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Michael Muller - One of the best experts on this subject based on the ideXlab platform.

  • Influence of the Temperature on the Release of Inorganic Species during High-Temperature Gasification of Hard Coal
    Energy & Fuels, 2010
    Co-Authors: Marc Bläsing, Tobias Melchior, Michael Muller
    Abstract:

    Several volatile inorganic species are of concern in future integrated gasification combined cycle (IGCC) power systems because of their relation to erosion, corrosion, fouling, and slagging. The aim of this work was to obtain more information on the influence of the temperature on the release of Na, K, Cl, and S species during gasification. Therefore, six hard Coals were gasified in lab-scale experiments in a helium/oxygen atmosphere at 1100, 1400, and 1700 °C. The results represent conditions in an entrained-flow gasifier. Hot-gas analysis was performed by molecular beam mass spectrometry. Species of interest were HCl, H2S, COS, SO2, NaCl, Na2SO4, KCl, and KOH. In principle, the results show a strong influence of the temperature and the Coal Composition on the release of the species under investigation; e.g., the release of KOH is strongly increased with an increasing temperature.

  • Mass spectrometric investigations on the release of inorganic species during gasification and combustion of German hard Coals
    Combustion and Flame, 2010
    Co-Authors: Marc Bläsing, Michael Muller
    Abstract:

    Abstract Na-, K-, Cl-, and S-species released during thermal conversion of Coal can cause several problems such as fouling, slagging and corrosion, especially in gas turbines and heat recovery systems. To reduce this problems an enhanced understanding of the underlying release mechanisms for Na-, K-, Cl-, and S-species is needed. Therefore, basic investigations have been performed in an atmospheric lab-scale tube furnace at 1400 °C under gasification and combustion conditions. Hot gas analysis has been carried out by molecular beam mass spectrometry. The release of H2S, HCl, K+, NaCl, COS, and SO2 has been qualitative and quantitative analysed and correlated with the Coal Composition. The results show a strong dependence of Coal Composition and reaction atmosphere on the release of Na-, K-, Cl-, and S-species. Additionally, thermodynamic equilibrium calculations with the software package FactSage 5.4.1 have been undertaken for comparison with the experimental results.

  • influence of Coal Composition and operating conditions on the release of alkali species during combustion of hard Coal
    Energy & Fuels, 2007
    Co-Authors: Holger Oleschko, Michael Muller
    Abstract:

    In solid fuel conversion systems, the release of alkali species can cause severe problems such as fouling, slagging, corrosion, and erosion. Especially in future Coal-fired combined cycle processes...

  • influence of Coal Composition on the release of na k cl and s species during the combustion of brown Coal
    Fuel, 2007
    Co-Authors: Holger Oleschko, Annette Schimrosczyk, Hannelore Lippert, Michael Muller
    Abstract:

    Abstract The use of brown Coal can cause severe problems in combustion systems as far as fouling and slagging are concerned. Especially alkali metals that are released during combustion are responsible for the formation of sticky deposits in the boiler. In order to tackle this problem, an increased understanding of the combustion chemistry of brown Coal is necessary. For this reason, laboratory combustion experiments with seven different German brown Coals from the Rheinland area were conducted at temperatures of 800 and 1200 °C. High pressure mass spectrometry was used for the on-line analysis of the combustion products such as HCl, NaCl, KCl, SO 2 and Na 2 SO 4 . The results show that the release of HCl, NaCl and KCl is strongly dependent on the Cl-content of the Coals. Furthermore, at temperatures of 1200 °C, NaCl and SO 2 were released in two steps, whereas at 800 °C these species were released in one step only.

  • Influence of Coal Composition on the release of Na-, K-, Cl-, and S-species during the combustion of brown Coal
    Fuel, 2007
    Co-Authors: Holger Oleschko, HARTMUT LIPPERT, Annette Schimrosczyk, Michael Muller
    Abstract:

    The use of brown Coal can cause severe problems in combustion systems as far as fouling and slagging are concerned. Especially alkali metals that are released during combustion are responsible for the formation of sticky deposits in the boiler. In order to tackle this problem, an increased understanding of the combustion chemistry of brown Coal is necessary. For this reason, laboratory combustion experiments with seven different German brown Coals from the Rheinland area were conducted at temperatures of 800 and 1200 °C. High pressure mass spectrometry was used for the on-line analysis of the combustion products such as HCl, NaCl, KCl, SO2and Na2SO4. The results show that the release of HCl, NaCl and KCl is strongly dependent on the Cl-content of the Coals. Furthermore, at temperatures of 1200 °C, NaCl and SO2were released in two steps, whereas at 800 °C these species were released in one step only. © 2007 Elsevier Ltd. All rights reserved.

Holger Oleschko - One of the best experts on this subject based on the ideXlab platform.

  • influence of Coal Composition and operating conditions on the release of alkali species during combustion of hard Coal
    Energy & Fuels, 2007
    Co-Authors: Holger Oleschko, Michael Muller
    Abstract:

    In solid fuel conversion systems, the release of alkali species can cause severe problems such as fouling, slagging, corrosion, and erosion. Especially in future Coal-fired combined cycle processes...

  • influence of Coal Composition on the release of na k cl and s species during the combustion of brown Coal
    Fuel, 2007
    Co-Authors: Holger Oleschko, Annette Schimrosczyk, Hannelore Lippert, Michael Muller
    Abstract:

    Abstract The use of brown Coal can cause severe problems in combustion systems as far as fouling and slagging are concerned. Especially alkali metals that are released during combustion are responsible for the formation of sticky deposits in the boiler. In order to tackle this problem, an increased understanding of the combustion chemistry of brown Coal is necessary. For this reason, laboratory combustion experiments with seven different German brown Coals from the Rheinland area were conducted at temperatures of 800 and 1200 °C. High pressure mass spectrometry was used for the on-line analysis of the combustion products such as HCl, NaCl, KCl, SO 2 and Na 2 SO 4 . The results show that the release of HCl, NaCl and KCl is strongly dependent on the Cl-content of the Coals. Furthermore, at temperatures of 1200 °C, NaCl and SO 2 were released in two steps, whereas at 800 °C these species were released in one step only.

  • Influence of Coal Composition on the release of Na-, K-, Cl-, and S-species during the combustion of brown Coal
    Fuel, 2007
    Co-Authors: Holger Oleschko, HARTMUT LIPPERT, Annette Schimrosczyk, Michael Muller
    Abstract:

    The use of brown Coal can cause severe problems in combustion systems as far as fouling and slagging are concerned. Especially alkali metals that are released during combustion are responsible for the formation of sticky deposits in the boiler. In order to tackle this problem, an increased understanding of the combustion chemistry of brown Coal is necessary. For this reason, laboratory combustion experiments with seven different German brown Coals from the Rheinland area were conducted at temperatures of 800 and 1200 °C. High pressure mass spectrometry was used for the on-line analysis of the combustion products such as HCl, NaCl, KCl, SO2and Na2SO4. The results show that the release of HCl, NaCl and KCl is strongly dependent on the Cl-content of the Coals. Furthermore, at temperatures of 1200 °C, NaCl and SO2were released in two steps, whereas at 800 °C these species were released in one step only. © 2007 Elsevier Ltd. All rights reserved.

Lan Qing - One of the best experts on this subject based on the ideXlab platform.

  • heterogeneity in Coal Composition and implications for lung cancer risk in xuanwei and fuyuan counties china
    Environment International, 2014
    Co-Authors: George S Downward, Wei Hu, David Large, Harry Veld, Jun Xu, Boris Reiss, Guoping Wu, Robert S Chapman, Nat Rothman, Lan Qing
    Abstract:

    article i nfo Background: Xuanwei and Fuyuan counties in Yunnan Province, China have among the highest lung cancer rates inthecountry.ThishasbeenassociatedwiththedomesticcombustionofbituminousCoal(referredtoas "smoky" Coal). Additionally, significant geographical variation in cancer rates among smoky Coal users has been observed, suggesting heterogeneity in fuel source Composition and/or combustion characteristics. Research thus far has in- dicated that smoky Coal emits high levels of polycyclic aromatic hydrocarbons (PAHs) and contains high concen- trations of fine grained crystalline quartz, however, much of this research is limited in terms of sample size and geographic scope. In order to more fully characterise geochemical and elemental Compositions of smoky and smokeless Coal use in Xuanwei and Fuyuan, we carried out a large exposure assessment study in households in this region. Methods: Fuel samples representing smoky and "smokeless" (anthracite, the major alternative Coal type in the region) Coals were collected from 137 homes in Xuanwei and Fuyuan. Rock-Eval, Leco-CS, XRF analysis and elec- tron microscopy were used to establish hydrocarbon content (to represent volatile organic compounds), major and trace element Composition and mineral Composition respectively. Heterogeneity in Coal characteristics be- tween and within Coal types was assessed by the Kruskal-Wallis test. Results: 145 Coal samples (116 smoky and 29 smokeless Coals) were analysed. Statistically significant differences between smoky and smokeless Coals with regard to hydrocarbon content, sulfur, trace elements and mineral Compositionwere observed.Of note,smokyCoalcontainedbetween5and15 timestheamountof volatileorgan- icmatterandtwicetheamountofquartz (includingrespirablequartz)thansmokelessCoal.SmokyCoalgenerally had lower levelsof traceelements (plus aluminium)than smokelessCoal. Significantvariation wasalsoobserved betweensmokyCoal samples fromdifferent geographicalareas with regard tohydrocarbon content and elemen- tal Composition (including aluminium and silicon). Discussion: This paper has identified Compositional differences between and within smoky and smokeless Coals sourced from Xuanwei and Fuyuan counties. A decreased ratio of aluminium to silicon in smoky Coal suggests el- evatedfreesilica,a finding consistentwith observed higher levels of quartz.Elevatedvolatile organic matter con- tent in smoky Coal (when compared to smokeless Coal) is consistent with the geochemical expectations for smoky and smokeless Coals. These findings also reflect previous observations of elevated volatile compound emissions (notably PAHs) from smoky Coal in the area. The observed heterogeneity in Coal Composition between and within Coal types may provide leads to the observed heterogeneity in cancer risk observed in this area.

Annette Schimrosczyk - One of the best experts on this subject based on the ideXlab platform.

  • influence of Coal Composition on the release of na k cl and s species during the combustion of brown Coal
    Fuel, 2007
    Co-Authors: Holger Oleschko, Annette Schimrosczyk, Hannelore Lippert, Michael Muller
    Abstract:

    Abstract The use of brown Coal can cause severe problems in combustion systems as far as fouling and slagging are concerned. Especially alkali metals that are released during combustion are responsible for the formation of sticky deposits in the boiler. In order to tackle this problem, an increased understanding of the combustion chemistry of brown Coal is necessary. For this reason, laboratory combustion experiments with seven different German brown Coals from the Rheinland area were conducted at temperatures of 800 and 1200 °C. High pressure mass spectrometry was used for the on-line analysis of the combustion products such as HCl, NaCl, KCl, SO 2 and Na 2 SO 4 . The results show that the release of HCl, NaCl and KCl is strongly dependent on the Cl-content of the Coals. Furthermore, at temperatures of 1200 °C, NaCl and SO 2 were released in two steps, whereas at 800 °C these species were released in one step only.

  • Influence of Coal Composition on the release of Na-, K-, Cl-, and S-species during the combustion of brown Coal
    Fuel, 2007
    Co-Authors: Holger Oleschko, HARTMUT LIPPERT, Annette Schimrosczyk, Michael Muller
    Abstract:

    The use of brown Coal can cause severe problems in combustion systems as far as fouling and slagging are concerned. Especially alkali metals that are released during combustion are responsible for the formation of sticky deposits in the boiler. In order to tackle this problem, an increased understanding of the combustion chemistry of brown Coal is necessary. For this reason, laboratory combustion experiments with seven different German brown Coals from the Rheinland area were conducted at temperatures of 800 and 1200 °C. High pressure mass spectrometry was used for the on-line analysis of the combustion products such as HCl, NaCl, KCl, SO2and Na2SO4. The results show that the release of HCl, NaCl and KCl is strongly dependent on the Cl-content of the Coals. Furthermore, at temperatures of 1200 °C, NaCl and SO2were released in two steps, whereas at 800 °C these species were released in one step only. © 2007 Elsevier Ltd. All rights reserved.

Xiao-chen Liu - One of the best experts on this subject based on the ideXlab platform.

  • Risk assessment of underground Coal fire development at regional scale
    International Journal of Coal Geology, 2011
    Co-Authors: Jian-jun Wu, Xiao-chen Liu
    Abstract:

    Underground Coal combustion is a phenomenon known worldwide. Coal fire monitoring and risk assessment provide important input data for the delineation of Coal fire zones and planning of extinguishing activities. At present, research on Coal fire risk focuses mainly on the probability assessment of spontaneous combustion at micro scale, based on laboratory investigations of Coal molecular structure and Composition, and their impact on the combustion process. Coal fire risk assessment at a larger scale, such as for mines, relies on geological factors and aspects of mining engineering and mine management. These scales, however, are insufficient when considering extinguishing activities in larger areas. In order to fill these gaps, we studied risk assessment of underground Coal fire development (UCFD) at a regional scale. The factors impacting on Coal fire development were analyzed under three different aspects: Coal Composition and structure which can influence the direction of underground Coal combustion; topography and geology which determine the burning environment; and climatic conditions and human activities which trigger combustion processes. Based on this analysis, a regional underground Coal fire risk assessment (UCF-RA) index system was established; it is predicated on the assumption that all indices contribute equally to Coal fire risk. Data layers of 1km×1km spatial resolution for each index were calculated and overlaid. Xinjiang Uygur Autonomous Region was selected as a validation area. In view of local conditions and the availability of relevant data, the index system was modified; the applied method, however, remained unchanged. Assessment results are generally satisfying and can be used for monitoring and extinguishing of underground Coal fires (UCFs) in Xinjiang.