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[en] In this paper the author builds the case for lignite retaining its fair share of base-load generation in Texas. If the responsibility for power project development shifts to the independent sector, Phillips Coal intends to be there as a fuel supplier. The author recognizes that lignite faces some serious challenges. In the paper, he addresses lignite's competition from natural gas and Western coal. Also, he discusses how lignite can overcome its perceived environmental disadvantage. He touches on the economics of choosing lignite as a base-load fuel source. He concludes that the economics of fuel balance will insure lignite's future market share
[en] Complete modeling of cadmium removal on Thar coal which is lignite in its nature has been carried out. A Design of Experiment (DoE) approach has been used for simultaneous optimization of different sorption parameters. DoE showed the positive effect of agitation time on removal of cadmium and negative effect of pH, interaction term pH and amount also showed a negative effect on removal. Values of sorption capacity calculated at optimum parameters for Langmuir, Freundlich and D-R isotherm were 100 mgg-1, 47.86 mgg-1 and 8.422 mgg-1 respectively. Among all tested kinetic models second order rate equation showed a best fit. (author)
[en] This paper discusses the influences of possible net transfer capacity (NTC) expansion at the Belgian-French and Belgian-German borders on electricity generation and related greenhouse gas (GHG) emissions in a European liberalized market. The impact of NTC expansions is simulated with the model E-Simulate. This model simulates the power generation in and the electricity trade between eight different zones: the Netherlands, Belgium, France, Germany, Spain, Portugal, Switzerland and Italy. The impact of several expansions in NTC on the Belgian-French and/or Belgian-German borders is investigated. When NTC expansions are modeled for the case where there is no cost linked to GHG emissions, we observe that, in general, if extra NTC becomes available (on the Belgian-French and/or Belgian-German borders), German electricity generation increases in favor of Dutch and Belgian electricity generation. The shifts in electricity generation are due to the great share of coal and lignite fired power stations in Germany and the large share of gas fired power stations in the Netherlands and Belgium. With no cost linked to GHG emissions, coal and lignite fired electricity generation is cheaper than gas fired generation. Changes in GHG emissions per country follow the shifts in electricity generation. In the second case, an environmental tax of 20 Euros/tonCO2-eq is established. This GHG tax is sufficient to make gas fired electricity generation now more favorable than coal fired electricity generation. Shifts in generation between countries due to NTC expansion occur now in a different direction but are less distinct
[en] This research is an attempt to upgrade Lakhra Lignite Coal using 'Dense Medium Separation' technique, to make it techno-environmentally acceptable product for different industries. The air-dried samples of ROM (Run of Mine) coal were crushed, screened, ground and subjected to initial analysis and specific gravity based sink-float tests. The initial analysis of air-dried samples shows the average values of moisture 19%, volatile matter 22.33%, ash 27.41 %, fixed carbon 31.26% and sulphur 4.98%. The investigational results of sink-float analysis indicate that physical cleaning at particle size range from-5.6 to +0.3 mm and 75% clean coal recovery can potentially reduce the ash yield and sulphur content of Lakhra coal up to 41 and 42.4 % respectively. This washed coal is techno-environmentally acceptable yield and simultaneously qualifies the quality parameters set by various industries of Pakistan. (author)
[en] The application of the magnetic separation method in the process of cleaning of the coal and the effect of the particular size of coal on the method was investigated in this study. The method is based on the fact that coal is weakly diamagnetic, while most of the minerals present are weakly to moderately paramagnetic. In the experimental studies, Manisa and Can lignites which have three different particular sizes (-1500+1000, -1000+500, -500+100 micron) were used. For the particular size of -1500+1000 micron, the magnetic fraction which was separated from Can lignite contained 24 % pyritic sulfur which was less than that of the ground coal. The amount of pyritic sulfur increased in the non-magnetic fraction of Manisa coal. The ash content of non-magnetic fraction which was separated from the particular size of -1000+500 micron of the Manisa coal reduced 20 %, while the value of calorie of coal was enhanced 15 % according to the ground coal. The amount of ash reduction in the non-magnetic fractions of Can lignites was slightly increased along with the value of calorie of coal was a little enhanced. (author)
[en] Within the Annual Conference 2009 of the VGB PowerTech e.V. (Essen, Federal Republic of Germany) from 23rd to 25th May, 2009, in Lyon (France) the following lectures were held: (1) Electricity demand, consequences of the financial and economic crisis - Current overview 2020 for the EU-27 (Hans ten Berge); (2) Status and perspectives of the electricity generation mix in France (Bernard Dupraz); (3) European electricity grid - status and perspective (Dominique Maillard); (4) Technologies and acceptance in the European energy market (Gordon MacKerran); (5) EPR construction in Finland, China, France, (Claude Jaouen); (6) EPR Flamanville 3: A project on the path towards nuclear revival (Jacques Alary); (7) Worldwide nuclear Revival and acceptance (Luc Geraets); (8) An overview on the status of final disposal of radioactive wastes worldwide (Piet Zuidema); (9) Who needs pumped storage plants? PSP are partner to grid stability and renewable energies (Hans-Christoph Funke); (10) Sustainable use of water resources to generate electricity safely and efficiently (Patrick Tourasse); (11) The growth strategy of RWE Innogy - Role of RES in RWE strategy (Fritz Vahrenholt); (12) Solar technologies towards grid parity - key factors and timeframe (G. Gigliucci); (13) Overview on CCS technologies and results of Vattenfalls oxyfuel pilot plant (Philippe Paelinck); (14) Development perspectives of lignite-based IGCC-plants with CCS (Dietmar Keller); (15) Post combustion capture plants - concept and plant integration (Wolfgang Schreier); (16) CCS fossil power generation in a carbon constraint world (Daniel Hofmann); (17) CEZ group strategy in Central and South Eastern Europe (Jan Zizka); (18) Strategy and projects of DONG Energy (Jens Erik Pedersen); (19) E.ON coal-based power generation of the future - The highly efficient power plant and downstream separation of carbon dioxide (Gerhard Seibel); (20) Final sage of first supercritical 460 MWel. CFB Boiler construction - firs experience (Damian Goral); (21) Technological development and actual quality in new power plants - rights and reality (M. Kehr); (22) Actual challenges in new materials and quality assurance for high efficiency power plants (M. Giehl).
[en] Because of its inexhaustible supplies hard fossil fuel will represent the pillar of the power systems of the 21st century. Only high-calorie fossil fuels have the market value and participate in the world trade. Low-calorie fossil fuels ((brown coal and lignite) are fuels spent on the spot and their value is indirectly expressed through manufactured kWh. For the purpose of determining the real value of a tonne of low-calorie coal, the criteria that help in establishing the value of a tonne of hard coal have to be corrected and thus evaluated and assessed at the market. (author)
[en] Full text: The multi-isotope approach using stable isotopes of various light elements offers possibilities to recognize chemical processes within the aquifers, interactions between ground and surface water, quantification of the balance of water or dissolved compounds in anthropogenic stressed landscapes. Especially in mining areas, the quality of ground- and surface water is one of the main problems during and after remediation measures. Caused by lowering of groundwater level, sulfide oxidation and consequently acidification of surface and groundwater systems are common processes. Successful remediation strategies require knowledge of the chemical and physical processes proceeding in dump sites, and of the groundwater flow dynamic. Experienced in using sulfur, hydrogen and oxygen isotopes in post-mining landscapes, we will present three key examples for assessing the sulfate reduction in dump sediments, the water balance of mining lakes, and sulfate input from different sulfur sources. (i) Sulfate reduction: During the long time saturation process the groundwater system of dumps can turn to reducing conditions as indicated by S- and O-isotope signatures of dissolved sulfate. Mainly in the overburden dump sediments of Cospuden mining area (south of Leipzig, Germany) sulfate reduction follows a continuous trend in time from younger to older parts. The input of oxidizing solutions can prevent the reduction process. Evidently, sulfate reduction is still underdeveloped in the conveyor bridge dump caused by penetration of sulfate and iron rich solutions from the weathering zone. A spatial and temporal development was evaluated in different age structured dump sediments using the δ34S and δ18O values of sulfate. (ii) Lake water and sulfate balance: The acidic mining lake 111 (Lusatia mining area, Germany, pH-value 2.6) exists for more than 40 years and reached stable hydrological and hydrochemical conditions about 30 years ago. Isotope data (H, O) were used to determine the annual groundwater in- and outflow of the lake and to calculate the amount of sulfate, iron, and acidity that is carried into the lake by groundwater. For the hydrological balance water samples for 18O-analyses were taken from sampling wells around the lake representing the in- and outflow area, from springs at the lake shore, and from the lake itself. The calculation of the hydrological balance by δ18O-values was carried out by a hydrological model. Besides the acquired field data long-term average values for precipitation, evaporation, temperature, humidity, and isotopic composition of the precipitation were taken into account. The calculated balance proposed an average residence time of the lake water of about 20 years. Considering the lake water sulfate as a mixture of the dump- and aquifer-input, the δ34S-values of lake- and groundwater-sulfate combined with the established annual inflow was used to calculate the annual sulfate input, and based on the hydrochemical data of the inflowing groundwater likewise for the annual iron-input. (iii) Sulfate balance during flooding: Different sources of sulfur have to be considered for the sulfur budget of mining lakes (in process of filling up): dissolved sulfate from aquifers in the surrounding, dissolved sulfate from water used for artificial flooding (river water or a drainage water from a neighboured mine), and sulfate from the interaction of lake water with aerated sediments bearing oxidized sulfides. Balance investigations can be supported by δ34S if the contributing sulfur sources can be characterized by known and sufficient different isotope signatures. The accompanying flooding of an extended system of abandoned open pits north of Leipzig (Goitsche) with water from the river Mulde was monitored by sulfur isotopic composition. The starting point was the existence of uncovered sediments with high primary sulfide content in parts of the future lake bottom and a very low pH in the drainage water. Thus, acidification of the lake water was apprehended. Actually, the influence of highly depleted sulfides (-25 per mille CDT) characterized the pre- and initial phase of flooding. In the later phase, δ34S was controlled more by groundwater than by river water (about +4.4 per mille) due to the much higher mean sulfate concentration in groundwater. Because of a large variation of δ34S values and sulfate concentrations measured in groundwater samples, only the δ34S of the mean groundwater input can be estimated. Based on this result, the contributions of the three mentioned main sources in the sulfur balance have been estimated. (author)
[en] The work at hand aims at deriving an optimized concept for a lignite-fired power plant with integrated fluidized bed driers under techno-economical aspects. The optimization is carried out using a heuristic-iterative method comparing different power plant concepts which are simulated with a software tool for thermodynamic cycle processes. The evaluation of different process variants is based on exergy analyses and a comparisons of efficiencies and actual costs of electricity.