Showing papers on "Coal published in 2006"
TL;DR: The uncertainty level decreased from +/- 78% (95% confidence interval) in the estimate of total emissions in 1995, to +/- 44% in 2003, primarily attributed to the decreased emissions from those Hg sources with the largest uncertainty in both activity levels and emission factors, such as artisanal gold smelting, mercury mining, and battery/fluorescent lamp production.
Abstract: We have developed multiple-year inventories of anthropogenic mercury emissions in China for 1995 through 2003. We estimate that total Hg emissions from all anthropogenic sources increased at an average annual rate of 2.9% during the period 1995−2003, reaching 696 (±307) t in 2003, with a speciation split of 395 t of Hg0, 230 t of Hg2+, and 70 t of Hgp. Nonferrous metals smelting and coal combustion continue to be the two leading mercury sources in China, as nonferrous metals production and coal consumption keep increasing. Nonferrous metals smelting and coal combustion together contributed ∼80% of total Hg emissions during the past decade. Hg emissions from coal combustion increased from 202 t in 1995 to 257 t in 2003 at an average annual rate of 3.0%. Among all of the coal consumption sectors, the power sector is the leading one in Hg emissions growth, up by 5.9% annually. Hg emissions from nonferrous metals smelting increased from 230 t in 1995 to 321 t in 2003 at an average annual rate of 4.2%. Althoug...
418 citations
TL;DR: In this paper, a comparison of state-of-the-art and advanced electricity and hydrogen production technologies with CO2 capture using coal and natural gas is performed, inspired by the large number of studies, of which the results can in fact not be compared due to specific assumptions made.
392 citations
TL;DR: In this article, a coal gasification model composed of a pyrolysis model, a char model, and a gas phase reaction model is proposed to evaluate the performance of an entrained flow coal gasifier.
363 citations
TL;DR: In this article, a combustion-driven entrained flow reactor equipped with an optical particle-sizing pyrometry diagnostic and a rapid-quench sampling probe has been used for this investigation.
359 citations
TL;DR: In this paper, a detailed high-resolution emission inventory of black carbon (BC) and organic carbon (OC) from China in the year 2000 is presented, and gridded emissions at 0.2°×0. 2° resolution are shown.
342 citations
TL;DR: In this article, the mineralogy and geochemistry of the No. 6 coal (Pennsylvanian) in the Junger Coalfield, Ordos Basin, China were discussed.
305 citations
TL;DR: In this article, the degree of market integration both within and between crude oil, coal, and natural gas markets was evaluated, and the results indicated that there is not a primary energy market.
Abstract: Prompted by the contemporaneous spike in coal, oil, and natural gas prices, this paper evaluates the degree of market integration both within and between crude oil, coal, and natural gas markets. Our approach yields parameters that can be readily tested against a priori conjectures. Using daily price data for five very different crude oils, we conclude that the world oil market is a single, highly integrated economic market. On the other hand, coal prices at five trading locations across the United States are cointegrated, but the degree of market integration is much weaker, particularly between Western and Eastern coals. Finally, we show that crude oil, coal, and natural gas markets are only very weakly integrated. Our results indicate that there is not a primary energy market. Despite current price peaks, it is not useful to think of a primary energy market, except in a very long run context.
302 citations
TL;DR: In this paper, the authors show that hydrogen produced from coal-based gasification can be competitive with production from natural gas provided the cost of natural gas remains above $4/10 6 Btu and the high reliability of gasification-based processes can be demonstrated.
272 citations
TL;DR: In this article, coal chars were produced by rapid pyrolysis of pulverized bituminous coals using a DTF with a nitrogen gas flow at 1670 K. Gasification rate equations and kinetic parameters applicable to a pore diffusion zone at high temperature were obtained for each coal.
268 citations
TL;DR: In this paper, the treatment of plastic waste by gasification in fluidized bed with air using dolomite as tar cracking catalyst has been studied, and a gas with a medium hydrogen content (up to 15% dry basis) and low tar content (less than 0.5 g/mn3) is obtained.
243 citations
TL;DR: In this paper, a process to capture carbon dioxide from air to reduce its atmospheric concentration and to mitigate climate change is studied, based on the absorption of carbon dioxide in a sodium hydroxide solution, its precipitation as calcium carbonate, and its release as pure gas stream through oxy-fuel calcination.
Abstract: A process to capture carbon dioxide from air to reduce its atmospheric concentration and to mitigate climate change is studied. It is based on the absorption of carbon dioxide in a sodium hydroxide solution, its precipitation as calcium carbonate, and its release as pure gas stream through oxy-fuel calcination. The process utilizes existing commercial technologies wherever possible, particularly in the case of the absorber, whose design is carried out in detail. The analysis allows deriving material and energy balances for the whole process and determining energy demands that can be used for a technical, economical, and environmental feasibility evaluation of the technology. In particular, it indicates that the real specific energy demand is larger than the heat released to emit the same amount of CO2 by the combustion of coal, and smaller than that of methane.
TL;DR: In this paper, three types of generic gasifiers (entrained flow, fluidised bed and fixed bed gasifiers) are described and their suitability for processing all types of coals is discussed.
TL;DR: In this paper, the effects of the mixed proportion between coal and waste tyre on the combustion process, ignition and burnout characteristics were also studied by means of thermogravimetric analysis (TGA) carried out at 20kmin−1 in the temperature range from ambient temperature to 1273k.
TL;DR: The results show that the zeolitic material considerably decreases the leaching of Cd, Co, Cu, Ni, and Zn, and the sorption of metals in soil clay minerals (illite) proved to be the main cause contributing to the immobilization of these pollutants.
TL;DR: In this paper, a uniaxial and triaxial laboratory study was carried out to explore the effects of the adsorption of CO 2 on the compressive strength and permeability of southeast Australian brown coal.
TL;DR: In this article, the combustion behavior and kinetics of various biomass chars, a lignite and a hard coal char and their blends were investigated using a power law model, and reaction kinetic parameters were obtained by modeling the combustion of biomass and coal chars as a single reaction.
TL;DR: In this article, the authors investigated the kinetics of coal-chars derived from typical South African inertinite-rich (high-ash) coals involving char reactions with carbon dioxide and steam and the effects of carbon monoxide and hydrogen.
TL;DR: In this article, the maximum coal bed methane (CBM) sorption capacity of coal seams is calculated as a function of pressure, temperature and coal rank, and the effects of in situ moisture content and maceral composition have been implemented.
TL;DR: In this article, fly ashes were collected from the electrostatic precipitator (ESP) and/or the baghouse of seven coal-fired power plants and examined for their mineralogies and elemental compositions.
TL;DR: In this paper, the emission factors of particles and their carbonaceous fractions, including black carbon (BC) and organic carbon (OC), were measured for residential burning of coal-chunks.
Abstract: [1] The emission factors (EFs) of particles and their carbonaceous fractions, including black carbon (BC) and organic carbon (OC), are measured for residential burning of coal-chunks. Nine types of coals with wide-ranged thermal maturities were used. Particulate emissions from coal-stove are collected on quartz fiber filters through a dilution sampling system and analyzed for BC and OC by thermal-optical method. The EFs of particulate matter, OC, and BC from bituminous coal burning are 16.77, 8.29, and 3.32 g/kg, respectively, on the basis of burned dry and ash-free (daf) coal mass. They were much higher than those of anthracites, which are 0.78, 0.04, and 0.004 g/kg, respectively. Annual emission inventories of particles, OC, and BC from household coal burning are also estimated based on the EFs and coal consumption. The results of the calculations are 917.8, 477.7, and 128.4 gigagrams (Gg) for total particles, OC, and BC emitted in China during the year 2000.
TL;DR: In this article, a coupled gas flow and solid deformation numerical model was developed and applied to simulate the evolutionary process of such catastrophic coal failures in underground collieries, which can be used to identify the outburst mechanisms, parameterizing the causative processes, and to define potential precursors of failure.
TL;DR: In this article, the concept of high-temperature air/steam-blown gasification technology for converting coal into low-caloric-value gas for power generation is proposed and evaluated experimentally.
Abstract: The concept of high-temperature air/steam-blown gasification technology for converting coal into low-caloric-value gas for power generation is proposed and evaluated experimentally. Preliminary experiments are performed in a 0.1 MW thermal input pressurized spout-fluid bed gasifier. The influences of the gasifying agent preheat temperature, the gasification temperature and pressure, the equivalence ratio, the ratio of steam-to-coal on gas composition, gas higher heating value, carbon conversion, and cold gas efficiency are examined. The experimental results prove the feasibility of high-temperature air/steam-blown gasification process. The gas heating value is increased by 23%, when the gasifying agent temperature is increased from 300 to 700 °C. For the operation conditions studied, the results show that gasification temperature is the most important factor influencing coal gasification in the spout-fluid bed. The gasifier performance is improved at elevated pressure mainly due to the better fluidization...
TL;DR: In this paper, high-pressure adsorption/desorption experiments with CO2/CH4 gas mixtures have been carried out on 10 coals of different rank and composition to investigate their selectivity with respect to the sorption of the two gases.
TL;DR: In this paper, the effects of syngas composition and diluents on the structure and emission characteristics of non-premixed flames were investigated, and it was shown that H2O is the most effective diluent on a mass basis, while CO2 is more effective than N2.
TL;DR: In this article, results of 3-D modeling of the top coal caving mechanism at the M3 longwall panel of Omerler Underground Mine located at Tuncbilek (Turkey) are presented by using a finite difference code called FLAC 3D.
TL;DR: The World average Se content in coals (coal Clarke of Se) for hard coals and brown coals are respectively 1.6 −0.1 and 1.0 −1.15 ppm as discussed by the authors.
TL;DR: The potential of coal seams for coal bed methane (CBM) is explored in this paper, where carbon and deuterium isotope data indicate that CO2 reduction is the main pathway of secondary biogenic methane generation in the eastern Australian coal seams.
Abstract: Coal bed methane (CBM) is rapidly becoming a significant contributor to energy needs along the eastern seaboard of Australia. The prospective coal seams for methane production in Australia range from Jurassic to Permian in age with ranks varying from sub-bituminous to low volatile bituminous coal. These coals contain mixed gas compositions comprising mainly methane and carbon dioxide with subsidiary amounts of ethane and higher hydrocarbons. Geochemical data for gases and coal indicate extensive microbial activity, especially in coal seams shallower than about 600 m. Microbial activity possibly occurred subsequent to uplift of the eastern Australian basins during the Late Cretaceous and Tertiary. Such microbial activity has contributed to considerable volumes of methane presently stored in the shallow coals of these basins. The two main pathways of biogenic methane generation in coal are the carbon dioxide (CO2-reduction) and acetate dependant (aceticlastic-reaction) methanogenesis by archaea. Carbon and deuterium isotope data indicate that CO2 reduction is the main pathway of secondary biogenic methane generation in the eastern Australian coal seams. 'Sweet spots' for CBM production are likely to be mainly confined to permeable coal seams where microbial activity has enhanced the methane saturation levels of the coals. In the Sydney Basin, for example, the CBM production rates are up to an order of magnitude higher in areas where coal contains considerable volumes of secondary biogenic gas compared to areas containing only thermogenic gas. In the high producing wells of the Sydney Basin, the isotope fractionation factor for CO2 and CH4 is >1.06 which indicates extensive methane generation from CO2 dependant methanogenesis.
TL;DR: In this article, an integrated gasification combined cycle (IGCC) and fuel cell (IGFC) system was tested in the USA, Europe and Japan employing gasifiers (Texaco, Lurgi and Eagle), and fuel cells.
TL;DR: In this paper, a preliminary study isotopically characterizes fuels and combustibles, as well as the isotopic relations existing with their combustion by-products, i.e. gases (CO2) and particles (bulk carbon).
Abstract: Stable (i.e. non-radioactive) carbon-isotope composition (δ13C) in fuels has been extensively used as an indicator of the processes leading to the generation of their parent crude-oil. With the example of those used in Paris (France), this preliminary study isotopically characterizes fuels and combustibles, as well as the isotopic relations existing with their combustion by-products, i.e. gases (CO2) and particles (bulk carbon). Results show that δ13C in fuels is clearly related to their physical state, with natural gas being strongly depleted in 13C while coal yields the highest δ13C, and liquid fuels display intermediate values. This relation is also valid for combustion gases, although δ13C values of combustion particles form a homogeneous range within which no clear distinction is observed. Combustion processes are accompanied by carbon-isotope fractionation (noted Δ13C) resulting from the combustion being incomplete. Carbon-isotope fractionation is strictly negative (Δ13C = −1.3‰) during the formatio...
TL;DR: In this paper, the performance of planar solid oxide fuel cells using coal syngas, with and without hydrogen sulfide (H2S), was studied and a state-of-the-art gas delivery system, data acquisition system, and test stand were designed and assembled for experimentation.