Showing papers on "Coal published in 2005"
TL;DR: A comprehensive review of CO2 capture in coal-fired combustion plants can be found in this article, where the status of the technology development and assessments providing comparisons with other power generation options, and suggests research needs.
1,450 citations
TL;DR: In this article, the storage of captured CO2 in coal seams has been studied and the potential storage capacity, the storage integrity of the geologic host, and the chemical and physical processes initiated by the deep underground injection of CO2.
Abstract: This article reviews the storage of captured CO2 in coal seams. Other geologic formations, such as depleted petroleum reservoirs, deep saline aquifers and others have received considerable attention as sites for sequestering CO2. This review focuses on geologic sequestration of CO2 in unmineable coalbeds as the geologic host. Key issues for geologic sequestration include potential storage capacity, the storage integrity of the geologic host, and the chemical and physical processes initiated by the deep underground injection of CO2. The review topics include (i) the estimated CO2 storage capacity of coal, along with the estimated amount and composition of coalbed gas; (ii) an evaluation of the coal seam properties relevant to CO2 sequestration, such as density, surface area, porosity, diffusion, permeability, transport, rank, adsorption/desorption, shrinkage/swelling, and thermochemical reactions; and (iii) a treatment of how coalbed methane (CBM) recovery and CO2-enhanced coalbed methane (ECBM) recovery a...
880 citations
TL;DR: Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification.
Abstract: Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.
865 citations
TL;DR: In this article, the authors investigated quantitatively the effects of reservoir pressure and sorption-induced volumetric strain on coal-seam permeability with constraints from the adsorption isotherm and associated volumetrized strain measured on a Cretaceous Mesaverde Group coal (Piceance basin) and derived a stressdependent permeability model.
Abstract: The permeability of deep (1000 m; 3300 ft) coal seams is commonly low. For deep coal seams, significant reservoir pressure drawdown is required to promote gas desorption because of the Langmuir-type isotherm that typifies coals. Hence, a large permeability decline may occur because of pressure drawdown and the resulting increase in effective stress, depending on coal properties and the stress field during production. However, the permeability decline can potentially be offset by the permeability enhancement caused by the matrix shrinkage associated with methane desorption. The predictability of varying permeability is critical for coalbed gas exploration and production-well management. We have investigated quantitatively the effects of reservoir pressure and sorption-induced volumetric strain on coal-seam permeability with constraints from the adsorption isotherm and associated volumetric strain measured on a Cretaceous Mesaverde Group coal (Piceance basin) and derived a stress-dependent permeability model. Our results suggest that the favorable coal properties that can result in less permeability reduction during earlier production and an earlier strong permeability rebound (increase in permeability caused by coal shrinkage) with methane desorption include (1) large bulk or Young's modulus; (2) large adsorption or Langmuir volume; (3) high Langmuir pressure; (4) high initial permeability and dense cleat spacing; and (5) low initial reservoir pressure and high in-situ gas content. Permeability variation with gas production is further dependent on the orientation of the coal seam, the reservoir stress field, and the cleat structure. Well completion with injection of N2 and displacement of CH4 only results in short-term enhancement of permeability and does not promote the overall gas production for the coal studied.
599 citations
TL;DR: In this article, an inventory of mercury emissions from anthropogenic activities in China is compiled for the year 1999 from official statistical data, which includes open biomass burning, but does not include natural sources or re-emission of previously deposited mercury.
598 citations
TL;DR: In this paper, the authors explore the reasons for and technical challenges associated with co-combustion of biomass and coal in boilers designed for coal (mainly pulverized coal) combustion.
572 citations
TL;DR: In this article, the authors investigated performances, costs and prospects of using commercially ready technology to convert coal to H2 and electricity, with CO2 capture and storage, in co-production plants.
425 citations
01 Jul 2005
TL;DR: Coal, residual coal, and residual coal treated with H3PO4 as a means of removal of phenol from wastewater is investigated and the results showed that the equilibrium data for all the phenol-sorbent systems fitted the Redlich-Peterson model best.
Abstract: The present work involves an investigation of the possible use of coal, residual coal, and residual coal treated with H3PO4 as a means of removal of phenol from wastewater. The study was realized using batch experiments, with synthetic wastewater having phenol concentration of 1000 ppm. Other low-cost adsorbents such as petroleum coke, coke breeze, rice husk, and rice husk char have also been used. The effect of system variables such as pH, contact time, and temperature has been investigated. The suitability of the Freundlich, Langmuir, and Redlich-Peterson adsorption models to the equilibrium data was investigated for each phenol-adsorbent system. The results showed that the equilibrium data for all the phenol-sorbent systems fitted the Redlich-Peterson model best. Kinetic modeling of removal of phenols was done using the Lagergren first-order rate expression. A series of column experiments were performed to determine the breakthrough curves.
422 citations
TL;DR: In this article, a review of the development and deployment of coal-based gasification technologies for power generation is provided, including the advantages and disadvantages of this means for coal utilisation.
419 citations
TL;DR: Anthracite coal should be selected preferentially and more advanced burning conditions should be applied in domestic combustion, from the viewpoint of both climate change and adverse health effects.
Abstract: Emission factors of carbonaceous particles, including black carbon (BC) and organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) were determined for five coals, which ranged in maturity from sub-bituminous to anthracite. They were burned in the form of honeycomb briquettes in a residential coalstove, one of the most common fuel/stove combinations in China. Smoke samples were taken through dilution sampling equipment, with a high volume sampler that could simultaneously collect emissions in both particulate and gaseous phases, and a cascade impactor that could segregate particles into six fractions. Particulate BC and OC were analyzed by a thermal-optical method, and PAHs in emissions of both phases were analyzed by GC−MS. Burning of bituminous coals produced the highest emission factors of particulate matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20 PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf) coal, while the anthracite honeycomb-briquette was the cleanest household ...
403 citations
TL;DR: In this paper, the authors investigated performances, costs and prospects of using commercially ready technology to convert coal to H2 and electricity, with CO2 capture and storage, and showed that the costs for ∼ 91% decarbonized energy (via quench gasification at 70 bar) are about 6.2 ¢ / kWh for electricity and about $ 1.0/kg (8.5 $/GJ, LHV) for hydrogen; these are, respectively, 35% and 19% higher than the corresponding energy costs with CO 2 venting.
Book•
27 Apr 2005
TL;DR: In this article, the authors present a coal analysis with the following properties: 1. Coal Analysis. 2. Proximate Analysis. 3. Extreme Analysis. 4. Mineral Matter. 5. Mechanical Properties. 6. Thermal Properties.
Abstract: Preface. 1. Coal Analysis. 2. Sampling and Sample Preparation. 3. Proximate Analysis. 4. Ultimate Analysis. 5. Mineral Matter. 6. Physical and Electrical Properties. 7. Thermal Properties. 8. Mechanical Properties. 9. Spectroscopic Properties. 10. Solvent Properties. Glossary. Common Conversion Factors. Index.
TL;DR: In this article, the authors compared coal combustion in air and the mixtures of O2/CO2 mixtures in a 20kW down-firing combustor and found that coal combustion with 30% CO2/70% O2 can produce matching gas temperature profiles.
TL;DR: In this article, the effect of Si/Al molar ratio of the fly ash source on the type of formed zeolite, which also is affected by the alkaline condition, was investigated.
TL;DR: In this article, a review of coal Clarke value of As is presented, which is a coal-phile element: it has strong affinity to coal matter and coal bed, and some peculiarities of the As geochemistry in environment.
TL;DR: In this article, fly ashes sourced from European pulverised coal burning power plants (from Spain, The Netherlands, Italy and Greece) were characterised in terms of their chemical composition, mineralogy and physical properties.
TL;DR: The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood, and concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels.
Abstract: This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (∼ 10 g/kg fuel) and polycyclic aromatic hydrocarbons (∼ 100 mg/kg fuel for ΣPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for ΣPCBs, 100s ng/kg fuel for ΣPCNs and 100 ng/kg fuel for ΣPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routine...
TL;DR: In this paper, the authors reviewed approximately 200 publications on mercury (Hg) in coal; topics reviewed in this paper include: analytical and historical introduction; some peculiarities of Hg environmental geochemistry; estimation of the Hg coal Clarke value; occurrence of high-Hg coals; mode of HGs occurrence in coal, factors influencing the distribution of Hgs in coal.
01 Oct 2005
TL;DR: Sorption-induced strain and permeability were measured as a function of pore pressure using subbituminous coal from the Powder River basin of Wyoming, U.S.A. as discussed by the authors.
Abstract: Sorption-induced strain and permeability were measured as a function of pore pressure using subbituminous coal from the Powder River basin of Wyoming, U.S.A. and high-volatile bituminous coal from the Uinta basin of Utah, U.S.A. We found that for these coal samples, cleat compressibility was not constant, but variable. Calculated variable cleat-compressibility constants were found to correlate well with previously published data for other coals. Sorption-induced matrix strain (shrinkage/swelling) was measured on uncon-strained samples for different gases: carbon dioxide, methane, and nitrogen. During permeability tests, sorption-induced matrix shrinkage was clearly demonstrated by higher perme-ability values at lower pore pressures while holding overbur-den pressure constant; this effect was more pronounced when gases with higher adsorption isotherms such as carbon dioxide were used. Measured permeability data were modeled using three different permeability models that take into account sorption-induced matrix strain. We found that when the measured strain data were applied, all three models poorly matched the measured permeability results. However, by ap-plying an experimentally derived expression to the strain data that accounts for the constraining stress of overburden pres-sure, pore pressure, coal type, and gas type; two of the models were greatly improved.
TL;DR: In this paper, an attempt has been made to assess the global generation of coal combustion residues, present utilisation and acceptability in Indian context, implications and future potentials to achieve environmental sound management.
Abstract: To meet the electric power requirement, the world population is greatly dependent on fossil fuel. Presently in India, about 75% of the total electrical energy (i.e. ∼100,000 MW) is generated from fossil fuel and about 105 million tons of coal combustion residues (CCRs) as solid waste/by-product is being released annually during combustion of pulverised bituminous, sub bituminous, and lignite coal. Indian coal typically has ash content of 30–60%, which results in low calorific value however low in sulphur, radioactive elements and heavy metals content. Mostly, the CCRs is being disposed to the ash pond as thin slurry, and more than 65,000 acres of land is occupied in India for storage of this huge quantity of ash which leads ecological and environmental problems. Presently about 27% of the total CCRs produced in India is being recycled and used in various applications. The major utilisation is in cement, concrete, bricks, wood substitute products, soil stabilisation, road base/embankment, and consolidation of ground, land reclamation and for agriculture. In this paper, an attempt has been made to assess the global generation of CCRs, present utilisation and acceptability in Indian context, implications and future potentials to achieve environmental sound management.
TL;DR: The No. 15 coal seam of the Pennsylvanian Taiyuan Formation and the No. 3 coal seams of the Permian Shanxi Formation in the Southeast Qinshui Basin are relatively thick (> 3 m), laterally continuous, and are of anthracite rank as discussed by the authors.
TL;DR: In this paper, an emerging market for cleaned coal is studied within a CGE model for China, and the macro approach catches the repercussions of coal cleaning through increased energy efficiency, lower coal transportation costs and crowding out effect of investments in coal washing plants.
TL;DR: In this paper, the authors introduce the hydrogeological conditions of coal mines and the potential water inrush disasters from aquifers under coal seams, and present the water in rush mechanism.
TL;DR: In this paper, the effect of microwave irradiation on the zeolite formation was investigated with emphasis on the change in yield of Zeolite during the reaction, which is due to the stimulated dissolution of SiO2 and Al2O3 from coal fly ash.
TL;DR: In this article, results of 3D modeling of the top-coal-caving mechanism by using the finite difference code FLAC3D at the M3 longwall panel of the Omerler Underground Mine located at Tuncbilek (Turkey) are presented.
TL;DR: In this article, the effect of reaction parameters such as the molar ratio of CaO to carbon in the woody biomass, reaction pressure, and reaction temperature was investigated on H 2 yield and conversion to gas.
Abstract: In H 2 production from woody biomass by steam gasification using CaO as a CO 2 sorbent, the effect of reaction parameters such as the molar ratio of CaO to carbon in the woody biomass ( [ Ca ] / [ C ] ) , reaction pressure, and reaction temperature was investigated on H 2 yield and conversion to gas. In the absence of CaO, the product gas contained CO 2 . On the other hand, in the presence of CaO ( [ Ca ] / [ C ] = 1 , 2 , and 4), no CO 2 was detected in the product gas. At a [ Ca ] / [ C ] of 2, the maximum yield of H 2 was obtained. The H 2 yield and conversion to gas were largely dependent on the reaction pressure, and exhibited the maximum value at 0.6 MPa . It is noteworthy that H 2 was obtained from woody biomass at a much lower pressure compared to other carbonaceous materials such as coal ( > 12 MPa ) and heavy oil ( > 4.2 MPa ) in steam gasification using a CO 2 sorbent. H 2 yield increased with increasing reaction temperature. Woody biomass is the one of the most appropriate carbonaceous materials in H 2 production by steam gasification using CaO as a CO 2 sorbent, taking the reaction pressure into account.
TL;DR: In this paper, a project was initiated to evaluate the possibility of extracting the alumina from fly ash and the major final product obtained with the solvent extraction method contained approximately 994% alumina, whilst the minor product contained 97% titanium oxide.
TL;DR: In this paper, the potential change in primary emissions and energy use from replacing the current U.S. fleet of fossil fuel on-road vehicles (FFOV) with hybrid electric fossil fuel vehicles or hydrogen fuel cell vehicles (HFCV) was examined.
TL;DR: In this article, experiments were carried out in a pilot scale CFB reactor with Meat and Bone Meal (MBM) blended with three coals, and the goal of the study was to select the most protective coal so that the portion of MBM in the feedstock could be maximised.
TL;DR: In this paper, the surface area of beech wood char and oil palm shell char with carbon dioxide and steam was determined as a function of the degree of conversion by the temperature-programmed desorption technique (TPD).