The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Tianhua Yang - One of the best experts on this subject based on the ideXlab platform.
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Interaction Characteristics of Mineral Matter and Nitrogen during Sewage Sludge Pyrolysis
Energy & Fuels, 2016Co-Authors: Tianhua YangAbstract:The conversion of nitrogen-containing species in sludge is influenced by Mineral Matter. Raw sludge and deMineralized sludge were pyrolyzed in a fixed-bed reactor in the temperature range of 500–800 °C to investigate the roles of the temperature and Mineral Matter on the nitrogen conversion in sewage sludge. To gain an in-depth knowledge and understanding of the nitrogen transformation mechanisms, we characterized the nitrogen-containing functional groups in raw sludge and chars via X-ray photoelectron spectroscopy, and the NOx precursors (HCN and NH3) were identified using a spectrophotometric method. According to the results, Mineral Matter has been proven to be able to affect the yields of char N, gas N, and other N (nitrogen in tar, N2, NO, and others). The interaction between Mineral Matter and N-containing species in sewage sludge is strongly limited by the temperature. Mineral Matter inhibits char N conversion at 500–600 °C and promotes char N conversion within the range of 600–800 °C. Meanwhile, m...
Sadriye Küçükbayrak - One of the best experts on this subject based on the ideXlab platform.
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Stepwise deMineralisation and chemical isolation of the Mineral Matter of Göynük lignite
Energy Conversion and Management, 2001Co-Authors: Serdar Yaman, Sadriye Küçükbayrak, Reha Yavuz, Yılmaz TaptıkAbstract:The Mineral Matter of coal contains a number of inorganic constituents, which play an important role in almost all coal utilisation systems. Some techniques have been applied to coal to separate its Mineral Matter from its organic part. In this study, an alternative method was applied to separate the Mineral Matter content of a Turkish lignite. For this purpose, Goynuk lignite was treated, in sequence, with acetic acid, ammonia, hydrochloric acid, hydrofluoric acid and nitric acid at 70°C for 60 min in order to remove individual Mineral species. After each stage, the lignite was treated with performic acid, the product of reaction between hydrogen peroxide and formic acid, at 50°C. The organic coal matrix was decomposed as a result of performic acid oxidation, and consequently, the recovered Mineral species were isolated. Ammonia, which has the potential of chemical comminution, was used to increase the effects of the subsequent reagents and enhance the extent of separation between the organic and inorganic phases. In each Mineral Matter removal stage, the lignite was treated with the reagents of the previous stage, and then, a new reagent was added to investigate whether the last stage has a different effect on the Mineral species. FT-IR and X-ray diffractometry techniques were used to determine the constituents of the isolated Mineral Matter after each stage.
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Effect of Mineral Matter on the reactivity of lignite
Thermochimica Acta, 1999Co-Authors: Hanzade Haykiri-acma, Reha Yavuz, Ayşegül Ersoy-meriçboyu, Sadriye KüçükbayrakAbstract:Abstract In this study, effects of total Mineral Matter content and of elements Ca, Mg, Na, K, Si and Al on the combustion reactivity of 25 lignite samples, originating from different areas of Turkey, was investigated. Non-isothermal thermogravimetry, where the sample was heated in air and the temperature of which increased at a linear rate of 40 K min−1 to 1273 K, has been used to investigate the combustion reactivities of the lignite samples. The calculated combustion activation energy values were related to the Mineral impurities and definite correlations were observed.
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The effect of Mineral Matter on the combustion characteristics of some Turkish lignite samples
Thermochimica Acta, 1996Co-Authors: Çiǧdem Şentorun, Sadriye KüçükbayrakAbstract:Abstract In this study, the burning profiles of twenty-five lignite samples originating from different parts of Turkey were obtained using a thermogravimetry technique (TGA). In the light of these profiles, the effect of the Mineral Matter content on the combustion behaviour of the lignite samples is discussed. The DTG curves of the lignite samples before and after Mineral Matter removal were obtained from TG applications under the same working conditions. Plots of the weight loss differences between the original and deMineralized lignite samples against temperature were derived from TG applications. The relationship of the weight loss (calculated on a dry, ash-free basis) differences between the original and deMineralized lignite samples at 1273 K with the Mineral species was investigated. All correlations were developed by means of regression analysis. Experiments have shown that the Mineral Matter content of the lignite samples plays an important role in determining the combustion characteristics. Data indicate that the effects of the Mineral species on the combustion characteristics are more pronounced at higher temperatures.
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Mineral Matter Identification of Some Turkish Lignites
Energy Sources, 1995Co-Authors: Serdar Yaman, Yılmaz Taptık, Sadriye KüçükbayrakAbstract:Samples of 15 Turkish lignites were oxidized by performic acid. Their Mineral Matter was isolated without any important chemical decomposition. The x-ray diffraction method was employed to determine the Mineral species in the isolated Mineral Matter and in the ashes of the lignite samples. The results were compared and discussed.
Chang Wen - One of the best experts on this subject based on the ideXlab platform.
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emission of inorganic pm10 from included Mineral Matter during the combustion of pulverized coals of various ranks
Fuel, 2015Co-Authors: Chang Wen, Xiangpeng GaoAbstract:Three density-separated (1.4−1.6 g/cm3) and size-fractioned (63−90 μm) Chinese coals (HLH lignite, PDS bituminous coal and CZ anthracite), containing dominantly included Mineral Matter, were prepared and then combusted in a drop-tube furnace in air at 1400 °C. Under the experimental conditions, the yields of particulate Matter (PM) with aerodynamic diameters of the PDS bituminous coal > the CZ anthracite. Such a rank dependence is attributed to the discrepancies in the properties of included Mineral Matter in these coals and the coal combustion characteristics. The partition of Fe in the PM1 from the HLH lignite appears to result from the fragmentation and disintegration of included siderite during coal combustion.
Oliver Lindqvist - One of the best experts on this subject based on the ideXlab platform.
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The impact of Mineral Matter in coal on its combustion, and a new approach to the determination of the calorific value of coal
Fuel, 1995Co-Authors: Ahmad Reza Shirazi, Olle Börtin, Lars Eklund, Oliver LindqvistAbstract:Abstract To estimate the influence of Mineral Matter in coal on coal combustion, fluidized bed combustion (FBC) and pulverized coal combustion (PCC) were simulated by simple models. The theoretical calorific values of some hypothetical coals of different rank and Mineral Matter content were calculated. The calculated calorific values of coals tend to decrease with increasing Mineral Matter content. This is due to endothermic reactions of decomposition of the Mineral Matter as well as the heat capacities of such Minerals. The resulting combustion energy loss can be very large. A new approach to the calculation of the calorific value of coals is also proposed.
Mihaela Grigore - One of the best experts on this subject based on the ideXlab platform.
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Mineral Matter in coals and their reactions during coking
International Journal of Coal Geology, 2008Co-Authors: Mihaela Grigore, Richard Sakurovs, David French, Veena SahajwallaAbstract:Abstract Degradation of coke in the blast furnace is influenced by its inherent Mineral Matter, the formation of which is itself dependent upon the nature of the coal Mineral Matter. To date few studies have been made of coke Mineralogy and its relationship to the Mineralogy of the parent coal. In this study the effect of carbonisation on coal Mineral Matter has been investigated by a detailed quantitative Mineralogical examination of nine cokes and their parent coals. The quantitative analysis was performed on X-ray diffraction patterns of the Mineral Matter of cokes and coals, using SIROQUANT ™ . Coke Mineralogy and its composition varied strongly between cokes, more strongly than variations in elemental composition of the ash. The Mineral Matter in the studied cokes consisted of crystalline Mineral phases and also significant levels of amorphous phase (ranging between 44 and 75%). Decomposition of clays such as kaolinite, montmorillonite, illite and chamosite produced the amorphous phase and some of the crystalline Mineral phases such as mullite, γ-alumina, spinel, cristobalite and leucite. The type of association of Mineral Matter in coals had an important role in how the clays decomposed. For example, association of kaolinite with silica-bearing Minerals in intimate intermixture favoured formation of mullite over γ-alumina. Akermanite and diopside result from reaction of kaolinite with associated calcium bearing Minerals (calcite, dolomite or ankerite). Quartz, fluorapatite and the three polymorphs of TiO 2 (anatase, brookite and rutile) were the coal Minerals that were least affected during carbonisation, as they were also found in the cokes, yet even they were affected in some cases.
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Quantification of Mineral Matter in commercial cokes and their parent coals
International Journal of Coal Geology, 2007Co-Authors: Richard Sakurovs, David French, Mihaela GrigoreAbstract:Abstract The nature of Mineral Matter in coke is an important factor in determining the behaviour of coke in the blast furnace. However, there have been few quantitative determinations of the types of Mineral Matter in coke and the feed coal. Here we use a technique of quantitative X-ray diffraction – SIROQUANT™ – to determine the nature and quantity of Mineral Matter in eleven cokes and their parent materials, using samples of coals and their cokes utilised commercially in blast furnaces around the world. In some of these coals a considerable proportion of the phosphorus was present as goyazite, an aluminium phosphate. In the cokes, most of the iron was incorporated into amorphous aluminosilicate material; metallic iron accounted for about 15% of the iron present, and a similar amount was present as sulfides. Potassium and sodium were largely present as amorphous aluminosilicate material. Most of the quartz in the coal was unaffected by the coking, but a small fraction was transformed into other Minerals. Quartz is not completely inert during coking. The amount of the catalytic forms of iron in the coke – iron, iron oxides and iron sulfides – was not related to the amount of pyrite and siderite in the starting coal, indicating that estimation of catalytic iron requires investigation of the Mineral Matter in coke directly and cannot be estimated from the Minerals in the coal.