Showing papers in "Energy Sources in 1995"
TL;DR: In this paper, an indium, a tin, and a lead electrode at a potential of −1·8 V versus Ag /AgCl saturated KCl was investigated in the range of 20−100°C.
Abstract: Electrochemical reduction of high-pressure carbon dioxide with an indium, a tin, and a lead electrode at a potential of −1·8 V versus Ag /AgCl saturated KCl was investigated in the range of 20–100°C. Under optimum experimental conditions, with the indium electrode, about 100% Faraday efficiency formic acid was selectively obtained at 20−60°C, and at 100°C the formation efficiency was 44·5%. With the tin electrode, 99·2% Faraday efficiency formic acid was obtained at 20°C. With increasing temperature, the Faraday efficiency of formic acid decreased and that of hydrogen increased. In the case of the lead electrode, Faraday efficiencies of formic acid and hydrogen were both about 50% at 20°C. A maximum Faraday efficiency of formic acid (91·2%) was obtained at 60°C. Hydrogen formation was lowest at that temperature. For the electrodes, the formation of carbon monoxide was minimal at the temperatures tested.
68 citations
TL;DR: In this paper, four renewable agricultural resources were considered in a process design analysis for the industrial production of ethanol, including wood, molasses, whey permeate, and starch.
Abstract: Four renewable agricultural resources were considered in a process design analysis for the industrial production of ethanol Raw materials considered were wood, molasses, whey permeate, and starch Final fermentation substrates were diluted and/or concentrated to give equivalent sugar concentrations for each case Renewable resource costs were expressed as $/kg of sugar rather than $/kg of the raw material Molasses sugars were cheaper than sugars derived from the other raw materials Various fermentation technologies were considered, including continuous culture and cell recycle Ethanol recovery was examined using pervaporation and costs compared with distillation The effects on ethanol prices of raw material costs, fermentation technology, product recovery, tax, plant size, and Lang factor are presented Cultures of Candida shehatae, Zymomonas mobilis, Kluyveromyces marxianus var Iactis and Saccharomyces cerevisiae (with Zymomonas mobilis) were used, depending on the substrate The report identifies
65 citations
TL;DR: In the coal mines of Springhill, Nova Scotia, the authors, water is pumped from the mines to act as the primary input to heat pumps for heating and cooling industrial buildings.
Abstract: Flooded former coal mines of Springhill, Nova Scotia, contain about 4,000,000 m3 of water which circulates by convection and may be recovered at the surface at a temperature of about 18°C. The heat in the water is derived from the normal heat of the rocks and the contribution from chemical heating is negligible. Water is pumped from the mines to act as the primary input to heat pumps for heating and cooling industrial buildings. Annual heat exchange with the mine by the largest user puts more heat into the mine in summer than is taken out in winter. Buildings without heavy machinery, such as office buildings, drain little heat from the mine, so that many heat exchange systems could operate indefinitely, without significant depletion of the heat source. Initial costs of heat pump installation are higher than the costs of conventional oil furnaces, but the operating costs are substantially lower. In the Springhill systems, heat pumps provide summer cooling as well as winter heating and total costs of geothe...
51 citations
TL;DR: In this article, the authors evaluate the energy consumption in solar photovoltaic (SPV) module production in India and examine its implications for large-scale introduction of SPV plants in the country.
Abstract: The objective of this article is to evaluate the energy consumption in solar photovoltaic (SPV) module production in India and examine its implications for large-scale introduction of SPV plants in the country. Data on energy used in SPV production were collected from existing manufacturing facilities in the country. The energy payback period turns out to be approximately 4 years. This is comparable to energy payback periods of similar modules produced internationally. However, if an ambitious program of introducing SPV power production is undertaken to contribute substantially to the power scenario in the country, an annual growth rate beyond 21% will render the program an energy sink rather than an energy source, as borne out by dynamic energy analysis. Policy implications are also discussed in light of this analysis.
46 citations
TL;DR: The concentration of 21 elements in fly ash from three boilers at the EGAT power plant, Mae Moh, Thailand, were determined by instrumental neutron activation analysis (INAA) as mentioned in this paper.
Abstract: The concentration of 21 elements in fly ash from three boilers (75 MW, 150 MW, and 300 MW) at the EGAT power plant, Mae Moh, Thailand, were determined by instrumental neutron activation analysis (INAA). The concentration of 10 major elements was determined by x-ray fluorescence 5XRF). Arsenic, Co, Cr, Ni, Mo, and Sb generally increase in concentration going from bottom ash (BA) through the sequence of electrostatic precipitator ashes (ESPA) and reach maxima of As (352 ppm), Co (45 ppm), Cr (105 ppm), Mo (32 ppm), Ni (106 ppm), and Sb (15 ppm) in the ESPA. Cerium, Cs, Fe, Hf, La, Sc, Ta, Tb, and Yb did not exhibit concentration trends or are variable except in the case of one boiler (unit 6), which showed an increase going from BA to ESPA. Only Br decreased in composition going from BA to ESPA. Rubidium, Sm, U, and Th showed marked variation in trends. Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) was used to identify element assemblages within discrete particles and particle morphology. Comparison of fly-ash morphology shows that the BA is composed of large angular shards/fragments with only a small amount of semispherical particles. Successive ESPA is composed mainly of spherical particles which decrease in average diameter with increasing distance from the boiler. The major elements identified by EDS were Al, Si, S, K, Ca, Fe, and Ba, with minor amounts of Mg, Na, Ti, Mn, and Sr. Aluminum, Si, K, and Ca occur together and are present in most of the fly-ash particles. Barium was found as a major component with Ca, Al, and Si. Iron and Ca are usually associated with sulfur. Some small spheres (<5 μm) are comprised almost entirely of Fe (probably as oxide). Symplectite textures are noted in high-Fe phases. All elements except Br are significantly enriched in the fly ash relative to the coal, which contains 35% ash. Particle chemistry is consistent with the major mineral phases identified by x-ray diffraction (XRD), which include: quartz, magnetite, mullite, gehlenite, anorthite, hematite, anhydrite, and clinopyroxene
27 citations
TL;DR: In this article, the authors summarized the available information on the technical characteristics and costs of those sulfur abatement technologies in operation at present or coming into operation in the near future.
Abstract: This study summarizes the available information on the technical characteristics and costs of those sulfur abatement technologies in operation at present or coming into operation in the near future. Relying on disaggregated source data and using engineering cost functions and various technical and economic assumptions, the least cost curves of sulfur abatement for all the European countries have been derived, and some examples are presented. Finally, a sensitivity analysis of abatement strategies and costs to some alternative assumptions about energy futures is presented.
25 citations
TL;DR: In this paper, the authors examined the causality issues between U.S. employment and energy consumption using Variate Vector Error Correction Models (VECMs) in conjunction with cointegrated systems.
Abstract: Trivariate vector error-correction models (VECMs), in conjunction with cointegrated systems, are used to examine the causality issues between U.S. employment and energy consumption. Results of the VECMs indicate a bidirectional causality between nonfarm employment and energy consumption and between total employment and energy consumption. Furthermore, the replication of prior studies, after log-transforming, adjusting for seasonality and correcting for unit roots, also produced a unidirectional causal relationship from total employment to energy consumption and a bidirectional causal relationship between nonfarm employment and energy consumption for the 1973·1−1984·6 sample period in the bivariate models. Extending the sample period further, however, completely eliminated the unidirectional causal relationship from total employment to energy consumption in the bivariate system.
21 citations
TL;DR: A review of fullerene research can be found in this paper, which covers methods of production and separation, mechanisms leading to closed-cage structure formation, structural characterization, reaction chemistry, and applications of this novel material.
Abstract: The recently discovered third allotrope of carbon, the fullerenes, are a subject of very active research, particularly for chemists. They have a closed-cage structure, made by interlocking pentagonal and hexagonal panels, and are the only soluble form of carbon. In this review an attempt has been made to summarize ongoing fullerene research. The review covers methods of fullerene production and separation, mechanisms leading to closed-cage structure formation, structural characterization, reaction chemistry, and applications of this novel material. The emerging directions of research are also discussed.
19 citations
TL;DR: In this article, a 1,000-household survey was used to study the type of energy carrier used by households in different income groups for different end-uses, such as cooking, water heating, and lighting.
Abstract: This article analyses the pattern of energy carrier consumption in the residential sector of Bangalore, a major city in south India. A 1,000-household survey was used to study the type of energy carrier used by households in different income groups for different end-uses, such as cooking, water heating, and lighting. The dependence of income on the carrier utilized is established using a carrier dependence index. Using regression analysis, the index analyses the impact of different explanatory variables such as family income, family size, and price of energy carrier on consumption. The results show that income plays an important rote not only in the selection of an energy carrier but also on the quantity of consumption per household. Also, a source-service matrix is prepared for Bangalore's residential sector, which shows the disaggregation of energy consumption by the type of energy carrier and end-use.
14 citations
TL;DR: In this article, the authors compared the performance of a bacteria and a fungus for an industrial polycyclic aromatic hydrocarbons (PAH) contaminated soil with three supplemental nutrient solutions.
Abstract: Contamination of the environment is not a new problem. For most of recorded history, the unwanted by-products of industrial and residential processes have been dumped into unlined pits or nearby streams. Althrough disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions we...
11 citations
TL;DR: In this paper, the authors proposed a multiobjective methodology for the integrated resource planning (IRP) problem using a combined analytic hierarchy process (AHP)-compromise programming (CP) model.
Abstract: This article proposes a multiobjective methodology for the integrated resource planning (IRP) problem using a combined analytic hierarchy process (AHP)-compromise programming (CP) model. Six objectives, of which five are qualitative in nature, have been considered to select demand- and supply-side resources for meeting future electricity demand. The quantitative objective (viz., cost) is employed directly in the CP model. AHP priorities are derived for the qualitative objectives (e.g., technological maturity) after eliciting expert judgements. These priorities are employed as coefficients of the decision variables in the objective functions corresponding to the qualitative objectives of the model. The two distinct advantages of this method are (1) explicit consideration of all important qualitative and quantitative aspects of demand-side management (DSM) and supply-side options, and (2) consideration of specific characteristics of various types of DSM options. An illustrative application is provi...
TL;DR: In this article, the authors present a system analysis based on energy models, which may support the necessary decisions by enhancing the understanding of energy systems, however, such models will not lead to correct or validated quantitative results, but to reasonable qualitative suggestions.
Abstract: Energy systems combine the sources of energy, the means for converting these sources to usable forms, the distribution devices and procedures, the using community and the ways it employs energy, and the surrounding natural and economic environment. Thus, energy systems are socioeconomic systems whose analysis includes various sciences with different limitations to scientific findings. While their physical behavior may be modeled on the computer with sufficient precision at least on a local or regional level, the parameters necessary for economic modeling are subject to large principle uncertainties. Qualitative parameters may enter the analysis via model restrictions or exogenous assumptions, which inevitably involve personal views. Solving the global energy problem is an urgent task that cannot be postponed until a provable scientific solution is found, especially since such a solution may never emerge. In this situation, systems analysis based on energy models may support the necessary decisions by enhancing the understanding of energy systems. However, such models will not lead to correct or validated quantitative results, but to reasonable qualitative suggestions.
TL;DR: In this article, a case study of full-fuel-cycle analysis methods applied to the evaluation of gasoline in the southeastern region of the United States is presented. And the authors demonstrate the significance of non-vehicle processes, such as fuel refining, in terms of energy expenditure and emissions production.
Abstract: The use of full-fuel-cycle analysis as a scientific, economic, and policy tool for the evaluation of alternative sources of transportation energy has become increasingly widespread. However, consistent methods for performance of these types of analyses are only now becoming recognized and utilized. The work presented here provides a case study of full-fuel-cycle analysis methods applied to the evaluation of gasoline in the southeastern region of the United States. Results of the study demonstrate the significance of nonvehicle processes, such as fuel refining, in terms of energy expenditure and emissions production. Unique to this work is the application of the MOBILE5 mobile emissions model in the full-fuel-cycle analysis. Estimates of direct and indirect greenhouse gas production are also presented and discussed using the full-fuel-cycle analysis method.
TL;DR: In this paper, an advanced bench scale process developed may be improved by scaling up the present work and undertaking further work on process economics and studies on the major engineering problems involved. But it is not suitable for coal-water or coal-oil mixture combustion and in diesel engines as a noncorrosive clean fuel.
Abstract: If coal must be used in industry to replace oil that becomes scarce, the coal should be demineralized to get a clean, high-heating-value, noncorrosive, free flowing solid fuel. Alkali leaching of coal under ambient pressure followed by acid leaching under milder conditions affords a convenient process for cleaning coal up to a degree of demineralization of 75%. The conditions for alkali-acid leaching have been optimized. Toxic mineral microconstituents are removed to give a clean coal for burning in thermal power stations or in industries. The demineralized, clean, high-heating-value coal can be used for coal-water or coal-oil mixture combustion and in diesel engines as a noncorrosive clean fuel. The advanced bench scale process developed may be improved by scaling up the present work and undertaking further work on process economics and studies on the major engineering problems involved.
TL;DR: In this paper, three coals were combusted in the Alberta Research Council laminar flow combustor in order to understand the changes in the physical structure that occur during pulverized coal combustion.
Abstract: Three coals were combusted in the Alberta Research Council laminar flow combustor in order to understand the changes in the physical structure that occur during pulverized coal combustion. A subbituminous (coal A), and both high-volatile (coal B) and low-volatile bituminous (coal C) coals were chosen to examine coals of different rank and reactivity. The subbituminous coal and the high-volatile bituminouss coal were very reactive, with burnouts of 95% and 88% achieved under stable operating conditions. The low-volatile butiminous coal was relatively unreactive. It was not possible to achieve a stable flame with the burnout decreasing below 50% in less than 1 h. Direct comparison of the partially burnt samples from the three coals was difficult because of the different reactivities. The subbituminous and high-volatile bituminous coals burned so rapidly that it was not possible to collect samples below 70% burnout. Conversely, it was not possible to generate samples of low-volatile bituminous coal char at burnouts above 72%. The subbituminous coal showed a continuous decrease in particle size with burnout. The high-volatile bituminous coal showed a significant size decrease only before 70% burnout, whereas the low-volatile bituminous coal actually increased in size up to 60% burnout, followed by a slight decrease. Surface area analysis of the subbituminous coal indicated a large surface area contained in micropores. At highlevels of burnout (above 90%), the surface area decreased. The same behavior was observed for the high-volatile bituminous coal. While the low-volatile bituminous coal also showed this large increase in surface area, the decrease occurred at about 50% burnout, much earlier than for the other coals. Results of mercury porosimetry tests on the partially burnt samples revealed a significant change in the pore volume for both the subbituminous and high-volatile bituminous coals, while no large changes were observed for the low-volatile bituminous sample. It was difficult to draw any conclusions from the porosimetry results due to the different particle size of the chars and wide variance in the measurements
TL;DR: Supercritical water oxidation is an emerging technology that exploits the supercritical properties of water as a reaction medium as mentioned in this paper, where a combustion reaction takes place unhindered in the homogeneous supercritical water phase using oxygen or air as an oxidant.
Abstract: Contaminated soil containing 3 wt. % hydrocarbons rich in polycyclic aromatic hydrocarbons (PAHs) has been cleaned to environmentally acceptable levels by the use of the supercritical water oxidation system. Supercritical water oxidation is an emerging technology that exploits the supercritical properties of water as a reaction medium. A combustion reaction takes place unhindered in the homogeneous supercritical water phase using oxygen or air as an oxidant. Since most organics dissolve readily in supercritical water, the oxidation reaction can proceed at very high kinetic rates. These kinetic rates allow for very short reactor residence times. The accelerated reaction makes supercritical water oxidation an ideal form of treatment for site remediation of hydrocarbon contaminated soil. Experiments conducted on the soil show a twofold beneficiation process, where hazardous material is extracted from the soil and completely destroyed by an oxidation reaction. The resulting bottoms produce a clean so...
TL;DR: In this paper, a theoretical framework within which the demand for electricity in the residential sector is studied is studied, and the cross-sectional household survey data is analyzed to estimate the consumption of electricity for different end uses by relating the household electricity consumption with the stock of electrical appliances.
Abstract: In this article a theoretical framework within which the demand for electricity in the residential sector is studied. The cross-sectional household survey data is analyzed to estimate the consumption of electricity for different end uses by relating the household electricity consumption with the stock of electrical appliances. Using these estimates, appliances elasticities are obtained. It is shown how these elasticities can be used to relate future electricity usage to changes in the stock of appliances for Bangalore, the capital of Kamataka state in southern India.
TL;DR: In this article, the global and strategic value of the technologies suitable for exploiting, on a large scale, oil shales, tar sands, and coals, in order to get liquid and gaseous fuels is discussed.
Abstract: The need for increasing amounts of liquid and gaseous hydrocarbons, all over the world, states in a pressing way the problem of turning to new nontraditional energy sources and forms. This article analyzes and discusses the global and strategic value of the technologies suitable for exploiting, on a large scale, oil shales, tar sands, and coals, in order to get liquid and gaseous fuels. On the basis of some specific projects, adopting totally or partially new extraction / conversion technologies, estimates of production cost and global impact on the economic system have been carried out. It becomes clear that current production costs for the various scenarios are much higher than the average prices of oil and gas; nonetheless the manifold advantages recommend adoption of these systems in all countries. Among the advantages are the numerous geographical areas of the original energy sources, the stabilization of prices, the subsequent international equilibrium of supply, the rise and development of...
TL;DR: In this paper, the authors present a theoretical and empirical representation of economic incentives for the implementation of pollution control strategies, and compare them with a simple standards setting in the form of critical loads, to see in an empirical way if economic instruments work better than regulations.
Abstract: This paper reviews and develops a theoretical and empirical representation of economic incentives for the implementation of pollution control strategies. A number of alternative available economic instruments may be thought of which, if applied internationally, could encourage implementation of the desired abatement strategies by countries. The paper considers means of pushing the countries to minimize abatement cost with them. A comparison between the pollution targets achieved by the imposition of a uniform charge rate and by differentiated charge rates is discussed and empirical results are provided with associated conclusions. These results are then compared with a simple standards setting in the form of critical loads, in order to see in an empirical way if economic instruments work better than regulations.
TL;DR: In this article, the potential coal and coalbed methane resource of the Groundhog coalfield is estimated to be 228 billion m{sup 3] or 8 trillion cubic feet (tcf).
Abstract: The Bowser Basin covers approximately 50,000 km{sup 2} within the northern part of the Intermontane Belt in northwestern British Columbia. The Groundhog coalfield encompasses approximately 5,000 km{sup 2} in the north-central part of the basin. Coal exploration in the coalfield for the last 100 years and a number of published research projects provide the raw data for an assessment of the potential coal and coalbed methane resource of the Groundhog coalfield. The main coal-bearing sequence in the coalfield is of Late Jurassic to Early Cretaceous age and outcrops on all four sides of the northwest-trending Mount Beirnes synclinorium, which is the most prominent regional structure in the coalfield. The rank of the coal varies from semi-anthracite to meta-anthracite. Coal seams are up to 7 m thick, and cumulative coal thickness in the coal-bearing section ranges up to 53 m. The coalfield contains a potential resource of 37 billion metric tons of coal. The estimated potential coalbed methane resource of the Groundhog coalfield is 228 billion m{sup 3} or 8 trillion cubic feet (tcf). The recoverable reserves will be considerably less. The resource value is large, but the complex structure within the Beirnes synclinorium may make recovery difficult. An adsorption isothermmore » on a drill-core sample of anthracite from the Groundhog coalfield corroborates Kim`s (1977) prediction of the high adsorptive capacity of coal of this rank at low pressure and temperature.« less
TL;DR: In this article, a reasonably complete computer model simulating the heat transfer in residential spaces is compared to actual measurements taken from a room space configured with two passive energy-conserving technologies: radiant barrier insulation and highly reflective ceramic paint.
Abstract: Comparisons are presented of predictions from a reasonably complete computer model simulating the heat transfer in residential spaces to actual measurements taken from a room space configured with two passive energy-conserving technologies: radiant barrier insulation and highly reflective ceramic paint. Closely correlated temperature responses are presented in comparative graphs validating the model as a quantitative design tool for use in previewing the merits of these new technology products. Energy usage data from a model home is included that indicates cost recovery in less than one year and supports the use of the energy-saving technologies.
TL;DR: In this paper, the feasibility of detecting and estimating gas desorption parameters accurately from a history match of Devonian shale well-test pressure data is examined, and based on the results of these analyses, a gas-desorption-specific well test design is proposed.
Abstract: The feasibility of detecting and estimating gas desorption parameters accurately from a history match of Devonian shale well-test pressure data is examined. Both drawdown and buildup tests are analyzed, and based on the results of these analyses, a desorption-specific well-test design is proposed. The results from a simulated desorption-specific test suggest that it may be possible to characterize gas desorption from a well test with reasonable accuracy, even when the effects of desorption are partially masked by wellbore storage and skin effects.
TL;DR: Albertite is a pre-oil bitumenn produced as a result of overpresuring due to a high rate of hydrocarbon generation and, as such, is largely preserved in an immature source rock.
Abstract: Fracturing of oil shale was coeval with albertite vein formation at Albert Mines early in the (Oogenetic history of the Lower Carboniferous Tournasian) Albert Formation. Albertite of this type locality is a pre-oil bitumenn produced as a result of overpres-suring due to a high rate of hydrocarbon generation and, as such, is largely preserved in an immature source rock. Dolomite precipitated in albertite during emplacement of the latter, and was sourced from an accompanying C02-rich fluid phase. Trace element contents of albertite are within the range of selected other major bitumen occurrences and, except for nickel, are lower than those of the host rock. Ratios of Ni/V are elevated in comparison with the host oil shale and with other bitumen occurrences. Carbon isotope values for albertite range from 27.92 to 30.80% o, S l3C, within the range of most conventional crudes.
TL;DR: The main thrust of as mentioned in this paper is on the tapping and use of non-conventional energy resources to reduce the contribution to global warming in the Indian context, and the steps taken by the government of India to promote nonconventional sources in India.
Abstract: The main thrust of this article is on the tapping and use of nonconventional energy resources to reduce the contribution to global warming in the Indian context. This article covers the steps taken by the government of India to promote nonconventional energy sources in India.
TL;DR: In this paper, a detailed elemental analysis was carried out for all coal seams and interburden in two drillholes, HV901-84 and HV904-84, to determine the quantity (range and mean values), affinity, and mode of occurrence of the elements present in these subbituminous coals.
Abstract: Coals from the Highvale Mine, central Alberta Plains, were studied in order to determine the quantity (range and mean values), affinity, and mode of occurrence of the elements present in these subbituminous coals Detailed elemental analyses were carried out for all coal seams and interburden in two drillholes, HV901-84 and HV904-84 In total, 49 samples were analyzed from the 16-m-deep HV904-84 drillhole (approximately three samples per meter of succession) and 33 samples from the 108-m-deep HV901-84 drillhole (also three samples per meter of succession) Mean concentration of various elements in the highvale Mine coals are as follows, all others are below detection limits: Sb, 074 ppm; As, 382 ppm; Br, 2864 ppm; Cl, 723 ppm; Cr, 115 ppm; Co, 325 ppm; Cu, 206 ppm; F, 743 ppm; Hg, 0012 ppb, Se, 165 ppm; U, 257 ppm; Th, 56 ppm; and V, 171 ppm by world standards, all mean concentrations, except Br in some instances, are relatively low and the coals are not enriched in any environmentally or industrially hazardous elements Therefore, the Highvale coals are considered clean by world standards and suitable for utilization The concentration of elements associated with minerals (clays and/or carbonates), such as K, Mg, Na, Th,more » U, V, and Zn, follows similar repetitive trends within coal seams throughout the coal-bearing succession, indicating that the pattern of coal formation is often cyclic and that these geochemical trends are related to the ash content of the coal and the parting location within the coal-bearing succession« less
TL;DR: In this paper, 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, and compared and discussed.
Abstract: 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.
TL;DR: In this article, a 300 cm3 semicontinuous system was used to remove polycyclic aromatic hydrocarbons (PAHs) from coal gassification and high-temperature processes.
Abstract: The contamination of soil by hazardous and toxic organic pollutants is an ever-growing problem facing the global community. One particular family of contaminants that are of major importance are polycyclic aromatic hydrocarbons (PAHs). PAHs are the result of coal gassification and high-temperature processes. Sludges from these town gas operations were generally disposed of into unlined pits and left there for eventual biodegradation. However, the high levels of PAH contained in the pits prevented the occurrence of biodegradation. PAH contaminated soil is now considered hazardous and must be cleaned to environmentally acceptable standards. One method for the remediation is extraction with supercritical water, Water in or about its critical region exhibits enhanced solvating power toward most organic compounds. Contaminated soil containing 4% by mass of hydrocarbons was ultra -cleaned in a 300-cm3 semicontinuous system to an environmentally acceptable standard of less than 200 ppm residual hydrocarbon conce...
TL;DR: In this article, the authors argue that the problems faced by the power sector are diverse, and privatization and deregulation cannot solve all of them, though the financial burden of the utilities may be eased.
Abstract: The wave of economic deregulation and privatization has been sweeping the world for quite some time. The energy sector is also touched by this wave, and there is a sort of competition among developing countries to move fast in order not to miss the train. The power subsector is a major area within the energy sector that is growing fast in the third world and is facing such problems as poor performance and high investment demand for capacity addition that is beyond the capability of the utility. Thus, the power subsector is a target for deregulation and privatization in many countries. However, in many cases the objectives of these programs are too narrow and are designed only to attract private investment. They argue that the problems faced by the power sector are diverse, and privatization and deregulation cannot solve all of them, though the financial burden of the utilities may be eased. At the same time, new institutional and regulatory issues will surface. The authors also argue that the privatization program may lead to neglect of long-term planning of the electricity sector and endanger the energy security of these countries. Finally, they argue for a harmonious cohabitation of private andmore » public utilities in a changed environment where each will play a role.« less
TL;DR: The relationship between coal ash content and opacity in the electrostatic precipitators (ESPs) is not clear, but there appears to be a correspondence between ash resistivity and ESP performance as mentioned in this paper.
Abstract: Mineralogical analysis of the Highvale Mine coals using X-ray diffraction (XRD) shows quartz, kaolinite, illite, and feldspars to dominate. Minor amounts of carbonate and unknown hydrate minerals are also present, and most minerals reported by XRD have been verified by scanning electron microscopy-energy-dispersive X-ray spectrometry (SEM-EDX) on selected samples using back-scattered electron imaging on coal pellets, The coal ash indices show the Highvale Mine coals to have low to medium propensity to form slagging or fouling deposits in the boilers. The relationship between ash content of mill samples and opacity in the electrostatic precipitators (ESPs) is not clear. However, there appears to be a correspondence between ash resistivity and ESP performance. As resistivity is a function of ash chemical composition, the differences in ash composition, notably in its Fe2O3 content, may have contributed to the increase in opacity recorded for seam 1. The production of submicron particles, via fragme...
TL;DR: In this paper, seven different energy resources that can be used for water pumping in urban households have been evaluated using 12 objectives representing the energy, economic, and environmental systems, of the 12 objectives, nine are quantifiable ones, while the remaining three are nonquantifiable.
Abstract: In this article, seven different energy resources that can be used for water pumping in urban households have been evaluated using 12 objectives representing the energy, economic, and environmental systems. Of the 12 objectives, nine are quantifiable ones, while the remaining three are nonquantifiable. To handle such a mixture of objectives, an integrated model using goal programming and analytic hierarchy process has been employed. A detailed sensitivity analysis has also been performed. The analyses indicate that while biogas and electricity generated from fuelwood gasification rank to be the best of the seven energy resources, photovoltaic electricity requires some reduction in its operating cost and/or increase in the electricity generation efficiency. Diesel and electricity generated from biogas or diesel do not provide any scope to be the preferred resources. An additional scenario has revealed that the nonpreference of grid electricity is due to high environmental emissions.