal experiments were carried out in a laboratory-scale fixed-bed reactor at 80 °C using simulated Fuel gas. In the case of iron oxide (Fe 2 O 3 ), the presence of HCl suppressed the Hg° removal rate. In the case of Fe 2 O 3 (2 or 5 wt%)/TiO 2 , the presence of HCl did not suppress the Hg° removal rate and the activity was stable. The Hg° removal performance of reagent FeS 2 was higher than that of the iron oxide, and not affected by the presence of HCl. The Hg° removal rate of iron oxide-Ca(OH) 2 was not effected by the presence of HCl, because HCl was captured by Ca(OH) 2 . The reagent FeS 2 showed higher Hg 0 removal activity than that of FeS 2 ore. However, the Hg° removal performance of ground and kneaded FeS 2 ore was comparable to that of reagent FeS 2 probably due to the increase in porosity of the FeS 2 ore by grinding and kneading.

  • characteristics of the removal of mercury vapor in coal Derived Fuel gas over iron oxide sorbents
    Fuel, 2006
    Co-Authors: Shengji Wu, Azhar Uddin, Eiji Sasaoka
    Abstract:

    Abstract The characteristics of a novel method for Hg removal using H 2 S and sorbents containing iron oxide were studied. Previously, we have suggested that this method is based on the reaction of Hg and H 2 S 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 2 S (400 ppm), CO (30%), H 2 (20%), H 2 O (8%), and N 2 (balance gas). The following results were obtained: (1) The presence of H 2 S 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 2 O 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.

Luis Teixeira De Lemos - One of the best experts on this subject based on the ideXlab platform.

  • refuse Derived Fuel from municipal solid waste rejected fractions a case study
    Energy Procedia, 2017
    Co-Authors: Isabel Bras, Maria Elisabete Silva, Germana Lobo, Ana Cordeiro, Miguel Faria, Luis Teixeira De Lemos
    Abstract:

    Abstract Portuguese legislation enforces adequate alternatives to municipal waste landfilling of organic wastes as well as others susceptible of valorisation. In the present work, the energetic valorisation of final municipal solid wastes rejected fractions is studied through the production of Refuse Derived Fuel (RDF). To accomplish this purpose several sampling campaigns were performed. Physical, chemical and energetic characterization of the rejected streams was done. Preliminary data allows us to conclude that studied materials have interesting potential to be used as RDF, particularly if blended with higher heating value materials in order to obtain RDF pellets with good combustion behavior, consistency and storage characteristics.

Fernando Albarrán - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of refuse-Derived Fuel from the municipal solid waste reject fraction and its compliance with quality standards
    Journal of Cleaner Production, 2014
    Co-Authors: Antonio Gallardo, Mar Carlos, María D. Bovea, Francisco J. Colomer, Fernando Albarrán
    Abstract:

    The final disposal of the Municipal Solid Waste is still a problem in many countries. The lack of space, the generation of leachate, and the emission of greenhouse gases as well as the requirements of the new legislation on waste dissuade the administrations involved from using the landfill option as a possible means of final disposal of MSW. The terms of the European Legislation on waste management and energy encourage member states to develop waste recovery techniques before sending it to a landfill. Therefore, member states have introduced source separation and mechanical-biological treatment to separate biodegradable recovery fractions (organic, paper-cardboard, plastic packaging, and glass) from the reject fraction, which is afterwards disposed of in landfills. One of the main aims of this study is to analyse the energy recovery properties of the reject fraction from a biological-mechanical treatment plant in Spain. For this purpose, this work presents a physical and chemical characterization of waste reject fraction from a real mechanical-biological treatment plant as well as the metal and halogen content. Additionally, the quality standards of the refused Derived Fuel processed at the laboratory and the atmospheric emissions of this type of Fuel have been determined.