Biofuels are expected to play an increasingly important role in the transportation market, as we search for ways to reduce fossil fuels depletion and emissions. However, the extent to which biofuel can displace petroleum-based fuels depends on the efficiency with which it can be produced. To demonstrate that biofuel has a positive energy balance--i.e. more energy is contained in the fuel than is used in the production--a life-cycle approach must be employed. This paper presents a Life-Cycle Energy Analysis of bioethanol (from sugar beet or wheat) and bioETBE systems in France. Physical and economic data was collected. A systemic description was implemented and the energy used throughout was calculated. A novel indicator aiming at characterizing the renewability of (bio)energy sources is proposed--the energy renewability efficiency (ERenEf). ERenEf measures the fraction of final fuel energy obtained from renewable sources. Inventory results--calculated using four different allocation approaches and ignoring co-product credits--are analyzed in order to understand the effect of allocation in the energy efficiency and renewability results. Sensitivity analysis shows that allocation has a major influence in the results. This research concludes that bioethanol produced in France is clearly favorable in terms of primary energy. A maximum ERenEf value of 48% was obtained for wheat-based ethanol (mass allocation)...
In order for solar energy to serve as a primary energy source, it must be paired with energy storage on a massive scale. At this scale, solar fuels and energy storage in chemical bonds is the only practical approach. Solar fuels are produced in massive amounts by photosynthesis with the reduction of CO(2) by water to give carbohydrates but efficiencies are low. In photosystem II (PSII), the oxygen-producing site for photosynthesis, light absorption and sensitization trigger a cascade of coupled electron-proton transfer events with time scales ranging from picoseconds to microseconds. Oxidative equivalents are built up at the oxygen evolving complex (OEC) for water oxidation by the Kok cycle. A systematic approach to artificial photo synthesis is available based on a ""modular approach"" in which the separate functions of a final device are studied separately, maximized for rates and stability, and used as modules in constructing integrated devices based on molecular assemblies, nanoscale arrays, self-assembled monolayers, etc. Considerable simplification is available by adopting a ""dyesensitized photoelectrosynthesis cell"" (DSPEC) approach inspired by dye-sensitized solar cells (DSSCs). Water oxidation catalysis is a key feature...
The search for alternatives to fossil fuels is boosting interest in biodiesel production. Among the crops used to produce biodiesel, palm trees stand out due to their high productivity and positive energy balance. This work assesses life cycle emissions and the energy balance of biodiesel production from palm oil in Brazil. The results are compared through a meta-analysis to previous published studies: Wood and Corley (1991) [Wood BJ, Corley RH. The energy balance of oil palm cultivation. In: PORIM intl. palm oil conference agriculture; 1991.], Malaysia; Yusoff and Hansen (2005) [Yusoff S. Hansen SB. Feasibility study of performing an life cycle assessment on crude palm oil production in Malaysia. International Journal of Life Cycle Assessment 2007;12:50-8], Malaysia; Angarita et al. (2009) [Angarita EE, Lora EE, Costa RE, Torres EA. The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia. Renewable Energy 2009;34:2905-13], Colombia; Pleanjai and Gheewala (2009) [Pleanjai S. Gheewala SH. Full chain energy analysis of biodiesel production from palm oil in Thailand. Applied Energy 2009;86:S209-14], Thailand; and Yee et al. (2009) [Yee KF, Tan KT, Abdullah AZ, Lee la. Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability. Applied Energy 2009;86:S189-96]...
Esta tese traz contribuições para a formulação do problema de atendimento de necessidades por energia, relacionadas à eletricidade e combustíveis no caso brasileiro. A argumentação pela expansão crescente da oferta de energia é expressão corrente no senso comum, nas agências de notícias, nos discursos oficiais e nos vários planos apresentados à sociedade, e se apóia nas ideologias do progresso e do desenvolvimento econômico. A busca por legitimação desse processo expansivo e acelerado passa por conceitos como soberania nacional, segurança energética e pela inserção do país como protagonista econômico no cenário Latino Americano. Os empreendimentos de infraestrutura na área de energia são intensivos na utilização dos recursos naturais, provocam deslocamentos populacionais importantes e deixam consequências e registro volumoso e inequívoco de passivos sociais e ambientais na historiografia e na sociologia relacionadas à energia. Neste trabalho faz-se um retrospecto das relações entre empresas privadas, estatais e estruturas de governo nos processos de consolidação da geração, produção e distribuição de eletricidade, desde a transição do capitalismo concorrencial ao capitalismo oligopolista-financeiro que encontra...
Diversas estratégias têm sido propostas para a introdução do hidrogênio na economia, especificamente no setor de transportes para se reduzir impactos ambientais em comparação com os combustíveis convencionais. Uma das estratégias implica na utilização de Hidrano (misturas de hidrogênio e Gás Natural Veicular), fazendo uso da infraestrutura de postos de GNV e dos veículos já existentes convertidos para uso de GNV. Dessa forma custos e prazos são reduzidos, tornando a introdução do hidrogênio mais promissora economicamente. Esta tese verifica se o hidrogênio pode ser imediatamente introduzido no mercado energético brasileiro através do Hidrano, com frações molares de hidrogênio de 10%, 20% e 30%. O hidrogênio será gerado através da eletrólise da água nos postos de GNV. Foram então determinados os custos do hidrogênio, os preços e a competitividade do Hidrano de forma a atender o perfil de vendas de um posto de porte médio nos Estados de São Paulo e Rio de Janeiro. O preço do Hidrano ao consumidor depende principalmente do preço de seu maior constituinte, o GNV, vendido na época a 1,308 R$/m3 no Estado de São Paulo e a 1,662 R$/m3 no Estado do Rio de Janeiro. O preço do Hidrano ao consumidor varia entre 1...
O objetivo principal deste trabalho é analisar os impactos futuros da aplicação de políticas energéticas mais eficientes no consumo de combustíveis fósseis para a geração de eletricidade na Venezuela. Os recursos principais utilizados na indústria elétrica são: gás natural, óleo diesel e óleo combustível. Esta análise foi feita projetando o desenvolvimento a médio prazo do setor elétrico em um horizonte de tempo de quinze anos. Diferentes cenários de crescimento econômico e mudanças tecnológicas foram assumidos a fim de realizar essas projeções. A ferramenta de simulação usada foi o programa de planejamento energético LEAP. Após simular um esquema de demanda e fixar as características de desenvolvimento de cada cenário, obtiveram-se os resultados de consumo e disponibilidade. O cenário de alto crescimento econômico e baixa eficiência (CRE) apresenta uma importação de gás natural de 15% da demanda total. Por outro lado, o cenário de baixo crescimento econômico e baixa eficiência (BAS), além de importações de gás natural, apresenta uma importação direta de eletricidade de 8% da demanda total. Estes cenários com baixa eficiência deixariam a Venezuela vulnerável em termos de segurança energética. Devido ao grande risco que apresentam esses cenários...
The purpose of this article is to analyse and
evaluate the economical, energetic and environmental impacts of
the increasing penetration of renewable energies and electrical
vehicles in isolated systems, such as Terceira Island in Azores
and Madeira Island.
Given the fact that the islands are extremely dependent on the
importation of fossil fuels - not only for the production of energy,
but also for the transportation’s sector – it’s intended to analyse
how it is possible to reduce that dependency and determine the
resultant reduction of pollutant gas emissions.
Different settings have been analysed - with and without the
penetration of EVs. The Terceira Island is an interesting case
study, where EVs charging during off-peak hours could allow an
increase in geothermal power, limited by the valley of power
demand. The percentage of renewable energy in the electric
power mix could reach the 74% in 2030 while at the same time, it
is possible to reduce the emissions of pollutant gases in 45% and
the purchase of fossil fuels in 44%. In Madeira, apart from wind,
solar and small hydro power, there are not so many endogenous
resources and the Island’s emission factor cannot be so reduced
as in Terceira. Although...
Coal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels...
Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer- Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA GRC is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface...
Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer-Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA Glenn Research Center is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface...
Efforts to produce green aerospace propellants from nonpetroleum sources are outlined. The paper begins with an overview of feedstock processing and relevant small molecule or C1 chemistry. Gas-to-liquid technologies, notably Fischer-Tropsch (FT) processing of synthesis gas (CO and H2), are being optimized to enhance the fraction of product stream relevant to aviation (and other transportation) fuels at the NASA Glenn Research Center (GRC). Efforts to produce optimized catalysts are described. Given the high cost of space launch, the recycling of human metabolic and plastic wastes to reduce the need to transport consumables to orbit to support the crew of a space station has long been recognized as a high priority. If the much larger costs of transporting consumables to the Moon or beyond are taken into account, the importance of developing waste recycling systems becomes still more imperative. One promising way to transform organic waste products into useful gases is steam reformation; this well-known technology is currently being optimized by a Colorado company for exploration and planetary surface operations. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs. A technology that has successfully demonstrated production of fuels and related chemicals from waste plastics developed in Northeast Ohio is described. Technologies being developed by a Massachusetts company to remove sulfur impurities are highlighted. Common issues and concerns for nonpetroleum fuel production are emphasized. Energy utilization is a concern for production of fuels whether a terrestrial operation or on the lunar (or Martian) surface; the term green relates to not only mitigating excess carbon release but also to the efficiency of grid-energy usage. For space exploration...
A materials compatibility and thermal stability investigation was conducted using five common liquid hydrocarbon fuels and two structural materials. The tests were performed at the NASA Glenn Research Center Heated Tube Facility under environmental conditions similar to those encountered in regeneratively cooled rocket engines. Scanning-electron microscopic analysis in conjunction with energy dispersive spectroscopy (EDS) was utilized to characterize the condition of the tube inner wall surface and any carbon deposition or corrosion that was formed during selected runs. Results show that the carbon deposition process in stainless steel tubes was relatively insensitive to fuel type or test condition. The deposition rates were comparable for all fuels and none of the stainless steel test pieces showed any signs of corrosion. For tests conducted with copper tubing, the sulfur content of the fuel had a significant impact on both the condition of the tube wall and carbon deposition rates. Carbon deposition rates for the lowest sulfur fuels (2 ppm) were slightly higher than those recorded in the stainless steel tubes with no corrosion observed on the inner wall surface. For slightly higher sulfur content (25 ppm) fuels, nodules that intruded into the flow area were observed to form on the inner wall surface. These nodules induced moderate tube pressure drop increases. The highest sulfur content fuels (400 ppm) produced extensive wall pitting and dendritic copper sulfide growth that was continuous along the entire tube wall surface. The result of this tube degradation was the inability to maintain flow rate due to rapidly increasing test section pressure drops. Accompanying this corrosion were carbon deposition rates an order of magnitude greater than those observed in comparable stainless steel tests. The results of this investigation indicate that trace impurities in fuels (i.e. sulfur) can significantly impact the carbon deposition process and produce unacceptable corrosion levels in copper based structural materials.
Results are presented of an investigation of gasification and clean fuels from coal. Factors discussed include: coal and coal transportation costs; clean liquid and gas fuel process efficiencies and costs; and cost, performance, and environmental intrusion elements of the integrated low-Btu coal gasification system. Cost estimates for the balance-of-plant requirements associated with advanced energy conversion systems utilizing coal or coal-derived fuels are included.
The role of various synthetic fuels, for ground transportation in the United States, was examined for the near term (by 1985) and the longer term applications (1985-2000 and beyond 2000). Feasible options include synthetic oil, methanol, electric propulsion, and hydrogen. It is concluded that (1) the competition during the next 50 years will be for the fuels of all types, rather than among the fuels; (2) extensive domestic oil and gas exploration should be initiated concurrent with the development of several alternate fuels and related ancillaries; and (3) hydrogen, as an automotive fuel, seems to be equivalent to gasoline for optimum fuel to air mixtures. As a pollution free, high energy density fuel, hydrogen deserves consideration as the logical replacement for the hydrocarbons. Several research and development requirements, essential for the implementation of hydrogen economy for ground transportation, were identified. Extensive engineering development and testing activities should be initiated to establish hydrogen as the future automotive fuel, followed by demonstration projects and concerted efforts at public education.
The effects of alternative public policies on the consumption and
prices of various forms of energy in the United States depends critically
on the nature of consumer demands for fuels and the supply characteristics
of these fuels. Previous work on energy demand has tended to concentrate
on the demand for a particular fuel as determined by standard economic
variables such as the price of the fuel, income levels, sometimes the
price of alternative fuels, and other demographic characteristics of the
consuming population. In this work the consumer decision making process
is viewed as being composed of two steps. First, the consumer decides
that he wants a particular service and, secondly, seeks to find the fuel
that will provide this service most cheaply. This view leads us to concentrate on substitution possibilities among fuels for particular services
rather than own-price elasticities for a particular fuel.
This paper presents results for the determinants of energy consumption in the residential and commercial sector in the United States.
First, a discussion of the conceptual model used for fuel choice decisions
is presented. Then, empirical results are given for appliance choices in
the residential sector for four selected appliances and for the "fuel-split"
of aggregate energy consumption among the three fuels used in the residential
and commercial sector. The own-price and cross-price elasticities are
estimated and discussed.
Two approaches to non-fossil energy manufacturing are suggested. This is an editorial-opinion that highlights why stimulating global economic growth and sustainable global peace are inextricably linked.
Entrapment of world leaders caught in the net of their polling data works wonders
to push popular measures rather than the balanced choices, the prudent options.
Energy deprivation is one cause whose effects are staggering. Energy politics is a
reason why a third of the world struggles to survive on about a dollar a day or less
than one meal a day. There are no major insurmountable barriers to alleviate this
dysfunctional energy dynamics except the ignorance of a few who choose to remain
scientifically illiterate. But governments are pawns in their hands! They are skilled
rebel rousers and formidable political operators. They are brilliant in massaging
public opinion and hence, polling figures, to force the implementation of policies
that fuels riots, wars, poverty and hunger but detracts from manufacturing energy.; Stimulating economic growth and sustainable global peace are inextricably linked.
Entrapment of world leaders caught in the net of their polling data works wonders
to push popular measures rather than the balanced choices...
Fonte: MIT Center for Energy and Environmental Policy ResearchPublicador: MIT Center for Energy and Environmental Policy Research
Tipo: working paperFormato: 16 p
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Government support of innovation - both technology creation and technology demonstration - is desirable to encourage private investors to adopt new technology. In this paper, I review the government role in encouraging technology innovation and the success of the Department of Energy (DOE) and its predecessor agencies in advancing technology in the energy sector. The DOE has had better success in the first stage of innovation (sponsoring R&D to create new technology options) than in the second stage (demonstrating technologies with the objective of encouraging adoption by the private sector). I argue that the DOE does not have the expertise, policy instruments, or contracting flexibility to manage successfully technology demonstration, and that consideration should be given to establishing a new mechanism for this purpose. The ill-fated 1980 Synthetic Fuels Corporation offers an interesting model for such a mechanism.