共查询到20条相似文献,搜索用时 15 毫秒
1.
Khanji Harijan Mujeebuddin Memon Mohammad A. Uqaili Umar K. Mirza 《Renewable & Sustainable Energy Reviews》2009,13(1):291-295
Pakistan is an energy-deficient country. The indigenous reserves of oil and gas are limited and the country is heavily dependent on the import of oil. The oil import bill is a serious strain on the country's economy and has been deteriorating the balance of payments situation. The country has become increasingly more dependent on fossil fuels and its energy security hangs on the fragile supply of imported oil that is subject to disruptions and price volatility. The transport sector has a 28% share in the total commercial energy consumption in Pakistan. About 1.15 million tonnes of gasoline was consumed by this sector during 2005–2006. The gasoline consumption in the transport sector is also a major source of environmental degradation especially in urban areas. Consequently, Pakistan needs to develop indigenous, environment-friendly energy resources, such as ethanol, to meet its transport sector's energy needs. Pakistan produces about 54 million tonnes of sugarcane every year. The estimated production potential of ethanol from molasses is about 500 million liters per annum. Ethanol can be used in the transport sector after blending with gasoline, in order to minimize the gasoline consumption and associated economical and environmental impacts. This paper presents the assessment of the potential contribution of ethanol in the transport sector of Pakistan. It is concluded that 5–10% of the annual gasoline consumption in transport sector could be met from ethanol by the year 2030 under different scenarios. About US$200–400 million per annum could be saved along with other environmental and health benefits by using gasol in the transport sector. 相似文献
2.
Sinia N. Dodi Stevan D. Popov Jelena M. Dodi Jovana A. Rankovi Zoltan Z. Zavargo 《Renewable & Sustainable Energy Reviews》2009,13(9):2722-2727
The Autonomous Province of Vojvodina is an Autonomous Province in Serbia, containing about 27% of its total population according to the 2002 Census. Contribution of renewable energy sources in total energy consumption of Vojvodina contemporary amounts to less than 1%, apropos 280 GWh/year. By combining of methods of introduction of new and renewable sources, systematic application of methods for increasing of energetic efficacy, as well as of introduction of the new technologies, percentage of contribution of the non-conventional energy sources in Vojvodina could be increased to as much as 20%. This paper presents the potential of development of bioethanol production in Vojvodina. Production of bioethanol on small farms can be successfully applied for processing of only 30 kg of corn per day, with obtaining of crude ethanol in the so-called “brandy ladle” and use of lygnocellulosic agricultural wastes as an energy source. In a case of construction of a larger number of such plants, the only possible solution is seen in the principle of construction of the so-called “satellite plants”, which will on small farm produce crude ethanol, with obtaining and consumption of stillage for animal feeding, and consumption of agricultural wastes as energetic fuels. If stillage is to be used as feed in wet feeding, it is estimated that, because of restrictions established by the magnitude of animal farm, the upper limit of capacity of such enterprises that process is at some 10–15 tons of corn per day, and production of 3000–3500 hL of absolute ethanol per day. In such a case, for animal feeding necessary is to have herd with 1300–1700 of milking cows or 5000–25,000 heads of sheep and/or pigs. Technological model of separate grain processing ad bioethanol production from dextrose hydrolysates of starch is interesting for countries possessing plants for bioethanol production from molasses and plants for cereals processing into starch and dextrose hydrolysates of starch. 相似文献
3.
Although Finland's forest resources have been utilized intensively, the size of the total volume of the growing stock has increased since the mid-1960s, and hence increasing amounts of carbon have been sequestered by forests. The net sequestration by forests has also been substantial when compared with the CO2 emissions resulting from energy generation and consumption based on fossil fuels and peat. It is also important, from the point of view of mitigating the effects of climate change, to assess how the sequestration capacity of forests may change under changing climatic conditions. This paper presents the results of a study assessing the development of the forest and wood-product carbon budget for Finland, based on regionally measured data, detailed dynamic models, and recent predictions concerning the changing climate. At the starting point for the simulation (1990), nearly 90% of the forest sector's carbon storage was found in the forest. Regular management transferred carbon from forests to wood products. Under the current climatic conditions, the simulated forest carbon storage increased 45% by the year 2100, and the wood-product storage by 320%, as a consequence of continuous production. Under changing climate conditions, the forest carbon storage increased, but started to decline when the temperature increase exceeded 2.5°C within 40 years. 相似文献
4.
This paper concentrates on the transport sector of six developing countries with similar common denominators, namely Turkey, Thailand, Pakistan, Morocco, Tunisia and Malaysia. By using standard econometric techniques, we analyse the evolution of oil demand for road transport in these countries in relation to independent variables such as income, population, price of gasoline and diesel etc. Unlike the treatment in the present literature on the subject, gasoline and diesel consumption are estimated separately due to the high share of diesel in the total transport sector consumption. On the basis of the estimation over the period 1970–1990, on a country by country basis, we forecast the demand for these six countries until 2010. The results of this study indicate that the transport sector will be the driving force for energy and oil demand as part of economic growth in these developing countries. Its share in the future energy market structure is expected to grow. Consequently, the (pricing) policies of oil products in this sector have a crucial role for shaping rational economic and energy strategies within the framework of rising environmental concern. 相似文献
5.
A number of issues related more particularly to green gases emissions and fuel availability has resulted worldwide from the transport sector expansion. Stringent regulation laws, improvement in engine efficiency and alternative fuel options have been proposed to address these issues. However, the suitability of an alternative fuel depends on its performance, cost and availability. By its versatility in use and its renewability, hydrogen, as an alternative fuel, offers the best potential for reducing greenhouse gases emission, improving engine efficiency and ensuring fuel security. 相似文献
6.
Hydrogen and fuel cell vehicles are often discussed as crucial elements in the decarbonisation of the transport systems. However, in spite of the fact that hydrogen and fuel cell vehicles have a long history, they are still seen only as a long-term mobility option. The major objective of this paper is to analyse key barriers to the increasing use of hydrogen and fuel cell vehicles. A special focus is put on their economic performance, because this will be most crucial for their future deployment. Mobility costs are calculated based on the total cost of ownership, and future developments are analysed based on technological learning. The major conclusion is that to achieve full benefits of hydrogen and fuel cells in the transport sector, it is necessary to provide stabile, long-term policy framework conditions, as well as to harmonize actions across regions to be able to take advantage of economies of scale. 相似文献
7.
Christopher Jung Linda Nagel Dirk Schindler Leonie Grau 《International Journal of Hydrogen Energy》2018,43(52):23161-23167
Wind-to-hydrogen (WH) is a promising option for reducing greenhouse gas emissions in the transport sector. Therefore, the reduction potential of fossil fuels by WH was estimated taking meteorological, geographical, and technical constraints into account. The wind resource estimation is based on the application of the high-resolution (200 m × 200 m) wind speed-wind shear model (WSWS). Together with the power curves of the six most frequently installed wind turbines in 2017, WSWS was used to assess Germany's technical wind energy potential. The WH and fossil fuel reduction potentials were calculated based on proton exchange membrane electrolysis. Results from the wind resource assessment demonstrate that in addition to the currently realized wind energy (89 TWh/yr in 2017), which is directly used for electricity generation, Germany's technical onshore potential for WH is 780 TWh/yr. This amount of renewable energy available for WH could replace 80.1% of the fossil fuels currently used in the transport sector. 相似文献
8.
《International Journal of Hydrogen Energy》2019,44(26):12918-12930
The substantial expansion of renewable energy sources is creating the foundation to successfully transform the German energy sector (the so-called ‘Energiewende’). A by-product of this development is the corresponding capacity demand for the transportation, distribution and storage of energy. Hydrogen produced by electrolysis offers a promising solution to these challenges, although the willingness to invest in hydrogen technologies requires the identification of competitive and climate-friendly pathways in the long run. Therefore, this paper employs a pathway analysis to investigate the use of renewable hydrogen in the German passenger car transportation sector in terms of varying market penetration scenarios for fuel cell-electric vehicles (FCEVs). The investigation focuses on how an H2 infrastructure can be designed on a national scale with various supply chain networks to establish robust pathways and important technologies, which has not yet been done. Therefore, the study includes all related aspects, from hydrogen production to fueling stations, for a given FCEV market penetration scenario, as well as the CO2 reduction potential that can be achieved for the transport sector. A total of four scenarios are considered, estimating an FCEV market share of 1–75% by the year 2050. This corresponds to an annual production of 0.02–2.88 million tons of hydrogen. The findings show that the most cost-efficient H2 supply (well-to-tank: 6.7–7.5 €/kgH2) can be achieved in high demand scenarios (FCEV market shares of 30% and 75%) through a combination of cavern storage and pipeline transport. For low-demand scenarios, however, technology pathways involving LH2 and LOHC truck transport represent the most cost-efficient options (well-to-tank: 8.2–11.4 €/kgH2). 相似文献
9.
《International Journal of Hydrogen Energy》2019,44(25):12554-12565
Battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) have been identified as two electromobility options which can help to achieve GHG emission reduction targets in the transport sector. However, both options will also impact the future energy system characterized by integration of various demand sectors and increasing intermittent power generation. The objective of this paper is to examine the optimal mix of both propulsion systems and to analyze the cost for renewable fuel supply. We propose a generic approach for dimensioning of fast charging and hydrogen refueling stations and optimization of the fuel supply system. The model is applied in a case study for passenger cars on German highways. The results indicate that a parallel build-up of stations for both technologies does not increase the overall costs. Moreover, the technology combination is also an optimal solution from the system perspective due to synergetic use of hydrogen but limited efficiency losses. Hence, BEVs and FCEVs should jointly contribute to the decarbonization of the future energy system. 相似文献
10.
G. Najafi B. Ghobadian T. Tavakoli T. Yusaf 《Renewable & Sustainable Energy Reviews》2009,13(6-7):1418-1427
The production of bioethanol from agricultural residues such as wheat, barley, sugar cane, corn and rice in Iran is investigated in this paper. In Iran, agricultural residues are not commonly used for energy application. This paper aims to cover several perspectives on the size of the bioethanol feedstock resource in Iran. Crop residues and sugar cane bagasse are included in feedstock for production of bioethanol. There are approximately 17.86 MT of wasted crops in Iran that can potentially produce 4.91 GL of bioethanol per year. Wheat, sugar cane bagasse, rice, barely and corn are the most favourable bioethanol production source in Iran. Agricultural waste materials can be used for production of bioethanol fuel. Bioethanol can be considered as the optimum alternative fuel for gasoline. Bioethanol is an environmentally friendly fuel and has the potential to provide comparable engine performance results. 相似文献
11.
The distribution of energy use in the transport sector in the United States of America is presented and analysed in terms of the efficient use of energy in various applications. Comparisons are drawn with other modelling efforts. 相似文献
12.
The aim of this paper is to review the factors already discussed in the literature and identify gaps or issues which seem to require further debate in relation of the introduction of hydrogen in the transport sector. Studies in the academic and grey literature have analysed transport systems with a rather wide range of hydrogen penetration rates, utilisation of the infrastructure, hypotheses on the dynamics of the systems, capital costs of the infrastructure and hydrogen price. Most of the issues which could widen the debate in the literature are related to policy instruments. In particular, more attention should be paid to the policy instruments needed to foster co-ordination among stakeholders, persuade drivers to buy hydrogen vehicles despite the existence of a sparse infrastructure; guarantee investment in the early, possibly loss-making, retail stations and to foster financially sustainable government commitments. The effect of limited availability of hydrogen vehicle models on the penetration rates in the literature and the sensitivity of the hydrogen price to taxation from the government are other two issues deserving a more in-depth discussion. 相似文献
13.
Transport constitutes a crucial factor to the quality of life, since many people depend greatly on access to a reliable transport system. However, there are concerns about the impacts of the transport system on the quality of life, since it constitutes one of the main sources of greenhouse gases and also gives rise to significant air pollution stemming from acidifying pollutants, ozone precursors and particulate matter. During the last decade, the demand for transport services in Greece has rapidly grown following the European trend. Transport policies have recognised the need to restrain transport growth and to improve the various transport modes. Technology and fuel improvements have resulted in decreases of emissions of certain pollutants. Taking into account the major role of road transport in Greece for both passenger and goods transport, this work is focused on the assessment of the Greek transport sector. The changes made in the Greek transport sector during the past decade as well as the adverse environmental impacts of the Greek transport sector are presented and analysed. This work aims to present, assess and investigate the progress of the Greek transport sector—over the past decade—in relation to its sustainability. The scope is to examine the effectiveness of various emission reduction measures, in terms of their effectiveness in reducing emissions from transport. 相似文献
14.
The core objective of this work is to analyse the possible future relevance of hydrogen from renewable energy sources in the transport sector from an economic point-of-view with special focus on Austria. The analysis is conducted in a dynamic framework until 2050. 相似文献
15.
This paper provides an industry leader's perspectives on the potential for transportation fuel cells, reviewing their development progress, describing their advantages and barriers, and identifying paths to successful commercial deployment. UTC Power has developed proton exchange membrane (PEM) fuel cell technology for transportation since 1998, building upon applicable innovations from the company's space fuel cell and stationary fuel cell programs. PEM fuel cell durability improvements are discussed, highlighting achievements in the understanding of decay mechanisms and the design of effective mitigations. The potential for high-volume production to make automotive fuel cells cost competitive with internal combustion engines is explained. The paper underscores the important role that initial deployment of PEM technology for transit buses can play, although development of automotive fuel cells must continue in parallel as the hydrogen infrastructure develops. Suggestions are offered on how policies and regulations, communication and education, and improved codes and standards can all help to promote the widespread use of fuel cells in transportation. 相似文献
16.
《International Journal of Hydrogen Energy》2023,48(73):28247-28261
This study provides an in-depth analysis of the potential role of hydrogen (H2) in the Belgian transport sector in the context of sustainable and environmentally friendly growth. This paper starts by examining the energy-climate roadmap and the emission mitigation programme defined by the Belgian federal government in the context of environmental sustainability. Then, the Belgian situation is critically evaluated in light of the needs for H2 fuel in the transport sector, as well as issues about a roadmap on environmental considerations for a sustainable future, while preserving the country's economic stakes. There are several key advances in this direction, especially as H2 is seen as one of the best viable options for sustained development, unlike other possibilities. This paper also highlights some limitations that make it difficult to accelerate the transition to a sustainable H2 energy future. Although there are many interests in favour of an advanced and non-polluting transport system, there are differing views on the approach to be taken in political decision-making at national level. Therefore, this study will help public authorities to better integrate environmental and sustainability issues in the context of a transition to a comprehensive hydrogen economy in the current transport sector. 相似文献
17.
《Energy Policy》2013
We examine energy efficiency in the Japanese transportation sector since the 1970s. Comparisons with the United States and other developed economies illustrate that Japan primarily stands out due to low activity levels and modal structure rather than modal energy intensity. On-road automobile energy intensity has shown little improvement, albeit from a low base, over the past four decades. We also consider policy measures undertaken by the Japanese government. Political arrangements in Japan after World War II made it attractive for politicians to pursue energy conservation by making transportation, particularly by automobile, expensive for the average Japanese citizen. The revenues raised from various fees and taxes on automobile transportation were redistributed to core supporters of the ruling Liberal Democratic Party. These political arrangements have come under fire in recent years, calling into question Japan's traditional approach towards transportation sector energy efficiency. 相似文献
18.
W. Jamsak S. Assabumrungrat P.L. Douglas E. Croiset N. Laosiripojana R. Suwanwarangkul S. Charojrochkul 《Journal of power sources》2007
A solid oxide fuel cell system integrated with a distillation column (SOFC–DIS) has been proposed in this article. The integrated SOFC system consists of a distillation column, an EtOH/H2O heater, an air heater, an anode preheater, a reformer, an SOFC stack and an afterburner. Bioethanol with 5 mol% ethanol was purified in a distillation column to obtain a desired concentration necessary for SOFC operation. The SOFC stack was operated under isothermal conditions. The heat generated from the stack and the afterburner was supplied to the reformer and three heaters. The net remaining heat from the SOFC system (QSOFC,Net) was then provided to the reboiler of the distillation column. The effects of fuel utilization and operating voltage on the net energy (QNet), which equals QSOFC,Net minus the distillation energy (QD), were examined. It was found that the system could become more energy sufficient when operating at lower fuel utilization or lower voltage but at the expense of less electricity produced. Moreover, it was found that there were some operating conditions, which yielded QNet of zero. At this point, the integrated system provides the maximum electrical power without requiring an additional heat source. The effects of ethanol concentration and ethanol recovery on the electrical performance at zero QNet for different fuel utilizations were investigated. With the appropriate operating conditions (e.g. CEtOH = 41%, Uf = 80% and EtOH recovery = 80%), the overall electrical efficiency and power density are 33.3% (LHV) and 0.32 W cm−2, respectively. 相似文献
19.
Transport systems perform vital societal functions, but in their present state cannot be considered “sustainable”. One of the most controversially discussed long-term solutions to climate change and air emission externalities is the introduction of hydrogen as an energy fuel and fuel cell vehicles. In this paper, we integrate the two debates on the sustainability of today's transport systems and on the opportunities, threats and possible transition paths towards a “hydrogen economy” in road transport. We focus our analysis on developed countries as well as the specific needs of the fast growing markets for car travel in the emerging economies. We conclude that the use of hydrogen can significantly reduce CO2 emissions of the transport sector, even if taking into account tailpipe and upstream emissions as well as alternative technology developments. Moreover, local air pollutants can be reduced up to 80%. Possible negative impacts, including accident risks, nuclear waste or increased biomass demand, need to be benchmarked against these benefits. Thus, we highlight the need for integrated energy and transport policies and argue for more reflexive and inclusive societal debate about the impacts and beneficiaries of hydrogen transport technologies. 相似文献
20.
This paper aims at analyzing particularities of the Brazilian electric system and at evaluating the potential contribution of thermal power plants targeting at its higher reliability. In special, the aim is at analyzing the insertion of thermal power production in the present context in which hydroplants start to be built in the Amazon area with small reservoir capacity. An assessment of the behavior of the energy inflows and of the regularization capacity of the Brazilian hydro power system emphazises the need for having a good quality thermal power expansion. The power production from sugarcane residues is specially considered due to the existing untapped potential (about 4 times higher than the installed capacity, considering the current availability of biomass) and the existing window opportunity due to the expansion of sugarcane industry in Brazil (mostly for ethanol production). 相似文献