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1.
《International Journal of Hydrogen Energy》2023,48(13):5186-5196
When blending hydrogen into existing natural gas pipelines, the non-uniform concentration distribution caused by the density difference between hydrogen and natural gas will result in the fluctuations of local hydrogen partial pressure, which may exceed the set one, leading to pipeline failure, leakage, measurement error, and terminal appliance. To solve the problem, the H2–CH4 stratification in the horizontal and undulated pipe was investigated experimentally and with numerical simulations. The results show that in the gas stagnant situation, hydrogen-methane blending process will cause an obvious stratification phenomenon. The relations between the elevation, pressure, hydrogen fraction, etc., and the gas stratification are figured out. Moreover, even when the blended gas flows at a low rate, the hydrogen-caused stratification should also be considered. Thereafter, the blended gas should be controlled into a situation with low pressure and high speed, which could help to set the pressure, speed, the fraction of H2. 相似文献
2.
《Energy Policy》2013
The non-Gazprom gas producers (NGPs) doubled their share of the Russian domestic gas market between 2000 and 2010 and have continued growing since then. For several years especially Novatek expanded. More recently, Rosneft has emerged as a key player, not least through its purchase of TNK-BP. This article begins with an overview of the companies in the Russian gas sector, their resource bases and capacities, and subsequently examines whether differences in field development costs and export market access may make it rational for Gazprom to continue ceding market share to the NGPs. With rising costs of Gazprom's queue of greenfield developments, any delays in Gazprom's investment program may be compensated through increased NGP production. The article argues that the NGPs are ready to fill the gap, may be allowed to do so and are already increasing their market share in an increasingly competitive market. The stage may now be set for a continued gradual transformation of the Russian gas market, in which the interests of Gazprom and the NGPs may be complementary or may be pitted against each other, but those of the Russian Federation are in any case likely to be better fulfilled than in the past. 相似文献
3.
Although Russia is the world's biggest producer of natural gas, its ability to maintain timely and reliable supply to meet the growing global demand has come under question in recent months. The gas war with Ukraine notwithstanding, concern has been raised by a number of observers that underinvestment in the gas sector will lead to a systemic failure of the state monopolist OAO Gazprom to increase or even maintain current levels of production. Yet with a quarter of European gas coming from Russia, and with increasing presence of Gazprom in European downstream operations (such as Germany, Hungary, and other CIS states) as well as seemingly closer ties with Algeria, another major supplier of gas to Europe, there has been a strong reaction from Europe's policy-makers to decrease dependence on Russian gas. 相似文献
4.
Ben-chieh Liu 《Energy Economics》1983,5(3):195-201
This article's primary objective is to estimate the own-price and cross-price elasticities of demand for natural gas in the residential, commercial and industrial sectors by DOE region in the USA. A simultaneous-equations model was developed and its reduced form was employed for natural gas consumption demand elasticity estimation in conjuction with the instrumental price variables. Data from 1967 to 1978 were used in the estimation, but the 1973 oil embargo effect was separated with the use of a dummy variable. The demand for natural gas was much more price elastic in the long run than in the short run, and the industrial sector was more less price sensitive than others. However, there were significant interregional and intersectoral variations among the elasticities estimated. 相似文献
5.
Previous analyses of Russia's dual pricing system and hidden subsidies for natural gas, have neglected to assess the dual pricing system as a domestic environmental policy. If dual pricing is considered as a policy to reduce conventional air pollutants, it is more than economically justified in Russia on the basis of avoided health risks. In the short term, the substitution of coal for natural gas may result in significant additional human health risk, which translates into economic damage. An alternative abatement possibility is expensive and unlikely enforceable, due to weak environmental regulation. The authors conclude that while the price differential can be expected to diminish over time, as Russia increasingly moves to a market economy, in the near-term, dual pricing of natural gas remains the most efficient environmental policy for Russia. 相似文献
6.
《International Journal of Hydrogen Energy》2022,47(24):12074-12095
Carbon neutral solutions are demanded to reduce the greenhouse gas (GHG) emissions from the mobility sector. In Brazil, alongside bioethanol, natural gas and biogas are potential solutions towards a low carbon future. While Brazilian natural gas market growth has increased due to recent offshore discoveries, its biogas potential is one of the largest in the world. Nevertheless, Brazil has currently no production of stock automobile by either gaseous fuel, despite of having the largest world flex fuel fleet (gasoline-ethanol). Therefore, the present research aims at evaluating critical points linked to the natural gas and biomethane businesses expansion in Brazil. The current scenario and outlook for energy usage is presented. RenovaBio, the recent governmental program to promote biofuels, is evaluated from the gas business point of view. And finally, the main incentive policies and regulations, price formation and limitations for the grid expansion are discussed. It is shown that biogas competitiveness as a vehicular fuel is limited mainly for the additional costs of its upgrading process to biomethane. Regarding the natural gas usage, the main limiting factor is the monopoly of production and transport in Brazil as it does not allow free competition and increases the end consumer price. Moreover, the current pipeline grid extension prioritizes the most industrialized regions and does not reach all potential natural gas users. New governmental policies and incentives were proven necessary to improve the economic viability and hence to fully benefit from the potential of both energy sources to reduce carbon footprint. 相似文献
7.
A supply model for crude oil and natural gas in the Middle East 总被引:2,自引:0,他引:2
Crude oil (CO) and natural gas (NG) play an important role in the world economy. The Arab countries (ACs) share 64% of the total oil reserves and 40% of the NG reserves [OPEC, 2003. The Annual Statistical Bulletin]. On the production side, ACs contribute to 30% and 9% of the world production of CO and NG, respectively. Accurate forecast models are needed to do better planning and create less risky business environment. In this paper, an econometric model is built to capture the behavior of CO and NG production in the ESCWA1 countries. The model is used to forecast future production trends of CO and NG, and thus provide a powerful tool for researchers, planners and investors working in the energy field. 相似文献
8.
The design and development of natural gas transmission pipeline networks are multidisciplinary problems that require various engineering knowledge. In this problem, the type, location, and installation schedule of major physical components of a network including pipelines and compressor stations are decided upon over a planning horizon with least cost goal and subject to network constraints. Practically, this problem has been viewed as a conceptual design case and not as an optimization problem that tries to select the best design option among a set of possible solutions. Consequently, conceptual design approaches are usually suboptimal and work only for short-run development planning. We propose an integrated nonlinear optimization model for this problem. This model provides the best development plans for an existing network over a long-run planning horizon with least discounted operating and capital costs. A heuristic random search optimization method is also developed to solve the model. We show the application of the model through a simple case study and discuss how non-economic objectives may also be incorporated into model. 相似文献
9.
Noel D. Uri 《Energy Conversion and Management》1981,21(3):205-211
This paper is directed at examining the impact of changing prices on the level of production of crude oil and natural gas in the United States. By using a cross-correlation test for unidirectional causality it is clearly demonstrated that, for both crude oil and natural gas, domestic production is affected by changing prices. The implications are clear. The decontrol of the price of crude oil and the deregulation of natural gas prices will lead to additional production in the near term. 相似文献
10.
The natural gas industry in Western Europe went through drastic changes induced by the unbundling of the national companies, followed by the liberalization of gas trade and the regulation of gas transmission. Natural gas transmission is operated through a network of interconnected grids, and is capacity constrained. Each of the grids is locally regulated in terms of price limits on transportation services. Local tariff differences may induce unnatural gas routing within a network, creating congestion in some part of it. This phenomena is referred to as the Jepma effect. Following Jepma [2001. Gaslevering onder druk. Stichting JIN. Available at: www.jiqweb.org (52pp) (in Dutch)] this may lead to misguided investment decisions. 相似文献
11.
A system dynamic model is presented, which considers the feedback between supply and demand and oil revenue of the existing system in Iran considering different sectors of the economy. Also the export of the oil surplus and the injection of the gas surplus into the oil reservoirs are seen in the model by establishing a balance between supply and demand. In this model the counter-effects and existing system feedbacks between supply and demand and oil revenue can be seen considering different sectors of the economy. As a result, the effects of oil and gas policies in different scenarios for different sectors of Iran’s economy together with the counter-effects of energy consumption and oil revenue are examined. Three scenarios, which show the worst, base and ideal cases, are considered to find future trends of major variables such as seasonal gas consumption in power plants, seasonal injected gas in oil reservoirs, economic growth in the industrial sector, oil consumption in the transportation sector, industrial gas consumption and exported gas. For example, it is shown that the exported gas will reach between 500 and 620 million cubic-meter per day in different scenarios and export revenues can reach up to $500 billion by 2025. 相似文献
12.
《International Journal of Hydrogen Energy》2022,47(79):33813-33826
Natural gas pipeline cost data collected by the Oil and Gas Journal (O&GJ) [1] for interstate pipelines constructed from 1980 through 2017 were used to develop capital cost estimating equations that are a function of pipeline diameter, length, and U.S. region. Equations were developed for material, labor, miscellaneous, and right-of-way costs, the four cost components in the O&GJ data, for six different regions of the United States (U.S.). Each equation is a function of pipeline diameter and length.Adjustment mechanisms were then developed for converting the natural gas pipeline equations into equations for estimating the costs of hydrogen pipelines. These adjustments were based in part on an analysis completed by the National Institute for Standards and Technology (NIST) [2,3]. The results of this work were used to update cost models in the Hydrogen Delivery Scenario Analysis Model (HDSAM) [4], developed by Argonne National Laboratory for the U.S. Department of Energy's Hydrogen Program. Our analysis shows a wide range of pipeline cost across different U.S. regions, especially with respect to labor and right-of-way costs. The developed cost formulas for hydrogen pipelines are both important and timely as hydrogen is being considered as a zero-carbon energy carrier with the potential to decarbonize all energy sectors, and the cost of hydrogen transportation is essential for techno-economic analysis of its potential use in these sectors. 相似文献
13.
Since the passage of the Natural Gas Policy Act (NGPA) of 1978, the US Federal Energy Regulatory Commission (FERC) has taken a number of important steps aimed at fostering competition at all levels of the gas industry. With the issuance of Order 451, FERC took the next logical step, eliminating separate price categories for old interstate supplies and establishing a single, higher, and generally above-market price ceiling for this gas. Using a simple model of a gas market with price controls, this paper investigates the general conditions under which the average price of gas may be expected to either rise or fall as a consequence of Order 451. The general conclusion of the paper is that, at least for the US market, the old gas stage of this multi-staged price deregulation should be expected to result in lower average gas prices and greater production. 相似文献
14.
Kazakhstan is endowed with significant oil and gas resources and is expected to become one of the world's top 10 oil producers within the next decade. The high cost of doing business in the country, however, means that Kazakhstan will need to improve its institutional framework to successfully compete for Western investment. A large degree of risk and uncertainty continues to plague the oil and gas sector as the government makes significant changes to the petroleum tax legislation and takes an aggressive approach in “rebalancing” contractual arrangements with industry. High levels of bureaucracy, regulatory burden, and corruption persist, and economic factors appear to be subordinated increasingly to geopolitical objectives aimed to strengthen relationships with China and Russia. The rapid pace of change and the high degree of uncertainty present significant challenges and risk to foreign investment. The purpose of this paper is to review the oil and gas sector in Kazakhstan and highlight recent developments in the petroleum legislation, business climate and government policy. 相似文献
15.
The introduction of natural-gas-powered thermoelectricity into the Brazilian generation sector can be considered as a very complex energy, economic, regulatory and institutional revision. Brazil is a country with very specific characteristics in electricity generation, as approximately 80% of the generating capacity is based on hydroelectricity, showing strong dependency on rain and management of water reservoirs. A low rate of investment in the Brazilian Electricity Industry in the period of 1995–2000, associated with periods of low rainfall, led to a dramatic lowering of the water stocks in the reservoirs. With this scenario and the growing supply of natural gas, both from within Brazil and imported, natural gas thermal electric plants became a good option to diversify the electrical supply system. In spite of the Brazilian Government's efforts to install such plants, the country was faced with severe electricity rationing in 2001. The objective of this work is to show the need to continue with the implementation of natural gas thermal electricity projects, in a manner that allows flexibility and guarantees greater working reliability for the entire Brazilian electricity sector. Taking into account the world trend towards renewable energy, the perspectives of usage of biofuels in the Brazilian Energy Matrix and in electrical energy generation are also analyzed. The very issue of electrical power efficiency in Brazil and its challenges and strategic proposals from the standpoint of Government Programs and results provided so far are presented. The technological constraints in order to put on stream the thermal electric plants are also analyzed. The article concludes with a positive perspective of the usage of natural gas as to be the third pillar in the Brazilian Energy Matrix for the years to come. 相似文献
16.
《Energy Policy》2015
Replacing conventional gasoline or diesel vehicles with natural gas vehicles (NGVs) is necessary if China hopes to significantly reduce its greenhouse gas emissions in the short term. Based on city-level data, this paper analyzes the enabling factors and barriers to China's NGV development. We find that a shortage in natural gas supply and a relatively high price ratio of natural gas compared to gasoline are the main factors impeding China's NGV development. Imbalanced development between natural gas refueling stations and NGVs also hinder the popularity of these lower-carbon vehicles. While various policies have been implemented in recent years to promote NGVs in China, only those encouraging adoption of NGVs by the private sector appear effective. To promote further NGV development in China, the following strategies are proposed: (1) improve natural gas delivery infrastructure across the country; (2) reasonably reduce the relative price of natural gas compared to gasoline; (3) give priority to middle-income and medium-sized cities and towns, since siting natural gas refueling stations is easier in these areas; and (4) promote the use of NGVs in the private sector. 相似文献
17.
Noel D. Uri 《国际能源研究杂志》1989,13(4):431-442
This study sets out to determine whether agricultural consumers of natural gas are responsive to changes in the relative prices of different types of energy. A demand model is specified and estimated. The conclusions strongly suggest that not only is the price of natural gas a factor having an impact on the quantity of natural gas demanded by agriculture, but that other types of energy are substitutes for natural gas and that income and weather (measured by heating degree days) likewise affect natural gas demand. 相似文献
18.
Natural gas is an important energy source for power generation, a chemical feedstock and residential usage. It is important to analyse the future production of conventional and unconventional natural gas. Analysis of the literature determined conventional URR estimates of 10,700–18,300 EJ, and the unconventional gas URR estimates were determined to be 4250–11,000 EJ. Six scenarios were assumed, with three static where demand and supply do not interact and three dynamic where it does. The projections indicate that world natural gas production will peak between 2025 and 2066 at 140–217 EJ/y (133–206 tcf/y). Natural gas resources are more abundant than some of the literature indicates. 相似文献
19.
D. Yap S.M. PeucheretA. Megaritis M.L. WyszynskiH. Xu 《International Journal of Hydrogen Energy》2006
Natural gas has a high auto-ignition temperature, requiring high compression ratios and/or intake charge heating to achieve homogenous charge compression ignition (HCCI) engine operation. It is shown here that hydrogen in the form of reformed gas helps in lowering the intake temperature required for stable HCCI operation. It has been shown that the addition of hydrogen advances the start of combustion in the cylinder. This is a result of the lowering of the minimum intake temperature required for auto-ignition to occur during the compression stroke, resulting in advanced combustion for the same intake temperatures. This paper documents experimental results using closed loop exhaust gas fuel reforming for production of hydrogen. When this reformed gas is introduced into the engine, a decrease in intake air temperature requirement is observed for a range of engine loads. Thus for a given intake temperature, lower engine loads can be achieved. This would translate to an extension of the HCCI lower load boundary for a given intake temperature. 相似文献
20.
Quickly declining natural gas reserves in some parts of the world, increasing demand in today's major gas consuming regions, the emergence of new demand centres and the globalization of natural gas markets caused by the rising importance of liquefied natural gas (LNG) are changing global gas supply structures and will continue to do so over the next decades. Applying a global gas market model, we produce a forecast for global gas supply to 2030 and determine the supplier-specific long-run average costs of gas supplied to three major consuming regions. Results for the three regions are compared and analysed with a focus on costs, supply diversification and the different roles of LNG. We find that while European and Japanese external gas supply will be less diversified in international comparison, gas can be supplied at relatively low costs due to the regions’ favourable locations in geographic proximity to large gas producers. The US market's supply structure on the other hand will significantly change from its current situation. The growing dependency on LNG imports from around the world will lead to significantly higher supply costs but will also increase diversification as gas will originate from an increasing number of LNG exporting countries. 相似文献