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Documented international enquiry on solid sedimentary fossil fuels; Coal: definitions, classifications, reserves-resources and energy potential

Alpern, B.; Lemos de Sousa, M. J.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2002 Português
Relevância na Pesquisa
66.67%
This paper deals with all solid sedimentary fossil fuels, i.e. coal, the main one for geological reserves and resources, peat, and oil shales. Definitions of coal ( < 50% ash) and coal seam (thickness and depth limits) are examined in view of an international agreement regarding new concepts for a common reserves and resources evaluation using the same nomenclature. The 50% ash limit, already adopted by UN-ECE for coal definition, allows the creation of a new category—the organic shales (50–75% ash)—comprising energetic materials still valuable for thermal use (coal shales) or to be retorted for oil production (oil shales). Geological relations between coals, oil shales, solid bitumen, liquid hydrocarbons, natural gas, and coalbed methane are also examined together with environmental problems. As a final synthesis of all topics, the paper discusses the problems related with a modern geological classification of all solid sedimentary fuels based on: various rank parameters (moisture content, calorific value, reflectance), maceral composition, and mineral matter content (and washability). Finally, it should be pointed out that the paper is presented as series of problems, some of them old ones, but never resolved until now. In order to facilitate the next generation of coal geologists to resolve these problems on the basis of international agreements...

Thermal behavior of renewable diesel from sugar cane, biodiesel, fossil diesel and their blends

Conconi, Charles C.; Crnkovic, Paula Manoel
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 6-11
Português
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Biofuels and their blends with fossil fuel are important energy resources, whose production and application have been largely increased internationally. This study focuses on the evaluation of the activation energy of the thermal decomposition of three pure fuels: farnesane (renewable diesel from sugar cane), biodiesel and fossil diesel and their blends (20% farnesene and 80% of fossil diesel - 20F80D and 20% farnesane, 50% fossil diesel and 30% biodiesel - 20F50D30B). Activation energy has been determined from thermogravimetry and Model-Free Kinetics. Results showed that not only the cetane number is important to understand the behavior of the fuels regarding ignition delay, but also the profile of the activation energy versus conversion curves shows that the chemical reactions are responsible for the performance at the beginning of the process. In addition, activation energy seemed to be suitable in describing reactivity in the case of blends of renewable and fossil fuels. © 2013 Elsevier B.V.

Electrochemical Determination of Organic Compounds in Automotive Fuels

Santos, Andre L.; Takeuchi, Regina M.; Munoz, Rodrigo A. A.; Angnes, Lucio; Stradiotto, Nelson R.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 233-242
Português
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56.65%
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); This article critically reviews the electroanalytical methods devoted for the determination of organic compounds in automotive fuels that can range from contaminants to additives typically introduced into liquid biofuels and liquid fossil fuels. Contaminants such as aldehydes and ketones in bioethanol, free fatty acids and glycerol in biodiesel, and sulfur and nitrogen organic compounds in gasoline and diesel fuel, and additives such as colour markers and antioxidants added to fuels were determined by electroanalytical methods. Special focus is given to electrodes, electrochemical techniques, and sample preparation strategies. Future directions of research on electroanalysis of liquid fuels are presented.

Optimization of low sulfur jerusalem artichoke juice for fossil fuels biodesulfurization process

Silva, Tiago P.; Paixão, Susana M.; Roseiro, J. Carlos; Alves, Luís Manuel
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 Português
Relevância na Pesquisa
66.71%
Most of the world’s energy is generated from the burning of fossil fuels such as oil and its derivatives. When burnt, these fuels release into the atmosphere volatile organic compounds, sulfur as sulfur dioxide (SO2) and the fine particulate matter of metal sulfates. These are pollutants which can be responsible for bronchial irritation, asthma attacks, cardio-pulmonary diseases and lung cancer mortality, and they also contribute for the occurrence of acid rains and the increase of the hole in the ozone layer. For these reasons countries around the world imposed legal maxima to sulfur concentration on fuels. Forcing companies to develop methods of removing the sulfur contained in the oil. The most common is hydrodesulfurization which employs high pressures and temperatures associated with complex metal catalysts making it extremely expensive. So, it becomes important to explore alternatives such as biodesulfurization (BDS). This process is based on the use of microorganisms for the removal of sulfur form even from the most recalcitrant compounds at atmospheric pressure and temperature, making it cheaper and more eco-friendly. However it still presents some drawbacks, such as being easily inhibited in the presence of sulfates, which have been shown to have great inhibitory effect even in amounts as low as 6 mg/l [1]. In order to further reduce the costs associated with BDS it is possible to explore alternative carbon sources...

Flow cytometric method for cell viability evaluation of Gordonia alkanivorans strain 1B in fossil fuels biodesulfurization processes

Teixeira, A. V.; Silva, Tiago P.; Silva, Teresa Lopes da; Paixão, Susana M.; Alves, Luís Manuel
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 Português
Relevância na Pesquisa
66.61%
The most commonly method used for sulfur removal from fossil fuels is hydrodesulfurization, a physico-chemical process at very high temperatures and pressures. An alternative to this process is biodedesulfurization (BDS), a microbiological process that works at atmospheric pressure and temperature making it easier to work with and less expensive. It also as the advantage of easily desulfurizing recalcitrant sulfur compounds which are hard to remove by hydrodesulfurization [1]. Several bacteria species, such as Gordonia alkanivorans strain1B [2], are able to desulfurize dibenzothiophene, a model compound used commonly in BDS studies, to 2-hydroxybiphenyl (2-HBP) via the 4S pathway without destroying the carbon structure [3], therefore maintaining the fuel potential energy. BDS limitations are related with process parameters and with the cost of maintaining bacterial cultures so to enhance the BDS process, it is necessary to monitor how changes in the experimental system affect the microbial cells viability and consequently the process efficiency. An alternative method to conventional microbial techniques to determine cell viability is flow cytometry. This method provides a fast and accurate quantitative method for measurement of thousands of individual cells...

Under What Conditions Does a Carbon Tax on Fossil Fuels Stimulate Biofuels?

Timilsina, Govinda R.; Csordas, Stefan; Mevel, Simon
Fonte: Banco Mundial Publicador: Banco Mundial
Português
Relevância na Pesquisa
56.8%
A carbon tax is an efficient economic instrument to reduce emissions of carbon dioxide released from fossil fuel burning. Its impacts on production of renewable energy depend on how it is designed -- particularly in the context of the penetration of biofuels into the energy supply mix for road transportation. Using a multi-sector, multi-country computable general equilibrium model, this study shows first that a carbon tax with the entire tax revenue recycled to households through a lump-sum transfer does not stimulate biofuel production significantly, even at relatively high tax rates. This reflects the high cost of carbon dioxide abatement through biofuels substitution, relative to other energy substitution alternatives; in addition, the carbon tax will have negative economy-wide consequences that reduce total demand for all fuels. A combined carbon tax and biofuel subsidy policy, where part of the carbon tax revenue is used to finance a biofuel subsidy, would significantly stimulate market penetration of biofuels. Although the carbon tax and biofuel subsidy policy would cause higher loss in global economic output compared with the carbon tax with lump sum revenue redistribution...

Political Determinants of Fossil Fuel Pricing

van Beers, Cees; Strand, Jon
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
Relevância na Pesquisa
56.81%
This paper provides an empirical analysis of economic and political determinants of gasoline and diesel prices for about 200 countries over the period 1991-2010. A range of both political and economic variables are found to systematically influence fuel prices, and in ways that differ systematically with countries per-capita income levels. For democracies, the analysis finds that fuel prices correlate positively with both duration of democracy and tenure of democratic leaders. In non-democratic societies there is more often no such relationship or it is the opposite of that for democracies. Regime switches -- transitions from non-democratic to democratic government, or vice versa -- reduce fuel prices. Fuel prices are also lower for more corrupt, or more centralized, governments. Higher levels of gross domestic product per capita lead to higher fuel prices, while export income from selling fossil fuels reduces these prices dramatically. Higher motor fuel consumption also appears to reduce fuel prices, most for gasoline. Absolute "pass-through" of crude oil price changes to fuel prices is found to be high on average.

Environmental Costs of Fossil Fuels : A Rapid Assessment Method with Application to Six Cities

Lvovsky, Kseniya; Hughes, Gordon; Maddison, David; Ostro, Bart; Pearce, David
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Português
Relevância na Pesquisa
56.92%
Among the key external effects of fossil fuel contribution are urban air pollution, and changes in global climate. A study of six cities in developing countries, and transition economies estimates the magnitude of these effects, and, examines how various fuels, and pollution sources contribute to health damages, and other environmental costs. The study develops a simple, but robust method for rapid assessment of these damages. By linking the damage to a particular fuel use, or pollution source, the method makes possible cost-benefit analysis of pollution abatement measures. The findings show very high levels of environmental damage, and reveal large sectoral differences. By far the greatest share of the total damage, is that to human health, from exposure to ambient particulates, caused mainly by small pollution sources, such as vehicles, and household stoves. Large industries, and power plants account for a smaller proportion of health damage, but are the major contributors to carbon dioxide emissions, which have an impact on global climate. The complex relationships between pollution sources...

Fossil Fuel Subsidies

Kojima, Masami; Koplow, Doug
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
Tipo: Trabalho em Andamento
Português
Relevância na Pesquisa
56.67%
Numbers ranging from half a trillion to two trillion dollars have been cited in recent years for global subsidies for fossil fuels. How are these figures calculated and why are they so different? The most commonly used methods for measuring subsidies are the price-gap approach -- quantifying the gap between free-market reference prices and the prices charged to consumers -- the inventory approach, which constructs an inventory of government actions benefiting production and consumption of fossil fuels. Practitioners are not faced with two choices. The two methods are complementary and should be used together -- price gaps cause distortions throughout the economy and quantification is needed for improving pricing policies; an inventory is useful for examining budgetary allocation. An inventory based on a full accounting framework for producer and consumer support estimates in fact captures price gaps as market transfers to producers or consumers. Differences in subsidy valuation arise from assumptions made to compensate for missing data and the scope of subsidy measurement. Having a common understanding of terms and standardizing calculation methods would go a long way in enabling comparison of subsidies across countries and sectors...

Fossil fuels in the 21st century

Lincoln, S.
Fonte: Royal Swedish Acad Sciences Publicador: Royal Swedish Acad Sciences
Tipo: Artigo de Revista Científica
Publicado em //2005 Português
Relevância na Pesquisa
66.73%
An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much of the 21st century and the sequestration of CO2 will be an increasingly important requirement.; http://ambio.allenpress.com/ambioonline/?request=get-abstract&issn=0044-7447&volume=034&issue=08&page=0621; Stephen F. Lincoln; © 2008 The Royal Swedish Academy of Sciences

Fossil fuels, alternative energy and economic growth

Barreto, R.A.
Fonte: EcoMod Press Publicador: EcoMod Press
Tipo: Conference paper
Publicado em //2015 Português
Relevância na Pesquisa
66.88%
We present a theoretical framework that incorporates energy within an endogenous growth model. The model explicitly allows for the interaction and substitution between fossil fuels, defined as a non-renewable resource derived from some fixed initial stock, and alternative energy, defined as renewable resource whose production requires capital input. The dynamics of the model depict a unique balance growth to a saddle point. The consumption path temporarily peaks, when fossil fuels are plentiful and cheap, followed by a fall, as fossil fuel become more scarce and alternative energy production has yet to take over, until finally the steady state is reached where alternative energy production fuels the entire economy. The model depicts a sort of energy rich heyday when fossil fuels are plentiful and cheap. As oil stocks fall, alternative energy sources become increasingly more viable until a time when alternative energy has almost completed replaced oil. Graphically, the model generates a hump in the growth path of consumption such that a short run “peak oil” heyday may be compared to the long run renewable energy dependent steady state.; Raul A. Barreto

Fire and Fuels: CO2 and SO2 Emissions in the Finnish Economy, 1800-2005

KUNNAS, Jan
Fonte: Instituto Universitário Europeu Publicador: Instituto Universitário Europeu
Tipo: Tese de Doutorado Formato: application/pdf
Português
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The full text available is only the introduction of the thesis.; Defence date: 15 June 2009; Supervisor: Giovanni Federico External supervisor: Timo Myllyntaus Examining Board: Giovanni Federico Bartolomé Yun Casalilla Magnus Lindmark Jan Luiten van Zanden; This thesis examines Finland‘s transition from a solar based energy system to a fossil fuel based one, and the environmental consequences of this transition. The period under examination is from the beginning of the 19th century to the present, covering Finland's transition from a proto-industrial agricultural society to a --post- industrial| society. The theoretical starting point has been the environmental Kuznets curve hypothesis, which proposes that some pollution or measures of environmental degradation would follow an inverted U-curve related to incomes, increasing at low income levels and decreasing at high income levels. Based on the historical approach used in this thesis, two new explanations for the existence of an environmental Kuznets curve are added: 1) The severity of environmental degradation might itself create a turning point for the emissions, or in some cases fear of severe effects. 2) What at a first glance seems to be a genuine environmental improvement might just be a transformation of one environmental problem into another. Some proponents of economic growth go as far as claiming that economic growth is a necessary condition for proper protection of the environment. This thesis turns the argument around...

Key Drivers of PPPs in Electricity Generation in Developing Countries : Cross-Country Evidence of Switching between PPP Investment in Fossil Fuel and Renewable-Based Generation

Vagliasindi, Maria
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
Português
Relevância na Pesquisa
56.91%
This paper presents new global evidence on the key determinants of public-private partnership investment in electricity generated by fossil fuels and renewable energy based on a panel data analysis for 105 developing countries over a period of 16 years from 1993 to 2008. It aims to identify the key factors affecting private investors' decision to enter electricity generation, through probit analysis, and the amount of investment sunk in this market segment, based on Heckman's sample selection analysis. The paper shows some evidence of switching from investment in fossil fuels to investment in hydro and renewables and within fossil fuels from oil to natural gas. An interesting result of the econometric analysis is that the likelihood of switching toward renewable investment is driven by long-run environmental factors, such as the increases in the price of oil and the introduction of the Kyoto protocol. Another interesting result is that sector governance support schemes, provided by feed-in tariffs, affect only the entry in renewable based electricity generation and have no impact in reducing the amount of investment in fossil fuel based generation. Economy-wide governance factors...

A Policy Framework for Green Transportation in Georgia : Achieving Reforms and Building Infrastructure for Sustainability

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Policy Note; Economic & Sector Work
Português
Relevância na Pesquisa
46.87%
The Government of Georgia is considering options for reducing fossil fuel imports in favor of introducing large scale use of domestic energy sources for public and private transportation. However, this must be considered within the overall context of green transportation-which will generate benefits well beyond the substitution of fossil fuels with domestic energy sources. The concept of green transportation has emerged in response to growing concerns about climate change; typically this refers to a transportation system characterized by low carbon emissions, i.e., Green House Gasses (GHG). In the context of Georgia, two other important development issues in green transportation in addition to GHG emissions are fossil fuel consumption and air pollution. For the purpose of this study, therefore, green transportation in Georgia refers to reducing the intensity of fossil fuel use and increasing reliance on indigenous energy sources (mainly hydropower), as well as minimizing adverse impacts on the global and local environment through reduced emissions of GHG and local pollutants. Greening transportation will create 'co-benefits': reducing fossil fuel use will help improve the balance of trade and energy security; and employing measures to avoid unnecessary trips and using fewer vehicles for the same number of trips (i.e....

Advanced Biofuel Technologies : Status and Barriers

Cheng, Jay J.; Timilsina, Govinda R.
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Publications & Research :: Policy Research Working Paper
Português
Relevância na Pesquisa
46.87%
Large-scale production of crop based (first generation) biofuels may not be feasible without adversely affecting global food supply or encroaching on other important land uses. Because alternatives to liquid fossil fuels are important to develop in order to address greenhouse gas mitigation and other energy policy objectives, the potential for increased use of advanced (non-crop, second generation) biofuel production technologies has significant policy relevance. This study reviews the current status of several advanced biofuel technologies. Technically, it would be possible to produce a large portion of transportation fuels using advanced biofuel technologies, specifically those that can be grown using a small portion of the world's land area (for example, microalgae), or those grown on arable lands without affecting food supply (for example, agricultural residues). However, serious technical barriers limit the near-term commercial application of advanced biofuels technologies. Key technical barriers include low conversion efficiency from biomass to fuel...

A computational study of ionic liquids used in the production of fuels and biofuels; Estudo computacional de líquidos iónicos usados na produção de combustíveis e biocombustíveis

Batista, Marta Luísa Salsas
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
56.67%
For the past decades it has been a worldwide concern to reduce the emission of harmful gases released during the combustion of fossil fuels. This goal has been addressed through the reduction of sulfur-containing compounds, and the replacement of fossil fuels by biofuels, such as bioethanol, produced in large scale from biomass. For this purpose, a new class of solvents, the Ionic Liquids (ILs), has been applied, aiming at developing new processes and replacing common organic solvents in the current processes. ILs can be composed by a large number of different combinations of cations and anions, which confer unique but desired properties to ILs. The ability of fine-tuning the properties of ILs to meet the requirements of a specific application range by mixing different cations and anions arises as the most relevant aspect for rendering ILs so attractive to researchers. Nonetheless, due to the huge number of possible combinations between the ions it is required the use of cheap predictive approaches for anticipating how they will act in a given situation. Molecular dynamics (MD) simulation is a statistical mechanics computational approach, based on Newton’s equations of motion, which can be used to study macroscopic systems at the atomic level...

Material Flow Analysis of Fossil Fuels in China during 2000–2010

Wang, Sheng; Dai, Jing; Su, Meirong
Fonte: The Scientific World Journal Publicador: The Scientific World Journal
Tipo: Artigo de Revista Científica
Publicado em 30/12/2012 Português
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46.92%
Since the relationship between the supply and demand of fossil fuels is on edge in the long run, the contradiction between the economic growth and limited resources will hinder the sustainable development of the Chinese society. This paper aims to analyze the input of fossil fuels in China during 2000–2010 via the material flow analysis (MFA) that takes hidden flows into account. With coal, oil, and natural gas quantified by MFA, three indexes, consumption and supply ratio (C/S ratio), resource consumption intensity (RCI), and fossil fuels productivity (FFP), are proposed to reflect the interactions between population, GDP, and fossil fuels. The results indicated that in the past 11 years, China's requirement for fossil fuels has been increasing continuously because of the growing mine productivity in domestic areas, which also leads to a single energy consumption structure as well as excessive dependence on the domestic exploitation. It is advisable to control the fossil fuels consumption by energy recycling and new energy facilities' popularization in order to lead a sustainable access to nonrenewable resources and decrease the soaring carbon emissions.

Sustainable Energy - without the hot air

MacKay, David
Fonte: UIT Cambridge Publicador: UIT Cambridge
Tipo: Book or Book Chapter
Português
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46.93%
This is the electronic version of the book which is also available in hardback and paperback.; We have an addiction to fossil fuels, and it?s not sustainable. The developed world gets 80% of its energy from fossil fuels; Britain, 90%. And this is unsustainable for three reasons. First, easily-accessible fossil fuels will at some point run out, so we?ll eventually have to get our energy from someplace else. Second, burning fossil fuels is having a measurable and very-probably dangerous effect on the climate. Avoiding dangerous climate change motivates an immediate change from our current use of fossil fuels. Third, even if we don?t care about climate change, a drastic reduction in Britain?s fossil fuel consumption would seem a wise move if we care about security of supply: continued rapid use of the North Sea Photo by Terry Cavner. oil and gas reserves will otherwise soon force fossil-addicted Britain to depend on imports from untrustworthy foreigners. (I hope you can hear my tongue in my cheek.) How can we get off our fossil fuel addiction? There?s no shortage of advice on how to ?make a difference,? but the public is confused, uncertain whether these schemes are fixes or figleaves. People are rightly suspicious when companies tell us that buying their ?green? product means we?ve ?done our bit.? They are equally uneasy about national energy strategy. Are ?decentralization? and ?combined heat and power...

Fructose rich alternative carbon sources for enhanced fossil fuels biodesulfurization

Silva, Tiago P.; Paixão, Susana M.; Alves, Luís Manuel
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 Português
Relevância na Pesquisa
66.61%
Biodesulfurization allows the removal of recalcitrant sulfur from fossil fuels at mild operating conditions with the aid of microorganisms. However the production of biocatalysts still has elevated costs which hinder its industrial application. So the use of agro-industrial by-products and wastes, as alternative carbon sources could present an opportunity to cheapen the process. In previous works we showed that Gordonia alkanivorans strain 1B has the ability to use materials such as recycled paper sludge hydrolysate and carob pulp liquor to grow and desulfurize after some optimization. Since this is a fructophilic bacterium it is important to compare the use of carbon sources progressively richer in fructose.

Law, the laws of nature and ecosystem energy services: a case of wilful blindness

Hodas,DR
Fonte: PER: Potchefstroomse Elektroniese Regsblad Publicador: PER: Potchefstroomse Elektroniese Regsblad
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
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47.03%
Ecosystems services include the collection, concentration, and storage of solar energy as fossil fuels (e.g., coal, petroleum, and natural gas). These concentrated forms of energy were produced by ancient ecosystem services. However, our legal and economic systems fail to recognise the value of the ecosystem service subsidies embedded in fossil fuels. This ecosystem services price subsidy causes overuse and waste of fossil fuels in the free market: fossil fuels are consumed more quickly than they can be replaced by ecosystem services and in far larger quantities than they would be if the price of fossil fuels included the cost of solar energy collection, concentration and manufacturing of raw fossil fuels. Moreover, burning fossil fuels produces enormous environmental, human health and welfare costs and damage. Virtually no legal literature on ecosystem services, sustainable development, or sustainable energy, considers fossil fuels in this context. Without understanding stored energy as an ecosystem service, we cannot reasonably expect to manage our fossil fuel energy resources sustainably. International and domestic energy law and policy systems generally ignore this feature of fossil fuel energy, a blind spot that explains why reducing greenhouse gas emissions from fossil fuels is fundamentally a political challenge. This paper will use new understandings emerging from the field of complex systems to critique existing legal decision-making models that do not adequately account for energy ecosystem services in policy design...