WorldWideScience

Sample records for wind-induced gas transport

  1. Direct monitoring of wind-induced pressure-pumping on gas transport in soil

    Science.gov (United States)

    Laemmel, Thomas; Mohr, Manuel; Schindler, Dirk; Schack-Kirchner, Helmer; Maier, Martin

    2017-04-01

    Gas exchange between soil and atmosphere is important for the biogeochemistry of soils and is commonly assumed to be governed by molecular diffusion. Yet a few previous field studies identified other gas transport processes such as wind-induced pressure-pumping to enhance soil-atmosphere fluxes significantly. However, since these wind-induced non-diffusive gas transport processes in soil often occur intermittently, the quantification of their contribution to soil gas emissions is challenging. To quantify the effects of wind-induced pressure-pumping on soil gas transport, we developed a method for in situ monitoring of soil gas transport. The method includes the use of Helium (He) as a tracer gas which was continuously injected into the soil. The resulting He steady-state concentration profile was monitored. Gas transport parameters of the soil were inversely modelled. We used our method during a field campaign in a well-aerated forest soil over three months. During periods of low wind speed, soil gas transport was modelled assuming diffusion as transport process. During periods of high wind speed, the previously steady diffusive He concentration profile showed temporary concentration decreases in the topsoil, indicating an increase of the effective gas transport rate in the topsoil up to 30%. The enhancement of effective topsoil soil gas diffusivity resulted from wind-induced air pressure fluctuations which are referred to as pressure-pumping. These air pressure fluctuations had frequencies between 0.1 and 0.01 Hz and amplitudes up to 10 Pa and occurred at above-canopy wind speeds greater than 5 m s-1. We could show the importance of the enhancement of the gas transport rate in relation with the wind intensity and corresponding air pressure fluctuations characteristics. We directly detected and quantified the pressure-pumping effect on gas transport in soil in a field study for the first time, and could thus validate and underpin the importance of this non

  2. Persistent wind-induced enhancement of diffusive CO2 transport in a mountain forest snowpack

    Science.gov (United States)

    D. R. Bowling; W. J. Massman

    2011-01-01

    Diffusion dominates the transport of trace gases between soil and the atmosphere. Pressure gradients induced by atmospheric flow and wind interacting with topographical features cause a small but persistent bulk flow of air within soil or snow. This forcing, called pressure pumping or wind pumping, leads to a poorly quantified enhancement of gas transport beyond the...

  3. Simulation of wind-induced snow transport in alpine terrain using a fully coupled snowpack/atmosphere model

    Science.gov (United States)

    Vionnet, V.; Martin, E.; Masson, V.; Guyomarc'h, G.; Naaim-Bouvet, F.; Prokop, A.; Durand, Y.; Lac, C.

    2013-06-01

    In alpine regions, wind-induced snow transport strongly influences the spatio-temporal evolution of the snow cover throughout the winter season. To gain understanding on the complex processes that drive the redistribution of snow, a new numerical model is developed. It couples directly the detailed snowpack model Crocus with the atmospheric model Meso-NH. Meso-NH/Crocus simulates snow transport in saltation and in turbulent suspension and includes the sublimation of suspended snow particles. A detailed representation of the first meters of the atmosphere allows a fine reproduction of the erosion and deposition process. The coupled model is evaluated against data collected around the experimental site of Col du Lac Blanc (2720 m a.s.l., French Alps). For this purpose, a blowing snow event without concurrent snowfall has been selected and simulated. Results show that the model captures the main structures of atmospheric flow in alpine terrain, the vertical profile of wind speed and the snow particles fluxes near the surface. However, the horizontal resolution of 50 m is found to be insufficient to simulate the location of areas of snow erosion and deposition observed by terrestrial laser scanning. When activated, the sublimation of suspended snow particles causes a reduction in deposition of 5.3%. Total sublimation (surface + blowing snow) is three times higher than surface sublimation in a simulation neglecting blowing snow sublimation.

  4. Simulation of wind-induced snow transport and sublimation in alpine terrain using a fully coupled snowpack/atmosphere model

    Science.gov (United States)

    Vionnet, V.; Martin, E.; Masson, V.; Guyomarc'h, G.; Naaim-Bouvet, F.; Prokop, A.; Durand, Y.; Lac, C.

    2014-03-01

    In alpine regions, wind-induced snow transport strongly influences the spatio-temporal evolution of the snow cover throughout the winter season. To gain understanding on the complex processes that drive the redistribution of snow, a new numerical model is developed. It directly couples the detailed snowpack model Crocus with the atmospheric model Meso-NH. Meso-NH/Crocus simulates snow transport in saltation and in turbulent suspension and includes the sublimation of suspended snow particles. The coupled model is evaluated against data collected around the experimental site of Col du Lac Blanc (2720 m a.s.l., French Alps). First, 1-D simulations show that a detailed representation of the first metres of the atmosphere is required to reproduce strong gradients of blowing snow concentration and compute mass exchange between the snowpack and the atmosphere. Secondly, 3-D simulations of a blowing snow event without concurrent snowfall have been carried out. Results show that the model captures the main structures of atmospheric flow in alpine terrain. However, at 50 m grid spacing, the model reproduces only the patterns of snow erosion and deposition at the ridge scale and misses smaller scale patterns observed by terrestrial laser scanning. When activated, the sublimation of suspended snow particles causes a reduction of deposited snow mass of 5.3% over the calculation domain. Total sublimation (surface + blowing snow) is three times higher than surface sublimation in a simulation neglecting blowing snow sublimation.

  5. Wind-induced contaminant transport in near-surface soils with application to radon entry into buildings

    Energy Technology Data Exchange (ETDEWEB)

    Riley, William Jowett [Univ. of California, Berkeley, CA (United States)

    1996-05-01

    Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind`s interactions with a building`s superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport.

  6. Wind-induced contaminant transport in near-surface soils with application to radon entry into buildings

    International Nuclear Information System (INIS)

    Riley, W.J.

    1996-05-01

    Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind's interactions with a building's superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport

  7. Gas transportation and storage

    International Nuclear Information System (INIS)

    1993-02-01

    This document presents a number of important issues relating to the development of gas transportation and storage in Great Britain. Many of the issues are complex and there are no ideal solutions. British Gas and OFGAS both recognise the crucial value of proper consultation on these issues. The chapters on 'The Core/Non-Core Concept', 'Network Operations and Balancing' and 'The Network Code' have been drafted by British Gas and commented on by OFGAS, who wish to reserve their position on these proposals pending comments from interested parties. (Author)

  8. Natural gas marketing and transportation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This book covers: Overview of the natural gas industry; Federal regulation of marketing and transportation; State regulation of transportation; Fundamentals of gas marketing contracts; Gas marketing options and strategies; End user agreements; Transportation on interstate pipelines; Administration of natural gas contracts; Structuring transactions with the nonconventional source fuels credit; Take-or-pay wars- a cautionary analysis for the future; Antitrust pitfalls in the natural gas industry; Producer imbalances; Natural gas futures for the complete novice; State non-utility regulation of production, transportation and marketing; Natural gas processing agreements and Disproportionate sales, gas balancing, and accounting to royalty owners

  9. Wind-induced transport of plaice ( Pleuronectes platessa ) early life-history stages in the Skagerrak-Kattegat

    DEFF Research Database (Denmark)

    Nielsen, Else; Bagge, O.; MacKenzie, Brian

    1998-01-01

    Identifying mechanisms of exchange between adjacent fish populations is important to understanding causes of fluctuations in abundance. This study addresses the hypothesis that the abundance of settled O-group plaice along the Danish coast of the Kattegat depends on transport from the Skagerrak. ...

  10. Strategic regulation of gas transport

    International Nuclear Information System (INIS)

    Nese, Gjermund; Straume, Odd Rune

    2005-01-01

    The basis of the article has been the steadily increasing focus particularly from EU, on increased competition in the natural gas markets. This could influence the profit distribution between the gas producing and consuming counties which is an important problem situation for Norway as a gas producer. The gas market value chain consist of three parts (production, transport and distribution). How the countries may use strategic regulation of the transport tariff for the transport and distribution systems in order to move as much as possible of the total profit to the part of the value chain in control is studied. The focus has been on how increased competition influences the incentives of the authorities through low or high transport tariff and to what extent increased competition influences the welfare level in the producer and consumer counties when strategic regulations of the transport occur. The analysis is based on a theoretical model developed in 2005. Some central mechanisms related to the natural gas market are mapped and Norway may counteract some negative effects of liberalisation of the European gas market through strategic adaptation of the transport tariff to the Norwegian gas transport systems

  11. Gas transport in porous media

    CERN Document Server

    Ho, Clifford K

    2006-01-01

    This book presents a compilation of state-of-the art studies on gas and vapor transport processes in porous and fractured media. A broad set of models and processes are presented, including advection/diffusion, the Dusty Gas Model, enhanced vapor diffusion, phase change, coupled processes, solid/vapor sorption, and vapor-pressure lowering. Numerous applications are also presented that illustrate these processes and models in current problems facing the scientific community. This book fills a gap in the general area of transport in porous and fractured media; an area that has historically been dominated by studies of liquid-phase flow and transport. This book identifies gas and vapor transport processes that may be important or dominant in various applications, and it exploits recent advances in computational modeling and experimental methods to present studies that distinguish the relative importance of various mechanisms of transport in complex media.

  12. Gas Transport in Bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Gutierre-Rodrigo, V.; Martin, P. I.; Romero, F. J.; Barcala, J. M.

    2013-07-01

    The gas permeability of the Spanish FEBEX bentonite compacted at dry densities of between 1.4 and 1.8 g/cm{sup 3} with high water contents was measured for different confining, injection and back pressures. The results were compared with results obtained in previous investigations for lower degrees of saturation. It was checked that gas permeability was greatly affected by dry density, decreasing about three orders of magnitude when it increased from 1.5 to 1.8 g/cm{sup 3} for similar water content. The increase of water content caused also a decrease in gas permeability. It was found that both gas permeability and the relative gas permeability were mainly related to the accessible porosity. These relationships could be fitted to potential expressions with exponents between 3 and 4, as well as the relationship between intrinsic permeability and void ratio. For gas pressures below 1.2 MPa no effect of the injection or confining pressures on the value of permeability was detected. For a given confining pressure the permeability value decreased as the effective pressure increased, especially if the increase in effective pressure was due to a decrease in gas back pressure. It was checked that the Klinkenberg effect was not significant for this material in the range of pressures applied in the tests. The gas breakthrough pressure values in FEBEX saturated bentonite were determined for different dry densities. They increased clearly with dry density and were always higher than the swelling pressure of the bentonite. In high density samples gas flow tended to stop abruptly after breakthrough, whereas in lower density samples gas flow decreased gradually until a given pressure gradient was reached. The permeabilities computed after breakthrough (which usually did not stabilise) were inversely related to dry density. This would indicate that, even if the flow took place predominantly through preferential pathways that sometimes closed quickly after breakthrough and others

  13. Gas transport in graphitic materials

    International Nuclear Information System (INIS)

    Hoinkis, E.

    1995-02-01

    The characterization of the gas transport properties of porous solids is of interest in several fields of science and technology. Many catalysts, adsorbents, soils, graphites and carbons are porous. The gas transport through most porous solids can be well described by the dusty gas model invented by Evans, Watson and Mason. This model includes all modes of gas tranport under steady-state conditions, which are Knudsen diffusion, combined Knudsen/continuum diffusion and continuum diffusion, both for gas pairs with equal and different molecular weights. In the absence of a pressure difference gas transport in a pore system can be described by the combined Knudsen/continuum diffusion coefficient D 1 for component 1 in the pores, the Knudsen diffusion coefficient D 1K in the pores, and the continuum diffusion coefficient D 12 for a binary mixture in the pores. The resistance to stationary continuum diffusion of the pores is characterized by a geometrical factor (ε/τ) 12 = (ε/τ)D 12 , were D 12 is the continuum diffusion coefficient for a binary mixture in free space. The Wicke-Kallenbach method was often used to measure D 1 as function of pressure. D 12 and D 1K can be derived from a plot 1/D 1 νs P, and ε/τcan be calculated since D 12 is known. D 1K and the volume of dead end pores can be derived from transient measurements of the diffusional flux at low pressures. From D 1K the expression (ε/τ c ) anti l por may be calculated, which characterizes the pore system for molecular diffusion, where collisions with the pore walls are predominant. (orig.)

  14. Strategic regulation of gas transport

    International Nuclear Information System (INIS)

    Nese, Gjermund; Straume, Odd Rune

    2005-02-01

    The basis of the article has been the growing focus on competition within the natural gas markets particularly in the EU. Increased competition whether upstream or downstream may influence the distribution of profit between producing and consuming countries. For Norway as a large exporter of natural gas to the European market this would be an important problem. The chain of values in the gas market consists of three complementary parts (production, problem definition and distribution). With this in mind it is studied how the countries would use strategic availability pricing for transport and distribution systems for moving as large a part of the total profit as possible to the parts of the chain of value they control themselves. The focus has been on how increased competition in the market for natural gas influence the authority incentives for stipulating a high or low availability price and to what extent increased competition influence the welfare level in the producing and consuming countries when they use strategic availability pricing. The analysis builds on a theoretical model developed by the company Nese and Straume (2005). Finally some of the more interesting results as to the Norwegian position as a gas producer are presented. One of the more surprising results was that for an exporting country and an importing country increased competition upwards may be an advantage for the exporting country while negative for the importing country. The result was valid also when a competing export country was included when this country did not use strategic availability pricing. If the competing country also acted strategically the result inverted. However, if the gas exporting countries were capable of perfect coordination of their availability pricing the case would revert to the situation with only one exporting country and the result would be valid. If a future formation of a ''gas-OPEC'' is considered where for example Norway and Russia cooperate in a gas

  15. Effect of air turbulence on gas transport in soil; comparison of approaches

    Science.gov (United States)

    Pourbakhtiar, Alireza; Papadikis, Konstantinos; Poulsen, Tjalfe; Bridge, Jonathan; Wilkinson, Stephen

    2017-04-01

    Greenhouse gases are playing the key role in global warming. Soil is a source of greenhouse gases such as methane (CH4). Radon (Rn) which is a radioactive gas can emit form subsurface into the atmosphere and leads to health concerns in urban areas. Temperature, humidity, air pressure and vegetation of soil can affect gas emissions inside soil (Oertel et al., 2016). It's shown in many cases that wind induced fluctuations is an important factor in transport of gas through soil and other porous media. An example is: landfill gas emissions (Poulsen et al., 2001). We applied an experimental equipment for measuring controlled air turbulence on gas transport in soil in relation to the depth of sample. Two approaches for measurement of effect of wind turbulence on gas transport were applied and compared. Experiments were carried out with diffusion of CO2 and air as tracer gases with average vertical wind speeds of 0 to 0.83 m s-1. In approach A, Six different sample thicknesses from 5 to 30 cm were selected and total of 4 different wind conditions with different speed and fluctuations were applied. In approach B, a sample with constant depth was used. Five oxygen sensors were places inside sample at different depths. Total of 111 experiments were carried out. Gas transport is described by advection-dispersion equation. Gas transport is quantified as a dispersion coefficient. Oxygen breakthrough curves as a function of distance to the surface of the sample exposed to wind were derived numerically with an explicit forward time, central space finite-difference based model to evaluate gas transport. We showed that wind turbulence-induced fluctuations is an important factor in gas transport that can increase gas transport with average of 45 times more than molecular diffusion under zero wind condition. Comparison of two strategies for experiments, indicated that, constant deep samples (Approach B) are more reliable for measurement of gas transport under influence of wind

  16. Investigation of the spatial variability and possible origins of wind-induced air pressure fluctuations responsible for pressure pumping

    Science.gov (United States)

    Mohr, Manuel; Laemmel, Thomas; Maier, Martin; Zeeman, Matthias; Longdoz, Bernard; Schindler, Dirk

    2017-04-01

    The exchange of greenhouse gases between the soil and the atmosphere is highly relevant for the climate of the Earth. Recent research suggests that wind-induced air pressure fluctuations can alter the soil gas transport and therefore soil gas efflux significantly. Using a newly developed method, we measured soil gas transport in situ in a well aerated forest soil. Results from these measurements showed that the commonly used soil gas diffusion coefficient is enhanced up to 30% during periods of strong wind-induced air pressure fluctuations. The air pressure fluctuations above the forest floor are only induced at high above-canopy wind speeds (> 5 m s-1) and lie in the frequency range 0.01-0.1 Hz. Moreover, the amplitudes of air pressure fluctuations in this frequency range show a clear quadratic dependence on mean above-canopy wind speed. However, the origin of these wind-induced pressure fluctuations is still unclear. Airflow measurements and high-precision air pressure measurements were conducted at three different vegetation-covered sites (conifer forest, deciduous forest, grassland) to investigate the spatial variability of dominant air pressure fluctuations, their origin and vegetation-dependent characteristics. At the conifer forest site, a vertical profile of air pressure fluctuations was measured and an array consisting of five pressure sensors were installed at the forest floor. At the grassland site, the air pressure measurements were compared with wind observations made by ground-based LIDAR and spatial temperature observations from a fibre-optic sensing network (ScaleX Campaign 2016). Preliminary results show that at all sites the amplitudes of relevant air pressure fluctuations increase with increasing wind speed. Data from the array measurements reveal that there are no time lags between the air pressure signals of different heights, but a time lag existed between the air pressure signals of the sensors distributed laterally on the forest floor

  17. Gas transport in solid oxide fuel cells

    CERN Document Server

    He, Weidong; Dickerson, James

    2014-01-01

    This book provides a comprehensive overview of contemporary research and emerging measurement technologies associated with gas transport in solid oxide fuel cells. Within these pages, an introduction to the concept of gas diffusion in solid oxide fuel cells is presented. This book also discusses the history and underlying fundamental mechanisms of gas diffusion in solid oxide fuel cells, general theoretical mathematical models for gas diffusion, and traditional and advanced techniques for gas diffusivity measurement.

  18. Hydrate Technology For Transporting Natural Gas

    OpenAIRE

    Dawe, R. A.

    2003-01-01

    Natural gas hydrate (NGH) is a viable alternative to LNG (Liquefied Natural Gas) or pipelines for the transportation of natural gas from source to demand. It involves three stages: production, transportation and re-gasification. The production of the hydrate occurs at pressures >50 bar at temperatures ~10oC in the presence of water and natural gas (particularly methane, ethane, propane). Transportation is by insulated bulk carrier at around –5 oC and atmospheric pressure or 0 oC at 10 bar, an...

  19. Investment in transport infrastructure, regulation, and gas-gas competition

    International Nuclear Information System (INIS)

    Gasmi, Farid; Oviedo, Juan Daniel

    2010-01-01

    This paper develops a simple model in which a regulated (upstream) transporter provides capacity to a marketer competing in output with an incumbent in the (downstream) gas commodity market. The equilibrium outcome of the firms' interaction in the downstream market is explicitly taken into account by the regulator when setting the transport charge. We consider various forms of competition in this market and derive the corresponding optimal transport charge policies. We then run simulations that allow us to perform a comparative welfare analysis of these transport infrastructure investment policies based on different assumptions about the intensity of the competition that prevails in the gas commodity market. (author)

  20. Gas transport in tight porous media Gas kinetic approach

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Wesselingh, Johannes

    2008-01-01

    We describe the flow of gas in a porous medium in the kinetic regime, where the viscous flow structure is not formed in separate pores. Special attention is paid to the dense kinetic regime, where the interactions within the gas are as important as the interaction with the porous medium....... The transport law for this regime is derived by means of the gas kinetic theory, in the framework of the model of "heavy gas in light one". The computations of the gas kinetic theory are confirmed by the dimension analysis and a simplified derivation revealing the considerations behind the kinetic derivation...

  1. Diffusive gas transport through flooded rice systems

    Science.gov (United States)

    van Bodegom, P. M.; Groot, T.; van den Hout, B.; Leffelaar, P. A.; Goudriaan, J.

    2001-09-01

    A fully mechanistic model based on diffusion equations for gas transport in a flooded rice system is presented. The model has transport descriptions for various compartments in the water-saturated soil and within the plant. Plant parameters were estimated from published data and experiments independent of the validation experiment. An independent experiment is described in which the diffusion coefficient of sulfurhexafluoride (SF6) in water-saturated soil was determined. The model was validated by experiments in which transport of SF6 through soil and plant was monitored continuously by photoacoustics. The independent default settings could reasonably predict gas release dynamics in the soil-plant system. Calculated transmissivities and concentration gradients at the default settings show that transport within the soil was the most limiting step in this system, which explains why most gases are released via plant-mediated transport. The root-shoot interface represents the major resistance for gas transport within the plant. A sensitivity analysis of the model showed that gas transport in such a system is highly sensitive to the estimation of the diffusion coefficient of SF6, which helps to understand diel patterns found for greenhouse gas emissions, and to the root distribution with depth. This can be understood from the calculated transmissivities. The model is less sensitive to changes in the resistance at the root-shoot interface and in the root fraction active in gas exchange. The model thus provides an understanding of limiting steps in gas transport, but quantitative predictions of in situ gas transport rates will be difficult given the plasticity of root distribution.

  2. Oil and gas impacts on transportation.

    Science.gov (United States)

    2015-01-01

    Colorados oil and gas industry is continually evolving, and there have been considerable changes in drilling techniques and geographic focus since the 2010 CDOT research study on Energy Development and the Transportation System. This research stud...

  3. Diffusive gas transport through flooded rice systems

    NARCIS (Netherlands)

    Bodegom, van P.M.; Groot, T.; Hout, van de B.; Leffelaar, P.A.; Goudriaan, J.

    2001-01-01

    A fully mechanistic model based on diffusion equations for gas transport in a flooded rice system is presented. The model has transport descriptions for various compartments in the water-saturated soil and within the plant. Plant parameters were estimated from published data and experiments

  4. Natural gas in the transportation sector

    Energy Technology Data Exchange (ETDEWEB)

    Ask, T.Oe.; Einang, P.M.; Stenersen, D. [MARINTEK (Norway)

    1996-12-01

    The transportation sector is responsible for more than 50% of all oil products consumed, and it is the fastest growing oil demand sector and the fastest growing source of emissions. During the last 10 years there have been a considerable and growing effort in developing internal combustion gas engines. This effort has resulted in gas engines with efficiencies comparable to the diesel engines and with emissions considerably lower than engines burning conventional fuels. This development offers us opportunities to use natural gas very efficiently also in the transportation sector, resulting in reduced emissions. However, to utilize all the built in abilities natural gas has as engine fuel, the natural gas composition must be kept within relatively narrow limits. This is the case with both diesel and gasoline today. A further development require therefore specified natural gas compositions, and the direct use of pipeline natural gas as today would only in limited areas be acceptable. An interesting possibility for producing a specified natural gas composition is by LNG (Liquid Natural Gas) production. (EG)

  5. Spin Transport in a Unitary Fermi Gas

    Science.gov (United States)

    Thywissen, Joseph

    2015-03-01

    We study spin transport in a quantum degenerate Fermi gas of 40K near an s-wave interaction resonance. The starting point of our measurements is a transversely spin-polarized gas, where each atom is in a superposition of the lowest two Zeeman eigenstates. In the presence of an external gradient, a spin texture develops across the cloud, which drives diffusive spin currents. Spin transport is described with two coefficients: D0⊥, the transverse spin diffusivity, and γ, the Leggett-Rice parameter. Diffusion is a dissipative effect that increases the entropy of the gas, eventually creating a mixture of spin states. γ parameterizes the rate at which spin current precesses around the local magnetization. Using a spin-echo sequence, we measure these transport parameters for a range of interaction strengths and temperatures. At unitarity, for a normal-state gas initially at one fifth of the Fermi temperature, we find D0⊥ = 2 . 3 (4) ℏ / m and γ = 1 . 08 (9) , where m is the atomic mass. In the limit of zero temperature, γ and D0⊥ are scale-invariant universal parameters of the unitary Fermi gas. The value of D0⊥ reveals strong scattering and is near its proposed quantum limit, such that the inferred value of the transport lifetime τ⊥ is comparable to ℏ /ɛF . This raises the possibility that incoherent transport may play a role. The nonzero value of γ tells us that spin waves in unitary Fermi gas are dispersive, or in other words, that the gas has a spin stiffness in the long-wavelength limit. Time permitting, we will also discuss a time-resolved measurement of the contact, through which we observe the microscopic transformation of the gas from ideal to strongly correlated.

  6. Power stabilized CO2 gas transport laser

    International Nuclear Information System (INIS)

    Foster, J.D.; Kirk, R.F.; Moreno, F.E.; Ahmed, S.A.

    1975-01-01

    The output power of a high power (1 kW or more) CO 2 gas transport laser is stabilized by flowing the gas mixture over copper plated baffles in the gas channel during operation of the laser. Several other metals may be used instead of copper, for example, nickel, manganese, palladium, platinum, silver and gold. The presence of copper in the laser gas circuit stabilizes output power by what is believed to be a compensation of the chemical changes in the gas due to the cracking action of the electrical discharge which has the effect of diminishing the capactiy of the carbon dioxide gas mixture to maintain the rated power output of the laser. (U.S.)

  7. Physics of gas breakdown for ion beam transport in gas

    International Nuclear Information System (INIS)

    Olson, C.L.; Poukey, J.W.; Hinshelwood, D.D.; Rose, D.V.; Hubbard, R.F.; Lampe, M.; Neri, J.M.; Ottinger, P.F.; Slinker, S.P.; Stephanakis, S.J.; Young, F.C.; Welch, D.R.

    1993-01-01

    Detailed analysis, experiments, and computer simulations are producing a new understanding of gas breakdown during intense ion beam transport in neutral gas. Charge neutralization of beam micro clumps is shown to limit the net clump potentials to a non-zero value π min , which can lead to divergence growth and axial energy spreading. At pressures approx-gt 1 Torr, plasma shielding should substantially reduce this effect Current neutralization has been studied in experiments on the GAMBLE II accelerator. The importance of fast electrons (knockons and runaways) has been established in IPROP simulations, which are in agreement with the experiments. For light ion fusion parameters with pressures approx-gt 1 Torr, very small net current fractions (much-lt 1%) appear feasible, permitting ballistic transport in gas. Self-pinched requires higher net current fractions (≥ 2%) and preliminary IPROP code results indicate that this appears achievable for small-radius intense beams in lower pressure gases (approx-gt Torr). Several self-pinched transport concepts look promising. The importance of these results for both light ion fusion and heavy ion fusion is discussed

  8. Ben Macdhui High Altitude Trace Gas and Aerosol Transport Experiment

    CSIR Research Space (South Africa)

    Piketh, SJ

    1999-01-01

    Full Text Available The Ben Macdhui High Altitude Aerosol and Trace Gas Transport Experiment (BHATTEX) was started to characterize the nature and magnitude of atmospheric, aerosol and trace gas transport paths recirculation over and exiting from southern Africa...

  9. Gas fuels for the transport sector; Denmark; Gas til transportsektoren

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    Recent analyses suggest that especially biogas, but also natural gas in macroeconomic terms will be attractive propellants, including for heavy transport. To implement a Danish expansion of gas infrastructure for transportation, the report recommends the following essential elements: 1) A Danish rollout should be closely linked to contracts with fleet owners with heavy vehicles / taxis / vans and the like, thus ensuring high utilization of filling stations; 2) About 10 larger, flexible CNG filling stations set up at major fleet owners is estimated as sufficient for an initial deployment phase, strategically distributed in and around Copenhagen, the major cities and along the main road network from Sweden to Germany; 3) A certain time-limited funding for the construction of infrastructure is likely to cause a rapid spread, if desired, and if other business conditions are in place; 4) There is a need for adjustment of tax terms - the rules for green taxes should be adjusted, and it should be considered to lower the taxes on CNG and biogas; 5) Natural gas mixed with biogas should be an integral element of a comprehensive strategy to ensure maximum CO{sub 2} displacement. (LN)

  10. Alternative ways to transport natural gas; Transporte alternativo de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Moura, N.R.; Campos, F.B. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The Brazilian energy matrix has been showing a huge increase in the demand of natural gas due mainly to industries and power plants. Today the Brazilian gas market is supplied with gas produced by PETROBRAS and imported from Bolivia. To increase the Brazilian gas supply, on the short and middle term, PETROBRAS will import LNG (liquefied natural gas) and exploit the new offshore fields discovered on the pre-salt area. The only proven technology available today to bring this offshore gas to the market is the pipeline, but its costs for the pre-salt area are high enough to keep the solution economically attractive. So, PETROBRAS are evaluating and developing alternative ways to transport offshore gas, such as LNG, CNG (Compressed Natural Gas), GTS (Gas-to-Solids or Natural Gas Hydrates) and ANG (Adsorbed Natural Gas). Using information available in the literature, this paper analyses the main concepts of CNG and LNG floating unities. This paper also presents the PETROBRAS R and D results on ANG and GTS aiming at offshore application. (author)

  11. Stochastic algorithm for simulating gas transport coefficients

    Science.gov (United States)

    Rudyak, V. Ya.; Lezhnev, E. V.

    2018-02-01

    The aim of this paper is to create a molecular algorithm for modeling the transport processes in gases that will be more efficient than molecular dynamics method. To this end, the dynamics of molecules are modeled stochastically. In a rarefied gas, it is sufficient to consider the evolution of molecules only in the velocity space, whereas for a dense gas it is necessary to model the dynamics of molecules also in the physical space. Adequate integral characteristics of the studied system are obtained by averaging over a sufficiently large number of independent phase trajectories. The efficiency of the proposed algorithm was demonstrated by modeling the coefficients of self-diffusion and the viscosity of several gases. It was shown that the accuracy comparable to the experimental one can be obtained on a relatively small number of molecules. The modeling accuracy increases with the growth of used number of molecules and phase trajectories.

  12. Natural Gas Container Transportation: the Alternative Way to Solve the World’s Energy Transportation Problems

    Directory of Open Access Journals (Sweden)

    A.M. Shendrik

    2014-03-01

    Full Text Available The container gas transportation for low and medium level consumers as an alternative to pipelines is considered. The options for gas supply schemes, based on road and rail transport are given. The advantages and disadvantages of both types of gas transporting are described, the areas of their effective using are separated in the article. Promising implementations of technology in environment of economic crisis and also considering world trends of energy development are presented. The most advanced organization of compressed gas condensate transportation of unprepared gas fields in large diameter universal cylindrical balloons (up to 1000 mm are reasoned. The problem of compressed gas sea transportation are well disclosed, but the alternative ways of gas transportation by land are not investigated enough. Compressed Natural Gas (CNG Technology - is new promising technology for natural gas transportation by specially designed vessels – CNG-vessels. The feature of this technology is that natural gas can be downloaded directly near gas deposits and unloaded - directly into the customer's network. This eliminates significant capital investments in underwater pipelining or gas liquefaction plants. The main objects of investment are CNG-vessels themselves. The most attractive places for implementation of CNG-technology are sea (offshore natural gas deposits. Numerous international experts estimate the natural gas transportation by CNG-vessels in 1.5-2.0 times more cost-beneficial in comparison with offshore pipelines transportation, or in comparison with LNG (Liquefied Natural Gas shipping with natural gas transportation volume between 0.5 and 4.0 billion cubic meters per year on the route from 250 to 2,500 sea miles. This technology makes possible to provide gas supplement to the mountain and abounding in water areas, remote and weakly gasified regions. Described technology deserves special attention in the case of depleted and low-power oil and

  13. Alaskan North Slope Oil & Gas Transportation Support

    Energy Technology Data Exchange (ETDEWEB)

    Lilly, Michael Russell [Geo-Watersheds Scientific LLC, Fairbanks, AK (United States)

    2017-03-31

    early or risk being caught on ice roads with flooded stream crossings, or unusable sections of ice road due to local melt. These challenges result in higher oil and gas field exploration and operational costs. Much of the scientific understanding to address transportation issues for oil and gas development on the North Slope exists, but has not been placed into a set of tools and data sets useful for industry and management agencies. Optimizing North Slope transportation networks during winter operation seasons is critical in managing increasing resource development and will provide a framework for environmentally-responsive development. Understanding the physical environment (such as snow, water, ice, soils) is necessary to ensure protection of fisheries and other natural resources on the sensitive tundra landscape. Solutions also have to do more than just describe current conditions, they need the ability to forecast short-term conditions. This will allow management agencies to respond to future variability in snow cover, soil temperature, and water availability more effectively. In turn, industry will then have more time to plan the significant mobilization taking place every winter season.

  14. Development of natural gas ocean transportation chain by means of natural gas hydrate (NGH)

    International Nuclear Information System (INIS)

    Nogami, T.; Oya, N.; Ishida, H.; Matsumoto, H.

    2008-01-01

    Recent studies in Japan have suggested that natural gas hydrate (NGH) transportation of natural gas is more economical than liquefied natural gas (LNG) transportation systems for small, medium and remote gas fields. Researchers in Japan have built a 600 kg per day NGH production and pelletizing plant and regasification facility. This paper discussed feasibility studies conducted in southeast Asia to determine the unit's commercialization potential with large natural gas-related businesses including shipping companies and electric power utilities. The total supply chain was compared with the corresponding liquefied natural gas (LNG) and compressed natural gas (CNG) supply chains. The study also examined natural gas reserves, energy policies, the positioning of natural gas supplies, and future forecasts of natural gas demand. A conceptual design for an NGH supply chain in Indonesia was presented. Results of the study have demonstrated that the NGH chain is an appropriate and economically feasible transportation method for many areas in southeast Asia. 8 refs., 10 figs

  15. Gasoline and other transportation fuels from natural gas in Canada

    International Nuclear Information System (INIS)

    Symons, E.A.; Miller, A.I.

    1981-03-01

    Ways in which natural gas might displace cude oil as a source of fuels for the Canadian transportation market are reviewed. Three approaches are possible: (1) direct use as compressed natural gas; (2)conversion of natural gas to methanol; and (3) further conversion of methanol to synthetic gasoline. (author)

  16. Gas Transport and Exchange through Wetland Plant Aerenchyma

    DEFF Research Database (Denmark)

    Sorrell, Brian Keith; Brix, Hans

    2013-01-01

    Aerenchyma, the large airspaces in aquatic plants, is a rapid gas transport pathway between atmosphere and soil in wetlands. Oxygen transport aerates belowground tissue and oxidizes rhizosphere soil, an important process in wetland biogeochemistry. Most plant O2 transport occurs by diffusion...

  17. The Contribution of Natural Gas Vehicles to Sustainable Transport

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The transport sector is currently responsible for 23% of energy-related CO2 emissions, and transport associated CO2 emissions will more than double by 2050. This working paper evaluates the potential costs and benefits of using natural gas as a vehicle fuel for road transportation, as well as the policy related to its market development.

  18. Gas transport in tight porous media Gas kinetic approach

    NARCIS (Netherlands)

    Shapiro, A. A.; Wesselingh, Johannes

    2008-01-01

    We describe the flow of gas in a porous medium in the kinetic regime, where the viscous flow structure is not formed in separate pores. Special attention is paid to the dense kinetic regime, where the interactions within the gas are as important as the interaction with the porous medium. The

  19. Transport Properties of operational gas mixtures used at LHC

    CERN Document Server

    Assran, Yasser

    2011-01-01

    This report summarizes some useful data on the transport characteristics of gas mixtures which are required for detection of charged particles in gas detectors. We try to replace Freon used for RPC detector in the CMS experiment with another gas while maintaining the good properties of the Freon gas mixture unchanged. We try to switch to freonless gas mixture because Freon is not a green gas, it is very expensive and its availability is decreasing. Noble gases like Ar, He, Ne and Xe (with some quenchers like carbon dioxide, methane, ethane and isobutene) are investigated. Transport parameters like drift velocity, diffusion, Townsend coefficient, attachment coefficient and Lorentz angle are computed using Garfield software for different gas mixtures and compared with experimental data.

  20. Temperature-dependent gas transport and its correlation with kinetic ...

    Indian Academy of Sciences (India)

    dependent gas transport and its correlation with kinetic diameter in polymer nanocomposite membrane. N K ACHARYA ... For the first time, the permeability and selectivity for nanocomposite membrane are reported as a function of temperature.

  1. Incorporating greenhouse gas (GHG) emissions in long range transportation planning.

    Science.gov (United States)

    2014-05-01

    Greenhouse gas (GHG) emissions continue to be an important focus area for state, local, and federal : agencies. The transportation sector is the second biggest contributor to GHG emissions in the U.S., and : Texas contributes the highest emissions am...

  2. Underground Coal Gasification: Rates of Post Processing Gas Transport

    Czech Academy of Sciences Publication Activity Database

    Soukup, Karel; Hejtmánek, Vladimír; Stanczyk, K.; Šolcová, Olga

    2014-01-01

    Roč. 68, č. 12 (2014), s. 1707-1715 ISSN 0366-6352 R&D Projects: GA MŠk 7C12017 Grant - others:RFCS(XE) RFCR-CT-2011-00002 Institutional support: RVO:67985858 Keywords : underground coal gas ification * gas transport * textural properties Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.468, year: 2014

  3. Water vapor and Gas Transport through Polymeric Membranes

    NARCIS (Netherlands)

    Metz, S.J.

    2003-01-01

    Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air).

  4. On the mechanism of gas transport in rigid polymer membranes

    NARCIS (Netherlands)

    Hensema, E.R.; Hensema, E.R.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.

    1993-01-01

    Conventional polymers are compared as gas separation membrane materials with tailormade polymers. The increased permeability of the latter are due to their higher free volume available for gas transport. The increased free volume is associated with the rigidity polymer backbone. Free volume is

  5. Magnetoelectronic transport of the two-dimensional electron gas in ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 72; Issue 2 ... CdSe quantum wells; 2D electron gas; magneto-electronic transport. Abstract. Hall mobility and magnetoresistance coefficient for the two-dimensional (2D) electron transport parallel to the heterojunction interfaces in a single quantum well of CdSe are ...

  6. Separation of British Gas' transportation and storage business

    International Nuclear Information System (INIS)

    McGregor, G.

    1992-12-01

    In making his substantive reference of the transportation and storage business of British Gas to the Monopolies and Mergers Commission, the Director General of Gas Supply identified the following principal effects adverse to the public interest: ''The absence of provision for the establishment of an independent undertaking to operate the pipe-line system and other facilities used by British Gas for the conveyance and storage of gas which would not be subject to conflicting interests in securing (a) transparency of the prices charged, the costs incurred and the operating methods in respect of the conveyance and storage of gas; (b) proper allocation to various parts of the Gas Supply Business of costs incurred and returns by that business; and (c) protection of information relating to the conveyance and storage of gas from which British Gas might obtain unfair commercial advantage, and thereby avoid the restriction or distortion of competition between British Gas and other persons whose business consists of or includes the supply of gas''. This paper considers the structural issues associated with achieving effective competition and looks at how the relationship between the businesses of supply and transportation might be organised in the short and longer term. (Author)

  7. Transport of natural gas; criterions for the infrastructure planning

    International Nuclear Information System (INIS)

    Unidad de Planeacion Minero Energetica, UPME

    1999-01-01

    The planning of the expansion of transport of natural gas system; should keep in mind the changes that are happening in the structure of this industry in the country. In this respect, it is growing the number of actors private present in her, what determines a indicative type planning, whose main objective is to serve as information or guide in decisions of investment involved agents in the maintenance and the amplification of the net of transport for the national supply of natural gas. An indicative plan has objectives different to those of an operative plan of short term. While this last search to establish a program of adjustments to manage commitments of transport and to maintain, this way, the validity of the gas pipeline, The indicative plan of transport is guided to quantify the intensity of the financial effort that is required so that the capacity of the gas pipeline net, responds to the prospective growth of the gas industry. In other words, the indicative plan should contribute to identify the type of works and the one mounts of the investments that the transport of gas system needs in the long term. In this sense, it is important to specify the function objective that will optimize, this precision it should take into account, in our case, the foreseen expansion of the electric sector, because this it depends in good measure of the costs and of the geographical readiness of fuels as the natural gas and the coal. Said otherwise, the function objective that should be optimized involves the expansion of the net of transport of natural gas and the expansion of the generation capacity simultaneously and of the infrastructure of electricity transmission

  8. Natural gas in transport. An assessment of different routes

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, B.; Croezen, H.; Aarnink, S. [CE Delft, Delft (Netherlands); Verbeek, R.; Ligterink, N.; Meulenbrugge, J.; Koornneef, G. [TNO, Delft (Netherlands); Kroon, P.; De Wilde, H. [ECN Policy Studies, Petten (Netherlands)

    2013-05-15

    Compressed or liquid natural gas (CNG, LNG) along with energy carriers produced from natural gas like electricity, hydrogen and Gas to Liquid (GTL) can limit emissions of greenhouse gases and air pollutants in the transport sector. This is particularly the case if electricity, hydrogen or CNG are used to power cars and buses, with LNG being used for trucks and ships. To reduce the overall greenhouse gas emissions of shipping, however, methane emissions also need to be limited. To ensure the safety of LNG, effective control of the distribution infrastructure is also required, moreover. This study compares various types of natural gas with diesel and petrol as primary energy sources in the transport sector. The analysis covers the environment, costs and safety. Taking 2025 as a horizon, the entire fuel chain is considered, from production at source to combustion in the engine.

  9. Case Study: Natural Gas Regional Transport Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Laughlin, M.; Burnham, A.

    2016-08-01

    Learn about Ryder System, Inc.'s experience in deploying nearly 200 CNG and LNG heavy-duty trucks and construction and operation of L/CNG stations using ARRA funds. Using natural gas in its fleet, Ryder mitigated the effects of volatile fuel pricing and reduced lifecycle GHGs by 20% and petroleum by 99%.

  10. Network ownership and optimal tariffs for natural gas transport

    International Nuclear Information System (INIS)

    Hagen, Kaare P.; Kind, Hans Jarle; Sannarnes, Jan Gaute

    2004-11-01

    This paper addresses the issue of national optimal tariffs for transportation of natural gas in a setting where national gas production in its entirety is exported to end-user markets abroad. In a situation where the transportation network is owned altogether by a vertically integrated national gas producer, it is shown that the optimal tariff depends on the ownership structure in the integrated transportation company as well as in the non-facility based gas company. There are two reasons why it is possibly optimal with a mark-up on marginal transportation costs. First, there is a premium on public revenue if domestic taxation is distorting. Second, with incomplete national taxation of rents from the gas sector, the transportation tariffs can serve as a second best way of appropriating rents accruing to foreigners. In a situation where the network is run as a separate entity subject to a rate of return regulation, it will be optimal to discriminate the tariffs between shippers for the usual Ramseyean reasons. (Author)

  11. Panorama 2009 - greenhouse gas emissions and the transport sector

    International Nuclear Information System (INIS)

    2008-01-01

    The fact that the transport sector is growing quickly brings advantages, such as quick access to any geographical location on earth, but also disadvantages: noise, congestion and polluting emissions such as carbon dioxide (CO 2 ), the greenhouse gas (GHG) primarily responsible for global warming. In the effort to bring GHG emissions under control, improving results in the transport sector is a prime long-term objective. What proportion of CO 2 emissions generated at global and national level are due to the road, air, maritime and rail transport sectors, respectively? What mechanisms can be used to reduce GHG emissions in the transport sector at large?

  12. The modifications on natural gas industry legislation: focus on the transportation sector; As alteracoes na legislacao da industria de gas natural: enfoque no setor de transporte

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Hirdan Katarina de Medeiros; Morales Udaeta, Miguel Edgar [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Programa Interunidades de Pos-Graduacao em Energia]. E-mails: hirdanmedeiros@iee.usp.br; udaeta@pea.usp.br; Ferreira, Jurandir Goncalves [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Economia, Administracao e Contabilidade]. E-mail: jurasferreira@gmail.com

    2006-07-01

    The present paper aims to dissertation, specifically, concerning to legislative proposals deal with the transport natural gas. In methodological sense we show one brief historical exposition of the natural gas industry in Brazil, as well as the approach given for the Law of the Oil and the Resolutions of the National Agency of Oil, Gas Natural and Bio fuels (ANP) for the natural gas transport. Therefore relevant questions to the natural gas transport are detailed in the Legislative Bills proposals for the natural gas Brazilian industry. As conclusions, it is presented a parallel between legal security and the accomplishment of investments in the sector of natural gas transport. (author)

  13. Feed gas contaminant control in ion transport membrane systems

    Science.gov (United States)

    Carolan, Michael Francis [Allentown, PA; Minford, Eric [Laurys Station, PA; Waldron, William Emil [Whitehall, PA

    2009-07-07

    Ion transport membrane oxidation system comprising an enclosure having an interior and an interior surface, inlet piping having an internal surface and adapted to introduce a heated feed gas into the interior of the enclosure, and outlet piping adapted to withdraw a product gas from the interior of the enclosure; one or more planar ion transport membrane modules disposed in the interior of the enclosure, each membrane module comprising mixed metal oxide material; and a preheater adapted to heat a feed gas to provide the heated feed gas to the inlet piping, wherein the preheater comprises an interior surface. Any of the interior surfaces of the enclosure, the inlet piping, and the preheater may be lined with a copper-containing metal lining. Alternatively, any of the interior surfaces of the inlet piping and the preheater may be lined with a copper-containing metal lining and the enclosure may comprise copper.

  14. Gas transport during in vitro and in vivo preclinical testing of inert gas therapies

    Directory of Open Access Journals (Sweden)

    Ira Katz

    2016-01-01

    Full Text Available New gas therapies using inert gases such as xenon and argon are being studied, which require in vitro and in vivo preclinical experiments. Examples of the kinetics of gas transport during such experiments are analyzed in this paper. Using analytical and numerical models, we analyze an in vitro experiment for gas transport to a 96 cell well plate and an in vivo delivery to a small animal chamber, where the key processes considered are the wash-in of test gas into an apparatus dead volume, the diffusion of test gas through the liquid media in a well of a cell test plate, and the pharmacokinetics in a rat. In the case of small animals in a chamber, the key variable controlling the kinetics is the chamber wash-in time constant that is a function of the chamber volume and the gas flow rate. For cells covered by a liquid media the diffusion of gas through the liquid media is the dominant mechanism, such that liquid depth and the gas diffusion constant are the key parameters. The key message from these analyses is that the transport of gas during preclinical experiments can be important in determining the true dose as experienced at the site of action in an animal or to a cell.

  15. Measurement of gas transport properties for chemical vapor infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Starr, T.L.; Hablutzel, N. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering

    1996-12-01

    In the chemical vapor infiltration (CVI) process for fabricating ceramic matrix composites (CMCs), transport of gas phase reactant into the fiber preform is a critical step. The transport can be driven by pressure or by concentration. This report describes methods for measuring this for CVI preforms and partially infiltrated composites. Results are presented for Nicalon fiber cloth layup preforms and composites, Nextel fiber braid preforms and composites, and a Nicalon fiber 3-D weave composite. The results are consistent with a percolating network model for gas transport in CVI preforms and composites. This model predicts inherent variability in local pore characteristics and transport properties, and therefore, in local densification during processing; this may lead to production of gastight composites.

  16. Greenhouse Gas Emissions Trading for the Transport Sector

    International Nuclear Information System (INIS)

    Holmgren, Kristina; Belhaj, Mohammed; Gode, Jenny; Saernholm, Erik; Zetterberg, Lars; Aahman, Markus

    2006-12-01

    In this study we have analysed different options to apply emissions trading for greenhouse gas emissions to the transport sector. The main focus has been on the EU transport sector and the possibility to include it in the current EU ETS in the trading period beginning in 2013. The purpose was to study how different alternatives will affect different actors. Focus has been on three sub-sectors; road transport, aviation and shipping. The railway sector has only been treated on a general level. The study includes the following three parts: 1. An economic analysis of the consequences of greenhouse gas emissions trading for the transport sector including an analysis of how the total cost for reaching an emission target will be affected by an integrated emissions trading system for the transport sector and the industry (currently included sectors) compared to separate systems for the sectors, 2. An analysis of design possibilities for the different sub-sectors. Discussion of positive and negative aspects with different choices of design parameters, such as trading entity, covered greenhouse gases, allocation of emission allowances and monitoring systems, 3. Examination of the acceptance among different actors for different options of using greenhouse gas emissions trading in the transport sector. When setting up an emissions trading scheme there are a number of design parameters that have to be analysed in order to find an appropriate system, with limited administrative and transaction costs and as small distortions as possible to competitiveness

  17. The research on natural gas pipeline transportation price formulation method

    Directory of Open Access Journals (Sweden)

    YU Wenjia

    2014-02-01

    Full Text Available This paper will introduce a method of natural gas pipeline transportation price on the basis of two-part tariff.Distance,investment and income have been taken into consideration.The total fee is divided into three parts:reservation fee,usage fee and peak-load regulation fee.Because there are different types of users in the natural gas market who show great difference in the continuity and reliability of gas supply,capacity of bearing price,elastic demand and balance use of gas,according to the method,the different types of users can pay reasonable fee.This method not only considers the investment income recovery but also considers the different types of users paying a reasonable fee.We hope the new pricing model can give a reference to the development of China's natural gas industry.

  18. Unconventional Gas. A Game Changer for Transport Too?

    International Nuclear Information System (INIS)

    Boncourt, Maite de

    2011-01-01

    A new technology trend, the development of natural gas vehicles, is emerging in the transport sector. While not new this technology is now being simultaneously revived by the discovery of significant amounts of unconventional gas, by the rise of oil prices, and by the decreased confidence in the sustainability of nuclear technology (and subsequent rising electricity prices in Europe). Natural gas could provide a path to a lower carbon intensive transport sector in both developed and developing countries. Gas is cheaper and less polluting than oil. It emits significantly less local pollutants than diesel and less CO 2 than gasoline. Historically present in Italy, South America, Iran and Pakistan natural gas vehicles are emerging in other countries: in some European countries, in the United States, in the Chinese provinces of Shaanxi and Henan, and in India. Asia and developing countries are expected to be responsible for a large share of the car market growth in the next years and consequently for a significant share of transport CO 2 emissions. The adoption of a given technology there could impact global markets and global CO 2 emissions significantly. While the trend is still loose, this paper responds to the possibility that this technology will expand: what would it imply? would it compete with the development of the electric vehicle? is it desirable? It appears that the advantages of natural gas vehicles are not as clear cut as they seem. Environmentally, they are beneficial only to countries with little -if no- CO 2 emissions standards. Several issues including the development of costly infrastructures are likely to raise costs. Natural gas vehicles development could also slow down the roll out of electric vehicles, hence delaying hopes of smoothing the integration of renewables into the power grid through the use of car batteries' storage capacity. But the main concern is the availability of cheap gas itself, on the basis of which this technology shift could

  19. Mixed Gas Transport Study Through Polymeric Membranes: a Novel Technique

    OpenAIRE

    Dhingra, Sukhtej Singh

    1997-01-01

    The gas transport and separation properties of polymers have been successfully exploited in commercial ventures. Industrial applications employing membrane processes range from production of pure gases to barrier coatings for protection against environmental elements. Membrane separations are simple, energy efficient processes, which can be economically competitive with traditional separation technologies. Membrane separation and permeation characteristics for a...

  20. Reducing greenhouse gas emissions from u.s. transportation

    Science.gov (United States)

    2010-01-01

    This report examines the prospects for substantially reducing the greenhouse gas (GHG) emissions from the U.S. transportation sector, which accounts for 27 percent of the GHG emissions of the entire U.S. economy and 30 percent of the world's transpor...

  1. Wind-Induced Reconfigurations in Flexible Branched Trees

    Science.gov (United States)

    Ojo, Oluwafemi; Shoele, Kourosh

    2017-11-01

    Wind induced stresses are the major mechanical cause of failure in trees. We know that the branching mechanism has an important effect on the stress distribution and stability of a tree in the wind. Eloy in PRL 2011, showed that Leonardo da Vinci's original observation which states the total cross section of branches is conserved across branching nodes is the best configuration for resisting wind-induced fracture in rigid trees. However, prediction of the fracture risk and pattern of a tree is also a function of their reconfiguration capabilities and how they mitigate large wind-induced stresses. In this studies through developing an efficient numerical simulation of flexible branched trees, we explore the role of the tree flexibility on the optimal branching. Our results show that the probability of a tree breaking at any point depends on both the cross-section changes in the branching nodes and the level of tree flexibility. It is found that the branching mechanism based on Leonardo da Vinci's original observation leads to a uniform stress distribution over a wide range of flexibilities but the pattern changes for more flexible systems.

  2. 2009 South American benchmarking study: natural gas transportation companies

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Nathalie [Gas TransBoliviano S.A. (Bolivia); Walter, Juliana S. [TRANSPETRO, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In the current business environment large corporations are constantly seeking to adapt their strategies. Benchmarking is an important tool for continuous improvement and decision-making. Benchmarking is a methodology that determines which aspects are the most important to be improved upon, and it proposes establishing a competitive parameter in an analysis of the best practices and processes, applying continuous improvement driven by the best organizations in their class. At the beginning of 2008, GTB (Gas TransBoliviano S.A.) contacted several South American gas transportation companies to carry out a regional benchmarking study in 2009. In this study, the key performance indicators of the South American companies, whose reality is similar, for example, in terms of prices, availability of labor, and community relations, will be compared. Within this context, a comparative study of the results, the comparative evaluation among natural gas transportation companies, is becoming an essential management instrument to help with decision-making. (author)

  3. Quantities of natural gas transported in August-December 2007

    International Nuclear Information System (INIS)

    2008-01-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. This document presents the available monthly key figures of GRTgaz activity from August to December 2007: Total quantities transmitted by GRTgaz (Inputs to the GRTgaz network/Outputs from the GRTgaz network); Maximum and minimum daily flow (Daily quantities transported, Daily consumption, Daily inputs excluding storage); Quantities exchanged on the wholesale market; Consumption on the GRTgaz Network (gross monthly consumption and Average monthly temperatures)

  4. Quantities of natural gas transported in January-December 2009

    International Nuclear Information System (INIS)

    2010-01-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. This document presents the monthly key figures of GRTgaz activity in 2009: Total quantities transmitted by GRTgaz (Inputs to the GRTgaz network/Outputs from the GRTgaz network); Maximum and minimum daily flow (Daily quantities transported, Daily consumption, Daily inputs excluding storage); Quantities exchanged on the wholesale market; Consumption on the GRTgaz Network (gross monthly consumption and Average monthly temperatures)

  5. Quantities of natural gas transported in January-December 2008

    International Nuclear Information System (INIS)

    2009-01-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. This document presents the monthly key figures of GRTgaz activity in 2008: Total quantities transmitted by GRTgaz (Inputs to the GRTgaz network/Outputs from the GRTgaz network); Maximum and minimum daily flow (Daily quantities transported, Daily consumption, Daily inputs excluding storage); Quantities exchanged on the wholesale market; Consumption on the GRTgaz Network (gross monthly consumption and Average monthly temperatures)

  6. Secondary current properties generated by wind-induced water waves in experimental conditions

    Directory of Open Access Journals (Sweden)

    Michio Sanjou

    2014-06-01

    Full Text Available Secondary currents such as the Langmuir circulation are of high interest in natural rivers and the ocean because they have striking impacts on scour, sedimentation, and mass transport. Basic characteristics have been well-studied in straight open-channel flows. However, little is known regarding secondary circulation induced by wind waves. The presented study describes the generation properties of wind waves observed in the laboratory tank. Wind-induced water waves are known to produce large scale circulations. The phenomenon is observed together with high-speed and low-speed streaks, convergence and divergence zones, respectively. Therefore, it is important to determine the hydrodynamic properties of secondary currents for wind-induced water waves within rivers and lakes. In this study, using two high-speed CMOS cameras, stereoscopic particle image velocimetry (PIV measurements were conducted in order to reveal the distribution of all three components of velocity vectors. The experiments allowed us to investigate the three-dimensional turbulent structure under water waves and the generation mechanism of large-scale circulations. Additionally, a third CMOS camera was used to measure the spanwise profile of thefree-surface elevation. The time-series of velocity components and the free-surface were obtained simultaneously. From our experiments, free-surface variations were found to influence the instantaneous velocity distributions of the cross-sectional plane. We also considered thegeneration process by the phase analysis related to gravity waves and compared the contribution of the apparent stress.

  7. Natural gas utilization as fuel in urban rail transport; Utilizacao do gas natural como combustivel no transporte ferroviario urbano

    Energy Technology Data Exchange (ETDEWEB)

    Salles Filho, Francisco de Assis; Rego Filho, Jose [Companhia de Gas do Ceara (CEGAS), Fortaleza, CE (Brazil)

    1995-12-31

    The majority of Brazilian big cities served by conventional railroad systems with routes starting in the center of the URBIS, destinate them the long distances transport of passengers and cargo. Actually, these systems are being transformed to become commuter trains which join a great capacity of transportation to a much lower costs of implantation than subway ones. The most important characteristic of this train, when talking about energy consumption, is the possibility of using different kinds of explosion engines from three cycles: Diesel, mixed (Diesel + Natural Gas), and Otto moved by natural gas, besides the traditional electric traction. The use of natural gas in Otto cycle engines shows itself competitive from the point of view of investments, operational costs and environmental preservation. (author). 10 refs., 1 fig

  8. Characterization of Nanoscale Gas Transport in Shale Formations

    Science.gov (United States)

    Chai, D.; Li, X.

    2017-12-01

    Non-Darcy flow behavior can be commonly observed in nano-sized pores of matrix. Most existing gas flow models characterize non-Darcy flow by empirical or semi-empirical methods without considering the real gas effect. In this paper, a novel layered model with physical meanings is proposed for both ideal and real gas transports in nanopores. It can be further coupled with hydraulic fracturing models and consequently benefit the storage evaluation and production prediction for shale gas recovery. It is hypothesized that a nanotube can be divided into a central circular zone where the viscous flow behavior mainly exists due to dominant intermolecular collisions and an outer annular zone where the Knudsen diffusion mainly exists because of dominant collisions between molecules and the wall. The flux is derived based on integration of two zones by applying the virtual boundary. Subsequently, the model is modified by incorporating slip effect, real gas effect, porosity distribution, and tortuosity. Meanwhile, a multi-objective optimization method (MOP) is applied to assist the validation of analytical model to search fitting parameters which are highly localized and contain significant uncertainties. The apparent permeability is finally derived and analyzed with various impact factors. The developed nanoscale gas transport model is well validated by the flux data collected from both laboratory experiments and molecular simulations over the entire spectrum of flow regimes. It has a decrease of as much as 43.8% in total molar flux when the real gas effect is considered in the model. Such an effect is found to be more significant as pore size shrinks. Knudsen diffusion accounts for more than 60% of the total gas flux when pressure is lower than 0.2 MPa and pore size is smaller than 50 nm. Overall, the apparent permeability is found to decrease with pressure, though it rarely changes when pressure is higher than 5.0 MPa and pore size is larger than 50 nm.

  9. International transport of incandescent gas mantles - an incident

    International Nuclear Information System (INIS)

    Singh, Khaidem R.K.

    2004-01-01

    Consumer products, though contain small quantities of radioactive material, are designed and manufactured with reference to prescribed safety standards; and supplied for use in public domain. On the basis of the nature of the exposures associated with such practices, which are quite low, the Regulatory Authority exempts the practices from many of the regulatory requirements. As they are inherently safe for handling, transporting and use, they are exempted from some of the requirements under the provisions of the regulations on the transport of radioactive material. Though the basic meaning and purpose of a radioactivity-based consumer product are similar to other commodities, there is a need to transport the former as per the regulations for safe transport of radioactive material till the product reaches at end user. The strict adherence to the transport regulations during transport of the radioactivity-based consumer product would ensure smooth carriage particularly in international arena. On the basis of an incident that happened during the transport of consumer products, this paper analyzes the provisions relating to radioactivity-based consumer products as envisaged in the basic safety standards of IAEA and their transport, particularly for natural thorium based consumer product gas mantles. (author)

  10. Multiparameter Analysis of Gas Transport Phenomena in Shale Gas Reservoirs: Apparent Permeability Characterization.

    Science.gov (United States)

    Shen, Yinghao; Pang, Yu; Shen, Ziqi; Tian, Yuanyuan; Ge, Hongkui

    2018-02-08

    The large amount of nanoscale pores in shale results in the inability to apply Darcy's law. Moreover, the gas adsorption of shale increases the complexity of pore size characterization and thus decreases the accuracy of flow regime estimation. In this study, an apparent permeability model, which describes the adsorptive gas flow behavior in shale by considering the effects of gas adsorption, stress dependence, and non-Darcy flow, is proposed. The pore size distribution, methane adsorption capacity, pore compressibility, and matrix permeability of the Barnett and Eagle Ford shales are measured in the laboratory to determine the critical parameters of gas transport phenomena. The slip coefficients, tortuosity, and surface diffusivity are predicted via the regression analysis of the permeability data. The results indicate that the apparent permeability model, which considers second-order gas slippage, Knudsen diffusion, and surface diffusion, could describe the gas flow behavior in the transition flow regime for nanoporous shale. Second-order gas slippage and surface diffusion play key roles in the gas flow in nanopores for Knudsen numbers ranging from 0.18 to 0.5. Therefore, the gas adsorption and non-Darcy flow effects, which involve gas slippage, Knudsen diffusion, and surface diffusion, are indispensable parameters of the permeability model for shale.

  11. Cross sections and transport properties for Na+ in (DXE gas

    Directory of Open Access Journals (Sweden)

    Nikitović Željka D.

    2016-01-01

    Full Text Available In this work we select most probable reactions of alkali metal ion Na+ with dimethoxyethane (DXE molecule. Appropriate gas phase enthalpies of formation for the products were used to calculate scattering cross section as a function of kinetic energy with Denpoh-Nanbu theory. Calculated cross sections were compared with existing experimental results obtained by guided ion beam tandem mass spectrometry. Three body association reactions of ions with DXE is studied and compared to experimental results. Calculated cross sections were used to obtain transport parameters for alkali metal ion in DXE gas. [Projekat Ministarstva nauke Republike Srbije, br. ON 171037 i br. III 410011

  12. The Lorentz gas in Kaluza's MHD: Transport equations

    Science.gov (United States)

    Sandoval-Villalbazo, Alfredo; Sagaceta-Mejia, Alma Rocio; Mondragon-Suarez, Jose Humberto

    2016-11-01

    Relativistic kinetic theory is applied to the study of the transport processes present in a Lorentz gas, using a geometric five-dimensional space-time. While the conventional transport equations are recovered in the Newtonian limit, it is shown that relativistic corrections to the conduction and diffusion fluxes arise within this formalism. A brief review of the conceptual advantages of the Kaluza-type approach to magnetohydrodynamics is also given. The authors acknowledge support from CONACyT through Grant CB2011/167563.

  13. Basic mechanisms of gas transport and past research using perfluorocarbons.

    Science.gov (United States)

    Spiess, Bruce D

    2010-03-01

    Perfluorocarbon compounds have been utilized either in pure (neat) form or as emulsions suspended in aqueous fluids. These man-made chemicals possess a unique physical property allowing them to dissolve much more respiratory gases than any water-based system. Understanding the basic physical chemistry surrounding these emerging medical technologies will assure they are utilized to maximum benefit for mankind. It is clear they should not simply be viewed as 'blood substitutes' but rather as enhanced gas transport pharmaceuticals.

  14. Transport of a relativistic electron beam through hydrogen gas

    International Nuclear Information System (INIS)

    Haan, P. de.

    1981-01-01

    In this thesis the author describes the transport properties of an electron beam through vacuum and through hydrogen gas with pressure ranging from 25 to 1000 Pa. Maximum beam energy and current are 0.8 MeV and 6 kA, respectively. The pulse length is around 150 ns. A description is given of the experimental device. Also the diagnostics for probing the beam and the plasma, produced by the beam, are discussed, as well as the data acquisition system. The interaction between the beam and hydrogen gas with a pressure around 200 Pa is considered. A plasma with density around 10 19 m -3 is produced within a few nanoseconds. Measurements yield the atomic hydrogen temperature, electron density, beam energy loss, and induced plasma current and these are compared with the results of a model combining gas ionization and dissociation, and turbulent plasma heating. The angular distribution of the beam electrons about the magnetic field axis is discussed. (Auth.)

  15. Contracts Take or Pay, for supply and transport of gas

    International Nuclear Information System (INIS)

    Velasquez Bermudez, Jesus Maria

    2000-01-01

    The present article has as objective to study the effect that has the contract of supply and of transport of gas that subscribe generators agents of the electric sector with the agents of the market of the gas. The article concentrates on the study of the denominated contracts take or pay. Initially the modeling is analyzed to include the effect of the contracts of gas in the mathematical models that are used to support the works of planning. Later on is studied of optimal form to determining the prices in spot markets of the industries associated to the contracts. Finally is presented the methodology and controlled experiments that allow to identify and to quantify the macro economic effect of the contracts

  16. Managing change : natural gas transportation to the eastern toll zone

    Energy Technology Data Exchange (ETDEWEB)

    Valiante, U. [Cogenerators Alliance, ON (Canada)

    2001-07-01

    The Cogenerators Alliance includes Ontario's largest end-use natural gas consumers, Tractebel Power, Westcoast Power, Lake Superior Power, TransAlta Energy, Cardinal Power of Canada and Whitby Cogeneration. Together, they represent 157,798 GJ/day contracted volume. This paper focused on the changing face of the natural gas industry in North America with closer economic ties between Canada, the United States and Mexico in a competitive energy market. The role of Alliance Pipeline in transporting natural gas to markets and the implication of regulation and toll increases were also discussed. It was noted that there is a need for regulatory changes to provide existing pipelines with the appropriate tools needed to ensure the competitive environment will function effectively. tabs., figs.

  17. Modeling methane fluxes in wetlands with gas-transporting plants. 1. Single-root scale

    NARCIS (Netherlands)

    Segers, R.; Leffelaar, P.A.

    2001-01-01

    Methane dynamics in a water-saturated soil layer with gas-transporting roots is modeled with a weighed set of single-root model systems. Each model system consists of a soil cylinder with a gas-transporting root along its axis or a soil sphere with a gas-transporting root at its center. The weights

  18. Modeling methane fluxes in wetlands with gas-transporting plants 2. Soil layer scale

    NARCIS (Netherlands)

    Segers, R; Rappoldt, C; Leffelaar, PA

    2001-01-01

    Methane dynamics in a water-saturated soil layer with gas-transporting roots is modeled with a weighed set of single-loot model systems. Each model system consists of a soil cylinder with a gas-transporting root along its axis or a soil sphere with a gas-transporting root at its centre. The weights

  19. The role of transportation technologies in reducing greenhouse gas emissions

    International Nuclear Information System (INIS)

    Anon.

    1995-11-01

    The potential role of passenger transportation technologies in reducing greenhouse gas emissions was discussed. The technologies considered in the report were those that affect ground transportation of passengers and were in at least the early stages of development in 1995. They were: (1) technologies to improve the fuel efficiency of cars and light trucks, (2) alternative fuels for internal combustion engines, (3) electric hybrid vehicles, (4) advanced technology transit buses, (5) intelligent transportation systems, (6) high speed rail, and (7) bicycles. For each option, the advantages and disadvantages were described. The feasibility of establishing a high-speed rail system serving Canada's most densely populated region, the Windsor to Quebec City corridor, was discussed. Economic and environmental studies of such a proposal are underway. tabs

  20. Reducing the Green House Gas Emissions from the Transportation Sector

    Directory of Open Access Journals (Sweden)

    Oyewande Akinnikawe

    2010-02-01

    Full Text Available In the United States, two thirds of the carbon monoxide and about one third of carbon dioxide emissions come from the transportation sector. Ways to reduce these emissions in the future include replacing gasoline and diesel by biofuels, or by blend of biofuels with conventional gasoline and diesel, or by compressed natural gas (CNG, or by replacing internal combustion engines by electric motors powered by hydrogen fuel cells or battery-powered electric vehicles recharged from the electric grid. This presentation will review these technologies the fuel production pathways, when they are likely to be available, and by what fraction transportation sector green house gas emissions could be reduced by each. A well-to-wheels (WTW analysis is performed on each vehicle/ fuel technology using the GREET model and the total energy use, the CO 2 emissions, NO x emissions, SO x emissions for the life cycle of the vehicle technologies are calculated. Prospects for reducing foreign oil dependence as well as mitigating green house gases emission from the transportation sector will be considered in the analysis.

  1. The development of a natural gas transportation logistics management system

    International Nuclear Information System (INIS)

    Pereira dos Santos, Sidney; Eugenio Leal, Jose; Oliveira, Fabricio

    2011-01-01

    Efficient management of the natural gas business chain - based on pipeline transmission networks and taking into consideration the interaction among the main players (e.g., shippers, suppliers, transmission companies and local distribution companies) - requires the use of decision-making support systems. These support systems maximise resources and mitigate contingencies due to gas supply shortfalls, operational contingencies from scheduled and non-scheduled equipment outages and market demand shortfalls. This study presents a practical use for technologies, such as a thermohydraulic simulation of gas flow through pipelines, a Monte Carlo simulation for compressor station availability studies, an economic risk evaluation related to potential revenue losses and contractual penalties and linear programming for the maximisation of income and the minimisation of contractual penalties. The proposed system allows the optimum availability level to be defined and maintained by the Transporter (by installing reserve capacity) to mitigate losses related to revenue and contractual penalties. It also economically identifies, quantifies and justifies the installation of stand-by compressor units that can mitigate the Transporter's exposure to losses caused by capacity shortfalls as a consequence of scheduled and non-scheduled outages. - Highlights: → We present a DSS to help the decision on investments on spare compressor units of pipelines systems. → The system may be applied to new or existing projects. → The system is able to estimate the revenue losses and the contractual penalties. → An economical evaluation shows the NPV for each configuration of spare units. → The method was applied to the case study of the Bolivia-Brazil gas pipeline.

  2. Logistic management system for natural gas transportation by pipelines; Sistema de gestao de logistica de transporte de gas por gasodutos

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Sidney Pereira dos; Castro, Antonio Orestes de Salvo [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Leal, Jose Eugenio [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)

    2008-07-01

    An efficient management of the natural gas business chain, based on pipeline transmission network and taking into consideration the interaction between the main players such as shippers, suppliers, transmission companies and local distribution companies, requires the use of decision-making support systems to maximize resources and mitigate contingencies due to gas supply shortfalls, operational contingencies from scheduled and non-scheduled equipment outages as well as market demand shortfalls. This work presents a practical utilization of technologies such as thermohydraulic simulation of gas flow through pipelines, Monte Carlo simulation for compressor station availability studies and economic risk evaluation related to potential revenue losses and contractual penalties and linear programming for maximization and minimization objective function. The proposed system allows the definition of the optimum availability level to be maintained by the Transporter, by means of installing redundancy, to mitigate losses related to revenue and contractual penalties. Identifies, quantifies and justifies economically the installation of stand-by compressor units, mitigating Transporter exposure to losses due to capacity shortfalls as consequence of scheduled and non-scheduled outages. (author)

  3. Gas transport in the bentonite barrier of AGP and their interfaces; Transporte de gas en la barrera de bentonita de un AGP y sus interfases

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Rodrigo, V.; Villar Gelicia, M. V.; Martin Martin, P. L.; Romero Alvarez, F. J.

    2014-07-01

    The research of gas transport processes through the barriers is of great relevance in the assessment of the behaviour of the repository. The main objective of this study is to determine the properties of gas transport in saturated bentonite samples and the interfaces between them. (Author)

  4. Gravity effects on wind-induced flutter of leaves

    Science.gov (United States)

    Clemmer, Nickalaus; Kopperstad, Karsten; Solano, Tomas; Shoele, Kourosh; Ordonez, Juan

    2017-11-01

    Wind-Induced flutter of leaves depends on both wind velocity and the gravity. To study the gravitational effects on the oscillatory behavior of leaves in the wind, a wind tunnel that can be tilted about the center of the test section is created. This unique rotation capability allows systematic investigation of gravitational effects on the fluttering response of leaves. The flow-induced vibration will be studied for three different leaves at several different tilting angles including the wind travels horizontally, vertically downward and vertically upward. In each situation, the long axis of a leaf is placed parallel to the wind direction and its response is studied at different flow speed. Oscillation of the leaf is recorded via high-speed camera at each of setup, and the effect of the gravity on stabilizing or destabilizing the fluttering response is investigated. Summer REU student at Florida State University.

  5. An Experimental Study on the Wind-Induced Response of Variable Message Signs

    Directory of Open Access Journals (Sweden)

    Debbie Meyer

    2017-11-01

    Full Text Available Variable message sign (VMS systems are widely used in motorways to provide traffic information to motorists. Such systems are subjected to wind-induced structural vibration that can lead to damage due to fatigue. The limited information that is available on the safe wind design of VMS motivated a large scale testing that was conducted at the wall of wind (WOW Experimental Facility at Florida International University (FIU. One of the objectives of the present study was to experimentally assess the wind-induced force coefficients on VMS of different geometries and utilize these results to provide improved design guidelines. A comprehensive range of VMS geometries was tested, and mean normal and lateral force coefficients, in addition to the twisting moment coefficient and eccentricity ratio, were determined using the measured data for each model, for wind directions of 0° and 45°. The results confirmed that the mean drag coefficient on a prismatic VMS is smaller than the value of 1.7 suggested by American Association of State Highway and Transportation Officials (AASHTO. An alternative to this value is presented in the form of a design matrix with coefficients ranging from 0.98 to 1.28, depending on the aspect and depth ratio of the VMS. Furthermore, results indicated that the corner modification on a VMS with chamfered edges demonstrated a reduction in the drag coefficient compared to sharper edges. Finally, the dynamic loading effects were considered by evaluating the gust effect factor, using the ASCE 7 formulations, for various VMS weights and geometries. The findings revealed a wide range of possible gust effect factors, both above and below the current AASHTO specification of 1.14. Future research may include different geometries of VMS and a wider range of wind directions.

  6. Transport Processes in Materials Processing Plasmas: Particulate Behavior and Neutral Gas Transport.

    Science.gov (United States)

    Kilgore, Michael Duane

    This research work focuses on two transport problems in low pressure plasma reactors which are used in thin film manufacturing processes. Computer simulation techniques are used to study particulate behavior in processing discharges and neutral species transport in high plasma density discharges. Particulate behavior is predicted by combining models of charging and transport with numerical plasma simulation. A charged particulate is influenced by discharge electric fields and by momentum transfer collisions with drifting plasma species. A particulate is also subject to other forces including neutral gas drag, thermophoresis, and gravity. For radio frequency capacitively coupled discharges, several forces which act on a particulate may be of comparable magnitude. This results in particulate trapping at plasma-sheath boundaries in many cases. For high plasma density discharges, high ion fluxes make the ion drag force dominate particulate behavior. This means that it is more difficult for particulates to be suspended in the plasma, compared to the situation in parallel plate systems. However, particulate contamination of a wafer can still occur in high density plasmas because particulates may be ejected from chamber walls and reach the wafer after residing very briefly in the gas phase. The direct simulation Monte Carlo method is applied to follow transition regime neutral gas transport in high plasma density processing discharges. Three effects are evaluated: neutral depletion by ionization; neutral heating by collisions with energetic plasma species; and gas flow and pumping. These effects are important for discharges that operate at relatively high fractional ionization. Results show the magnitude of these effects in an electron cyclotron resonance reactor and in an inductively coupled reactor operated under a range of typical conditions. The neutral gas transport simulation is extended to investigate neutral beam processing. A high density inductively coupled

  7. 30 CFR 75.1106-2 - Transportation of liquefied and nonliquefied compressed gas cylinders; requirements.

    Science.gov (United States)

    2010-07-01

    ... compressed gas cylinders; requirements. 75.1106-2 Section 75.1106-2 Mineral Resources MINE SAFETY AND HEALTH... Fire Protection § 75.1106-2 Transportation of liquefied and nonliquefied compressed gas cylinders; requirements. (a) Liquefied and nonliquefied compressed gas cylinders transported into or through an...

  8. Ecoefficiency indicators for natural gas transportation companies; Proposta de indicadores de desempenho ambiental para empresas do segmento de transporte de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    La Rovere, Emilio Lebre; Mariano, Jacqueline Barboza; Garcia, Katia Cristina; Salgado, Vivian Gullo [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Planejamento Energetico; Faertes, Denise [TRANSPETRO - PETROBRAS Transporte, Rio de Janeiro, RJ (Brazil); Barata, Martha Macedo de Lima [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    This paper aims to present a cast of environmental indicators, more specifically ecoefficiency indicators, to natural gas pipeline transportation companies. So as to do that, are defined the concepts of ecoefficiency and sustainability with its principal related environmental indicators. The environmental impacts and aspects of the natural gas pipeline transportation are discussed, and the concept of cleaner service and production is considered in the context of this activity. Are also presented and analyzed the most important indicators of environmental performance used by oil and gas companies and by natural gas transportation companies, so as to support the choice of the proposed indicators. Finally, the cast of the indicators, which was based on the assessment of the Brazilian Northeast System of gas pipelines, operated by PETROBRAS Transporte S.A., TRANSPETRO, is presented. (author)

  9. Secure and economic operational of a gas transportation system; Operacion economica y segura de un sistema de transporte de gas

    Energy Technology Data Exchange (ETDEWEB)

    Sardi, Oscar Jose; Trichilo, Claudia; Valpreda, Carlos [Transportadora de Gas del Sur S.A. (Argentina)

    2003-07-01

    Since 1992, Transportadora de Gas del Sur (TGS) has been operating the longest gas pipeline system in South America. Prior to that date, the system was managed by GE, a state-owned company. Early on in the administration of the company, some improvement opportunities were identified in the technical, commercial, management and personnel fields. An integrated transformation process was developed which involved major investments, acquisition of new technology, re-design of the work force, and new work methodologies. The course of action followed by the company was based on an attempt to achieve permanent improvement on business results. This paper is the result of the improvements applied to our gas transportation system. Due to the time and cost assessment required by scheduled turbine compressor maintenance works (83 - 538.220 hp), a Contingency Plan for turbine compressor breakdowns was established as well as an Economic Dispatch, which can determine low-cost operations in specific periods of time (during the year). This work details the actions taken. (author)

  10. Lateral gas transport in soil adjacent to an old landfill: factors governing gas migration

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter

    2001-01-01

    was observed. There was a good correlation between pressure above the barometric pressure and the methane concentration in the soil, indicating that advective flow was the controlling process. This was confirmed by calculations. Diurnal measurement during a drop in barometric pressure showed that lateral......Field experiments investigating lateral gas transport in soil adjacent to an old landfill in Denmark during a one-year period were conducted. A significant seasonal variation, with low concentrations of methane and high concentrations of carbon dioxide in the summer, caused by methane oxidation...

  11. Expert System for natural gas transportation network management; Sistema especialista para gerenciamento de redes de transporte de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jonny Carlos da; Porciuncula, Gilson Simoes [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica Lab. de Sistemas Hidraulicos e Pneumaticos

    2003-07-01

    This paper presents a project to integrate expert system and dynamic simulation of natural gas transportation network applying the concept of agents. Natural gas pipeline operation requires the intermittent analysis of hundreds interrelated operational parameters, which represent the network state. The combination of expert system and dynamic simulation is a synergic solution for this kind of problem. With expert system techniques, it is possible to implement rules that describe the relationship between current operational parameters and the network normal operational conditions based on heuristic knowledge. By applying such rules, the system aims to evaluate the real network state and to predict abnormal conditions via dynamic simulation, allowing time analysis of operational situation in advance. At the current stage, the project presents a well defined model. The process of knowledge acquisition and representation has taken place following an incremental approach, considered as development paradigm. The project objectives are to reduce costs, increase the reliability and organize pipeline operation and maintenance information. This work is part of SEGRED project established as partnership among LASHIP/UFSC, SCGAS, TBG and PETROBRAS. The project also received support from FINEP. (author)

  12. Full-scale investigation of wind-induced vibrations of mast-arm traffic signal structures.

    Science.gov (United States)

    2014-08-01

    Because of their inherent : fl : exibility and low damping ratios, cantilevered mast : - : arm : tra : ffi : c signal structures are suscepti : b : le to : wind : - : induced vibrations. : These vibrations : cause stru : ctural stresses and strains t...

  13. Impact of compression on gas transport in non-woven gas diffusion layers of high temperature polymer electrolyte fuel cells

    Science.gov (United States)

    Froning, Dieter; Yu, Junliang; Gaiselmann, Gerd; Reimer, Uwe; Manke, Ingo; Schmidt, Volker; Lehnert, Werner

    2016-06-01

    Gas transport in non-woven gas diffusion layers of a high-temperature polymer electrolyte fuel cell was calculated with the Lattice Boltzmann method. The underlying micro structure was taken from two sources. A real micro structure was analyzed in the synchrotron under the impact of a compression mask mimicking the channel/rib structure of a flow field. Furthermore a stochastic geometry model based on synchrotron X-ray tomography studies was applied. The effect of compression is included in the stochastic model. Gas transport in these micro structures was simulated and the impact of compression was analyzed. Fiber bundles overlaying the micro structure were identified which affect the homogeneity of the gas flow. There are significant deviations between the impact of compression on effective material properties for this type of gas diffusion layers and the Kozeny-Carman equation.

  14. The open access and the natural gas ducts: transport and distribution; O livre acesso e os dutos de gas natural: transporte e distribuicao

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Mariana de; Xavier, Yanko Marcius de Alencar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The present research, attempting for the economic relevance of the natural gas sector, for the lack of a law that disciplines it and, still, for the structural question of the natural gas ducts activities; it analyzes, in a comparative way, the monopoly of the natural gas ducts activities and the mechanisms of competition chosen to brighten up it: the open access and the by pas. The transport and the distribution of the natural gas are really similar, but the ways to insert the competition in its areas are not. (author)

  15. Density-driven transport of gas phase chemicals in unsaturated soils.

    Science.gov (United States)

    Fen, Chiu-Shia; Sun, Yong-Tai; Cheng, Yuen; Chen, Yuanchin; Yang, Whaiwan; Pan, Changtai

    2018-01-01

    Variations of gas phase density are responsible for advective and diffusive transports of organic vapors in unsaturated soils. Laboratory experiments were conducted to explore dense gas transport (sulfur hexafluoride, SF 6 ) from different source densities through a nitrogen gas-dry soil column. Gas pressures and SF 6 densities at transient state were measured along the soil column for three transport configurations (horizontal, vertically upward and vertically downward transport). These measurements and others reported in the literature were compared with simulation results obtained from two models based on different diffusion approaches: the dusty gas model (DGM) equations and a Fickian-type molar fraction-based diffusion expression. The results show that the DGM and Fickian-based models predicted similar dense gas density profiles which matched the measured data well for horizontal transport of dense gas at low to high source densities, despite the pressure variations predicted in the soil column were opposite to the measurements. The pressure evolutions predicted by both models were in trend similar to the measured ones for vertical transport of dense gas. However, differences between the dense gas densities predicted by the DGM and Fickian-based models were discernible for vertically upward transport of dense gas even at low source densities, as the DGM-based predictions matched the measured data better than the Fickian results did. For vertically downward transport, the dense gas densities predicted by both models were not greatly different from our experimental measurements, but substantially greater than the observations obtained from the literature, especially at high source densities. Further research will be necessary for exploring factors affecting downward transport of dense gas in soil columns. Use of the measured data to compute flux components of SF 6 showed that the magnitudes of diffusive flux component based on the Fickian-type diffusion

  16. Wind induced errors on retrieving SSS with SMOS brightness temperature

    Science.gov (United States)

    Yin, X.; Boutin, J.; Martin, N.; Vergely, J.; Spurgeon, P.

    2012-04-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite, launched in November 2009, carries the first interferometric radiometer at L-band (1.4GHz) in orbit. The global distribution of SMOS SSS is very encouraging [Font et al., 2011]. In particular, the latitudinal variation of SSS is well captured by SMOS [Yin et al., 2012] and SSS anomalies in tropical regions seen by ARGO floats also appear on SMOS SSS [Boutin et al., 2011]. However, large discrepancies between SMOS SSS and Argo are noticed when there are large differences between SSMI wind and ECMWF wind, which is used for initializing iterations of SSS retrieval. SMOS does not carry microwave scatterometer or microwave radiometer at high frequency to simultaneously measure roughness, although it's proved in this paper that SMOS retrieved wind speed in the center of the swath (± 300 km) is partly (but not entirely) corrected for inconsistencies between ECMWF wind speeds and true wind speeds, whereas it's not possible to correct wind speed in the border of the swath. Two main aspects of wind induced errors on retrieving SSS with SMOS are: 1) The difference between and ECMWF forecast model wind and neutral equivalent wind which is defined for microwave remote sensing 2) The difference between wind used as prior and the truth. When the discrepancies between ECMWF wind and SSMI wind is out of SMOS's capability of wind correction, the retrieved SSS is biases. In this paper, we show some examples of large discrepancies between SMOS SSS and Argo when there are large differences between SSMI wind and ECMWF wind: 1) The SMOS is systematically to high in the equatorial area in the Eastern Pacific in Summer of 2010, where there is a strong westward current. 2) A case with strong wind front in the southern Pacific ocean. In this paper, we study the precision on SMOS SSS when SSMI wind speed is used as prior and compare it with SSS when ECMWF wind speed is used as prior. We also present the result of SMOS SSS when ECMWF wind

  17. Multiscale model reduction for shale gas transport in fractured media

    KAUST Repository

    Akkutlu, I. Y.

    2016-05-18

    In this paper, we develop a multiscale model reduction technique that describes shale gas transport in fractured media. Due to the pore-scale heterogeneities and processes, we use upscaled models to describe the matrix. We follow our previous work (Akkutlu et al. Transp. Porous Media 107(1), 235–260, 2015), where we derived an upscaled model in the form of generalized nonlinear diffusion model to describe the effects of kerogen. To model the interaction between the matrix and the fractures, we use Generalized Multiscale Finite Element Method (Efendiev et al. J. Comput. Phys. 251, 116–135, 2013, 2015). In this approach, the matrix and the fracture interaction is modeled via local multiscale basis functions. In Efendiev et al. (2015), we developed the GMsFEM and applied for linear flows with horizontal or vertical fracture orientations aligned with a Cartesian fine grid. The approach in Efendiev et al. (2015) does not allow handling arbitrary fracture distributions. In this paper, we (1) consider arbitrary fracture distributions on an unstructured grid; (2) develop GMsFEM for nonlinear flows; and (3) develop online basis function strategies to adaptively improve the convergence. The number of multiscale basis functions in each coarse region represents the degrees of freedom needed to achieve a certain error threshold. Our approach is adaptive in a sense that the multiscale basis functions can be added in the regions of interest. Numerical results for two-dimensional problem are presented to demonstrate the efficiency of proposed approach. © 2016 Springer International Publishing Switzerland

  18. Leveling the playing field of transportation fuels: Accounting for indirect emissions of natural gas

    International Nuclear Information System (INIS)

    Sexton, Steven; Eyer, Jonathan

    2016-01-01

    Natural gas transportation fuels are credited in prior studies with greenhouse gas emissions savings relative to petroleum-based fuels and relative to the total emissions of biofuels. These analyses, however, overlook a source of potentially large indirect emissions from natural gas transportation fuels, namely the emissions from incremental coal-fired generation caused by price-induced substitutions away from natural-gas-fired electricity generation. Because coal-fired generation emits substantially more greenhouse gases and criteria air pollutants than natural-gas-fired generation, this indirect coal-use change effect diminishes potential emissions savings from natural gas transportation fuels. Estimates from a parameterized multi-market model suggest the indirect coal-use change effect rivals in magnitude the indirect land-use change effect of biofuels and renders natural gas fuels as carbon intensive as petroleum fuels. - Highlights: •Natural gas used in transport causes indirect emissions in the electricity sector. •These emissions result from increased coal use in electricity generation. •They rival in magnitude indirect land use change (ILUC) emissions of biofuels. •Natural gas fuels are estimated to be as carbon intensive as the petroleum fuels. •Policy ignores indirect emissions from natural gas.

  19. Ion transport membrane module and vessel system with directed internal gas flow

    Science.gov (United States)

    Holmes, Michael Jerome; Ohrn, Theodore R.; Chen, Christopher Ming-Poh

    2010-02-09

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an inlet adapted to introduce gas into the interior of the vessel, an outlet adapted to withdraw gas from the interior of the vessel, and an axis; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region; and (c) one or more gas flow control partitions disposed in the interior of the pressure vessel and adapted to change a direction of gas flow within the vessel.

  20. Modeling of Gas Production from Shale Reservoirs Considering Multiple Transport Mechanisms.

    Science.gov (United States)

    Guo, Chaohua; Wei, Mingzhen; Liu, Hong

    2015-01-01

    Gas transport in unconventional shale strata is a multi-mechanism-coupling process that is different from the process observed in conventional reservoirs. In micro fractures which are inborn or induced by hydraulic stimulation, viscous flow dominates. And gas surface diffusion and gas desorption should be further considered in organic nano pores. Also, the Klinkenberg effect should be considered when dealing with the gas transport problem. In addition, following two factors can play significant roles under certain circumstances but have not received enough attention in previous models. During pressure depletion, gas viscosity will change with Knudsen number; and pore radius will increase when the adsorption gas desorbs from the pore wall. In this paper, a comprehensive mathematical model that incorporates all known mechanisms for simulating gas flow in shale strata is presented. The objective of this study was to provide a more accurate reservoir model for simulation based on the flow mechanisms in the pore scale and formation geometry. Complex mechanisms, including viscous flow, Knudsen diffusion, slip flow, and desorption, are optionally integrated into different continua in the model. Sensitivity analysis was conducted to evaluate the effect of different mechanisms on the gas production. The results showed that adsorption and gas viscosity change will have a great impact on gas production. Ignoring one of following scenarios, such as adsorption, gas permeability change, gas viscosity change, or pore radius change, will underestimate gas production.

  1. Modeling of Gas Production from Shale Reservoirs Considering Multiple Transport Mechanisms.

    Directory of Open Access Journals (Sweden)

    Chaohua Guo

    Full Text Available Gas transport in unconventional shale strata is a multi-mechanism-coupling process that is different from the process observed in conventional reservoirs. In micro fractures which are inborn or induced by hydraulic stimulation, viscous flow dominates. And gas surface diffusion and gas desorption should be further considered in organic nano pores. Also, the Klinkenberg effect should be considered when dealing with the gas transport problem. In addition, following two factors can play significant roles under certain circumstances but have not received enough attention in previous models. During pressure depletion, gas viscosity will change with Knudsen number; and pore radius will increase when the adsorption gas desorbs from the pore wall. In this paper, a comprehensive mathematical model that incorporates all known mechanisms for simulating gas flow in shale strata is presented. The objective of this study was to provide a more accurate reservoir model for simulation based on the flow mechanisms in the pore scale and formation geometry. Complex mechanisms, including viscous flow, Knudsen diffusion, slip flow, and desorption, are optionally integrated into different continua in the model. Sensitivity analysis was conducted to evaluate the effect of different mechanisms on the gas production. The results showed that adsorption and gas viscosity change will have a great impact on gas production. Ignoring one of following scenarios, such as adsorption, gas permeability change, gas viscosity change, or pore radius change, will underestimate gas production.

  2. The regulation of transportation contracts for natural gas: the issue of contractual dirigisme; A regulacao dos contratos de transporte de gas natural: a questao do dirigismo contratual

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Lizziane Souza; Siqueira, Mariana; Vasconcellos, Mariana Vannucci [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2004-07-01

    The old principals that that rules the liberal idea of contract are replaced for a new Theory that allows the State to interfere in the private sector to please the public interest. The Gas Transport Contract has the influence of open access and its public regulation is necessary to provide the most important needs of Brazilian market. After this word about the problem, we realize the meaning of the public intervention on the Transport Contracts to protect the nation's interests and to limit the private power. This paper try to clear the meaning of the contracts regulation to the gas natural market and its influence in a Brazilian interests. (author)

  3. Understanding and controlling wind-induced vibrations of bridge cables: Results from the Femern Crossing research project

    DEFF Research Database (Denmark)

    Georgakis, Christos T.; Jakobsen, J. B.; Koss, Holger

    Following the successful completion of the Storebælt and Øresund Crossings, the Danish Ministry of Transport appointed Femern A/S to be in charge of preparation, investigations and planning in relation to the establishment of a fixed link across the Fehmarnbelt. To further investigate the causes...... behind the cable vibrations that were observed on the cable-supported bridges forming part of the aforementioned crossings, Femern A/S commissioned a 5-year international collaborative research project, entitled “Understanding and controlling wind-induced vibrations of bridge cables”. The ultimate goal...... of the project has been the establishment of novel vibration mitigation schemes that could be readily, economically, and effectively implemented on a cable-supported bridge that might form part of the fixed link. In support of the proposed research, Femern A/S commissioned a new climatic wind tunnel, designed...

  4. Understanding and controlling wind-induced vibrations of bridge cables: Results from the Femern Crossing research project

    DEFF Research Database (Denmark)

    Georgakis, Christos T.; Jakobsen, J. B.; Koss, Holger

    of the project has been the establishment of novel vibration mitigation schemes that could be readily, economically, and effectively implemented on a cable-supported bridge that might form part of the fixed link. In support of the proposed research, Femern A/S commissioned a new climatic wind tunnel, designed......Following the successful completion of the Storebælt and Øresund Crossings, the Danish Ministry of Transport appointed Femern A/S to be in charge of preparation, investigations and planning in relation to the establishment of a fixed link across the Fehmarnbelt. To further investigate the causes...... behind the cable vibrations that were observed on the cable-supported bridges forming part of the aforementioned crossings, Femern A/S commissioned a 5-year international collaborative research project, entitled “Understanding and controlling wind-induced vibrations of bridge cables”. The ultimate goal...

  5. Reducing Greenhouse Gas Emissions in Transport: All in One Basket?

    Directory of Open Access Journals (Sweden)

    Nicholas Rivers

    2018-02-01

    Full Text Available Analysis after analysis has shown consistently that if policy-makers aiming to meet climate goals are looking for the most-efficient, least-distortionary way to target emissions growth, there is simply nothing better than abandoning all emissions regulations except for one: A straight, revenue-neutral carbon tax. Nothing works through more channels, at a lower cost. Alas, policy-makers are not always looking for the most-efficient, least-distortionary way to target emissions growth. That’s because many of those same analyses show that in order to reach emissions targets, the price on carbon would have to be so punitive as to be politically unbearable, raising the price of gasoline, for example, by about a dollar a litre. That leads politicians to mix in other policies that are less visible to the consumer but also less efficient, less effective and more expensive in abating carbon dioxide. The recently negotiated Pan-Canadian Framework on Clean Growth and Climate Change intends to follow that model, relying on a blend of different policies to help reach Canada’s Paris climate targets. But while the government seems therefore determined to rule out the possibility of a nothing-but-a-carbon-tax plan, it is possible, through the careful application of just the right sort of emission-reduction approaches, to reduce the costs of abatement in a key policy target — namely, road transportation — to a level that at least approaches the lower cost of a carbon tax. The government will likely consider several options in trying to reduce emissions from road transportation. Typical tools include requiring manufacturers to meet standards for new vehicles that mandate fuel economy and greenhouse gas emissions; gasoline taxes; taxes on emissions-intensive vehicles; subsidies for low-emission or zero-emission vehicles; and subsidies for public transit. Indications are that a low-carbon fuel standard (LCFS will play a significant role in the Pan

  6. Water vapor and gas transport through PEO PBT block copolymers

    NARCIS (Netherlands)

    Metz, S.J.; Potreck, Jens; Mulder, M.H.V.; Wessling, Matthias

    2002-01-01

    Introduction At the bore well natural gas is saturated with water. Downstream the presence of water may cause: formation of methane hydrates (blocking eventually the pipeline), condensation of water in the pipeline and corrosion effects. A process used for the dehydration of natural gas is glycol

  7. Engineering development of ceramic membrane reactor system for converting natural gas to hydrogen and synthesis gas for liquid transportation fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through April 1998.

  8. Greenhouse gas emissions from aviation and marine transportation : mitigation potential and policies

    Science.gov (United States)

    2009-12-01

    This paper provides an overview of greenhouse gas (GHG) emissions : from aviation and marine transportation and the various mitigation options to reduce these emissions. Reducing global emissions by 50 to 80 percent below 1990 levels by 2050reduct...

  9. Integrated modeling for optimized regional transportation with compressed natural gas fuel

    Directory of Open Access Journals (Sweden)

    Hossam A. Gabbar

    2016-03-01

    Full Text Available Transportation represents major energy consumption where fuel is considered as a primary energy source. Recent development in the vehicle technology revealed possible economical improvements when using natural gas as a fuel source instead of traditional gasoline. There are several fuel alternatives such as electricity, which showed potential for future long-term transportation. However, the move from current situation where gasoline vehicle is dominating shows high cost compared to compressed natural gas vehicle. This paper presents modeling and simulation methodology to optimize performance of transportation based on quantitative study of the risk-based performance of regional transportation. Emission estimation method is demonstrated and used to optimize transportation strategies based on life cycle costing. Different fuel supply scenarios are synthesized and evaluated, which showed strategic use of natural gas as a fuel supply.

  10. Methodology for in situ gas sampling, transport and laboratory analysis of gases from stranded cetaceans.

    Science.gov (United States)

    Bernaldo de Quirós, Yara; González-Díaz, Oscar; Saavedra, Pedro; Arbelo, Manuel; Sierra, Eva; Sacchini, Simona; Jepson, Paul D; Mazzariol, Sandro; Di Guardo, Giovanni; Fernández, Antonio

    2011-01-01

    Gas-bubble lesions were described in cetaceans stranded in spatio-temporal concordance with naval exercises using high-powered sonars. A behaviourally induced decompression sickness-like disease was proposed as a plausible causal mechanism, although these findings remain scientifically controversial. Investigations into the constituents of the gas bubbles in suspected gas embolism cases are highly desirable. We have found that vacuum tubes, insulin syringes and an aspirometer are reliable tools for in situ gas sampling, storage and transportation without appreciable loss of gas and without compromising the accuracy of the analysis. Gas analysis is conducted by gas chromatography in the laboratory. This methodology was successfully applied to a mass stranding of sperm whales, to a beaked whale stranded in spatial and temporal association with military exercises and to a cetacean chronic gas embolism case. Results from the freshest animals confirmed that bubbles were relatively free of gases associated with putrefaction and consisted predominantly of nitrogen.

  11. Transport evaluation of a gas-liquid scrubber

    International Nuclear Information System (INIS)

    Brodner, A.J.; Bistline, J.E.; Weber, S.E.

    1982-10-01

    The hydraulics and the mass-transfer behavior of a five-tray, single-bubble-cap, single-downcomer, gas-liquid contactor were studied for use as a gas scrubber. Flooding was not observed at the maximum available liquid and gas flow rates of 0.32 and 464 L/min, respectively. The maximum liquid entrainment was 33% at a gross liquid flow rate of 0.05 L/min. The Murphree-tray efficiencies for absorption of CO 2 (5000 ppM in air) into demineralized water ranged from 0.14 to 0.74 for volumetric liquid-to-gas ratios of 4 x 10 -4 and 2 x 10 -4 , respectively, for k/sub L/a values ranging from 0.088 to 0.36 min -1 . 12 figures, 10 tables

  12. Dynamics of CO 2 transport and injection strategies in a depleted gas field

    NARCIS (Netherlands)

    Veltin, J.; Belfroid, S.P.C.

    2012-01-01

    As Carbon Capture and Storage slowly gets accepted and integrated as a mean for cleaner utilization of fossil fuels, accurate knowledge of the transport of CO2 through pipelines and into wells becomes crucial. A representative North Sea transport and injection scenario into a depleted gas field is

  13. Correlating Gas Transport Parameters and X-ray Computed Tomography Measurements in Porous Media

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Hamamoto, Shoichiro; Kawamoto, Ken

    2013-01-01

    Gas transport parameters and X-ray computed tomography (CT) measurements in porous medium under controlled and identical conditions provide a useful methodology for studying the relationships among them, ultimately leading to a better understanding of subsurface gaseous transport and other soil p...

  14. Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Air Products and Chemicals

    2008-09-30

    An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

  15. Gas transport in unsaturated porous media: the adequacy of Fick's law

    Science.gov (United States)

    Thorstenson, D.C.; Pollock, D.W.

    1989-01-01

    The increasing use of natural unsaturated zones as repositories for landfills and disposal sites for hazardous wastes (chemical and radioactive) requires a greater understanding of transport processes in the unsaturated zone. For volatile constituents an important potential transport mechanism is gaseous diffusion. Diffusion, however, cannot be treated as an independent isolated transport mechanism. A complete understanding of multicomponent gas transport in porous media (unsaturated zones) requires a knowledge of Knudsen transport, the molecular and nonequimolar components of diffusive flux, and viscous (pressure driven) flux. This review presents a brief discussion of the underlying principles and interrelationships among each of the above flux mechanisms. -from Authors

  16. Light-induced phenomena in one-component gas: The transport phenomena

    Science.gov (United States)

    Chermyaninov, I. V.; Chernyak, V. G.

    2016-09-01

    The article presents the theory of transport processes in a one-component gas located in the capillary under the action of resonant laser radiation and the temperature and pressure gradients. The expressions for the kinetic coefficients determining heat and mass transport in the gas are obtained on the basis of the modified Boltzmann equations for the excited and unexcited particles. The Onsager reciprocal relations for cross kinetic coefficients are proven for all Knudsen numbers and for any law interaction of gas particles with each other and boundary surface. Light-induced phenomena associated with the possible non-equilibrium stationary states of system are analyzed.

  17. Novel transport delay problem solutions for gas plant inlet pressure control

    Directory of Open Access Journals (Sweden)

    Mahmoud A.R. AboShady

    2014-09-01

    Full Text Available The process of transferring the natural gas from the gas well to the gas separation plant encountered some delay time depending on the distance between this well and the factory, the cross section of the transport line, the geometry of this transport line, the well pressure and others. To control the factory inlet pressure by controlling the choke valve existing at the well head, the delay time makes the traditional control systems to fail. In this framework we aim to solve this problem by presenting a novel controller design and delay modeling technique. The presented technique is compared to the previous control system design and delay approximation techniques.

  18. Radiation transport in ionizing gas flow within the quasi-steady plasma accelerator

    Science.gov (United States)

    Kozlov, A. N.; Konovalov, V. S.

    2018-01-01

    Investigation of the radiation transport in the ionizing gas flow in the channel of the quasi-steady plasma accelerator is presented. The model is based on the magnetohydrodynamic (MHD) equations and equation of the radiation transport. In theMHD model the approximation of the local thermodynamic equilibrium was used in the three-component medium consisting of atoms, ions and electrons. The model of the radiation transport includes the basic mechanisms of emission and absorption for different portions of spectrum.

  19. An improved model of fission gas atom transport in irradiated uranium dioxide

    Science.gov (United States)

    Shea, J. H.

    2018-04-01

    The hitherto standard approach to predicting fission gas release has been a pure diffusion gas atom transport model based upon Fick's law. An additional mechanism has subsequently been identified from experimental data at high burnup and has been summarised in an empirical model that is considered to embody a so-called fuel matrix 'saturation' phenomenon whereby the fuel matrix has become saturated with fission gas so that the continued addition of extra fission gas atoms results in their expulsion from the fuel matrix into the fuel rod plenum. The present paper proposes a different approach by constructing an enhanced fission gas transport law consisting of two components: 1) Fick's law and 2) a so-called drift term. The new transport law can be shown to be effectively identical in its predictions to the 'saturation' approach and is more readily physically justifiable. The method introduces a generalisation of the standard diffusion equation which is dubbed the Drift Diffusion Equation. According to the magnitude of a dimensionless Péclet number, P, the new equation can vary from pure diffusion to pure drift, which latter represents a collective motion of the fission gas atoms through the fuel matrix at a translational velocity. Comparison is made between the saturation and enhanced transport approaches. Because of its dependence on P, the Drift Diffusion Equation is shown to be more effective at managing the transition from one type of limiting transport phenomenon to the other. Thus it can adapt appropriately according to the reactor operation.

  20. Estimation of Energy Consumption and Greenhouse Gas Emissions of Transportation in Beef Cattle Production

    Directory of Open Access Journals (Sweden)

    Narayanan Kannan

    2016-11-01

    Full Text Available Accounting for transportation is an important part of the life cycle analysis (LCA of beef cattle production because it is associated with energy consumption and greenhouse gas emissions. This paper describes the development and application of a model that estimates energy consumption and greenhouse gas emissions of transport in beef cattle production. The animal transport model is based on the weight and number of animals in each weight category, type of trailer, vehicle, and fuel used. The energy consumption and greenhouse gas emission estimates of animal feed transportation are based on the weight of a truckload and the number of truckloads of feed transported. Our results indicate that a truckload is travelling approximately 326 km in connection with beef cattle production in the study region. The fuel consumption amounts to 24 L of fossil fuel per 1000 kg of boneless beef. The corresponding greenhouse gas emission is 83 kg. It appears from our results that the majority of energy consumption and greenhouse gas emissions are associated with sending the finished cattle to slaughterhouses and bringing feeder cattle to feedlots. Our results point out appreciable reductions in energy consumption and greenhouse gas emissions by changing from conventional fuel to bio-fuel.

  1. Thinking on Sichuan-Chongqing gas pipeline transportation system reform under market-oriented conditions

    Science.gov (United States)

    Duan, Yanzhi

    2017-01-01

    The gas pipeline networks in Sichuan and Chongqing (Sichuan-Chongqing) region have formed a fully-fledged gas pipeline transportation system in China, which supports and promotes the rapid development of gas market in Sichuan-Chongqing region. In the circumstances of further developed market-oriented economy, it is necessary to carry out further the pipeline system reform in the areas of investment/financing system, operation system and pricing system to lay a solid foundation for improving future gas production and marketing capability and adapting itself to the national gas system reform, and to achieve the objectives of multiparty participated pipeline construction, improved pipeline transportation efficiency and fair and rational pipeline transportation prices. In this article, main thinking on reform in the three areas and major deployment are addressed, and corresponding measures on developing shared pipeline economy, providing financial support to pipeline construction, setting up independent regulatory agency to enhance the industrial supervision for gas pipeline transportation, and promoting the construction of regional gas trade market are recommended.

  2. Quantities of natural gas transported in January-December 2010. Quantities of natural gas transmitted in January-December 2010

    International Nuclear Information System (INIS)

    2011-01-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. This document presents the monthly key figures of GRTgaz activity in 2010: Total quantities transmitted by GRTgaz (Inputs to the GRTgaz network/Outputs from the GRTgaz network); Maximum and minimum daily flow (Daily quantities transported, Daily consumption, Daily inputs excluding storage); Quantities exchanged on the wholesale market; Consumption on the GRTgaz Network (gross monthly consumption and Average monthly temperatures)

  3. Quantities of natural gas transmitted in January-December 2012. Quantities of natural gas transported in January-December 2012

    International Nuclear Information System (INIS)

    2013-01-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. This document presents the monthly key figures of GRTgaz activity in 2012: Total quantities transmitted by GRTgaz (Inputs to the GRTgaz network/Outputs from the GRTgaz network); Maximum and minimum daily flow (Daily quantities transported, Daily consumption, Daily inputs excluding storage); Quantities exchanged on the wholesale market; Consumption on the GRTgaz Network (gross monthly consumption and Average monthly temperatures)

  4. Quantities of natural gas transmitted in January-December 2011. Quantities of natural gas transported in January-December 2011

    International Nuclear Information System (INIS)

    2012-01-01

    GRTgaz is a European leader in natural gas transmission, a world expert in gas transmission networks and systems, and an operator firmly committed to the energy transition. It owns and operates the gas transmission network throughout most of France and it manages the transmission network in Germany, thereby helping to ensure correct operation of the French and European gas market. It contributes to the energy security of regional supply systems and performs a public service mission to ensure the continuity of consumer supply. This document presents the monthly key figures of GRTgaz activity in 2011: Total quantities transmitted by GRTgaz (Inputs to the GRTgaz network/Outputs from the GRTgaz network); Maximum and minimum daily flow (Daily quantities transported, Daily consumption, Daily inputs excluding storage); Quantities exchanged on the wholesale market; Consumption on the GRTgaz Network (gross monthly consumption and Average monthly temperatures)

  5. Appraisal of transport and deformation in shale reservoirs using natural noble gas tracers

    Energy Technology Data Exchange (ETDEWEB)

    Heath, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gardner, William Payton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. of Montana, Missoula, MT (United States)

    2015-09-01

    This report presents efforts to develop the use of in situ naturally-occurring noble gas tracers to evaluate transport mechanisms and deformation in shale hydrocarbon reservoirs. Noble gases are promising as shale reservoir diagnostic tools due to their sensitivity of transport to: shale pore structure; phase partitioning between groundwater, liquid, and gaseous hydrocarbons; and deformation from hydraulic fracturing. Approximately 1.5-year time-series of wellhead fluid samples were collected from two hydraulically-fractured wells. The noble gas compositions and isotopes suggest a strong signature of atmospheric contribution to the noble gases that mix with deep, old reservoir fluids. Complex mixing and transport of fracturing fluid and reservoir fluids occurs during production. Real-time laboratory measurements were performed on triaxially-deforming shale samples to link deformation behavior, transport, and gas tracer signatures. Finally, we present improved methods for production forecasts that borrow statistical strength from production data of nearby wells to reduce uncertainty in the forecasts.

  6. Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream

    Science.gov (United States)

    Kromer, Brian R.; Litwin, Michael M.; Kelly, Sean M.

    2016-09-27

    A method and system for generating electrical power in which a high pressure synthesis gas stream generated in a gasifier is partially oxidized in an oxygen transport membrane based reactor, expanded and thereafter, is combusted in an oxygen transport membrane based boiler. A low pressure synthesis gas slip stream is split off downstream of the expanders and used as the source of fuel in the oxygen transport membrane based partial oxidation reactors to allow the oxygen transport membrane to operate at low fuel pressures with high fuel utilization. The combustion within the boiler generates heat to raise steam to in turn generate electricity by a generator coupled to a steam turbine. The resultant flue gas can be purified to produce a carbon dioxide product.

  7. Description of the Gas Transport through Dynamic Liquid Membrane.

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Setničková, Kateřina; Tseng, H.-H.; Šíma, Vladimír; Petričkovič, Roman

    2017-01-01

    Roč. 184, AUG 31 (2017), s. 152-157 ISSN 1383-5866 Grant - others:AV ČR(CZ) MOST-16-04 Program:Bilaterální spolupráce Institutional support: RVO:67985858 Keywords : gas separation * liquid membrane * solurion-diffusion model Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  8. Marine transportation of liquefied natural gas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Curt, R.P.; Delaney, T.D.

    1973-01-01

    This report covers in some detail most of the major areas of consideration involved in the marine carriage of LNG. Some of the fields investigated and reviewed are the world's total energy picture and the particular requirements of natural gas in the United States in the near future. (GRA)

  9. Gas transport properties of polybenzoxazinoneimides and their prepolymers

    Czech Academy of Sciences Publication Activity Database

    Polotskaya, G.; Goikhman, M.; Podeshvo, I.; Kudryavtsev, V.; Pientka, Zbyněk; Brožová, Libuše; Bleha, Miroslav

    2005-01-01

    Roč. 46, č. 11 (2005), s. 3730-3736 ISSN 0032-3861 Grant - others:Russian Foundation for Basic Research(RU) 03_03_32379 Institutional research plan: CEZ:AV0Z40500505 Keywords : polybenzoxazinoneimide * membranes * gas separation Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.849, year: 2005

  10. Analysis of volatile phase transport in soils using natural radon gas as a tracer

    International Nuclear Information System (INIS)

    Chen, C.; Thomas, D.M.

    1992-01-01

    We have conducted a field study of soil gas transport processes using radon gas as a naturally occurring tracer. The experiment monitored soil gas radon activity, soil moisture, and soil temperature at three depths in the shallow soil column; barometric pressure, rainfall and wind speed were monitored at the soil surface. Linear and multiple regression analysis of the data sets has shown that the gas phase radon activities under natural environmental conditions are influenced by soil moisture content, barometric pressure variations, soil temperature and soil structure. The effect of wind speed on subsurface radon activities under our field conditions has not been demonstrated

  11. Report of the experts group on the taxation of the access to gas transport and distribution network

    International Nuclear Information System (INIS)

    2001-04-01

    In the framework of a new french gas industry organization (directive of the 22 june 1998), a concerting mission has been realized on prices taxation for the transport and distribution facilities. The following topics have been debated: the integration and competition of the european gas market, the gas market liberalization consistency and the taxation of transport and distribution network access. (A.L.B.)

  12. Suspended chains damp wind-induced oscillations of tall flexible structures

    Science.gov (United States)

    Reed, W. H., III

    1968-01-01

    Hanging-chain system, which is a form of impact damper, suppresses wind-induced bending oscillations of tall cylindrical antenna masts. A cluster of chains enclosed in a neoprene shroud is suspended inside the tip of the antenna mast, forming a simple method of damping structural vibrations.

  13. METHANOL PRODUCTION FROM BIOMASS AND NATURAL GAS AS TRANSPORTATION FUEL

    Science.gov (United States)

    Two processes are examined for production of methanol. They are assessed against the essential requirements of a future alternative fuel for road transport: that it (i) is producible in amounts comparable to the 19 EJ of motor fuel annually consumed in the U.S., (ii) minimizes em...

  14. Magnetoelectronic transport of the two-dimensional electron gas in ...

    Indian Academy of Sciences (India)

    Abstract. Hall mobility and magnetoresistance coefficient for the two-dimensional (2D) electron transport parallel to the heterojunction interfaces in a single quantum well of. CdSe are calculated with a numerical iterative technique in the framework of Fermi–Dirac statistics. Lattice scatterings due to polar-mode longitudinal ...

  15. Multicomponent Counter-Current Gas Diffusion: Determination of Transport Parameters

    Czech Academy of Sciences Publication Activity Database

    Šolcová, Olga; Schneider, Petr

    2003-01-01

    Roč. 244, č. 1 (2003), s. 1-9 ISSN 0926-860X R&D Projects: GA ČR GA104/01/0546; GA AV ČR IAA4072915 Institutional research plan: CEZ:AV0Z4072921 Keywords : diffusion * mass transfer * transport processes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.825, year: 2003

  16. Membranes for Flue Gas Treatment - Transport behavior of water and gas in hydrophilic polymer membranes

    NARCIS (Netherlands)

    Potreck, Jens

    2009-01-01

    Fossil fuel fired power plants produce electricity and in addition to that large volume flows of flue gas, which mainly contain N2, O2, and CO2, but also large quantities of water vapor. To prevent condensation of the water vapor present in this flue gas stream, water needs to be removed before

  17. Transport Insight 2009. An annual behind-the-scenes view in North West European gas transmission

    International Nuclear Information System (INIS)

    2009-09-01

    Transport Insight provides the users of the gas network, customers (shippers) and other stakeholders with clear and coherent information every year, directly from the source; the Transmission System Operators. TSOs Gas Transport Services (GTS) and Gasunie Deutschland (GUD) have worked closely together to present Transport Insight 2009 as a joint publication. Section 1 describes the major developments and circumstances that affected the gas transmission system in 2008. Section 2 gives in-depth analyses of actual gas transmission at the border clusters of the Gas Transport Services and Gasunie Deutschland grids. These are illustrated in graphs by means of key figures from 2008 and show details of availability, contracted capacity and usage. Section 3 considers trends in Europe, specifically looking at the production decline and swing decline. These sections are followed by the themes in section 4. In these themes a specific topic is discussed in more detail. The first theme describes developments concerning the Title Transfer Facility (TTF) and the Virtual Trading Place (VHP). The second theme focuses on trends in gas storage in Europe.

  18. Transport of Gas and Solutes in Permeable Estuarine Sediments

    Science.gov (United States)

    2010-09-30

    the orientation of the core. − Mapping of the spatial and temporal distribution of high sedimentary photosynthetic production and oxygen...used to map areas of benthic photosynthetic oxygen production . − Determination of gas content, distribution and migration in the surface sediment...generated by microalgae in the surface layer of submerged sand can be detected non-invasively with our acoustic method. The working hypothesis was that our

  19. Description of the Gas Transport through Dynamic Liquid Membrane.

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Setničková, Kateřina; Tseng, H.-H.; Šíma, Vladimír; Petričkovič, Roman

    2017-01-01

    Roč. 184, AUG 31 (2017), s. 152-157 ISSN 1383-5866 Grant - others:AV ČR(CZ) MOST-16-04 Program:Bilaterální spolupráce Institutional support: RVO:67985858 Keywords : gas separation * liquid membrane * solurion-diffusion model Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 3.359, year: 2016

  20. Wind-induced flow velocity effects on nutrient concentrations at Eastern Bay of Lake Taihu, China.

    Science.gov (United States)

    Jalil, Abdul; Li, Yiping; Du, Wei; Wang, Jianwei; Gao, Xiaomeng; Wang, Wencai; Acharya, Kumud

    2017-07-01

    Shallow lakes are highly sensitive to respond internal nutrient loading due to wind-induced flow velocity effects. Wind-induced flow velocity effects on nutrient suspension were investigated at a long narrow bay of large shallow Lake Taihu, the third largest freshwater lake in China. Wind-induced reverse/compensation flow and consistent flow field probabilities at vertical column of the water were measured. The probabilities between the wind field and the flow velocities provided a strong correlation at the surface (80.6%) and the bottom (65.1%) layers of water profile. Vertical flow velocity profile analysis provided the evidence of delay response time to wind field at the bottom layer of lake water. Strong wind field generated by the west (W) and west-north-west (WNW) winds produced displaced water movements in opposite directions to the prevailing flow field. An exponential correlation was observed between the current velocities of the surface and the bottom layers while considering wind speed as a control factor. A linear model was developed to correlate the wind field-induced flow velocity impacts on nutrient concentration at the surface and bottom layers. Results showed that dominant wind directions (ENE, E, and ESE) had a maximum nutrient resuspension contribution (nutrient resuspension potential) of 34.7 and 43.6% at the surface and the bottom profile layers, respectively. Total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) average concentrations were 6.38, 1.5, and 0.03 mg/L during our field experiment at Eastern Bay of Lake Taihu. Overall, wind-induced low-to-moderate hydrodynamic disturbances contributed more in nutrient resuspension at Eastern Bay of Lake Taihu. The present study can be used to understand the linkage between wind-induced flow velocities and nutrient concentrations for shallow lakes (with uniform morphology and deep margins) water quality management and to develop further models.

  1. Particle transport and gas feed during gun injection

    International Nuclear Information System (INIS)

    Fowler, T K.

    1999-01-01

    It is shown that ion and neutral transport during gun injection tends to equalize the density in the spheromak to that in the open-line current channel. Since a gun operating at or near the ion saturation current requires a minimum density, because of transport these gun requirements also determine a minimum density in the spheromak that increases as the field increases. Hence attaining high fields by gun injection sets lower limits on the density, which in turn limits the temperature of the plasma and increases its ohmic resistance. Estimates of these effects are given using 0-D models calibrated to CTX, as guidance to 2-D UEDGE calculations in progress. For gun power levels in SSPX and the Pulsed Spheromak reactor, we find that buildup persists to the highest field levels of interest

  2. Transportation and Greenhouse Gas Emissions Trading. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Steve Winkelman; Tim Hargrave; Christine Vanderlan

    1999-10-01

    The authors conclude in this report that an upstream system would ensure complete regulatory coverage of transportation sector emissions in an efficient and feasible manner, and as such represents a key component of a national least-cost GHG emissions abatement strategy. The broad coverage provided by an upstream system recommends this approach over vehicle-maker based approaches, which would not cover emissions from heavy-duty vehicles and the aviation, marine and off-road sub-sectors. The on-road fleet approach unfairly and inefficiently burdens vehicle manufacturers with responsibility for emissions that they cannot control. A new vehicles approach would exclude emissions from vehicles on the road prior to program inception. The hybrid approach faces significant technical and political complications, and it is not clear that the approach would actually change behavior among vehicle makers and users, which is its main purpose. They also note that a trading system would fail to encourage many land use and infrastructure measures that affect VMT growth and GHG emissions. They recommend that this market failure be addressed by complementing the trading system with a program specifically targeting land use- and infrastructure-related activities. A key issue that must be addressed in designing a national GHG control strategy is whether or not it is necessary to guarantee GHG reductions from the transport sector. Neither an upstream system nor a downstream approach would do so, since both would direct capital to the least-cost abatement opportunities wherever they were found. They review two reasons why it may be desirable to force transportation sector reductions: first, that the long-term response to climate change will require reductions in all sectors; and second, the many ancillary benefits associated with transportation-related, and especially VMT-related, emissions reduction activities. If policy makers find it desirable to establish transportation

  3. Energy policy act transportation study: Interim report on natural gas flows and rates

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-17

    This report, Energy Policy Act Transportation Study: Interim Report on Natural Gas Flows and Rates, is the second in a series mandated by Title XIII, Section 1340, ``Establishment of Data Base and Study of Transportation Rates,`` of the Energy Policy Act of 1992 (P.L. 102--486). The first report Energy Policy Act Transportation Study: Availability of Data and Studies, was submitted to Congress in October 1993; it summarized data and studies that could be used to address the impact of legislative and regulatory actions on natural gas transportation rates and flow patterns. The current report presents an interim analysis of natural gas transportation rates and distribution patterns for the period from 1988 through 1994. A third and final report addressing the transportation rates and flows through 1997 is due to Congress in October 2000. This analysis relies on currently available data; no new data collection effort was undertaken. The need for the collection of additional data on transportation rates will be further addressed after this report, in consultation with the Congress, industry representatives, and in other public forums.

  4. Transport and transformation of mercury during wet flue gas cleaning process of nonferrous metal smelting.

    Science.gov (United States)

    Liu, Zhilou; Wang, Dongli; Peng, Bing; Chai, Liyuan; Liu, Hui; Yang, Shu; Yang, Bentao; Xiang, Kaisong; Liu, Cao

    2017-10-01

    Reducing mercury emission is hot topic for international society. The first step for controlling mercury in fuel gas is to investigate mercury distribution and during the flue gas treatment process. The mercury transport and transformation in wet flue gas cleaning process of nonferrous smelting industry was studied in the paper with critical important parameters, such as the solution temperature, Hg 0 concentration, SO 2 concentration, and Hg 2+ concentration at the laboratory scale. The mass ratio of the mercury distribution in the solution, flue gas, sludge, and acid fog from the simulated flue gas containing Hg 2+ and Hg 0 was 49.12~65.54, 18.34~35.42, 11.89~14.47, and 1.74~3.54%, respectively. The primary mercury species in the flue gas and acid fog were gaseous Hg 0 and dissolved Hg 2+ . The mercury species in the cleaning solution were dissolved Hg 2+ and colloidal mercury, which accounted for 56.56 and 7.34% of the total mercury, respectively. Various mercury compounds, including Hg 2 Cl 2 , HgS, HgCl 2 , HgSO 4 , and HgO, existed in the sludge. These results for mercury distribution and speciation are highly useful in understanding mercury transport and transformation during the wet flue gas cleaning process. This research is conducive for controlling mercury emissions from nonferrous smelting flue gas and by-products.

  5. Transport Membrane Condenser for Water and Energy Recovery from Power Plant Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Dexin Wang

    2012-03-31

    The new waste heat and water recovery technology based on a nanoporous ceramic membrane vapor separation mechanism has been developed for power plant flue gas application. The recovered water vapor and its latent heat from the flue gas can increase the power plant boiler efficiency and reduce water consumption. This report describes the development of the Transport Membrane Condenser (TMC) technology in details for power plant flue gas application. The two-stage TMC design can achieve maximum heat and water recovery based on practical power plant flue gas and cooling water stream conditions. And the report includes: Two-stage TMC water and heat recovery system design based on potential host power plant coal fired flue gas conditions; Membrane performance optimization process based on the flue gas conditions, heat sink conditions, and water and heat transport rate requirement; Pilot-Scale Unit design, fabrication and performance validation test results. Laboratory test results showed the TMC system can exact significant amount of vapor and heat from the flue gases. The recovered water has been tested and proved of good quality, and the impact of SO{sub 2} in the flue gas on the membrane has been evaluated. The TMC pilot-scale system has been field tested with a slip stream of flue gas in a power plant to prove its long term real world operation performance. A TMC scale-up design approach has been investigated and an economic analysis of applying the technology has been performed.

  6. Transport phenomena in non-uniform gas subjected to laser radiation

    Science.gov (United States)

    Chermyaninov, I. V.; Chernyak, V. G.

    2017-04-01

    The paper discusses the theory of transport processes in one-component gas located in capillary subjected to resonant laser radiation and both temperature and pressure gradients. The equations for the kinetic coefficients determining heat- and mass transport in the gas are derived on the basis of modified Boltzmann equations for the excited and unexcited particles. The cross kinetic coefficients satisfy the Onsager reciprocity for all Knudsen numbers and laws of gas particles interaction with each other and with boundary surface of the capillary. Analysis of possible non-equilibrium stationary states of first and second order for the one-component gas in the capillary has been developed on the basis of the Prigogine theorem of stationary states. Equations describing the stationary states in Knudsen limit (Kn >> 1) and slip-flow regime (Kn << 1) were derived.

  7. Transportation Energy Futures Series: Effects of the Built Environment on Transportation: Energy Use, Greenhouse Gas Emissions, and Other Factors

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D.; Brown, A.; Dunphy, R. T.; Vimmerstedt, L.

    2013-03-01

    Planning initiatives in many regions and communities aim to reduce transportation energy use, decrease emissions, and achieve related environmental benefits by changing land use. This report reviews and summarizes findings from existing literature on the relationship between the built environment and transportation energy use and greenhouse gas emissions, identifying results trends as well as potential future actions. The indirect influence of federal transportation and housing policies, as well as the direct impact of municipal regulation on land use are examined for their effect on transportation patterns and energy use. Special attention is given to the 'four D' factors of density, diversity, design and accessibility. The report concludes that policy-driven changes to the built environment could reduce transportation energy and GHG emissions from less than 1% to as much as 10% by 2050, the equivalent of 16%-18% of present-day urban light-duty-vehicle travel. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  8. Transportation Energy Futures Series. Effects of the Built Environment on Transportation. Energy Use, Greenhouse Gas Emissions, and Other Factors

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States); Brown, A. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States); Dunphy, R. T. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States); Vimmerstedt, L. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States)

    2013-03-15

    Planning initiatives in many regions and communities aim to reduce transportation energy use, decrease emissions, and achieve related environmental benefits by changing land use. This report reviews and summarizes findings from existing literature on the relationship between the built environment and transportation energy use and greenhouse gas emissions, identifying results trends as well as potential future actions. The indirect influence of federal transportation and housing policies, as well as the direct impact of municipal regulation on land use are examined for their effect on transportation patterns and energy use. Special attention is given to the 'four D' factors of density, diversity, design and accessibility. The report concludes that policy-driven changes to the built environment could reduce transportation energy and GHG emissions from less than 1% to as much as 10% by 2050, the equivalent of 16%-18% of present-day urban light-duty-vehicle travel. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  9. Integral Transport Analysis Results for Ions Flowing Through Neutral Gas

    Science.gov (United States)

    Emmert, Gilbert; Santarius, John

    2017-10-01

    Results of a computational model for the flow of energetic ions and neutrals through a background neutral gas will be presented. The method models reactions as creating a new source of ions or neutrals if the energy or charge state of the resulting particle is changed. For a given source boundary condition, the creation and annihilation of the various species is formulated as a 1-D Volterra integral equation that can quickly be solved numerically by finite differences. The present work focuses on multiple-pass, 1-D ion flow through neutral gas and a nearly transparent, concentric anode and cathode pair in spherical, cylindrical, or linear geometry. This has been implemented as a computer code for atomic (3He, 3He +, 3He + +) and molecular (D, D2, D-, D +, D2 +, D3 +) ion and neutral species, and applied to modeling inertial-electrostatic connement (IEC) devices. The code yields detailed energy spectra of the various ions and energetic neutral species. Calculations for several University of Wisconsin IEC and ion implantation devices will be presented. Research supported by US Dept. of Homeland Security Grant 2015-DN-077-ARI095, Dept. of Energy Grant DE-FG02-04ER54745, and the Grainger Foundation.

  10. Non-linear effects on neutral gas transport in divertors

    International Nuclear Information System (INIS)

    Reiter, D.; May, C.; Baelmans, M.; Boerner, P.

    1997-01-01

    The effects of neutral particles on the condition of the plasma edge play a key role in divertor and limiter physics. In computational models they are usually treated in the linear test particle approximation. However, in some divertor concepts a large neutral gas pressure is required in the divertor chamber to provide sufficient neutral-plasma interaction in the plasma fan (momentum removal and energy dissipation) and to permit adequate pumping performance. In such regimes viscous effects in the neutral gas may become relevant. We have extended the EIRENE code to solve the Boltzmann equation with a non-linear BGK-model collision term added to its standard linear collision integrals. The linear in-elastic collision integrals are reconsidered with respect to volume recombination and momentum removal efficiency from the plasma. The numerical procedure in the EIRENE Monte Carlo code is outlined. A simple test application (Couette flow) shows that the procedure works properly. First numerical studies have been carried out and the results are discussed. (orig.)

  11. Ion transport membrane reactor systems and methods for producing synthesis gas

    Science.gov (United States)

    Repasky, John Michael

    2015-05-12

    Embodiments of the present invention provide cost-effective systems and methods for producing a synthesis gas product using a steam reformer system and an ion transport membrane (ITM) reactor having multiple stages, without requiring inter-stage reactant injections. Embodiments of the present invention also provide techniques for compensating for membrane performance degradation and other changes in system operating conditions that negatively affect synthesis gas production.

  12. Opportunities for Synergy Between Natural Gas and Renewable Energy in the Electric Power and Transportation Sectors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A.; Zinaman, O.; Logan, J.

    2012-12-01

    Use of both natural gas and renewable energy has grown significantly in recent years. Both forms of energy have been touted as key elements of a transition to a cleaner and more secure energy future, but much of the current discourse considers each in isolation or concentrates on the competitive impacts of one on the other. This paper attempts, instead, to explore potential synergies of natural gas and renewable energy in the U.S. electric power and transportation sectors.

  13. Specialists' meeting on fission product release and transport in gas-cooled reactors. Summary report

    International Nuclear Information System (INIS)

    1985-01-01

    The purpose of the Meeting on Fission Product Release and Transport in Gas-Cooled Reactors was to compare and discuss experimental and theoretical results of fission product behaviour in gas-cooled reactors under normal and accidental conditions and to give direction for future development. The technical part of the meeting covered operational experience and laboratory research, activity release, and behaviour of released activity

  14. Gas Transport through Fractured Rock near the U20az Borehole, Pahute Mesa, Nevada.

    Science.gov (United States)

    Rockhold, M.; Lowrey, J. D.; Kirkham, R.; Olsen, K.; Waichler, S.; White, M. D.; Wurstner White, S.

    2017-12-01

    Field experiments were performed in 2012-13 and 2016-17 at the U-20az testbed at the Nevada National Security Site to develop and evaluate capabilities for monitoring and modeling noble gas transport associated with underground nuclear explosions (UNE). Experiments were performed by injecting both chemical (CF2BR2, SF6) and radioactive (37Ar, 127Xe) gas species into the deep subsurface at this legacy UNE site and monitoring the breakthrough of the gases at different locations on or near the ground surface. Gas pressures were also monitored in both the chimney and at ground surface. Field experiments were modeled using the parallel, non-isothermal, two-phase flow and transport simulator, STOMP-GT. A site conceptual-numerical model was developed from a geologic framework model, and using a dual-porosity/permeability model for the constitutive relative permeability-saturation-capillary pressure relations of the fractured rock units. Comparisons of observed and simulated gas species concentrations show that diffusion is a highly effective transport mechanism under ambient conditions in the water-unsaturated fractured rock. Over-pressurization of the cavity during one of the field campaigns, and barometric pressure fluctuations are shown to result in enhanced gas transport by advection through fractures.

  15. The tariffs of use of liquefied natural gas transportation networks and facilities

    International Nuclear Information System (INIS)

    2005-01-01

    The new tariff proposals for the use of natural gas transportation networks were transmitted to the French Ministry of economy, finances and industry on October 27, 2004 by the commission of energy regulation. These proposals have been adopted and are the object of three legislative texts: the decree no. 2005-607 from May 27 2005 relative to the tariffing rules, the by-law from May 27, 2005 relative to the definition of balancing areas, and the advice from May 27, 2005 relative to the tariffs of use of natural gas transportation networks. In application of article 7 of the law from January 3, 2003, the implementation of the first tariffs of use of natural gas transportation networks and of liquefied natural gas (LNG) facilities is defined in the decree no. 2004-994 from September 21, 2004. On the main transportation network, the tariffing is of 'input-output' type and does not depend on the distance, while at the regional network scale, the tariffing is linked with the distance. The tariff of use of LNG facilities is the sum of 4 terms: a fixed term applied to each batch unloaded at the methane terminal, a term proportional to the unloaded LNG quantities, a term depending on the duration of use of LNG storage facilities and a term covering the gas consumptions of LNG facilities. This document gathers these different legislative texts with their appendixes. (J.S.)

  16. Greenhouse gas emissions from the production and use of alternative transport fuels

    International Nuclear Information System (INIS)

    Le Cornu, J.K.

    1990-01-01

    A number of the commonly proposed alternative transport fuels were ranked according to both the cumulative greenhouse gas emissions and the production costs incurred between the recovery of the prime resource and the fuel's end use by the Australian transport fleet. An examination of the emissions of each greenhouse gas at each production stage confirmed the common presumption that the low levels of secondary greenhouse gas emissions involved contribute little to the overall greenhouse impact of a fuel's production and use. From a greenhouse point of view the transport fuels studied could be reasonable well ranked by considering their carbon dioxide emissions alone. A possible exception may apply in the case of the compressed natural gas option, which may need to separate consideration of the effect of fugitive emissions of methane from gas distribution systems. An assumption involved in reaching this result was that nitrous oxide emissions, on which there was inadequate hard data, would not form more than 1% of the total nitrogen oxide emissions. At such an emission level it could contribute up to 5% of a fuel's total greenhouse impact. It is concluded that apart from some small niche opportunities, there is no Australian alternative transport fuel option whose production cost and greenhouse impact makes it one which policy should favour over other fuels. It is stressed that this is no more than a preliminary scouting study of generic options, which addresses only greenhouse issues. 17 refs., 1 tab., 8 figs

  17. Applications of ZigBee Technology in the Safety Monitoring System of Low Gas Pipeline Transportation

    Directory of Open Access Journals (Sweden)

    Wei Deyu

    2015-01-01

    Full Text Available The existing safety monitoring system of low gas pipeline transportation establishes a wired communication network monitoring system mainly on the basis of industrial bus. It has problems such as large transmission signal attenuation, complex wiring, high-labor intensity, inconvenient installation and maintenance, high maintenance cost, and so on. Featuring low cost, power-saving, reliability, stability and flexibility, the wireless sensor network established by ZigBee wireless communication technology can realize the real-time all-dimensional dynamic monitoring on parameters of low gas pipeline transportation system and overcome the shortcomings and deficiencies of wired network system.

  18. Multimodel analysis of anisotropic diffusive tracer-gas transport in a deep arid unsaturated zone

    Science.gov (United States)

    Green, Christopher T.; Walvoord, Michelle Ann; Andraski, Brian J.; Striegl, Robert G.; Stonestrom, David A.

    2015-01-01

    Gas transport in the unsaturated zone affects contaminant flux and remediation, interpretation of groundwater travel times from atmospheric tracers, and mass budgets of environmentally important gases. Although unsaturated zone transport of gases is commonly treated as dominated by diffusion, the characteristics of transport in deep layered sediments remain uncertain. In this study, we use a multimodel approach to analyze results of a gas-tracer (SF6) test to clarify characteristics of gas transport in deep unsaturated alluvium. Thirty-five separate models with distinct diffusivity structures were calibrated to the tracer-test data and were compared on the basis of Akaike Information Criteria estimates of posterior model probability. Models included analytical and numerical solutions. Analytical models provided estimates of bulk-scale apparent diffusivities at the scale of tens of meters. Numerical models provided information on local-scale diffusivities and feasible lithological features producing the observed tracer breakthrough curves. The combined approaches indicate significant anisotropy of bulk-scale diffusivity, likely associated with high-diffusivity layers. Both approaches indicated that diffusivities in some intervals were greater than expected from standard models relating porosity to diffusivity. High apparent diffusivities and anisotropic diffusivity structures were consistent with previous observations at the study site of rapid lateral transport and limited vertical spreading of gas-phase contaminants. Additional processes such as advective oscillations may be involved. These results indicate that gases in deep, layered unsaturated zone sediments can spread laterally more quickly, and produce higher peak concentrations, than predicted by homogeneous, isotropic diffusion models.

  19. Transformative Reduction of Transportation Greenhouse Gas Emissions. Opportunities for Change in Technologies and Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vimmerstedt, Laura [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brown, Austin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Newes, Emily [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Markel, Tony [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schroeder, Alex [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yimin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chipman, Peter [U.S. Department of Transportation, Washington, D.C. (United States); Johnson, Shawn [U.S. Department of Transportation, Washington, D.C. (United States)

    2015-04-30

    The transportation sector is changing, influenced by concurrent, ongoing, dynamic trends that could dramatically affect the future energy landscape, including effects on the potential for greenhouse gas emissions reductions. Battery cost reductions and improved performance coupled with a growing number of electric vehicle model offerings are enabling greater battery electric vehicle market penetration, and advances in fuel cell technology and decreases in hydrogen production costs are leading to initial fuel cell vehicle offerings. Radically more efficient vehicles based on both conventional and new drivetrain technologies reduce greenhouse gas emissions per vehicle-mile. Net impacts also depend on the energy sources used for propulsion, and these are changing with increased use of renewable energy and unconventional fossil fuel resources. Connected and automated vehicles are emerging for personal and freight transportation systems and could increase use of low- or non-emitting technologies and systems; however, the net effects of automation on greenhouse gas emissions are uncertain. The longstanding trend of an annual increase in transportation demand has reversed for personal vehicle miles traveled in recent years, demonstrating the possibility of lower-travel future scenarios. Finally, advanced biofuel pathways have continued to develop, highlighting low-carbon and in some cases carbon-negative fuel pathways. We discuss the potential for transformative reductions in petroleum use and greenhouse gas emissions through these emerging transportation-sector technologies and trends and present a Clean Transportation Sector Initiative scenario for such reductions, which are summarized in Table ES-1.

  20. Noble Gas Surface Flux Simulations And Atmospheric Transport

    Energy Technology Data Exchange (ETDEWEB)

    Carrigan, Charles R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sun, Yunwei [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Simpson, Matthew D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-30

    Signatures from underground nuclear explosions or UNEs are strongly influenced by the containment regime surrounding them. The degree of gas leakage from the detonation cavity to the surface obviously affects the magnitude of surface fluxes of radioxenon that might be detected during the course of a Comprehensive Test Ban Treaty On-Site Inspection. In turn, the magnitude of surface fluxes will influence the downwind detectability of the radioxenon atmospheric signature from the event. Less obvious is the influence that leakage rates have on the evolution of radioxenon isotopes in the cavity or the downwind radioisotopic measurements that might be made. The objective of this letter report is to summarize our attempt to better understand how containment conditions affect both the detection and interpretation of radioxenon signatures obtained from sampling at the ground surface near an event as well as at greater distances in the atmosphere. In the discussion that follows, we make no attempt to consider other sources of radioactive noble gases such as natural backgrounds or atmospheric contamination and, for simplicity, only focus on detonation-produced radioxenon gases. Summarizing our simulations, they show that the decay of radioxenon isotopes (e.g., Xe-133, Xe-131m, Xe-133m and Xe-135) and their migration to the surface following a UNE means that the possibility of detecting these gases exists within a window of opportunity. In some cases, seeps or venting of detonation gases may allow significant quantities to reach the surface and be released into the atmosphere immediately following a UNE. In other release scenarios – the ones we consider here – hours to days may be required for gases to reach the surface at detectable levels. These release models are most likely more characteristic of “fully contained” events that lack prompt venting, but which still leak gas slowly across the surface for periods of months.

  1. Linking particle and pore-size distribution parameters to soil gas transport properties

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Møldrup, Per; Schjønning, Per

    2012-01-01

    Accurate estimation of soil gas diffusivity (Dp/Do, the ratio of gas diffusion coefficients in soil and free air) and air permeability (ka) from basic texture and pore characteristics will be highly valuable for modeling soil gas transport and emission and their field-scale variations. From......, respectively) and the Campbell water retention parameter b were used to characterize particle and pore size distributions, respectively. Campbell b yielded a wide interval (4.6–26.2) and was highly correlated with α, β, and volumetric clay content. Both Dp/Do and ka followed simple power-law functions (PLFs...

  2. Membranes for Flue Gas Treatment - Transport behavior of water and gas in hydrophilic polymer membranes

    OpenAIRE

    Potreck, Jens

    2009-01-01

    Fossil fuel fired power plants produce electricity and in addition to that large volume flows of flue gas, which mainly contain N2, O2, and CO2, but also large quantities of water vapor. To prevent condensation of the water vapor present in this flue gas stream, water needs to be removed before emission to the atmosphere. Commercial dehydration processes such as the use of a condenser or a desiccant system have several disadvantages and membrane technology is an attractive, energy efficient a...

  3. Effect of biochar on soil structural characteristics: water retention and gas transport

    DEFF Research Database (Denmark)

    Sun, Zhencai; Møldrup, Per; Vendelboe, Anders Lindblad

    Biochar addition to agricultural soil has been reported to reduce climate gas emission, as well as improve soil fertility and crop productivity. Little, however, is known about biochar effects on soil structural characteristics. This study investigates if biochar-application changes soil structural...... characteristics, as indicated from water retention and gas transport measurements on intact soil samples. Soil was sampled from a field experiment on a sandy loam with four control plots (C) without biochar and four plots (B) with incorporated biochar at a rate of 20 tons per hectare (plot size, 6 x 8 m). The C......-gas diffusivity on intact 100cm3 soil samples (5 replicates in each plot). We found that biochar application significantly decreased soil bulk density, hereby creating higher porosity. At the same soil-water matric potential, all the soil-gas phase parameters (air-filled porosity, air permeability and gas...

  4. Auction design for gas pipeline transportation capacity-The case of Nabucco and its open season

    International Nuclear Information System (INIS)

    Pickl, Matthias; Wirl, Franz

    2011-01-01

    As a response to the Russian dominance of the EU's natural gas supplies and the EU's increasing gas demands, major gas pipeline projects are currently under way to enhance the EU's energy supply security. Oftentimes to raise financing and to allocate gas transportation capacities, auctions are carried out to allow gas shippers to book transportation rights. In recent years, auctions have emerged as one of the most successful allocation mechanisms in the microeconomic theory. However, different auction designs can lead to different outcomes making the choice of auction design a decisive one, especially for divisible-good auctions. This paper seeks to give a formulation of an optimal auction design for gas pipeline transportation capacity. Specifically three different mechanisms are tested: (i) NPV allocation; (ii) pro rata allocation; and (iii) optimization. In addition, Nabucco is taken as a case study to empirically show results of such auction designs. Results show that a trade-off between revenue optimization and fair allocation can be observed: allocation per optimization is the favorable auction design when revenue maximization is more important than fair allocation. On the other hand, pro rata allocation is the auction design to be chosen when fairness of allocation is considered most central. - Research highlights: → Auction design for gas pipeline transportation capacity. → Empirical market-survey of Nabucco pipeline project auction as input data. → Testing of three different allocation mechanisms: (i) NPV allocation; (ii) pro rata allocation; and (iii) optimization. → Results show a trade-off between revenue optimization and fair allocation. → Allocation per optimization is the favorable auction design when revenue maximization is more important than fair allocation. → On the other hand, pro rata allocation is the auction design to be chosen when fairness of allocation is considered most central.

  5. Life cycle energy and greenhouse gas emissions from transportation of Canadian oil sands to future markets

    International Nuclear Information System (INIS)

    Tarnoczi, Tyler

    2013-01-01

    Oil sands transportation diversification is important for preventing discounted crude pricing. Current life cycle assessment (LCA) models that assess greenhouse gas (GHG) emissions from crude oil transportation are linearly-scale and fail to account for project specific details. This research sets out to develop a detailed LCA model to compare the energy inputs and GHG emissions of pipeline and rail transportation for oil sands products. The model is applied to several proposed oils sands transportation routes that may serve as future markets. Comparison between transportation projects suggest that energy inputs and GHG emissions show a high degree of variation. For both rail and pipeline transportation, the distance over which the product is transported has a large impact on total emissions. The regional electricity grid and pump efficiency have the largest impact on pipeline emissions, while train engine efficiency and bitumen blending ratios have the largest impact on rail transportation emissions. LCA-based GHG regulations should refine models to account for the range of product pathways and focus efforts on cost-effective emission reductions. As the climate-change impacts of new oil sands transportation projects are considered, GHG emission boundaries should be defined according to operation control. -- Highlights: •A life cycle model is developed to compare transportation of oil sands products. •The model is applied to several potential future oil sands markets. •Energy inputs and GHG emissions are compared. •Model inputs are explored using sensitivity analysis. •Policy recommendations are provided

  6. PUC review of LDC gas purchasing practices and transportation agreements

    International Nuclear Information System (INIS)

    Lemon, R.

    1992-01-01

    The optimal paradigm for the PUC review of LDC purchasing and contracting starts with a regulatory paradigm that assigns risk upon the LDC. There are profits and risks in a market economy. Being exposed to risk causes firms to expend costs to minimize the risk, including lowering costs and altering input combinations. The transition within the industry implies greater need for planning, for optimization based on both economics and engineering, and less upon political directives. But the transition is far more encompassing than adding a new layer of regulatory oversight at the state level. States must revise their regulation to get out front - to give those incentives. The management audits will be internally profitable to the firms. If LDCs don't adjust, there will be other firms that will evaluate where poor management exists within this industry, and they will buy them out and lower the costs both for the profit they can obtain and to the betterment of ratepayers who experience lower rates. An a priori incentive process needs to govern PUC review of purchasing practices and transportation agreements. Lessons can be learned from the competitive market on how to structure this dynamic process which yields consumer benefits. This paper is organized as follows. First it identifies the forces which drive change - both historical bias and new options stemming from federal policy. Second, problems with 'improved' traditional regulatory review are discussed. Third, dimensions to an optimal PUC review process are set forth

  7. Modeling methane fluxes in wetlands with gas-transporting plants. 3. Plot scale.

    NARCIS (Netherlands)

    Segers, R.; Leffelaar, P.A.

    2001-01-01

    A process model based on kinetic principles was developed for methane fluxes from wetlands with gas-transporting plants and a fluctuating water table. Water dynamics are modeled with the 1-D Richards equation. For temperature a standard diffusion equation is used. The depth-dependent dynamics of

  8. Non-equilibrium reacting gas flows kinetic theory of transport and relaxation processes

    CERN Document Server

    Nagnibeda, Ekaterina; Nagnibeda, Ekaterina

    2009-01-01

    This volume develops the kinetic theory of transport phenomena and relaxation processes in the flows of reacting gas mixtures. The theory is applied to the modeling of non-equilibrium flows behind strong shock waves, in the boundary layer, and in nozzles.

  9. Transport of water vapor and inert gas mixtures through highly selective and highly permeable polymer membranes

    NARCIS (Netherlands)

    Metz, S.J.; van de Ven, W.J.C.; Potreck, Jens; Mulder, M.H.V.; Wessling, Matthias

    2005-01-01

    This paper studies in detail the measurement of the permeation properties of highly permeable and highly selective polymers for water vapor/nitrogen gas mixtures. The analysis of the mass transport of a highly permeable polymer is complicated by the presence of stagnant boundary layers at feed and

  10. Fuel-cycle greenhouse gas emissions impacts of alternative transportation fuels and advanced vehicle technologies.

    Science.gov (United States)

    1998-11-15

    At an international conference on global warming, held in Kyoto, Japan, in December 1997, the United States committed to reduce its greenhouse gas (GHG) emissions by 7% over its 1990 level by the year 2012. To help achieve that goal, transportation G...

  11. Quantification of soil pore network complexity with X-ray computed tomography and gas transport measurements

    DEFF Research Database (Denmark)

    Katuwal, Sheela; Arthur, Emmanuel; Tuller, M.

    2015-01-01

    Flow and transport of gases through soils are largely controlled by pore structural attributes. The quantification of pore network characteristics is therefore essential for accurate prediction of air permeability and gas diffusivity. In this study, the pore network characteristics of seven diffe...

  12. Model for ballistic spin-transport in ferromagnet/two-dimensional electron gas/ferromagnet structures

    NARCIS (Netherlands)

    Schapers, T; Nitta, J; Heersche, HB; Takayanagi, H

    The spin dependent conductance of a ferromagnet/two-dimensional electron gas ferromagnet structure is theoretically examined in the ballistic transport regime. It is shown that the spin signal can be improved considerably by making use of the spin filtering effect of a barrier at the ferromagnet

  13. Spin-polarized transport in a two-dimensional electron gas with interdigital-ferromagnetic contacts

    DEFF Research Database (Denmark)

    Hu, C.-M.; Nitta, Junsaku; Jensen, Ane

    2001-01-01

    Ferromagnetic contacts on a high-mobility, two-dimensional electron gas (2DEG) in a narrow gap semiconductor with strong spin-orbit interaction are used to investigate spin-polarized electron transport. We demonstrate the use of magnetized contacts to preferentially inject and detect specific spi...

  14. The Significance of Gas-Phase Mass Transport in Assessment of kchem and Dchem

    DEFF Research Database (Denmark)

    Lohne, Ørjan Fossmark; Søgaard, Martin; Wiik, Kjell

    2013-01-01

    In this work, the validity of electrical conductivity relaxation (ECR) as a method for the assessment of chemical surface exchange, kchem, and bulk diffusion, Dchem, coefficients is investigated with respect to mass transport limitations in the gas phase. A model encompassing both the oxygen...

  15. Gas Transport in Glassy Polymers: Prediction of Diffusional Time Lag

    Directory of Open Access Journals (Sweden)

    Matteo Minelli

    2018-02-01

    Full Text Available The transport of gases in glassy polymeric membranes has been analyzed by means of a fundamental approach based on the nonequilibrium thermodynamic model for glassy polymers (NET-GP that considers the penetrant chemical potential gradient as the actual driving force of the diffusional process. The diffusivity of a penetrant is thus described as the product of a purely kinetic quantity, the penetrant mobility, and a thermodynamic factor, accounting for the chemical potential dependence on its concentration in the polymer. The NET-GP approach, and the nonequilibrium lattice fluid (NELF model in particular, describes the thermodynamic behavior of penetrant/polymer mixtures in the glassy state, at each pressure or composition. Moreover, the mobility is considered to follow a simple exponential dependence on penetrant concentration, as typically observed experimentally, using only two adjustable parameters, the infinite dilution penetrant mobility L10 and the plasticization factor β, both determined from the analysis of the dependence of steady state permeability on upstream pressure. The available literature data of diffusional time lag as a function of penetrant upstream pressure has been reviewed and compared with model predictions, obtained after the values of the two model parameters (L10 and β, have been conveniently determined from steady state permeability data. The model is shown to be able to describe very accurately the experimental time lag behaviors for all penetrant/polymer pairs inspected, including those presenting an increasing permeability with increasing upstream pressure. The model is thus more appropriate than the one based on Dual Mode Sorption, which usually provides an unsatisfactory description of time lag and required an ad hoc modification.

  16. Growth dynamics and gas transport mechanism of nanobubbles in graphene liquid cells

    Science.gov (United States)

    Shin, Dongha; Park, Jong Bo; Kim, Yong-Jin; Kim, Sang Jin; Kang, Jin Hyoun; Lee, Bora; Cho, Sung-Pyo; Hong, Byung Hee; Novoselov, Konstantin S.

    2015-02-01

    Formation, evolution and vanishing of bubbles are common phenomena in nature, which can be easily observed in boiling or falling water, carbonated drinks, gas-forming electrochemical reactions and so on. However, the morphology and the growth dynamics of the bubbles at nanoscale have not been fully investigated owing to the lack of proper imaging tools that can visualize nanoscale objects in the liquid phase. Here, we demonstrate for the first time that the nanobubbles in water encapsulated by graphene membrane can be visualized by in-situ ultra-high vacuum transmission electron microscopy. Our microscopic results indicate two distinct growth mechanisms of merging nanobubbles and the existence of a critical radius of nanobubbles that determines the unusually long stability of nanobubbles. Interestingly, the gas transport through ultrathin water membranes at nanobubble interface is free from dissolution, which is clearly different from conventional gas transport that includes condensation, transmission and evaporation.

  17. Mitigating Wind Induced Noise in Outdoor Microphone Signals Using a Singular Spectral Subspace Method

    Directory of Open Access Journals (Sweden)

    Omar Eldwaik

    2018-01-01

    Full Text Available Wind induced noise is one of the major concerns of outdoor acoustic signal acquisition. It affects many field measurement and audio recording scenarios. Filtering such noise is known to be difficult due to its broadband and time varying nature. In this paper, a new method to mitigate wind induced noise in microphone signals is developed. Instead of applying filtering techniques, wind induced noise is statistically separated from wanted signals in a singular spectral subspace. The paper is presented in the context of handling microphone signals acquired outdoor for acoustic sensing and environmental noise monitoring or soundscapes sampling. The method includes two complementary stages, namely decomposition and reconstruction. The first stage decomposes mixed signals in eigen-subspaces, selects and groups the principal components according to their contributions to wind noise and wanted signals in the singular spectrum domain. The second stage reconstructs the signals in the time domain, resulting in the separation of wind noise and wanted signals. Results show that microphone wind noise is separable in the singular spectrum domain evidenced by the weighted correlation. The new method might be generalized to other outdoor sound acquisition applications.

  18. Performance Analysis of Wind-Induced Piezoelectric Vibration Bimorph Cantilever for Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Gongbo Zhou

    2015-01-01

    Full Text Available Harvesting the energy contained in the running environment of rotating machinery would be a good way to supplement energy to the wireless sensor. In this paper, we take piezoelectric bimorph cantilever beam with parallel connection mode as energy collector and analyze the factors which can influence the generation performance. First, a modal response theory model is built. Second, the static analysis, modal analysis, and piezoelectric harmonic response analysis of the wind-induced piezoelectric bimorph cantilever beam are given in detail. Finally, an experiment is also conducted. The results show that wind-induced piezoelectric bimorph cantilever beam has low resonant frequency and stable output under the first modal mode and can achieve the maximum output voltage under the resonant condition. The output voltage increases with the increase of the length and width of wind-induced piezoelectric bimorph cantilever beam, but the latter increasing amplitude is relatively smaller. In addition, the output voltage decreases with the increase of the thickness and the ratio of metal substrate to piezoelectric patches thickness. The experiment showed that the voltage amplitude generated by the piezoelectric bimorph cantilever beam can reach the value simulated in ANSYS, which is suitable for actual working conditions.

  19. Modeling and Mechanism of Rain-Wind Induced Vibration of Bundled Conductors

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    2016-01-01

    Full Text Available Under the certain rain-wind conditions, bundled conductors exhibit a rain-wind induced large-amplitude vibration. This type of vibration can cause the fatigue fractures of conductors and fatigue failures of spacers, which threaten the safety operation and serviceability of high-voltage transmission line. To reveal the mechanism of rain-wind induced vibration of bundled conductors, a series of 2-dimensional CFD models about the twin bundled conductors with rivulets are developed to obtain the curves of aerodynamic coefficients with the upper rivulet angle. The influences of the forward conductor’s aerodynamic shielding and the upper rivulet’s aerodynamic characteristics on the leeward conductor are discussed. Furthermore, a 2-dimensional 3DOF model for the rain-wind induced vibration of the leeward conductor is established. The model is solved by finite element method and Newmark method, and the effects of the wind velocity and the upper rivulet’s motion on vibration amplitude of the leeward conductor are analyzed. By contrast with the wake-induced vibration, it can easily find that the characteristics of rain-wind vibration are obviously different from those of the wake-induced vibration, and the main reason of the rain-induced vibration may be due to the upper rivulet’s motion.

  20. Three mechanisms model of shale gas in real state transport through a single nanopore

    Science.gov (United States)

    Li, Dongdong; Zhang, Yanyu; Sun, Xiaofei; Li, Peng; Zhao, Fengkai

    2018-02-01

    At present, the apparent permeability models of shale gas consider only the viscous flow and Knudsen diffusion of free gas, but do not take into account the influence of surface diffusion. Moreover, it is assumed that shale gas is in ideal state. In this paper, shale gas is assumed in real state, a new apparent permeability model for shale gas transport through a single nanopore is developed that captures many important migration mechanisms, such as viscous flow and Knudsen diffusion of free gas, surface diffusion of adsorbed gas. According to experimental data, the accuracy of apparent permeability model was verified. What’s more, the effects of pressure and pore radius on apparent permeability, and the effects on the permeability fraction of viscous flow, Knudsen diffusion and surface diffusion were analysed, separately. Finally, the results indicate that the error of the developed model in this paper was 3.02%, which is less than the existing models. Pressure and pore radius seriously affect the apparent permeability of shale gas. When the pore radius is small or pressure is low, the surface diffusion cannot be ignored. When the pressure and the pore radius is big, the viscous flow occupies the main position.

  1. Small gas leakage rate measuring and monitoring system for spent fuel transport/storage cask

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Ryoji [Hitachi Zosen Corp., Tokyo (Japan); Aritomi, Masanori; Matsuzaki, Mitsuo; Kawa, Tsunemichi

    1997-12-01

    A containment function of transport and/or storage casks of radioactive materials is essential to prevent the materials from being released excessively into the environment. It is not practical for containment tests to measure directly the radioactivity release so that gas volumetric leakage rates are usually assessed and gas pressure decrease or increase method is usually applied. As gas flow model for evaluation, the ISO standards has deleted the concept of choked flow which is adopted by ANSI N14.5. Provided that the choked flow is not adopted to the leakage rate evaluation, the criteria of the test should be severe, and a new leakage rate measuring system with high accuracy and reasonable measuring time is required. Transport casks are often inspected in a temporary cask-storage facility where simultaneous measurement of many casks is required. In a storage cask system, multiple casks are monitored on their containment function during a storage period, and the method for simultaneous monitoring at many points for long term is required. In this study, two kinds of small gas leakage rate measuring systems are developed. One is to measure gas leakage rates directly and is called `flow measuring system`, which can measure gas leakage rate of 10{sup -4} to 10{sup -2} cm{sup 3}/s with high accuracy and short measuring time. The other is to measure the pressure decreasing rate and is called `pressure decreasing rate measuring system`, which can monitor the pressure change at many points simultaneously. (author)

  2. Cold flame on Biofilm - Transport of Plasma Chemistry from Gas to Liquid Phase

    Science.gov (United States)

    Kong, Michael

    2014-10-01

    One of the most active and fastest growing fields in low-temperature plasma science today is biological effects of gas plasmas and their translation in many challenges of societal importance such as healthcare, environment, agriculture, and nanoscale fabrication and synthesis. Using medicine as an example, there are already three FDA-approved plasma-based surgical procedures for tissue ablation and blood coagulation and at least five phase-II clinical trials on plasma-assisted wound healing therapies. A key driver for realizing the immense application potential of near room-temperature ambient pressure gas plasmas, commonly known as cold atmospheric plasmas or CAP, is to build a sizeable interdisciplinary knowledge base with which to unravel, optimize, and indeed design how reactive plasma species interact with cells and their key components such as protein and DNA. Whilst a logical objective, it is a formidable challenge not least since existing knowledge of gas discharges is largely in the gas-phase and therefore not directly applicable to cell-containing matters that are covered by or embedded in liquid (e.g. biofluid). Here, we study plasma inactivation of biofilms, a jelly-like structure that bacteria use to protect themselves and a major source of antimicrobial resistance. As 60--90% of biofilm is made of water, we develop a holistic model incorporating physics and chemistry in the upstream CAP-generating region, a plasma-exit region as a buffer for as-phase transport, and a downstream liquid region bordering the gas buffer region. A special model is developed to account for rapid chemical reactions accompanied the transport of gas-phase plasma species through the gas-liquid interface and for liquid-phase chemical reactions. Numerical simulation is used to illustrate how key reactive oxygen species (ROS) are transported into the liquid, and this is supported with experimental data of both biofilm inactivation using plasmas and electron spin spectroscopy (ESR

  3. Barometric gas transport along faults and its application to nuclear test-ban monitoring

    International Nuclear Information System (INIS)

    Carrigan, C.R.; Heinle, R.A.; Hudson, G.M.; Nitao, J.J.; Zucca, J.J.

    1997-05-01

    Underground nuclear explosions produce a unique but evanescent set of radionuclide gases that potentially can be used in the context of an on-site, test-ban monitoring program to differentiate them from other detected events such as earthquakes or mining activity. In Part I of this report we describe an experiment to evaluate the upward transport of gases from an underground explosion using two gas tracers with very different diffusivities that were released in a 400-m-deep, chemical explosive detonation. The less diffusive (more massive) tracer was detected on a nearby geologic fault 50 days following the detonation while the more diffusive tracer was detected 375 days after release. Computer simulations indicate that the arrival time and the chromatographic behavior of transport are characteristic of barometrically induced flow in a fractured, porous matrix regime. For a hypothetical 1-kiloton fission explosion subject to the same weather and gas transport conditions of the chemical explosion, simulations predict the detectability of argon-37 after 80 days in spite of depletion by radioactive decay. Largely because of the earlier arrival of xenon-133, owing to its lower binary gas diffusivity, the exceedingly short lived isotope should also be detectable - arriving about 30 days earlier than argon. In Part II we consider that our prediction of the detectability of argon and xenon is based upon the small volume (0.00001 m 3 ) sampling technique of the NPE tracer-gas sampling study while actual sampling for radionuclides would involve drawing much larger volume (possibly 0.1-1 m 3 ) gas samples from the near-surface. Extraction of such a large volume of gas from 1-5 meter depths in the soil raises the possibility of significant atmospheric infiltration, leading to substantial dilution of the extracted gas sample. However, an infiltration experiment suggests that significant dilution would not, in fact, occur at the most prolific sampling stations of the earlier gas

  4. Preliminary assessment of the availability of U.S. natural gas resources to meet U.S. transportation energy demand

    International Nuclear Information System (INIS)

    Singh, M. K.; Moore, J. S.

    2002-01-01

    Recent studies have indicated that substitutes for conventional petroleum resources will be needed to meet U.S. transportation energy demand in the first half of this century. One possible substitute is natural gas which can be used as a transportation fuel directly in compressed natural gas or liquefied natural gas vehicles or as resource fuel for the production of hydrogen for fuel cell vehicles. This paper contains a preliminary assessment of the availability of U.S. natural gas resources to meet future U.S. transportation fuel demand. Several scenarios of natural gas demand, including transportation demand, in the U.S. to 2050 are developed. Natural gas resource estimates for the U. S. are discussed. Potential Canadian and Mexican exports to the U.S. are estimated. Two scenarios of potential imports from outside North America are also developed. Considering all these potential imports, U.S. natural gas production requirements to 2050 to meet the demand scenarios are developed and compared with the estimates of U.S. natural gas resources. The comparison results in a conclusion that (1) given the assumptions made, there are likely to be supply constraints on the availability of U.S. natural gas supply post-2020 and (2) if natural gas use in transportation grows substantially, it will have to compete with other sectors of the economy for that supply-constrained natural gas

  5. Greenhouse gas emissions from heavy-duty natural gas, hybrid, and conventional diesel on-road trucks during freight transport

    Science.gov (United States)

    Quiros, David C.; Smith, Jeremy; Thiruvengadam, Arvind; Huai, Tao; Hu, Shaohua

    2017-11-01

    Heavy-duty on-road vehicles account for 70% of all freight transport and 20% of transportation-sector greenhouse gas (GHG) emissions in the United States. This study measured three prevalent GHG emissions - carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) - from seven heavy-duty vehicles, fueled by diesel and compressed natural gas (CNG), and compliant to the MY 2007 or 2010 U.S. EPA emission standards, while operated over six routes used for freight movement in California. Total combined (tractor, trailer, and payload) weights were 68,000 ± 1000 lbs. for the seven vehicles. Using the International Panel on Climate Change (IPCC) radiative forcing values for a 100-year time horizon, N2O emissions accounted for 2.6-8.3% of total tailpipe CO2 equivalent emissions (CO2-eq) for diesel vehicles equipped with Diesel Oxidation Catalyst, Diesel Particulate Filter, and Selective Catalytic Reduction system (DOC + DPF + SCR), and CH4 emissions accounted for 1.4-5.9% of CO2-eq emissions from the CNG-powered vehicle with a three-way catalyst (TWC). N2O emissions from diesel vehicles equipped with SCR (0.17-0.30 g/mi) were an order of magnitude higher than diesel vehicles without SCR (0.013-0.023 g/mi) during highway operation. For the vehicles selected in this test program, we measured 11-22% lower CO2-eq emissions from a hybrid compared to conventional diesel vehicles during transport over lower-speed routes of the freight transport system, but 20-27% higher CO2-eq emissions during higher-speed routes. Similarly, a CNG vehicle emitted up to 15% lower CO2-eq compared to conventional diesel vehicles over more neutral-grade highway routes, but emitted up to 12% greater CO2-eq emissions over routes with higher engine loads.

  6. On the development and benchmarking of an approach to model gas transport in fractured media with immobile water storage

    Science.gov (United States)

    Harp, D. R.; Ortiz, J. P.; Pandey, S.; Karra, S.; Viswanathan, H. S.; Stauffer, P. H.; Anderson, D. N.; Bradley, C. R.

    2017-12-01

    In unsaturated fractured media, the rate of gas transport is much greater than liquid transport in many applications (e.g., soil vapor extraction operations, methane leaks from hydraulic fracking, shallow CO2 transport from geologic sequestration operations, and later-time radionuclide gas transport from underground nuclear explosions). However, the relatively immobile pore water can inhibit or promote gas transport for soluble constituents by providing storage. In scenarios with constant pressure gradients, the gas transport will be retarded. In scenarios with reversing pressure gradients (i.e. barometric pressure variations) pore water storage can enhance gas transport by providing a ratcheting mechanism. Recognizing the computational efficiency that can be gained using a single-phase model and the necessity of considering pore water storage, we develop a Richard's solution approach that includes kinetic dissolution/volatilization of constituents. Henry's Law governs the equilibrium gaseous/aqueous phase partitioning in the approach. The approach is implemented in a development branch of the PFLOTRAN simulator. We verify the approach with analytical solutions of: (1) 1D gas diffusion, (2) 1D gas advection, (3) sinusoidal barometric pumping of a fracture, and (4) gas transport along a fracture with uniform flow and diffusive walls. We demonstrate the retardation of gas transport in cases with constant pressure gradients and the enhancement of gas transport with reversing pressure gradients. The figure presents the verification of our approach to the analytical solution of barometric pumping of a fracture from Nilson et al (1991) where the x-axis "Horizontal axis" is the distance into the matrix block from the fracture.

  7. Improving estimates of subsurface gas transport in unsaturated fractured media using experimental Xe diffusion data and numerical methods

    Science.gov (United States)

    Ortiz, J. P.; Ortega, A. D.; Harp, D. R.; Boukhalfa, H.; Stauffer, P. H.

    2017-12-01

    Gas transport in unsaturated fractured media plays an important role in a variety of applications, including detection of underground nuclear explosions, transport from volatile contaminant plumes, shallow CO2 leakage from carbon sequestration sites, and methane leaks from hydraulic fracturing operations. Gas breakthrough times are highly sensitive to uncertainties associated with a variety of hydrogeologic parameters, including: rock type, fracture aperture, matrix permeability, porosity, and saturation. Furthermore, a couple simplifying assumptions are typically employed when representing fracture flow and transport. Aqueous phase transport is typically considered insignificant compared to gas phase transport in unsaturated fracture flow regimes, and an assumption of instantaneous dissolution/volatilization of radionuclide gas is commonly used to reduce computational expense. We conduct this research using a twofold approach that combines laboratory gas experimentation and numerical modeling to verify and refine these simplifying assumptions in our current models of gas transport. Using a gas diffusion cell, we are able to measure air pressure transmission through fractured tuff core samples while also measuring Xe gas breakthrough measured using a mass spectrometer. We can thus create synthetic barometric fluctuations akin to those observed in field tests and measure the associated gas flow through the fracture and matrix pore space for varying degrees of fluid saturation. We then attempt to reproduce the experimental results using numerical models in PLFOTRAN and FEHM codes to better understand the importance of different parameters and assumptions on gas transport. Our numerical approaches represent both single-phase gas flow with immobile water, as well as full multi-phase transport in order to test the validity of assuming immobile pore water. Our approaches also include the ability to simulate the reaction equilibrium kinetics of dissolution

  8. The Effect of Moisture Content On Gas Permeability of Unsaturated Sandstones: Implications For Vapour Transport

    Science.gov (United States)

    Griffiths, K. J.; Bloomfield, J. P.; Williams, P. J.; Gooddy, D. C.

    Work has been undertaken to assess the impact of moisture content on the gas perme- ability of sandstones and the implications this may have for transport of Volatile Or- ganic Carbon compounds (VOCs) within the unsaturated zone. Different lithologies from the Permo-Triassic Sandstones of the UK were selected and laboratory stud- ies conducted to evaluate their permeability and capillary pressure-saturation (PcSw) behaviour. Measured gas permeabilities have been compared with modelled relative permeabilities which have been derived by applying the van Genuchten function to the PcSw curves. For some of the lithologies gas permeability was found to increase by several orders of magnitude as moisture content was reduced to conditions equating to field capacity. Some of the finer-grained lithologies show very little increase in perme- ability even at field capacity. For these lithologies moisture contents within the unsat- urated zone may therefore have considerable implications for the transport of VOCs. Seasonal variations in moisture content may significantly reduce gas permeability in parts of the unsaturated zone at certain times of the year. By identifying which litholo- gies are most sensitive to moisture content related changes in permeability, a coherent model of the pathways and barriers to vapour transport can be developed.

  9. Pore size distribution effect on rarefied gas transport in porous media

    Science.gov (United States)

    Hori, Takuma; Yoshimoto, Yuta; Takagi, Shu; Kinefuchi, Ikuya

    2017-11-01

    Gas transport phenomena in porous media are known to strongly influence the performance of devices such as gas separation membranes and fuel cells. Knudsen diffusion is a dominant flow regime in these devices since they have nanoscale pores. Many experiments have shown that these porous media have complex structures and pore size distributions; thus, the diffusion coefficient in these media cannot be easily assessed. Previous studies have reported that the characteristic pore diameter of porous media can be defined in light of the pore size distribution; however, tortuosity factor, which is necessary for the evaluation of diffusion coefficient, is still unknown without gas transport measurements or simulations. Thus, the relation between pore size distributions and tortuosity factors is required to obtain the gas transport properties. We perform numerical simulations to prove the relation between them. Porous media are numerically constructed while satisfying given pore size distributions. Then, the mean-square displacement simulation is performed to obtain the tortuosity factors of the constructed porous media.. This paper is based on results obtained from a project commissioned by the New Energy and Industrial Development Organization (NEDO).

  10. A liquefied energy chain for transport and utilization of natural gas for power production with CO2 capture and storage - Part 4: Sensitivity analysis of transport pressures and benchmarking with conventional technology for gas transport

    International Nuclear Information System (INIS)

    Aspelund, Audun; Gundersen, Truls

    2009-01-01

    A novel energy and cost effective transport chain for stranded natural gas utilized for power production with CO 2 capture and storage is developed. It includes an offshore section, a combined gas carrier and an integrated receiving terminal. In the offshore section, natural gas (NG) is liquefied to LNG by liquid carbon dioxide (LCO 2 ) and liquid inert nitrogen (LIN), which are used as cold carriers. In the onshore process, the cryogenic exergy in the LNG is utilized to cool and liquefy the cold carriers, LCO 2 and LIN. The transport pressures for LNG, LIN and LCO 2 will influence the thermodynamic efficiency as well as the ship utilization; hence sensitivity analyses are performed, showing that the ship utilization for the payload will vary between 58% and 80%, and the transport chain exergy efficiency between 48% and 52%. A thermodynamically optimized process requires 319 kWh/tonne LNG. The NG lost due to power generation needed to operate the LEC processes is roughly one third of the requirement in a conventional transport chain for stranded NG gas with CO 2 capture and sequestration (CCS)

  11. First in situ determination of gas transport coefficients (DO2, DAr and DN2) from bulk gas concentration measurements (O2, N2, Ar) in natural sea ice

    DEFF Research Database (Denmark)

    Crabeck, O.; Delille, B.; Rysgaard, Søren

    2014-01-01

    We report bulk gas concentrations of O2, N2, and Ar, as well as their transport coefficients, in natural landfast subarctic sea ice in southwest Greenland. The observed bulk ice gas composition was 27.5% O2, 71.4% N2, and 1.09% Ar. Most previous studies suggest that convective transport is the main...... evolution of an internal gas peak within the ice, we deduced the bulk gas transport coefficients for oxygen (DO2), argon (DAr), and nitrogen (DN2). The values fit to the few existing estimates from experimental work, and are close to the diffusivity values in water (1025 cm2 s21). We suggest that gas...

  12. Application of CFRP with High Hydrogen Gas Barrier Characteristics to Fuel Tanks of Space Transportation System

    Science.gov (United States)

    Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo

    In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.

  13. CASCADER: An m-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Cawlfield, D.E.; Been, K.B.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

    1993-06-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or diffusion. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. This is volume two to the CASCADER series, titled CASCADR8. It embodies the concepts presented in volume one of this series. To properly understand how the CASCADR8 model works, the reader should read volume one first. This volume presents the input and output file structure for CASCADR8, and a set of realistic scenarios for buried sources of radon gas

  14. CASCADER: An M-chain gas-phase radionuclide transport and fate model

    International Nuclear Information System (INIS)

    Cawlfield, D.E.; Emer, D.F.; Lindstrom, F.T.; Shott, G.J.

    1993-09-01

    Chemicals and radionuclides move either in the gas-phase, liquid-phase, or both phases in soils. They may be acted upon by either biological or abiotic processes through advection and/or dispersion. Additionally during the transport of parent and daughter radionuclides in soil, radionuclide decay may occur. This version of CASCADER called CASCADR9 starts with the concepts presented in volumes one and three of this series. For a proper understanding of how the model works, the reader should read volume one first. Also presented in this volume is a set of realistic scenarios for buried sources of radon gas, and the input and output file structure for CASCADER9

  15. There Will Be Gas: Gazprom's Transport Strategy in Europe

    International Nuclear Information System (INIS)

    Bros, Aurelie

    2015-10-01

    The key role played by Ukraine in the transport of Russian gas and the underground gas storage facilities are a legacy of the Soviet era. The collapse of the USSR forced the Russian Federation to formulate its own national energy strategy after the Soviet Republics and satellite states went independent, to readjust it over time and to define new relationships with these countries regarding the gas sector. The collapse also had the effect of complicating gas transport after 1991 - a reality that had never been a thorny issue before since Ukraine had been formerly integrated into the territory of the Soviet Union. From the mid-1990's onwards, Gazprom has repeatedly tried to control gas transit through Ukraine and other infrastructures from the Soviet era. This effort has been double-pronged: the acquisition of shares in the Ukrainian transit sector (100% owned by the Ukrainian state) and the creation of a joint venture in order to exercise indirect control over the network. Neither of these resulted in success. During the 2000's, especially after the 2004 Orange Revolution, most of the arguments between Ukraine and Russia were based on transit contract, supply agreements, gas debts and management of the transit network. Such a situation led Gazprom-with the support of the Russian government-to adopt a more assertive stance toward Ukraine, i.e. cutting off gas flows intended for Ukraine. The two most serious crises of this nature occurred in 2006 and 2009. Gazprom developed major projects in collaboration with European energy companies to diversify gas supply routes at a time when it anticipated a major increase in European gas demand and the import needs of Russian gas. The Nord Stream pipeline is certainly the best illustration of Gazprom's bypassing policy. From a Russian perspective, transporting gas through the Nord Stream pipeline is much more attractive than Ukraine as Gazprom thereby avoids political tensions, keeps control of the situation and

  16. CNG (compressed natural gas) as fuel for the transport sector in Trinidad and Tobago

    Energy Technology Data Exchange (ETDEWEB)

    So`Brien, G.C.; Persad, P.; Satcunanathan, S. [University of the West Indies, St. Augustine (Trinidad)

    1996-08-01

    Several studies have established that Trinidad and Tobago is well positioned to consider the substitution of compressed natural gas (CNG) for gasoline or diesel in the transport sector. Consequently a programme of conversion of private motors was initiated. Despite considerable advertisement programs projecting CNG as an environmentally friendly and cheap fuel, there is not yet widespread acceptance of the technology. The reasons for this are analysed. It is recommended that the policy of CNG usage be reviewed and the emphasis be shifted to transport fleets. It is also recommended that tax credits be considered as an incentive to users. (author)

  17. Light-induced cross transport phenomena in a single-component gas

    Energy Technology Data Exchange (ETDEWEB)

    Chermyaninov, I. V.; Chernyak, V. G., E-mail: Vladimir.Chernyak@usu.ru [Ural Federal University (Russian Federation)

    2013-07-15

    The cross transport processes that occur in a single-component gas in a capillary and are caused by resonance laser radiation and pressure and temperature gradients are studied. An expression for entropy production is derived using a system of kinetic Boltzmann equations in a linear approximation. The kinetic coefficients that determine the transport processes are shown to satisfy the Onsager reciprocal relations at any Knudsen numbers and any character of the elastic interaction of gas particles with the capillary surface. The light-induced baro- and thermoeffects that take place in a closed heat-insulated system in the field of resonance laser radiation are considered. Analytical expressions are obtained for the Onsager coefficients in an almost free-molecular regime. The light-induced pressure and temperature gradients that appear in a closed heat-insulated capillary under typical experimental conditions are numerically estimated.

  18. Gas transport through porous media; Sur le transport des gaz a travers les milieux poreux

    Energy Technology Data Exchange (ETDEWEB)

    Breton, J.P. [Commissariat a l' Energie Atomique Saclay (France). Centre d' Etudes Nucleaires

    1968-06-01

    In the first part of this work we derive a rigorous transport theory for a mixture of gases passing through a bed of spheres, when the temperature is uniform. We solve the Boltzmann equation, putting boundary conditions in the solution. Two different methods are used, according to the nature of the flow. The second part deals with the experimental work: measurements of permeability, of separation and of interdiffusion. In the last part, with the help of the new theory presented here, we are for the first time able to explain all the experimental data. (author) [French] Dans la premiere partie de ce travail nous developpons une theorie rigoureuse du transport d'un melange de gaz a travers un lit de spheres, quand la temperature est uniforme. Nous integrons l'equation de Boltzmann en introduisant des conditions aux limites dans la solution. Nous utilisons deux methodes differentes selon le regime d'ecoulement. La seconde partie est consacree a l'etude experimentale: mesures de permeametrie, de separation et d'interdiffusion. Dans la derniere partie, a l'aide de la nouvelle theorie developpee ici, nous expliquons tous les resultats experimentaux, ce qui n'avait pas ete fait jusque la. (auteur)

  19. Gas Phase Transport, Adsorption and Surface Diffusion in Porous Glass Membrane

    Czech Academy of Sciences Publication Activity Database

    Yang, J.; Čermáková, Jiřina; Uchytil, Petr; Hamel, Ch.; Seidel-Morgenstern, A.

    2005-01-01

    Roč. 104, 2-4 (2005), s. 344-351 ISSN 0920-5861. [International Conference on Catalysis in Membrane Reactors /6./. Lahnstein, 06.07.2004-09.07.2004] R&D Projects: GA AV ČR(CZ) IAA4072402 Institutional research plan: CEZ:AV0Z40720504 Keywords : gas phase transport * vycor glass * adsorption Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.365, year: 2005

  20. Liquefied natural gas as a transportation fuel for heavy-duty trucks: Volume I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    This document contains Volume 1 of a three-volume manual designed for use with a 2- to 3-day liquefied natural gas (LNG) training course. Transportation and off-road agricultural, mining, construction, and industrial applications are discussed. This volume provides a brief introduction to the physics and chemistry of LNG; an overview of several ongoing LNG projects, economic considerations, LNG fuel station technology, LNG vehicles, and a summary of federal government programs that encourage conversion to LNG.

  1. Fuel-cycle greenhouse gas emissions impacts of alternative transportation fuels and advanced vehicle technologies

    International Nuclear Information System (INIS)

    Wang, M. Q.

    1998-01-01

    At an international conference on global warming, held in Kyoto, Japan, in December 1997, the United States committed to reduce its greenhouse gas (GHG) emissions by 7% over its 1990 level by the year 2012. To help achieve that goal, transportation GHG emissions need to be reduced. Using Argonne's fuel-cycle model, I estimated GHG emissions reduction potentials of various near- and long-term transportation technologies. The estimated per-mile GHG emissions results show that alternative transportation fuels and advanced vehicle technologies can help significantly reduce transportation GHG emissions. Of the near-term technologies evaluated in this study, electric vehicles; hybrid electric vehicles; compression-ignition, direct-injection vehicles; and E85 flexible fuel vehicles can reduce fuel-cycle GHG emissions by more than 25%, on the fuel-cycle basis. Electric vehicles powered by electricity generated primarily from nuclear and renewable sources can reduce GHG emissions by 80%. Other alternative fuels, such as compressed natural gas and liquefied petroleum gas, offer limited, but positive, GHG emission reduction benefits. Among the long-term technologies evaluated in this study, conventional spark ignition and compression ignition engines powered by alternative fuels and gasoline- and diesel-powered advanced vehicles can reduce GHG emissions by 10% to 30%. Ethanol dedicated vehicles, electric vehicles, hybrid electric vehicles, and fuel-cell vehicles can reduce GHG emissions by over 40%. Spark ignition engines and fuel-cell vehicles powered by cellulosic ethanol and solar hydrogen (for fuel-cell vehicles only) can reduce GHG emissions by over 80%. In conclusion, both near- and long-term alternative fuels and advanced transportation technologies can play a role in reducing the United States GHG emissions

  2. Fuel-cycle greenhouse gas emissions impacts of alternative transportation fuels and advanced vehicle technologies.

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M. Q.

    1998-12-16

    At an international conference on global warming, held in Kyoto, Japan, in December 1997, the United States committed to reduce its greenhouse gas (GHG) emissions by 7% over its 1990 level by the year 2012. To help achieve that goal, transportation GHG emissions need to be reduced. Using Argonne's fuel-cycle model, I estimated GHG emissions reduction potentials of various near- and long-term transportation technologies. The estimated per-mile GHG emissions results show that alternative transportation fuels and advanced vehicle technologies can help significantly reduce transportation GHG emissions. Of the near-term technologies evaluated in this study, electric vehicles; hybrid electric vehicles; compression-ignition, direct-injection vehicles; and E85 flexible fuel vehicles can reduce fuel-cycle GHG emissions by more than 25%, on the fuel-cycle basis. Electric vehicles powered by electricity generated primarily from nuclear and renewable sources can reduce GHG emissions by 80%. Other alternative fuels, such as compressed natural gas and liquefied petroleum gas, offer limited, but positive, GHG emission reduction benefits. Among the long-term technologies evaluated in this study, conventional spark ignition and compression ignition engines powered by alternative fuels and gasoline- and diesel-powered advanced vehicles can reduce GHG emissions by 10% to 30%. Ethanol dedicated vehicles, electric vehicles, hybrid electric vehicles, and fuel-cell vehicles can reduce GHG emissions by over 40%. Spark ignition engines and fuel-cell vehicles powered by cellulosic ethanol and solar hydrogen (for fuel-cell vehicles only) can reduce GHG emissions by over 80%. In conclusion, both near- and long-term alternative fuels and advanced transportation technologies can play a role in reducing the United States GHG emissions.

  3. Synthesis and Transport Properties of Novel MOF/PIM-1/MOF Sandwich Membranes for Gas Separation

    Directory of Open Access Journals (Sweden)

    Alessio Fuoco

    2017-02-01

    Full Text Available Metal-organic frameworks (MOFs were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1. Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8 and Copper benzene tricarboxylate ((HKUST-1, were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes. The pure gas permeabilities of He, H2, O2, N2, CH4, CO2 were studied to understand the effect of the surface modification on the basic transport properties and evaluate the potential use of these membranes for industrially relevant gas separations. The pure gas transport was discussed in terms of permeability and selectivity, highlighting the effect of the MOF growth on the diffusion coefficients of the gas in the new composite polymer membranes. The results confirm that the growth of MOFs on polymer membranes can enhance the selectivity of the appropriately functionalized PIM-1, without a dramatic decrease of the permeability.

  4. Synthesis and Transport Properties of Novel MOF/PIM-1/MOF Sandwich Membranes for Gas Separation.

    Science.gov (United States)

    Fuoco, Alessio; Khdhayyer, Muhanned R; Attfield, Martin P; Esposito, Elisa; Jansen, Johannes C; Budd, Peter M

    2017-02-11

    Metal-organic frameworks (MOFs) were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1). Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8) and Copper benzene tricarboxylate ((HKUST-1), were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA) -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes. The pure gas permeabilities of He, H₂, O₂, N₂, CH₄, CO₂ were studied to understand the effect of the surface modification on the basic transport properties and evaluate the potential use of these membranes for industrially relevant gas separations. The pure gas transport was discussed in terms of permeability and selectivity, highlighting the effect of the MOF growth on the diffusion coefficients of the gas in the new composite polymer membranes. The results confirm that the growth of MOFs on polymer membranes can enhance the selectivity of the appropriately functionalized PIM-1, without a dramatic decrease of the permeability.

  5. Wind-induced response of CN-Tower: comparison of model and full scale

    International Nuclear Information System (INIS)

    Monbaliu, J.; Ruigrok, C.; Isyumov, N.

    1985-01-01

    The approximately 555-m high CN Communications Tower in Toronto has now been operational for nearly a decade. The action of wind on this tower was extensively tested at the Boundary Layer Wind Tunnel Laboratory during the design of the tower. This study provided information on the overall wind loads and responses of the structure, the action of wind on various components, and its effects on the tower performance including transmission quality. A program of monitoring and recording the wind induced response and various meteorological data was started in 1977. This paper presents some results of that program and makes comparisons with wind tunnel model data. (author)

  6. A risk analysis for gas transport network planning expansion under regulatory uncertainty in Western Europe

    International Nuclear Information System (INIS)

    Pelletier, C.; Wortmann, J.C.

    2009-01-01

    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. In this paper a multi-stage linear program is used to simulate the repartition of the natural gas flow in an interconnected grid system on a succession of contracting periods. By this simulation, the risk linked to infrastructure investment is assessed. The risk measured can be seen as the probability of a negative present net value for the investment. The model is applied on an example of two grids that are on alternative routes serving same destinations. When applied to a specific situation of North-West Europe (Germany and The Netherlands), the model clearly demonstrates that the risks turn out to be too high to invest: there are hardly any scenarios under which an acceptable ROI will be realized. Given the current tariff policy and current publicly available forecasts of demand and supply, it is unlikely that market forces will attract additional investments in transportation capacity. This reluctance to invest can be prohibitive for further growth of supply if the demand would increase significantly

  7. GH-3PAD - a new numerical solver for multiphase transport in porous media - new insights on gas hydrate and free gas co-existence

    Science.gov (United States)

    Burwicz, E.; Rupke, L.; Wallmann, K.

    2013-12-01

    Gas Hydrate-3 Phase Advanced Dynamics (GH-3PAD) code has been developed to study the geophysical and biochemical processes associated with gas hydrate as well as free methane gas formation and dissolution in marine sediments. Biochemical processes influencing in-situ organic carbon decay and, therefore, gas hydrate formation, such as Anaerobic Oxidation of Methane (AOM), sulfate reduction, and methanogenesis have been considered. The new model assumes a Lagrangian reference frame that is attached to the deposited sedimentary layers, which compact according to their individual lithological properties. Differential motion of the pore fluids and free gas is modeled as Darcy flow. Gas hydrate and free gas formation is either controlled by 1) instant gas hydrate crystallization assuming local thermodynamical equilibrium or by a 2) kinetically controlled rate of gas hydrate growth. The thermal evolution is computed from an energy equation that includes contributions from all phases present in the model (sediment grains, saline pore fluids, gas hydrate, and free gas). A first application of the GH-3PAD model has been the Blake Ridge Site, offshore South Carolina. Here seismic and well data points to the out-of-equilibrium co-existence of gas hydrate and free gas. It has been reported that these two distinct phases appear within sediment column with a gaseous phase tending to migrate upwards throughout the Gas Hydrate Stability Zone (GHSZ) until it reaches the seafloor despite relatively low gas hydrate content (4 - 7 vol. % after Paull et al., 1996). With the GH-3PAD model we quantify the complex transport- reaction processes that control three phase (gas hydrate, free gas, and dissolved CH4) out-of-equilibrium state. References: Paull C. K., Matsumoto R., Wallace P. J., 1996. 9. Site 997, Shipboard Scientific Party. Proceeding of the Ocean Drilling Program, Initial Reports, Vol. 164.

  8. Heat transport and afterheat removal for gas cooled reactors under accident conditions

    International Nuclear Information System (INIS)

    2001-01-01

    The Co-ordinated Research Project (CRP) on Heat Transport and Afterheat Removal for Gas Cooled Reactors Under Accident Conditions was organized within the framework of the International Working Group on Gas Cooled Reactors (IWGGCR). This International Working Group serves as a forum for exchange of information on national programmes, provides advice to the IAEA on international co-operative activities in advanced technologies of gas cooled reactors (GCRs) and supports the conduct of these activities. Advanced GCR designs currently being developed are predicted to achieve a high degree of safety through reliance on inherent safety features. Such design features should permit the technical demonstration of exceptional public protection with significantly reduced emergency planning requirements. For advanced GCRs, this predicted high degree of safety largely derives from the ability of the ceramic coated fuel particles to retain the fission products under normal and accident conditions, the safe neutron physics behaviour of the core, the chemical stability of the core and the ability of the design to dissipate decay heat by natural heat transport mechanisms without reaching excessive temperatures. Prior to licensing and commercial deployment of advanced GCRs, these features must first be demonstrated under experimental conditions representing realistic reactor conditions, and the methods used to predict the performance of the fuel and reactor must be validated against these experimental data. Within this CRP, the participants addressed the inherent mechanisms for removal of decay heat from GCRs under accident conditions. The objective of this CRP was to establish sufficient experimental data at realistic conditions and validated analytical tools to confirm the predicted safe thermal response of advance gas cooled reactors during accidents. The scope includes experimental and analytical investigations of heat transport by natural convection conduction and thermal

  9. Regional disparity of urban passenger transport associated GHG (greenhouse gas) emissions in China: A review

    International Nuclear Information System (INIS)

    Hao, Han; Geng, Yong; Wang, Hewu; Ouyang, Minggao

    2014-01-01

    With China’s urbanization and motorization, greenhouse gas (GHG) emissions from urban passenger transport increased rapidly over recent years. As we estimated, China’s urban passenger transport associated motorized travel, energy consumption and lifecycle GHG emissions reached 2815 billion passenger kilometers (pkm), 77 million tons of oil equivalent (toe) and 335 million ton CO 2 equivalent in 2010, over half of which were located in eastern provinces. Over national level, GHG emissions by private passenger vehicles, business passenger vehicles, taxis, motorcycles, E-bikes, transit buses and urban rails accounted for 57.7%, 13.0%, 7.7%, 8.6%, 1.8%, 10.5% and 0.7% of the total. Significant regional disparity was observed. The province-level per capita GHG emissions ranged from 285 kg/capita in Guizhou to 1273 kg/capita in Beijing, with national average of 486 kg/capita. Depending on province context and local policy orientation, the motorization pathways of China’s several highest motorized provinces are quite diverse. We concluded that motorization rate and transport structure were the substantial factors determining urban passenger transport associated GHG emissions. Considering the great potential of urban passenger transport growth in China, policies guiding the optimization of transport structure should be in place with priority in eastern provinces. - Highlights: • Province-leveled motorized travel, energy consumption and GHG emissions in China were studied. • Significant regional disparities on urban passenger transport were observed. • Region-specific sustainable transport energy policies were discussed

  10. Revisiting low-fidelity two-fluid models for gas-solids transport

    Science.gov (United States)

    Adeleke, Najeem; Adewumi, Michael; Ityokumbul, Thaddeus

    2016-08-01

    Two-phase gas-solids transport models are widely utilized for process design and automation in a broad range of industrial applications. Some of these applications include proppant transport in gaseous fracking fluids, air/gas drilling hydraulics, coal-gasification reactors and food processing units. Systems automation and real time process optimization stand to benefit a great deal from availability of efficient and accurate theoretical models for operations data processing. However, modeling two-phase pneumatic transport systems accurately requires a comprehensive understanding of gas-solids flow behavior. In this study we discuss the prevailing flow conditions and present a low-fidelity two-fluid model equation for particulate transport. The model equations are formulated in a manner that ensures the physical flux term remains conservative despite the inclusion of solids normal stress through the empirical formula for modulus of elasticity. A new set of Roe-Pike averages are presented for the resulting strictly hyperbolic flux term in the system of equations, which was used to develop a Roe-type approximate Riemann solver. The resulting scheme is stable regardless of the choice of flux-limiter. The model is evaluated by the prediction of experimental results from both pneumatic riser and air-drilling hydraulics systems. We demonstrate the effect and impact of numerical formulation and choice of numerical scheme on model predictions. We illustrate the capability of a low-fidelity one-dimensional two-fluid model in predicting relevant flow parameters in two-phase particulate systems accurately even under flow regimes involving counter-current flow.

  11. Vadose Zone Fate and Transport Simulation of Chemicals Associated with Coal Seam Gas Extraction

    Science.gov (United States)

    Simunek, J.; Mallants, D.; Jacques, D.; Van Genuchten, M.

    2017-12-01

    The HYDRUS-1D and HYDRUS (2D/3D) computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this presentation is to provide an overview of the HYDRUS models and their add-on modules, and to demonstrate applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the vadose zone. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated) provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the coupled HYDRUS-PHREEQC module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in the vadose zone leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration is complexation of

  12. Parameter Analysis on Wind-Induced Vibration of UHV Cross-Rope Suspension Tower-Line

    Directory of Open Access Journals (Sweden)

    Xilai Li

    2017-01-01

    Full Text Available This paper analyzes the influences of important structural design parameters on the wind-induced response of cross-rope suspension tower-line. A finite element model of cross-rope suspension tower-line system is established, and the dynamic time-history analysis with harmonic wave superposition method is conducted. The two important structural design parameters such as initial guy pretension and sag-span ratio of suspension-rope are studied, as well as their influences on the three wind-induced vibration responses such as tensile force on guys, the reaction force on mast supports, and the along-wind displacement of the mast top; the results show that the value of sag-span ratio of suspension-rope should not be less than 1/9 and the value of guy pretension should be less than 30% of its design bearing capacity. On this occasion, the tension in guys and compression in masts would be maintained in smaller values, which can lead to a much more reasonable structure.

  13. Wind-induced transmission tower foundation loads. A field study-design code comparison

    Energy Technology Data Exchange (ETDEWEB)

    Savory, E. [Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ont. (Canada); Parke, G.A.R.; Disney, P.; Toy, N. [School of Engineering, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2008-06-15

    This paper presents a comparison between the wind-induced foundation loads measured on a type L6 transmission line tower during a field study in the UK and those computed using the UK Code of Practice for lattice tower and transmission line design (BS8100). In this work, the Code provisions have been generalised to give the wind-induced strain in each of the tower legs immediately above the foundation as a function of wind direction and wind speed at the top of the tower. The complete data set from the field monitoring has been decomposed to provide a similar formulation for comparison purposes. The analysis shows excellent agreement between the Code calculations and the measured results, within the overall accuracy of the field data. This indicates that, at least for the tower type examined here, the existing design Code provides a reliable transformation of the local wind speed at the top of the tower into tension and compression loads on the foundations. (author)

  14. Wind-induced ventilation of the giant nests of the leaf-cutting ant Atta vollenweideri

    Science.gov (United States)

    Kleineidam, Christoph; Ernst, Roman; Roces, Flavio

    2001-06-01

    To understand the significance of elaborate nest architecture for the control of nest climate, we investigated the mechanisms governing nest ventilation in a large field nest of Atta vollenweideri. Surface wind, drawing air from the central tunnels of the nest mound, was observed to be the main driving force for nest ventilation during summer. This mechanism of wind-induced ventilation has so far not been described for social insect colonies. Thermal convection, another possible force driving ventilation, contributed very little. According to their predominant airflow direction, two functionally distinct tunnel groups were identified: outflow tunnels in the upper, central region, and inflow tunnels in the lower, peripheral region of the nest mound. The function of the tunnels was independent of wind direction. Outflow of air through the central tunnels was followed by a delayed inflow through the peripheral tunnels. Leaf-cutting ants design the tunnel openings on the top of the nest with turrets which may reinforce wind-induced nest ventilation.

  15. Evaluation and analysis method for natural gas hydrate storage and transportation processes

    International Nuclear Information System (INIS)

    Hao Wenfeng; Wang Jinqu; Fan Shuanshi; Hao Wenbin

    2008-01-01

    An evaluation and analysis method is presented to investigate an approach to scale-up a hydration reactor and to solve some economic problems by looking at the natural gas hydrate storage and transportation process as a whole. Experiments with the methane hydration process are used to evaluate the whole natural gas hydrate storage and transportation process. The specific contents and conclusions are as follows: first, batch stirring effects and load coefficients are studied in a semi-continuous stirred-tank reactor. Results indicate that batch stirring and appropriate load coefficients are effective in improving hydrate storage capacity. In the experiments, appropriate values for stirring velocity, stirring time and load coefficient were found to be 320 rpm, 30 min and 0.289, respectively. Second, throughput and energy consumption of the reactor for producing methane hydrates are calculated by mass and energy balance. Results show that throughput of this is 1.06 kg/d, with a product containing 12.4% methane gas. Energy consumption is 0.19 kJ, while methane hydrates containing 1 kJ heat are produced. Third, an energy consumption evaluation parameter is introduced to provide a single energy consumption evaluation rule for different hydration reactors. Parameter analyses indicate that process simplicity or process integration can decrease energy consumption. If experimental gas comes from a small-scale natural gas field and the energy consumption is 0.02 kJ when methane hydrates containing 1 kJ heat are produced, then the decrease is 87.9%. Moreover, the energy consumption evaluation parameter used as an economic criterion is converted into a process evaluation parameter. Analyses indicate that the process evaluation parameter is relevant to technology level and resource consumption for a system, which can make it applicable to economic analysis and venture forecasting for optimal capital utilization

  16. Approximating the nonlinear density dependence of electron transport coefficients and scattering rates across the gas-liquid interface

    Science.gov (United States)

    Garland, N. A.; Boyle, G. J.; Cocks, D. G.; White, R. D.

    2018-02-01

    This study reviews the neutral density dependence of electron transport in gases and liquids and develops a method to determine the nonlinear medium density dependence of electron transport coefficients and scattering rates required for modeling transport in the vicinity of gas-liquid interfaces. The method has its foundations in Blanc’s law for gas-mixtures and adapts the theory of Garland et al (2017 Plasma Sources Sci. Technol. 26) to extract electron transport data across the gas-liquid transition region using known data from the gas and liquid phases only. The method is systematically benchmarked against multi-term Boltzmann equation solutions for Percus-Yevick model liquids. Application to atomic liquids highlights the utility and accuracy of the derived method.

  17. Describing and compensating gas transport dynamics for accurate instantaneous emission measurement

    Science.gov (United States)

    Weilenmann, Martin; Soltic, Patrik; Ajtay, Delia

    Instantaneous emission measurements on chassis dynamometers and engine test benches are becoming increasingly usual for car-makers and for environmental emission factor measurement and calculation, since much more information about the formation conditions can be extracted than from the regulated bag measurements (integral values). The common exhaust gas analysers for the "regulated pollutants" (carbon monoxide, total hydrocarbons, nitrogen oxide, carbon dioxide) allow measurement at a rate of one to ten samples per second. This gives the impression of having after-the-catalyst emission information with that chronological precision. It has been shown in recent years, however, that beside the reaction time of the analysers, the dynamics of gas transport in both the exhaust system of the car and the measurement system last significantly longer than 1 s. This paper focuses on the compensation of all these dynamics convoluting the emission signals. Most analysers show linear and time-invariant reaction dynamics. Transport dynamics can basically be split into two phenomena: a pure time delay accounting for the transport of the gas downstream and a dynamic signal deformation since the gas is mixed by turbulence along the way. This causes emission peaks to occur which are smaller in height and longer in time at the sensors than they are after the catalyst. These dynamics can be modelled using differential equations. Both mixing dynamics and time delay are constant for modelling a raw gas analyser system, since the flow in that system is constant. In the exhaust system of the car, however, the parameters depend on the exhaust volume flow. For gasoline cars, the variation in overall transport time may be more than 6 s. It is shown in this paper how all these processes can be described by invertible mathematical models with the focus on the more complex case of the car's exhaust system. Inversion means that the sharp emission signal at the catalyst out location can be

  18. The contribution of diffusion to methane transport in deep underground gas deposits; Der Beitrag der Diffusion zum Methantransport in tiefliegenden Gas-Lagerstaetten

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, W. [Institut fuer Erdoel- und Erdgasforschung, Clausthal-Zellerfeld (Germany)

    1998-12-31

    Optimisation of gas production necessitates accurate knowledge of gas transport mechanisms. In view of the extreme temperatures, pressures, and permeability conditions of underground gas deposits, linear transfer of existing knowledge will be inappropriate. The author therefore uses a simple capillary bundle model with exemplary pressures, temperatures and permeabilities in order to assess the contribution of transport by diffusion. The diffusion coefficients, which are required for this and so far could not be measured under pressure, were determined by a new experimental method whose results will permit a better interpretation of the concentration dependence of the diffusion coefficient. The velocity of methane inflow and outflow in the water-filled pore space may provide knowledge on problems of gas storage in the pore space. (orig.) [Deutsch] Fuer den Foerderprozess und insbesondere seine Optimierung ist eine genaue Kenntnis der Transportmechanismen wesentlich. Unter den drastischen Bedingungen fuer Temperatur, Druck und Permeabilitaet tiefliegender Gas-Lagerstaetten mag die Uebertragung der bisherigen Vorstellungen ueber den Transport in der Lagerstaette zu einer unvollstaendigen Beschreibung fuehren. Unter Anwendung eines einfachen Kapillarbuendelmodells wird mit Beispielen fuer Druck, Temperatur und Permeabilitaet der moegliche Beitrag des Transports durch Diffusion abgeschaetzt. Zur Bestimmung der hierfuer notwendigen und bisher unter Druckbeaufschlagung nicht gemessenen Diffusionskoeffizienten wurde eine neue experimentelle Methode angewandt, deren Ergebnisse eine weiterfuehrende Interpretation der Konzentrationsabhaengigkeit des Diffusionskoeffizienten ermoeglichen. Auch fuer Fragestellungen der Speicherung von Gas im Porenraum kann die Geschwindigkeit der Ein- und Ausloesung von Methan im wasserhaltigen Porenraum von Interesse sein. (orig.)

  19. Gas Transport and Control in Thick-Liquid Inertial Fusion PowerPlants

    Energy Technology Data Exchange (ETDEWEB)

    Debonnel, Christophe Sylvain [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    Among the numerous potential routes to a commercial fusion power plant, the inertial path with thick-liquid protection is explored in this doctoral dissertation. Gas dynamics phenomena in such fusion target chambers have been investigated since the early 1990s with the help of a series of simulation codes known as TSUNAMI. For this doctoral work, the code was redesigned and rewritten entirely to enable the use of modern programming techniques, languages and software; improve its user-friendliness; and refine its ability to model thick-liquid protected chambers. The new ablation and gas dynamics code is named “Visual Tsunami” to emphasize its graphics-based pre- and post-processors. It is aimed at providing a versatile and user-friendly design tool for complex systems for which transient gas dynamics phenomena play a key role. Simultaneously, some of these improvements were implemented in a previous version of the code; the resulting code constitutes the version 2.8 of the TSUNAMI series. Visual Tsunami was used to design and model the novel Condensation Debris Experiment (CDE), which presents many aspects of a typical Inertial Fusion Energy (IFE) system and has therefore been used to exercise the code. Numerical and experimental results are in good agreement. In a heavy-ion IFE target chamber, proper beam and target propagation set stringent requirements for the control of ablation debris transport in the target chamber and beam tubes. When the neutralized ballistic transport mode is employed, the background gas density should be adequately low and the beam tube metallic surfaces upstream of the neutralizing region should be free of contaminants. TSUNAMI 2.8 was used for the first simulation of gas transport through the complex geometry of the liquid blanket of a hybrid target chamber and beam lines. Concurrently, the feasibility of controlling the gas density was addressed with a novel beam tube design, which introduces magnetic shutters and a long low

  20. Life cycle greenhouse emissions of compressed natural gas-hydrogen mixtures for transportation in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, P. [Instituto de Energia y Desarrollo Sustentable, CNEA, CONICET, Av. del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina); Dawidowski, L.; Gomez, D. [Gerencia Quimica, CNEA, Av. Gral. Paz 1499, San Martin (Argentina); Pasquevich, D. [Instituto de Energia y Desarrollo Sustentable, CNEA, CONICET, Av. del Libertador 8250, Ciudad Autonoma de Buenos Aires (Argentina); Centro Atomico Bariloche, CNEA, Av. Bustillo 9500, S.C. de Bariloche (Argentina)

    2010-06-15

    We have developed a model to assess the life cycle greenhouse emissions of compressed natural gas-hydrogen (CNG-H{sub 2}) mixtures used for transportation in Argentina. The overall fuel life cycle is assessed through a well-to-wheel (WTW) analysis for different hydrogen generation and distribution options. The combustion stage in road vehicles is modeled using the COPERT IV model. Hydrogen generation options include classical steam methane reforming (SMR) and water electrolysis (WE) in central plants and distributed facilities at the refueling stations. Centralized hydrogen generation by electrolysis in nuclear plants as well as the use of solar photovoltaic and wind electricity is also considered. Hydrogen distribution options include gas pipeline and refrigerated truck transportation for liquefied hydrogen. A total number of fifteen fuel pathways are studied; in all the cases the natural gas-hydrogen mixture is made at the refueling station. The use of WE using nuclear or wind electricity appears to be less contaminant that the use of pure CNG. (author)

  1. Radon as a natural tracer for gas transport within uranium waste rock piles

    International Nuclear Information System (INIS)

    Silva, N.C.; Chagas, E.G.L.; Dias, D.C.S.; Guerreiro, E.T.Z.; Alberti, H.L.C.; Braz, M.L.; Abreu, C.B.; Lopez, D.; Branco, O.; Fleming, P.

    2014-01-01

    Acid mine drainage (AMD) has been identified as the main cause for outflow of acid water and radioactive/non-radioactive contaminants. AMD encompasses pyrites oxidation when water and oxygen are available. AMD was identified in uranium waste rock piles (WRPs) of Industrias Nucleares do Brasil-Caldas facility (Brazilian uranium mine), resulting in high costs for water treatment. AMD reduction is the main challenge, and scientific investigation has been conducted to understand oxygen and water transportation within WRPs, where 222 Rn is used as natural tracer for oxygen transportation. The study consists of soil radon gas mapping in the top layer of WRP4 using active soil gas pumping, radon adsorption in active charcoal and 222 Rn determination using high-resolution gamma-ray spectrometry. A sampling network of 71 points was built where samples were collected at a depth of 40 cm. Soil radon gas concentration ranged from 33.7 to 1484.2 kBq m -3 with mean concentration of 320.7±263.3 kBq m -3 . (authors)

  2. Synthesis and Gas Transport Properties of Hyperbranched Polyimide–Silica Hybrid/Composite Membranes

    Directory of Open Access Journals (Sweden)

    Masako Miki

    2013-12-01

    Full Text Available Hyperbranched polyimide–silica hybrids (HBPI–silica HBDs and hyperbranched polyimide–silica composites (HBPI–silica CPTs were prepared, and their general and gas transport properties were investigated to clarify the effect of silica sources and preparation methods. HBPI–silica HBDs and HBPI–silica CPTs were synthesized by two-step polymerization of A2 + B3 monomer system via polyamic acid as precursor, followed by hybridizing or blending silica sources. Silica components were incorporated by the sol-gel reaction with tetramethoxysilane (TMOS or the addition of colloidal silica. In HBPI-silica HBDs, the aggregation of silica components is controlled because of the high affinity of HBPI and silica caused by the formation of covalent bonds between HBPI and silica. Consequently, HBPI-silica HBDs had good film formability, transparency, and mechanical properties compared with HBPI-silica CPTs. HBPI-silica HBD and CPT membranes prepared via the sol-gel reaction with TMOS showed specific gas permeabilities and permselectivities for CO2/CH4 separation, that is, both CO2 permeability and CO2/CH4 selectivity increased with increasing silica content. This result suggests that gas transport can occur through a molecular sieving effect of the porous silica network derived from the sol-gel reaction and/or through the narrow interfacial region between the silica networks and the organic matrix.

  3. Analysis of CO2 Separation from Flue Gas, Pipeline Transportation, and Sequestration in Coal

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Robertson

    2007-09-01

    This report was written to satisfy a milestone of the Enhanced Coal Bed Methane Recovery and CO2 Sequestration task of the Big Sky Carbon Sequestration project. The report begins to assess the costs associated with separating the CO2 from flue gas and then injecting it into an unminable coal seam. The technical challenges and costs associated with CO2 separation from flue gas and transportation of the separated CO2 from the point source to an appropriate sequestration target was analyzed. The report includes the selection of a specific coal-fired power plant for the application of CO2 separation technology. An appropriate CO2 separation technology was identified from existing commercial technologies. The report also includes a process design for the chosen technology tailored to the selected power plant that used to obtain accurate costs of separating the CO2 from the flue gas. In addition, an analysis of the costs for compression and transportation of the CO2 from the point-source to an appropriate coal bed sequestration site was included in the report.

  4. Hybrid life-cycle assessment of natural gas based fuel chains for transportation.

    Science.gov (United States)

    Strømman, Anders Hammer; Solli, Christian; Hertwich, Edgar G

    2006-04-15

    This research compares the use of natural gas, methanol, and hydrogen as transportation fuels. These three fuel chains start with the extraction and processing of natural gas in the Norwegian North Sea and end with final use in Central Europe. The end use is passenger transportation with a sub-compact car that has an internal combustion engine for the natural gas case and a fuel cell for the methanol and hydrogen cases. The life cycle assessment is performed by combining a process based life-cycle inventory with economic input-output data. The analysis shows that the potential climate impacts are lowest for the hydrogen fuel scenario with CO2 deposition. The hydrogen fuel chain scenario has no significant environmental disadvantage compared to the other fuel chains. Detailed analysis shows that the construction of the car contributes significantly to most impact categories. Finally, it is shown how the application of a hybrid inventory model ensures a more complete inventory description compared to standard process-based life-cycle assessment. This is particularly significant for car construction which would have been significantly underestimated in this study using standard process life-cycle assessment alone.

  5. Gas turbines for natural gas transport and storage; Turbina a gas quale moderno motore per l`azionamento dei compressori del sistema di trasporto e stoccaggio del gas in Italia

    Energy Technology Data Exchange (ETDEWEB)

    Zampieri, G. [SNAM SpA, Milan (Italy); Sabella, D. [Nuovo Pignone, Florence (Italy)

    1992-12-31

    In order to compensate for pressure drop, the long distance transport of natural gas along pipeline networks requires the use of compression stations spaced from 100 to 200 km apart. In the past, conventional equipment for this purpose consisted of alternative compressors driven by alternative engines or fixed speed electric motors. Subsequently, to allow operation in conditions characterized by wide ranging pressures and flow rates, gas distribution system operators began to use gas turbines combined with variable speed centrifugal compressors. Today, the gas turbine, due to its great flexibility of use, auxiliary fuel independence, good performance and environmental compatibility represents the optimum driving unit for gas compressors. To illustrate this point, this paper reviews the main design, operation and performance characteristics of the Nuovo Pignone PGT-10 and PGT-25 gas turbines. The gas generator design of the latter 23, 300 kW gas generator-power turbine unit is based on that of the General Electric TF 39/CF-6 jet engine used on Boeing 747`s and DC-10`s.

  6. Earthquake loss estimation for a gas lifeline transportation system in Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Yamin, L.E.; Arambula, S.; Reyes, J.C. [Universidad de los Andes, Bogota (Colombia). Centro de Innovacion y Desarrollo Tecnologico; Belage, S.; Vega, A.; Gil, W. [TransGas de Occidente S.A., Bogota (Colombia)

    2004-07-01

    Methodologies are needed to estimate the seismic risk facing natural gas distribution systems in Colombia in order to establish insurance strategies, risk assessments and emergency plans. This study estimated the maximum probable losses associated with Colombia's 770 km long gas transportation system which stretches from Mariquita to Cali. The pipeline is vulnerable to seismic events, volcanic eruptions, extreme hydrological conditions, and their associated effects such as landslides, liquefaction and avalanches. A geographic information system (GIS) which includes seismic, volcanic, landslide and liquefaction hazards was used to estimate earthquake loss estimates for the natural gas distribution system. Elastic and inelastic finite element methods were used to evaluate the vulnerability of pipelines, bridges, underground crossings and valves. The results were incorporated into the GIS and were used to quantify the probable maximum losses for the system, the most critical associated event, the system's critical zones and the probable damage scenarios. The information was used to define insurance strategies, emergency and contingency plans. It was concluded that due to natural hazards, the natural gas distribution system is at moderate risk despite the low vulnerability of its components. Volcanic eruptions and large earthquakes could produce indirect phenomena such as landslides and liquefaction which could greatly influence the system and which would require adequate risk management. 14 refs., 1 tab., 8 figs.

  7. Lateral gas transport in soil adjacent to an old landfill: factors governing emissions and methane oxidation

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter; Holst, Helle

    2001-01-01

    Field investigations of lateral gas transport and subsequent emissions in soil adjacent to an old landfill in Denmark have been conducted during a one-year period. A significant seasonal variation in the emissions with high carbon dioxide and low methane fluxes in the summer (May to October......) was observed. This was attributed to methane oxidation. Diurnal measurements during a drop in barometric pressure showed that the fluxes of landfill gas changed dramatically within a very short time. The concentrations and the soil moisture content in the upper part of the soil profile had significant...... influence on the fluxes, as did the distance from the landfill border, temperature, barometric pressure and the pressure gradient. Statistical analyses proved that soil moisture described the largest part of the variation. No methane at all emitted during the summer. Calculations and isotope analyses showed...

  8. A case study of electrostatic accidents in the process of oil-gas storage and transportation

    International Nuclear Information System (INIS)

    Hu, Yuqin; Liu, Jinyu; Gao, Jianshen; Wang, Diansheng

    2013-01-01

    Ninety nine electrostatic accidents were reviewed, based on information collected from published literature. All the accidents over the last 30 years occurred during the process of oil-gas storage and transportation. Statistical analysis of these accidents was performed based on the type of complex conditions where accidents occurred, type of tanks and contents, and type of accidents. It is shown that about 85% of the accidents occurred in tank farms, gas stations or petroleum refineries, and 96% of the accidents included fire or explosion. The fishbone diagram was used to summarize the effects and the causes of the effects. The results show that three major reasons were responsible for accidents, including improper operation during loading and unloading oil, poor grounding and static electricity on human bodies, which accounted for 29%, 24% and 13% of the accidents, respectively. Safety actions are suggested to help operating engineers to handle similar situations in the future.

  9. Panorama 2009 - greenhouse gas emissions and the transport sector; Panorama 2009 - les emissions de gaz a effet de serre des transports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    The fact that the transport sector is growing quickly brings advantages, such as quick access to any geographical location on earth, but also disadvantages: noise, congestion and polluting emissions such as carbon dioxide (CO{sub 2}), the greenhouse gas (GHG) primarily responsible for global warming. In the effort to bring GHG emissions under control, improving results in the transport sector is a prime long-term objective. What proportion of CO{sub 2} emissions generated at global and national level are due to the road, air, maritime and rail transport sectors, respectively? What mechanisms can be used to reduce GHG emissions in the transport sector at large?.

  10. Evaluation of alternatives for reducing the consumption of natural gas fuel at city-gates of Brazilian transport systems; Avaliacao das alternativas de reducao do consumo de gas natural combustivel nos pontos de entrega dos sistemas de transporte brasileiros

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Almir B. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil); Augusto, Cristiane R.; Seidl, Peter R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Goncalves, Raquel G. [UNISUAM - Centro Universitario Augusto Motta, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    This work aims to identify actions that can be implemented to increase the energy efficiency of processes involved in the value chain of natural gas, specifically in the process of heating in existing city-gates of transporting natural gas Brazilians plants. The goal is increase supply of gas in Brazil. The main function of city-gates is to deliver the natural gas in contract terms (flow, pressure, temperature and quality). The main issue related to the consumption of natural gas fuel in city-gates is related to the operation (set-up and control) of natural gas combustion, in other words, depends on how the heating system is adjusted dynamically to burn, efficiently, the exact amount of gas required by this system, depending on temperature, pressure, temperature, quality and flow of natural gas at the 'city-gates'. The main objective of this work is to present a study on alternatives at design, set-up and control of natural gas city-gates (transport) in Brazil, aiming to increase the energy efficiency of this facility, and thus contributing to the growth in supply of natural gas available to the market. (author)

  11. Neutral Transport Simulations of Gas Puff Imaging Experiments on Alcator C-Mod

    International Nuclear Information System (INIS)

    Stotler, D.P.; LaBombard, B.; Terry, J.L.; Zweben, S.J.

    2002-01-01

    Visible imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results.Visibl e imaging of gas puffs has been used on the Alcator C-Mod tokamak to characterize edge plasma turbulence, yielding data that can be compared with plasma turbulence codes. Simulations of these experiments with the DEGAS 2 Monte Carlo neutral transport code have been carried out to explore the relationship between the plasma fluctuations and the observed light emission. By imposing two-dimensional modulations on the measured time-average plasma density and temperature profiles, we demonstrate that the spatial structure of the emission cloud reflects that of the underlying turbulence. However, the photon emission rate depends on the plasma density and temperature in a complicated way, and no simple scheme for inferring the plasma parameters directly from the light emission patterns is apparent. The simulations indicate that excited atoms generated by molecular dissociation are a significant source of photons, further complicating interpretation of the gas puff imaging results

  12. Potential of greenhouse gas emission reduction in Thai road transport by ethanol bus technology

    International Nuclear Information System (INIS)

    Chollacoop, Nuwong; Saisirirat, Peerawat; Sukkasi, Sittha; Tongroon, Manida; Fukuda, Tuenjai; Fukuda, Atsushi; Nivitchanyong, Siriluck

    2013-01-01

    Highlights: ► Energy demand modeling in Thai road transportation sector was developed. ► Such model was used to assess environment impact by ethanol bus technology (ED95). ► Ethanol bus technology (ED95) shows beneficial impacts to Thailand. ► Increase in ethanol demand and decrease in GHG emission in Thailand by ethanol bus. ► Ethanol bus (ED95) has been successfully demonstrated in Thailand. -- Abstract: Over decades, Thailand energy consumption has been concentrated in three main sectors, namely manufacturing, power and transportation. Energy consumption in transportation sector has also been dominated by road transport due to limited coverage by rail and water transportation. Hence, road transport has been a major contributor for greenhouse gas emission in Thailand over recent years. Along with global warming concern throughout the world, Thailand has taken various adaptation and mitigation measures, especially the strong policy push to use carbon–neutral biofuel in transportation sector due to Thailand competitive advantage in agriculture sector. National Renewable Energy Plan (2008–2022) has set challenging targets of 9 and 4.5 million liters/day of ethanol and biodiesel consumption by 2022, respectively. Various blends of ethanol in gasoline (10%, 20% and 85%) and biodiesel in diesel (up to 5%) have been commercially available. However, since current consumption of diesel is twice as much of gasoline, ethanol blend in gasoline would widen the imbalance consumption of gasoline and diesel. The present study however offers an insight into a possibility to use ethanol as diesel substitute. A case study of ethanol bus technology was investigated by recourse to energy demand modeling. Necessary data, such as a number of vehicles (NVs) for various vehicle types, vehicle kilometer of travel (VKT) and fuel economy (FE) were collected, with reasonable assumptions made for those unavailable data, to construct predicative energy demand model. Scenario

  13. Focal spot size predictions for beam transport through a gas-filled reactor

    International Nuclear Information System (INIS)

    Yu, S.S.; Lee, E.P.; Buchanan, H.L.

    1980-01-01

    Results from calculations of focal spot size for beam transport through a gas-filled reactor are summarized. In the converging beam mode, we find an enlargement of the focal spot due to multiple scattering and zeroth order self-field effects. This enlargement can be minimized by maintaining small reactors together with a careful choice of the gaseous medium. The self-focused mode, on the other hand, is relatively insensitive to the reactor environment, but is critically dependent upon initial beam quality. This requirement on beam quality can be significantly eased by the injection of an electron beam of modest current from the opposite wall

  14. The 4-dimensional plant: effects of wind- induced canopy movement on light fluctuations and photosynthesis

    Directory of Open Access Journals (Sweden)

    Alexandra Jacquelyn Burgess

    2016-09-01

    Full Text Available Physical perturbation of a plant canopy brought about by wind is a ubiquitous phenomenon and yet its biological importance has often been overlooked. This is partly due to the complexity of the issue at hand: wind-induced movement (or mechanical excitation is a stochastic process which is difficult to measure and quantify; plant motion is dependent upon canopy architectural features which, until recently, were difficult to accurately represent and model in 3-dimensions; light patterning throughout a canopy is difficult to compute at high-resolutions, especially when confounded by other environmental variables. Recent studies have reinforced the expectation that canopy architecture is a strong determinant of productivity and yield; however, links between the architectural properties of the plant and its mechanical properties, particularly its response to wind, are relatively unknown. As a result, biologically relevant data relating canopy architecture, light dynamics and short-scale photosynthetic responses in the canopy setting are scarce. Here, we hypothesise that wind-induced movement will have large consequences for the photosynthetic productivity of our crops due to its influence on light patterning. To address this issue, in this study we combined high resolution 3D reconstructions of a plant canopy with a simple representation of canopy perturbation as a result of wind using solid body rotation in order to explore the potential effects on light patterning, interception and photosynthetic productivity. We looked at two different scenarios: firstly a constant distortion where a rice canopy was subject to a permanent distortion throughout the whole day; and secondly, a dynamic distortion, where the canopy was distorted in incremental steps between two extremes at set time points in the day. We find that mechanical canopy excitation substantially alters light dynamics; light distribution and modelled canopy carbon gain. We then discuss methods

  15. Legal and regulatory possibility of connection between interstate natural gas distribution networks instead of constructing transport pipelines; Possibilidade juridoco-regulatoria da conexao interestadual entre redes de distribuicao de gas natural como alternativa a construcao de gasodutos de transporte

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Gustavo Mano [Andrade, Mano - Advogados, Rio de Janeiro, RJ (Brazil)

    2012-07-01

    According to Revista Brasil Energia (2011a), the local natural gas distribution concessionaire in the State of Sao Paulo Gas Brasiliano Distribuidora - GBD, plans to expand its distribution pipeline network in western Sao Paulo up to the border of the State of Minas Gerais, near the region known as Minas Triangle where a connection with the pipeline network of the State of Minas Gerais' natural gas distribution company, Companhia de Gas de Minas Gerais - GASMIG shall be built in order to supply natural gas to an ammonia plant to be built by PETROBRAS in the City of Uberaba. Still according to the publication, the project described above would be an alternative to the construction of a transportation pipeline that, since the enforcement of the Gas Law - Law No. 11.909/09 (Brasil, 2009), should be subject to concession contracts preceded by a complex, and probably delayed, planning and procurement. However, there is a transportation pipeline project, deriving from the Bolivia-Brazil transportation pipeline near the city of Sao Carlos, in Sao Paulo, crossing the Minas Triangle and finishing in the State of Goias. This project is owned by TGBC Company. The existence of two gas pipeline projects with very similar paths to supply virtually the same regions and based on different regulatory frameworks, one consisting of a connection between the distribution networks of different States and another based on the concept of pipeline transportation of gas under the legal and regulatory federal jurisdiction raises the discussion about the possibility of legal and regulatory interstate connections of distribution pipeline networks as an alternative to planning, allocation and construction of a transportation pipelines. This article aims to examine the legal and regulatory foundations of both alternatives and delineate the limits of performance of States and Federal Government on legislation and regulation concerning the movement of natural gas pipeline through the Country

  16. Environmental impact assessment methodological framework for liquefied natural gas terminal and transport network planning

    International Nuclear Information System (INIS)

    Papadopoulou, Maria P.; Antoniou, Constantinos

    2014-01-01

    The recent discovery of significant offshore natural gas reserves in the Aphrodite field, south of the island of Cyprus in the Mediterranean Sea, changes the energy landscape in the greater Mediterranean-Middle East-Caucasian Region. In this paper, different alternative locations for the construction and operation of a liquefied natural gas (LNG) terminal station in Cyprus were evaluated, explicitly considering also their connection to the power generation station of Mari and the country's gateway. The problem of determining the optimal location for an LNG terminal in Cyprus has been approached using multiple methodological components, which consider environmental and transportation issues, both technocratic in nature, as well as more subjective and based on expert opinion. The first step was a REGIME multi-criteria decision analysis used to prioritize alternative LNG terminal locations. Then, multiple modes (railroad and pipeline) of transportation connections were evaluated and geometric alignments were proposed, considering a multitude of restrictions. Finally an environmental impact assessment based on a structured questionnaire and an expert panel was conducted to validate and assess the impact of the alternative options (combination of location and transportation mode and route). During the evaluation process parameters such as safety, existing infrastructure, and access were also considered. - Highlights: • Determined the optimal location for an LNG terminal in Cyprus. • REGIME multi-criteria analysis used to prioritize alternative LNG terminal locations. • Multiple modes of transportation connections were evaluated and geometric alignments were proposed. • Environmental impact assessment and validation was undertaken based on a structured questionnaire and an expert panel. • Parameters such as safety, existing infrastructure, and access were also considered

  17. Greenhouse gas emissions from Thailand’s transport sector: Trends and mitigation options

    International Nuclear Information System (INIS)

    Pongthanaisawan, Jakapong; Sorapipatana, Chumnong

    2013-01-01

    Rapid growth of population and economy during the past two decades has resulted in continuing growth of transport’s oil demand and greenhouse gas (GHG) emissions. The objectives of this study are to examine pattern and growth in energy demand as well as related GHG emissions from the transport sector and to analyze potential pathways of energy demand and GHG emissions reduction from this sector of the measures being set by the Thai Government. A set of econometric models has been developed to estimate the historical trend of energy demand and GHG emissions in the transport sector during 1989–2007 and to forecast future trends to 2030. Two mitigation option scenarios of fuel switching and energy efficiency options have been designed to analyze pathways of energy consumption and GHG emissions reduction potential in Thailand’s transport sector compared with the baseline business-as-usual (BAU) scenario, which assumed to do nothing influences the long-term trends of transport energy demand. It has been found that these two mitigation options can reduce the GHG emissions differently. The fuel-switching option could significantly reduce the amount of GHG emissions in a relatively short time frame, albeit it will be limited by its supply resources, whereas the energy efficiency option is more effective for GHG emissions mitigation in the long term. Therefore, both measures should be implemented simultaneously for both short and long term mitigation effects in order to more effectively achieve GHG emissions reduction target.

  18. Seasonal patterns of wind-induced upwelling/downwelling in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Andrew Bakun

    2001-09-01

    Full Text Available The historical file of wind observations from maritime weather reports is summarized to identify the characteristic seasonal distributions of wind-induced Ekman upwelling and downwelling in the Mediterranean Sea. Both coastal upwelling/downwelling and wind-stress curl-driven open ocean upwelling/downwelling are treated in a unified description. Vigorous upwelling zones are found in the eastern Aegean Sea, off the west coast of Greece, and in the Gulf of Lyons. The southern coast of the Mediterranean is found to be primarily a downwelling area, although significant coastal upwelling does appear in the Gulf of Sidra during the spring and summer seasons, and along the Algerian coast during summer.

  19. Analysis of wind-induced vibrations in high-rise buildings

    DEFF Research Database (Denmark)

    Persson, Peter; Austrell, Per-Erik; Kirkegaard, Poul Henning

    2016-01-01

    Buildings are getting taller due to increased urbanisation and densification of cities. More advanced construction methods and the desire to construct impressive buildings is also supporting the trend. Due to their inherent slenderness resulting in low eigenfrequencies, these buildings...... are susceptible to wind-induced vibrations which can be highly disturbing for occupants. Already barely perceivable acceleration levels within the low-frequency range relevant to whole-body vibrations can cause nausea and discomfort, while high acceleration levels can cause alarm and fea r amongst the occupants....... The paper summarises acceptable acceleration levels in high -rise buildings (here referred to as buildings over 200 m in height) stated in different building codes and previous work on the subject. Accelerations of a high-rise building subjected to wind-loads are evaluated using a full numerical model...

  20. Observation and modeling of tide- and wind-induced surface currents in Galway Bay

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2015-10-01

    Full Text Available A high-frequency radar system has been deployed in Galway Bay, a semi-enclosed bay on the west coast of Ireland. The system provides surface currents with fine spatial resolution every hour. Prior to its use for model validation, the accuracy of the radar data was verified through comparison with measurements from acoustic Doppler current profilers (ADCPs and a good correlation between time series of surface current speeds and directions obtained from radar data and ADCP data. Since Galway Bay is located on the coast of the Atlantic Ocean, it is subject to relatively windy conditions, and surface currents are therefore strongly wind-driven. With a view to assimilating the radar data for forecasting purposes, a three-dimensional numerical model of Galway Bay, the Environmental Fluid Dynamics Code (EFDC, was developed based on a terrain-following vertical (sigma coordinate system. This study shows that the performance and accuracy of the numerical model, particularly with regard to tide- and wind-induced surface currents, are sensitive to the vertical layer structure. Results of five models with different layer structures are presented and compared with radar measurements. A variable vertical structure with thin layers at the bottom and the surface and thicker layers in the middle of the water column was found to be the optimal layer structure for reproduction of tide- and wind-induced surface currents. This structure ensures that wind shear can properly propagate from the surface layer to the sub-surface layers, thereby ensuring that wind forcing is not overdamped by tidal forcing. The vertical layer structure affects not only the velocities at the surface layer but also the velocities further down in the water column.

  1. Observation and modeling of tide- and wind-induced surface currents in Galway Bay

    Directory of Open Access Journals (Sweden)

    Lei REN

    2015-10-01

    Full Text Available A high-frequency radar system has been deployed in Galway Bay, a semi-enclosed bay on the west coast of Ireland. The system provides surface currents with fine spatial resolution every hour. Prior to its use for model validation, the accuracy of the radar data was verified through comparison with measurements from acoustic Doppler current profilers (ADCPs and a good correlation between time series of surface current speeds and directions obtained from radar data and ADCP data. Since Galway Bay is located on the coast of the Atlantic Ocean, it is subject to relatively windy conditions, and surface currents are therefore strongly wind-driven. With a view to assimilating the radar data for forecasting purposes, a three-dimensional numerical model of Galway Bay, the Environmental Fluid Dynamics Code (EFDC, was developed based on a terrain-following vertical (sigma coordinate system. This study shows that the performance and accuracy of the numerical model, particularly with regard to tide- and wind-induced surface currents, are sensitive to the vertical layer structure. Results of five models using different layer structures are presented and compared with radar measurements. A variable vertical structure with thin layers at the bottom and the surface and thicker layers in the middle of the water column was found to be the optimal layer structure for reproduction of tide- and wind-induced surface currents. This structure ensures that wind shear can properly propagate from the surface layer to the sub-surface layers, thereby ensuring that wind forcing is not overdamped by tidal forcing. The vertical layer structure affects not only the velocities at the surface layer but also the velocities further down in the water column.

  2. A Comprehensive Model for Real Gas Transport in Shale Formations with Complex Non-planar Fracture Networks.

    Science.gov (United States)

    Yang, Ruiyue; Huang, Zhongwei; Yu, Wei; Li, Gensheng; Ren, Wenxi; Zuo, Lihua; Tan, Xiaosi; Sepehrnoori, Kamy; Tian, Shouceng; Sheng, Mao

    2016-11-07

    A complex fracture network is generally generated during the hydraulic fracturing treatment in shale gas reservoirs. Numerous efforts have been made to model the flow behavior of such fracture networks. However, it is still challenging to predict the impacts of various gas transport mechanisms on well performance with arbitrary fracture geometry in a computationally efficient manner. We develop a robust and comprehensive model for real gas transport in shales with complex non-planar fracture network. Contributions of gas transport mechanisms and fracture complexity to well productivity and rate transient behavior are systematically analyzed. The major findings are: simple planar fracture can overestimate gas production than non-planar fracture due to less fracture interference. A "hump" that occurs in the transition period and formation linear flow with a slope less than 1/2 can infer the appearance of natural fractures. The sharpness of the "hump" can indicate the complexity and irregularity of the fracture networks. Gas flow mechanisms can extend the transition flow period. The gas desorption could make the "hump" more profound. The Knudsen diffusion and slippage effect play a dominant role in the later production time. Maximizing the fracture complexity through generating large connected networks is an effective way to increase shale gas production.

  3. Integral diagnostic in the failure causes of external corrosion of a natural gas transport pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Mendoza, J.L.; Saucedo-Robles, L.C.; Rodriguez-Clemente, H. [PEMEX Gas y Petroquimica Basica, Subdireccion de Ductos; Marina Nacional 329, Edificio B-1, Piso 8, Col. Huasteca, D.F., CP 11311 (Mexico); Gonzalez-Nunez, M.A. [Instituto de Investigaciones Electricas, Reforma 113, Col. Palmira, Cuernavaca, Morelos, CP 62490 (Mexico); Zavala-Olivares, G.; Hernandez-Gayosso, M.J. [Instituto Mexicano del Petroleo, Direccion de Exploracion y Produccion, Eje Central Lazaro Cardenas Norte 152, Col. San Bartolo Atepehuacan, D.F., CP 07730 (Mexico)

    2011-08-15

    The objective of this study consisted in investigating the possible causes which give rise to the presence of low wall pipe thicknesses on a 16'' natural gas transport pipeline, even though during the last 12-year period cathodic protection (CP) potentials were kept in the protection range at which external corrosion should not occur. Results from in-line inspection from a 16'' natural gas transport pipeline showed 46 indications with more than 80% wall thickness lost due to external corrosion in the second segment of the pipeline. Direct inspection at the indication locations, review of the CP system performance, pipeline maintenance programs and studies, allowed to make an integral diagnostic where it was found out that the main cause of external corrosion was an inappropriate coating application since the pipeline construction, this situation has originated the increase of CP shielding effects through time. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport

    Science.gov (United States)

    Sheng, Zhizhi; Wang, Honglong; Tang, Yongliang; Wang, Miao; Huang, Lizhi; Min, Lingli; Meng, Haiqiang; Chen, Songyue; Jiang, Lei; Hou, Xu

    2018-01-01

    The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gases and liquids under a steady-state applied pressure, nearly eliminate fouling, and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores’ deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles. PMID:29487906

  5. Large-scale application of natural gas as an engine fuel in public transport

    International Nuclear Information System (INIS)

    Verstegen, P.; Nieuwenhuis, A.; Van Schagen, G.J.

    1993-02-01

    Options and bottlenecks for the use of compressed natural gas (CNG) as an automotive fuel in public transportation have been inventorized and discussed. Based on interviews with representatives of transportation businesses and their umbrella organizations the demands and wishes are listed in chapter one. In chapter two several types of natural gas storage cylinders, focusing on the weight and the costs of the cylinders and the consequences for the road tax. In chapter three attention is paid to the delivery possibilities of the bus manufacturers DAF, Mercedes-Benz, Volvo and MAN. Technical specifications and data on the energy consumption, emission and other aspects are presented. In chapter three the characteristics of fastfill stations and slowfill stations are assessed for implementing problems, costs and reliability. The costs for the use of CNG in buses, as discussed in chapter five, consist of additional costs for the bus, maintenance, road tax, filling station, safety provisions, and reduced costs for the fuel. In chapter six the regulations and legislation for the use of CNG in vehicles, filling stations and storage cylinders is dealt with. In the final chapters seven and eight the necessity of introductory courses and training is briefly discussed, and an overview of current projects in the Netherlands is given. 13 figs., 14 tabs., refs

  6. Wind driven vertical transport in a vegetated, wetland water column with air-water gas exchange

    Science.gov (United States)

    Poindexter, C.; Variano, E. A.

    2010-12-01

    Flow around arrays of cylinders at low and intermediate Reynolds numbers has been studied numerically, analytically and experimentally. Early results demonstrated that at flow around randomly oriented cylinders exhibits reduced turbulent length scales and reduced diffusivity when compared to similarly forced, unimpeded flows (Nepf 1999). While horizontal dispersion in flows through cylinder arrays has received considerable research attention, the case of vertical dispersion of reactive constituents has not. This case is relevant to the vertical transfer of dissolved gases in wetlands with emergent vegetation. We present results showing that the presence of vegetation can significantly enhance vertical transport, including gas transfer across the air-water interface. Specifically, we study a wind-sheared air-water interface in which randomly arrayed cylinders represent emergent vegetation. Wind is one of several processes that may govern physical dispersion of dissolved gases in wetlands. Wind represents the dominant force for gas transfer across the air-water interface in the ocean. Empirical relationships between wind and the gas transfer coefficient, k, have been used to estimate spatial variability of CO2 exchange across the worlds’ oceans. Because wetlands with emergent vegetation are different from oceans, different model of wind effects is needed. We investigated the vertical transport of dissolved oxygen in a scaled wetland model built inside a laboratory tank equipped with an open-ended wind tunnel. Plastic tubing immersed in water to a depth of approximately 40 cm represented emergent vegetation of cylindrical form such as hard-stem bulrush (Schoenoplectus acutus). After partially removing the oxygen from the tank water via reaction with sodium sulfite, we used an optical probe to measure dissolved oxygen at mid-depth as the tank water re-equilibrated with the air above. We used dissolved oxygen time-series for a range of mean wind speeds to estimate the

  7. 50 CFR 29.21-9 - Rights-of-way for pipelines for the transportation of oil, natural gas, synthetic liquid or...

    Science.gov (United States)

    2010-10-01

    ... transportation of oil, natural gas, synthetic liquid or gaseous fuels, or any refined product produced therefrom... Regulations § 29.21-9 Rights-of-way for pipelines for the transportation of oil, natural gas, synthetic liquid... of oil, natural gas, synthetic liquid or gaseous fuels, or any refined product produced therefrom...

  8. Multiscale model reduction for shale gas transport in poroelastic fractured media

    Science.gov (United States)

    Akkutlu, I. Yucel; Efendiev, Yalchin; Vasilyeva, Maria; Wang, Yuhe

    2018-01-01

    Inherently coupled flow and geomechanics processes in fractured shale media have implications for shale gas production. The system involves highly complex geo-textures comprised of a heterogeneous anisotropic fracture network spatially embedded in an ultra-tight matrix. In addition, nonlinearities due to viscous flow, diffusion, and desorption in the matrix and high velocity gas flow in the fractures complicates the transport. In this paper, we develop a multiscale model reduction approach to couple gas flow and geomechanics in fractured shale media. A Discrete Fracture Model (DFM) is used to treat the complex network of fractures on a fine grid. The coupled flow and geomechanics equations are solved using a fixed stress-splitting scheme by solving the pressure equation using a continuous Galerkin method and the displacement equation using an interior penalty discontinuous Galerkin method. We develop a coarse grid approximation and coupling using the Generalized Multiscale Finite Element Method (GMsFEM). GMsFEM constructs the multiscale basis functions in a systematic way to capture the fracture networks and their interactions with the shale matrix. Numerical results and an error analysis is provided showing that the proposed approach accurately captures the coupled process using a few multiscale basis functions, i.e. a small fraction of the degrees of freedom of the fine-scale problem.

  9. Operational Challenges in Gas-To-Liquid (GTL) Transportation Through Trans Alaska Pipeline System (TAPS)

    Energy Technology Data Exchange (ETDEWEB)

    Godwin A. Chukwu; Santanu Khataniar; Shirish Patil; Abhijit Dandekar

    2006-06-30

    Oil production from Alaskan North Slope oil fields has steadily declined. In the near future, ANS crude oil production will decline to such a level (200,000 to 400,000 bbl/day) that maintaining economic operation of the Trans-Alaska Pipeline System (TAPS) will require pumping alternative products through the system. Heavy oil deposits in the West Sak and Ugnu formations are a potential resource, although transporting these products involves addressing important sedimentation issues. One possibility is the use of Gas-to-Liquid (GTL) technology. Estimated recoverable gas reserves of 38 trillion cubic feet (TCF) on the North Slope of Alaska can be converted to liquid with GTL technology and combined with the heavy oils for a product suitable for pipeline transport. Issues that could affect transport of this such products through TAPS include pumpability of GTL and crude oil blends, cold restart of the pipeline following a prolonged winter shutdown, and solids deposition inside the pipeline. This study examined several key fluid properties of GTL, crude oil and four selected blends under TAPS operating conditions. Key measurements included Reid Vapor Pressure, density and viscosity, PVT properties, and solids deposition. Results showed that gel strength is not a significant factor for the ratios of GTL-crude oil blend mixtures (1:1; 1:2; 1:3; 1:4) tested under TAPS cold re-start conditions at temperatures above - 20 F, although Bingham fluid flow characteristics exhibited by the blends at low temperatures indicate high pumping power requirements following prolonged shutdown. Solids deposition is a major concern for all studied blends. For the commingled flow profile studied, decreased throughput can result in increased and more rapid solid deposition along the pipe wall, resulting in more frequent pigging of the pipeline or, if left unchecked, pipeline corrosion.

  10. Improving the accuracy of vehicle emissions profiles for urban transportation greenhouse gas and air pollution inventories.

    Science.gov (United States)

    Reyna, Janet L; Chester, Mikhail V; Ahn, Soyoung; Fraser, Andrew M

    2015-01-06

    Metropolitan greenhouse gas and air emissions inventories can better account for the variability in vehicle movement, fleet composition, and infrastructure that exists within and between regions, to develop more accurate information for environmental goals. With emerging access to high quality data, new methods are needed for informing transportation emissions assessment practitioners of the relevant vehicle and infrastructure characteristics that should be prioritized in modeling to improve the accuracy of inventories. The sensitivity of light and heavy-duty vehicle greenhouse gas (GHG) and conventional air pollutant (CAP) emissions to speed, weight, age, and roadway gradient are examined with second-by-second velocity profiles on freeway and arterial roads under free-flow and congestion scenarios. By creating upper and lower bounds for each factor, the potential variability which could exist in transportation emissions assessments is estimated. When comparing the effects of changes in these characteristics across U.S. cities against average characteristics of the U.S. fleet and infrastructure, significant variability in emissions is found to exist. GHGs from light-duty vehicles could vary by -2%-11% and CAP by -47%-228% when compared to the baseline. For heavy-duty vehicles, the variability is -21%-55% and -32%-174%, respectively. The results show that cities should more aggressively pursue the integration of emerging big data into regional transportation emissions modeling, and the integration of these data is likely to impact GHG and CAP inventories and how aggressively policies should be implemented to meet reductions. A web-tool is developed to aide cities in improving emissions uncertainty.

  11. Water transport in gas diffusion media for PEM fuel cells. Experimental and numerical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Joerg

    2010-08-20

    The water flux in partially saturated hydrophobic carbon fibre paper for polymer electrolyte membrane fuel cell applications is investigated and compared with the frequently used constitutive two-phase flow model based on Darcy's law. Further, the first steps towards a math-based material design for gas diffusion media are explored in this thesis. Two self-developed ex-situ experiments to investigate the liquid water transport are introduced. The first is a newly developed buoyancy-based measurement of the pressuresaturation relationship on thin porous material with an accuracy of 0.5 kPa for the pressure and {+-} 5% for the saturation. The second experiment measures the pressure drop in dependence of flow rates down to magnitudes of {mu}L/s across the partially saturated thin porous material. This flow rate is relevant for the fuel cell application. The liquid water transport through Toray 060 carbon fibre paper, impregnated with 7% and 10% PTFE is investigated at wet and dry boundary conditions. The experiments are also accompanied by analytical and numerical free surface modelling with the consideration of the material morphology and liquid-solid interaction. The imbibing and draining cases of an arrangement of six fibres at varying solid-liquid interaction and boundary conditions are studied with 'Surface Evolver'. In order to evaluate the findings of ex-situ and modelling work for applicability to water transport in fuel cell operation, the technique of nuclear magnetic resonance (NMR) imaging is assessed. The focus is on the visualisation of 2D and 3D water distribution in the operating fuel cell. The compatibility of the NMR experiment with fuel cell operation in relation to material selection, operating temperature, and current density is addressed. NMR imaging is employed for different current densities, stoichiometries, and fuel cell arrangements. The fuel cell arrangements differ by the cathode diffusion medium. Plain, hydrophobic, and

  12. Ammonia gas transport and reactions in unsaturated sediments: Implications for use as an amendment to immobilize inorganic contaminants

    International Nuclear Information System (INIS)

    Zhong, L.; Szecsody, J.E.; Truex, M.J.; Williams, M.D.; Liu, Y.

    2015-01-01

    Highlights: • Ammonia transport can be predicted from gas movement and equilibrium partitioning. • Ammonia diffusion rate in unsaturated sediment is a function of water contents. • High pH induced by ammonia causes mineral dissolution and sequential precipitation. • Ammonia treatment effectively immobilized uranium from contaminated sediments. - Abstract: Use of gas-phase amendments for in situ remediation of inorganic contaminants in unsaturated sediments of the vadose zone may be advantageous, but there has been limited development and testing of gas remediation technologies. Treatment with ammonia gas has a potential for use in treating inorganic contaminants (such as uranium) because it induces a high pore-water pH, causing mineral dissolution and subsequent formation of stable precipitates that decrease the mobility of some contaminants. For field application of this treatment, further knowledge of ammonia transport in porous media and the geochemical reactions induced by ammonia treatment is needed. Laboratory studies were conducted to support calculations needed for field treatment design, to quantify advective and diffusive ammonia transport in unsaturated sediments, to evaluate inter-phase (gas/sediment/pore water) reactions, and to study reaction-induced pore-water chemistry changes as a function of ammonia delivery conditions, such as flow rate, gas concentration, and water content. Uranium-contaminated sediment was treated with ammonia gas to demonstrate U immobilization. Ammonia gas quickly partitions into sediment pore water and increases the pH up to 13.2. Injected ammonia gas advection front movement can be reasonably predicted by gas flow rate and equilibrium partitioning. The ammonia gas diffusion rate is a function of the water content in the sediment. Sodium, aluminum, and silica pore-water concentrations increase upon exposure to ammonia and then decline as aluminosilicates precipitate when the pH declines due to buffering. Up to 85% of

  13. Accounting for exhaust gas transport dynamics in instantaneous emission models via smooth transition regression.

    Science.gov (United States)

    Kamarianakis, Yiannis; Gao, H Oliver

    2010-02-15

    Collecting and analyzing high frequency emission measurements has become very usual during the past decade as significantly more information with respect to formation conditions can be collected than from regulated bag measurements. A challenging issue for researchers is the accurate time-alignment between tailpipe measurements and engine operating variables. An alignment procedure should take into account both the reaction time of the analyzers and the dynamics of gas transport in the exhaust and measurement systems. This paper discusses a statistical modeling framework that compensates for variable exhaust transport delay while relating tailpipe measurements with engine operating covariates. Specifically it is shown that some variants of the smooth transition regression model allow for transport delays that vary smoothly as functions of the exhaust flow rate. These functions are characterized by a pair of coefficients that can be estimated via a least-squares procedure. The proposed models can be adapted to encompass inherent nonlinearities that were implicit in previous instantaneous emissions modeling efforts. This article describes the methodology and presents an illustrative application which uses data collected from a diesel bus under real-world driving conditions.

  14. Gas transport in low-permeability formations: a review of experimental evidence and modeling approaches

    International Nuclear Information System (INIS)

    Marschall, Paul; Keller, Lukas; Lanyon, Bill; Senger, Rainer

    2012-01-01

    This paper presents a review of phenomenological studies on immiscible fluid flow in porous media, clarifies terminology as used by different disciplines and discusses the different modeling approaches. It concludes with a discussion on the transferability of classical two-phase flow concepts on gas transport processes in low-permeability clay-stones. From a phenomenological point of view, advection and diffusion of dissolved species represent the simplest transport mechanisms in a water-saturated porous medium. The propagation of the dissolved species is controlled by the water velocity and its extent is controlled by the hydrodynamic dispersion - a well-known aggregate representation of the mixing processes due to diffusion, Taylor dispersion and tortuosity. Usually, the dissolution of a gaseous species in water is described by Henry's law, the diffusion of the dissolved gas is represented by Fick's law and the viscous losses of the pore water flow in the pore network are expressed by Darcy's law. Two-phase flow conditions occur when gas invades as a separate phase a water-saturated porous medium. This process is often called drainage, because the non-wetting fluid (gas) displaces a wetting fluid (pore water, 'defending' fluid). The propagation of the gas front is controlled by the complex interaction of gravity, viscous forces and capillary forces. Lenormand et al. (1988) conducted two-phase flow experiments for a wide range of capillary numbers Ca and viscosity ratios M. They identified 3 major flow regimes in the C a -M-space, which they coined viscous fingering, capillary fingering and stable displacement. The regime of stable displacement applies for the special case where the invading fluid has a higher viscosity than the defending fluid (e.g. water imbibition in a gas-filled porous medium). Viscous and capillary fingering are associated with instable displacement of a wetting fluid by the non-wetting fluid, giving rise to phenomena such as migration

  15. Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas; Deteccion de fugas por radiotrazado en ducto marino para transporte de gas LP

    Energy Technology Data Exchange (ETDEWEB)

    Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e mail: efrp@nuclear.inin.mx

    2008-07-01

    In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO{sub 3}){sub 3} 6H{sub 2}O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

  16. Simulation of Gas Transport in Tight/Shale Gas Reservoirs by a Multicomponent Model Based on PEBI Grid

    Directory of Open Access Journals (Sweden)

    Longjun Zhang

    2015-01-01

    Full Text Available The ultra-low permeability and nanosize pores of tight/shale gas reservoir would lead to non-Darcy flow including slip flow, transition flow, and free molecular flow, which cannot be described by traditional Darcy’s law. The organic content often adsorbs some gas content, while the adsorbed amount for different gas species is different. Based on these facts, we develop a new compositional model based on unstructured PEBI (perpendicular bisection grid, which is able to characterize non-Darcy flow including slip flow, transition flow, and free molecular flow and the multicomponent adsorption in tight/shale gas reservoirs. With the proposed model, we study the effect of non-Darcy flow, length of the hydraulic fracture, and initial gas composition on gas production. The results show both non-Darcy flow and fracture length have significant influence on gas production. Ignoring non-Darcy flow would underestimate 67% cumulative gas production in lower permeable gas reservoirs. Gas production increases with fracture length. In lower permeable reservoirs, gas production increases almost linearly with the hydraulic fracture length. However, in higher permeable reservoirs, the increment of the former gradually decreases with the increase in the latter. The results also show that the presence of CO2 in the formation would lower down gas production.

  17. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface ground water: background, base cases, shallow reservoirs, short-term gas and water transport

    Science.gov (United States)

    Researchers examined gas and water transport between a deep tight shale gas reservoir and a shallow overlying aquifer in the two years following hydraulic fracturing, assuming a pre-existing connecting pathway.

  18. Transportation's role in reducing U.S. greenhouse gas emissions, volume 1 and volume 2 : report to Congress, U.S. Department of Transportation

    Science.gov (United States)

    2010-04-01

    This study evaluates potentially viable strategies to reduce transportation : greenhouse gas (GHG) emissions. The study was mandated by the Energy : Independence and Security Act (P.L. 110-140, December 2007). The Act directed : the U.S. Department o...

  19. Transportation's role in reducing U.S. greenhouse gas emissions, volume 1 : report to Congress, U.S. Department of Transportation

    Science.gov (United States)

    2010-04-01

    This study evaluates potentially viable strategies to reduce transportation : greenhouse gas (GHG) emissions. The study was mandated by the Energy : Independence and Security Act (P.L. 110-140, December 2007). The Act directed : the U.S. Department o...

  20. Transportation's role in reducing U.S. greenhouse gas emissions, volume 2 : report to Congress, U.S. Department of Transportation

    Science.gov (United States)

    2010-04-01

    This study evaluates potentially viable strategies to reduce transportation greenhouse gas (GHG) emissions. The study was mandated by the Energy Independence and Security Act (P.L. 110-140, December 2007). The Act directed the U.S. Department of Tran...

  1. Modeling gravity effects on water retention and gas transport characteristics in plant growth substrates

    DEFF Research Database (Denmark)

    Deepagoda Thuduwe Kankanamge Kelum, Chamindu; Jones, Scott B.; Tuller, Markus

    2014-01-01

    utilization to conserve energy and to limit transport costs, native materials mined on Moon or Mars are of primary interest for plant growth media in a future outpost, while terrestrial porous substrates with optimal growth media characteristics will be useful for onboard plant growth during space missions....... Due to limited experimental opportunities and prohibitive costs, liquid and gas behavior in porous substrates under reduced gravity conditions has been less studied and hence remains poorly understood. Based on ground-based measurements, this study examined water retention, oxygen diffusivity and air...... permeability characteristics of six plant growth substrates for potential applications in space, including two terrestrial analogs for lunar and Martian soils and four particulate substrates widely used in reduced gravity experiments. To simulate reduced gravity water characteristics, the predictions...

  2. Free volumes and gas transport in polymers: amine-modified epoxy resins as a case study.

    Science.gov (United States)

    Patil, Pushkar N; Roilo, David; Brusa, Roberto S; Miotello, Antonio; Aghion, Stefano; Ferragut, Rafael; Checchetto, Riccardo

    2016-02-07

    The CO2 transport process was studied in a series of amine-modified epoxy resins having different cross-linking densities but the same chemical environment for the penetrant molecules. Positron Annihilation Lifetime Spectroscopy (PALS) was used to monitor the free volume structure of the samples and experimentally evaluate their fractional free volume fh(T) and its temperature evolution. The analysis of the free volume hole size distribution showed that all the holes have a size large enough to accommodate the penetrant molecules at temperatures T above the glass transition temperature Tg. The measured gas diffusion constants at T > Tg have been reproduced in the framework of the free volume theory of diffusion using a novel procedure based on the use of fh(T) as an input experimental parameter.

  3. Electricity and gas market design to supply the German transport sector with hydrogen

    International Nuclear Information System (INIS)

    Robinius, Martin

    2015-01-01

    The German government has set targets to reduce greenhouse gas emissions by 40% by 2020, 55% by 2030, 70% by 2040 and 80-95% by 2050 compared to 1990 as reference year. As well as meeting other requirements, these targets can be achieved by raising the contribution of renewably-generated power to Germany's gross electricity consumption to 80% by 2050. Based on Germany's potential, intermittent energy sources (IES) such as on- and offshore wind, as well as photovoltaics, are necessary sources that must be utilized in order to achieve these ambitious targets. Because of the intermittency of these sources, there will be times in which surplus power generated could be used for example for the transport sector. During these periods of surplus power, the storage capacity of hydrogen allows for a socalled ''power-to-gas'' concept whereby the surplus power can be used to produce hydrogen and oxygen by means of electrolyzers. The aim of this thesis is to identify and develop a market design that is characterized by high penetration levels of IES, supplemented by the use of hydrogen in the transport sector. Furthermore, the aim was to develop a model in which the electricity and gas sector, including a hydrogen pipeline grid, is represented so as to analyze and validate selected market designs. Therefore, potential electricity and gas markets, as well as the most important potential share and stakeholders of a hydrogen infrastructure, are analyzed. With the model developed in this thesis, an existing energy concept has been developed, analyzed and evaluated. In addition, the distribution of the hydrogen production costs was calculated by employing a Monte Carlo Simulation analysis. The developed energy concept relies on 170 GW onshore and 60 GW offshore wind capacity and these dominate the model. This leads to surplus power, especially in the federal states of Lower Saxony, Schleswig-Holstein and Mecklenburg-Western Pomerania. To supply the

  4. Effective transport coefficients in PEM fuel cell catalyst and gas diffusion layers: Beyond Bruggeman approximation

    Energy Technology Data Exchange (ETDEWEB)

    Das, Prodip K. [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON (Canada); Institute for Fuel Cell Innovation, National Research Council, Vancouver, BC (Canada); Li, Xianguo [Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON (Canada); Liu, Zhong-Sheng [Institute for Fuel Cell Innovation, National Research Council, Vancouver, BC (Canada)

    2010-09-15

    The Bruggeman approximation has widely been used for estimating the effective conductivity and diffusivity of both the catalyst and gas diffusion layers of polymer electrolyte membrane (PEM) fuel cells. This approximation is based on the Bruggeman's Effective Medium Theory [Bruggeman D. Berechnung verschiedener physikalischer konstanten von heterogenen substanzen. Ann Phys (Leipzig) 1935;24:636-79], which provides empirical correlation for the effective properties of a composite system. Since it is an empirical correlation, a unique correlation based on the Bruggeman approximation does not always hold for the PEM fuel cell effective properties. Rather, the Bruggeman correlation is a cell specific and experiment dependent correlation that depends on structure, phase composition, water saturation, experimental parameters, etc. Further, this correlation needs to be combined with other correlations to estimate the effective diffusivities. In this article, a set of mathematical formulations has been proposed for the effective transport properties in both the catalyst and gas diffusion layers of a PEM fuel cell. The effective conductivity and diffusivity expressions are derived from the mathematical formulations of the Hashin Coated Sphere model [Hashin Z. The elastic moduli of heterogeneous materials. J Appl Mech 1962;29:143-50], which provides an identical mathematical foundation for each of these effective properties rather than an empirical correlation and avoid to use of multiple correlations together. The present model formulations agree well with the results available in literature for the limiting case. Hence, the proposed formulations for the effective transport properties will be a useful estimating tool in the numerical modeling of PEM fuel cells. (author)

  5. The use of the natural-gas pipeline infrastructure for hydrogen transport in a changing market structure

    Energy Technology Data Exchange (ETDEWEB)

    Haeseldonckx, Dries; D' haeseleer, William [Division of Energy Conversion, University of Leuven (K.U. Leuven), Celestijnenlaan 300A, 3001 Leuven (Belgium)

    2007-07-15

    In this paper, the transport and distribution aspects of hydrogen during the transition period towards a possible full-blown hydrogen economy are carefully looked at. Firstly, the energetic and material aspects of hydrogen transport through the existing natural-gas (NG) pipeline infrastructure is discussed. Hereby, only the use of centrifugal compressors and the short-term security of supply seem to constitute a problem for the NG to hydrogen transition. Subsequently, the possibility of percentwise mixing of hydrogen into the NG bulk is dealt with. Mixtures containing up to 17 vol% of hydrogen should not cause difficulties. As soon as more hydrogen is injected, replacement of end-use applications and some pipelines will be necessary. Finally, the transition towards full-blown hydrogen transport in (previously carrying) NG pipelines is treated. Some policy guidelines are offered, both in a regulated and a liberalised energy (gas) market. As a conclusion, it can be stated that the use of hydrogen-natural gas mixtures seems well suited for the transition from natural gas to hydrogen on a distribution (low pressure) level. However, getting the hydrogen gas to the distribution grid, by means of the transport grid, remains a major issue. In the end, the structure of the market, regulated or liberalised, turns out not to be important. (author)

  6. A Simple Expression for the Tortuosity of Gas Transport Paths in Solid Oxide Fuel Cells’ Porous Electrodes

    Directory of Open Access Journals (Sweden)

    Wei Kong

    2015-12-01

    Full Text Available Based on the three-dimensional (3D cube packing model, a simple expression for the tortuosity of gas transport paths in solid oxide fuel cells’ (SOFC porous electrodes is developed. The proposed tortuosity expression reveals the dependence of the tortuosity on porosity, which is capable of providing results that are very consistent with the experimental data in the practical porosity range of SOFC. Furthermore, for the high porosity (>0.6, the proposed tortuosity expression is also accurate. This might be helpful for understanding the physical mechanism for the tortuosity of gas transport paths in electrodes and the optimization electrode microstructure for reducing the concentration polarization.

  7. Growth of Cd0.96Zn0.04Te single crystals by vapor phase gas transport method

    Directory of Open Access Journals (Sweden)

    S. H. Tabatabai Yazdi

    2006-03-01

    Full Text Available   Cd0.96Zn0.04Te crystals were grown using vapor phase gas transport method (VPGT. The results show that dendritic crystals with grain size up to 3.5 mm can be grown with this technique. X-ray diffraction and Laue back-reflection patterns show that dendritic crystals are single-phase, whose single crystal grains are randomly oriented with respect to the gas-transport axis. Electrical measurements, carried out using Van der Pauw method, show that the as-grown crystals have resistivity of about 104 Ω cm and n-type conductivity.

  8. Simulation of Gas Transport in Tight/Shale Gas Reservoirs by a Multicomponent Model Based on PEBI Grid

    OpenAIRE

    Zhang, Longjun; Li, Daolun; Wang, Lei; Lu, Detang

    2015-01-01

    The ultra-low permeability and nanosize pores of tight/shale gas reservoir would lead to non-Darcy flow including slip flow, transition flow, and free molecular flow, which cannot be described by traditional Darcy’s law. The organic content often adsorbs some gas content, while the adsorbed amount for different gas species is different. Based on these facts, we develop a new compositional model based on unstructured PEBI (perpendicular bisection) grid, which is able to characterize non-Darcy ...

  9. Transition of Gas-Liquid Stratified Flow in Oil Transport Pipes

    Directory of Open Access Journals (Sweden)

    D. Lakehal

    2011-12-01

    Full Text Available Large-Scale Simulation results of the transition of a gas-liquid stratified flow to slug flow regime in circular 3D oil transport pipes under turbulent flow conditions expressed. Free surface flow in the pipe is treated using the Level Set method. Turbulence is approached via the LES and VLES methodologies extended to interfacial two-phase flows. It is shown that only with the Level Set method the flow transition can be accurately predicted, better than with the two-fluid phase-average model. The transition from stratified to slug flow is found to be subsequent to the merging of the secondary wave modes created by the action of gas shear (short waves with the first wave mode (high amplitude long wave. The model is capable of predicting global flow features like the onset of slugging and slug speed. In the second test case, the model predicts different kinds of slugs, the so-called operating slugs formed upstream that fill entirely the pipe with water slugs of length scales of the order of 2-4 D, and lower size (1-1.5 D disturbance slugs, featuring lower hold-up (0.8-0.9. The model predicts well the frequency of slugs. The simulations revealed important parameter effects on the results, such as two-dimensionality, pipe length, and water holdup.

  10. Gas Transport and Density Control in the HYLIFE Heavy-Ion Beam Lines

    International Nuclear Information System (INIS)

    Debonnel, Christophe S.; Welch, Dale R.; Rose, David V.; Lawrence, Simon S.Yu; Peterson, Per F.

    2003-01-01

    The effective propagation and focusing of heavy-ion beams in the final-focus magnet region of inertial fusion target chambers require controlling the background gas density and pressure in the beam tubes. Liquid vortexes will coat the inside of the tubes next to the beam ports and will help eliminate the need for mechanical shutters to mitigate the venting of target chamber background gas into the final-focus magnet region. Before the neutralizing region, the beam space charge is high, and ablation and target debris deposition in the final-focus magnet region may cause voltage breakdown. Previous studies focused on evaluating the amount of target chamber debris reaching the entrance of the beam ports. The TSUNAMI code has now been used to assess the density, temperature, and velocity of the vortex debris transported ∼3 m up the beam tubes and reaching the final-focus magnet region, assuming that the liquid vortexes are perfectly absorbing surfaces. To further mitigate debris deposition in the final-focus magnet region, and prevent voltage breakdown, a 'magnetic shutter' has been envisaged to divert the debris out of the final-focus region. This shutter will prevent the hot ablation debris from reaching the magnet region and, coupled to some ionizing scheme, will conveniently suppress early ingression of debris into the final-focus magnet region

  11. Porewater methane transport within the gas vesicles of diurnally migrating Chaoborus spp.: An energetic advantage

    Science.gov (United States)

    McGinnis, Daniel F.; Flury, Sabine; Tang, Kam W.; Grossart, Hans-Peter

    2017-03-01

    Diurnally-migrating Chaoborus spp. reach populations of up to 130,000 individuals m-2 in lakes up to 70 meters deep on all continents except Antarctica. Linked to eutrophication, migrating Chaoborus spp. dwell in the anoxic sediment during daytime and feed in the oxic surface layer at night. Our experiments show that by burrowing into the sediment, Chaoborus spp. utilize the high dissolved gas partial pressure of sediment methane to inflate their tracheal sacs. This mechanism provides a significant energetic advantage that allows the larvae to migrate via passive buoyancy rather than more energy-costly swimming. The Chaoborus spp. larvae, in addition to potentially releasing sediment methane bubbles twice a day by entering and leaving the sediment, also transport porewater methane within their gas vesicles into the water column, resulting in a flux of 0.01-2 mol m-2 yr-1 depending on population density and water depth. Chaoborus spp. emerging annually as flies also result in 0.1-6 mol m-2 yr-1 of carbon export from the system. Finding the tipping point in lake eutrophication enabling this methane-powered migration mechanism is crucial for ultimately reconstructing the geographical expansion of Chaoborus spp., and the corresponding shifts in the lake’s biogeochemistry, carbon cycling and food web structure.

  12. Transport of Gas-Phase Anthropogenic VOCs to the Remote Troposphere During the NASA ATom Mission

    Science.gov (United States)

    Hornbrook, R. S.; Apel, E. C.; Hills, A. J.; Asher, E. C. C.; Emmons, L. K.; Blake, D. R.; Blake, N. J.; Simpson, I. J.; Barletta, B.; Meinardi, S.; Montzka, S. A.; Moore, F. L.; Miller, B. R.; Sweeney, C.; McKain, K.; Wofsy, S. C.; Daube, B. C.; Commane, R.; Bui, T. V.; Hanisco, T. F.; Wolfe, G. M.; St Clair, J. M.; Ryerson, T. B.; Thompson, C. R.; Peischl, J.; Ray, E. A.

    2017-12-01

    The NASA Atmospheric Tomography (ATom) project aims to study the impact of human-produced air pollution on greenhouse gases and on chemically reactive gases in the atmosphere. During the first two deployments, ATom-1 and ATom-2, which took place August 2016 and February 2017, respectively, a suite of trace gas measurement instruments were deployed on the NASA DC-8 which profiled the atmosphere between 0.2 and 13 km from near-pole to near-pole around the globe, sampling in the most remote regions of the atmosphere over the Arctic, Pacific, Southern, and Atlantic Oceans. Volatile organic compounds (VOCs) with a range of lifetimes from days to decades quantified using the Trace Organic Gas Analyzer (TOGA), Whole Air Sampler (WAS) and Programmable Flask Packages (PFPs) demonstrate a significant impact on the remote atmosphere from urban and industrial sources. Comparisons between the transport and fate of pollutants during Northern Hemisphere summer and winter will be presented. Observations of the distributions of anthropogenic VOCs will be compared with simulations using the Community Atmosphere Model with chemistry (CAM-chem).

  13. Gas transport below artificial recharge ponds: insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment.

    Science.gov (United States)

    Clark, Jordan F; Hudson, G Bryant; Avisar, Dror

    2005-06-01

    A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (approximately 4 m day(-1)). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at approximately 24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was approximately 25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable.

  14. Electrical detection of spin transport in Si two-dimensional electron gas systems

    Science.gov (United States)

    Chang, Li-Te; Fischer, Inga Anita; Tang, Jianshi; Wang, Chiu-Yen; Yu, Guoqiang; Fan, Yabin; Murata, Koichi; Nie, Tianxiao; Oehme, Michael; Schulze, Jörg; Wang, Kang L.

    2016-09-01

    Spin transport in a semiconductor-based two-dimensional electron gas (2DEG) system has been attractive in spintronics for more than ten years. The inherent advantages of high-mobility channel and enhanced spin-orbital interaction promise a long spin diffusion length and efficient spin manipulation, which are essential for the application of spintronics devices. However, the difficulty of making high-quality ferromagnetic (FM) contacts to the buried 2DEG channel in the heterostructure systems limits the potential developments in functional devices. In this paper, we experimentally demonstrate electrical detection of spin transport in a high-mobility 2DEG system using FM Mn-germanosilicide (Mn(Si0.7Ge0.3)x) end contacts, which is the first report of spin injection and detection in a 2DEG confined in a Si/SiGe modulation doped quantum well structure (MODQW). The extracted spin diffusion length and lifetime are l sf = 4.5 μm and {τ }{{s}}=16 {{ns}} at 1.9 K respectively. Our results provide a promising approach for spin injection into 2DEG system in the Si-based MODQW, which may lead to innovative spintronic applications such as spin-based transistor, logic, and memory devices.

  15. The regulation of greenhouse gas emissions in the field of transport

    International Nuclear Information System (INIS)

    2009-03-01

    Since 1990, CO 2 emissions in the transport sector have increased by nearly 20%, mainly because of increased car traffic. Reducing them by 20% between now and 2020, in accordance with the draft law tabled by the Grenelle Environment Forum - and by much more between now and 2050 in the context of reducing European emissions by 75% - presupposes recourse to economic instruments such as the climate-energy contribution envisaged by the Forum. However, the methods of evaluation and implementation remain to be defined. The order of magnitude of such instruments could correspond to the value defined for the socio-economic calculations of public projects by a Centre d'Analyse Strategique mission that was set up at the request of the Prime Minister and chaired by Alain Quinet. It will thus be close to 30 euros per CO 2 ton today, rising to 100 euros in 2030 and between 150 and 350 euros in 2050. However, this value cannot be used as such in the economy - and particularly in the form of a tax - without precautions, both for social reasons and reasons of economic competitiveness. The purpose of this Strategic Newswatch is to contribute to the debate by envisaging, within a European framework, the different forms that the regulation of transport greenhouse gas emissions could take. (author)

  16. Greenhouse gas options, policy and measures for the Canadian Transportation Equipment Manufacturing Industry - Final report

    International Nuclear Information System (INIS)

    2000-02-01

    This report summarizes and analyses the work that have been carried out by the Transportation Equipment Manufacturing Sector (TEMS) Working Group of the National Climate Change Industry Table over the last 14 months, and presents the Group's view of appropriate policies for greenhouse gas emission reduction in Canada. To develop its approach, the Working Group conducted five separate studies which are included in this report as annexes. Annex A is a Foundation Paper, which provides an overview of the sector's performance vis-a-vis energy use and greenhouse gas production. Annex B analyzes the competitive position of the industry by reviewing growth trends in each of the industry sub-sectors and the key factors in maintaining and enhancing the sector's international competitive position. Annex C is a technology assessment. It provides an overview of the uptake of energy saving technology in the sector. Annex D provides a facility level analysis focusing on energy use in the automotive parts manufacturing sector. Annex E is a review of American policies on climate change, summarizing the approach currently being taken towards greenhouse gas emission reduction in the United States. Some of the key findings of this report are: (1) business-as-usual emissions will greatly exceed the implicit Kyoto target of six per cent reduction from 1990 levels, (2) relatively few opportunities exist for major emissions reductions through the use of existing technology, (3) sector-specific policies appear to be ill-advised, but cross-cutting policies provide good opportunities for the transportation equipment manufacturing sector to do its part in helping Canada meeting its Kyoto commitment. The report recommends investigation of barriers to adoption of new technologies and examination of market imperfections, promotion of cogeneration where it makes economic sense, and consideration of the use of flexible instruments such as carbon taxes and tradable emission permits. Overall, the

  17. Tracing natural gas transport into shallow groundwater using dissolved nitrogen and alkane chemistry in Parker County, Texas

    Science.gov (United States)

    Larson, T.; Nicot, J. P.; Mickler, P. J.; Darvari, R.

    2015-12-01

    Dissolved methane in shallow groundwater drives public concern about the safety of hydraulic fracturing. We report dissolved alkane and nitrogen gas concentrations and their stable isotope values (δ13C and δ15N, respectively) from 208 water wells in Parker county, Texas. These data are used to differentiate 'stray' natural gas and low temperature microbial methane, and (2) estimate the ratio of stray gas to groundwater. The ratio of (gas-phase) stray natural gas to groundwater is estimated by correlating dissolved methane and nitrogen concentrations and dissolved nitrogen δ15N values. Our hypothesis is groundwater exposed to high volumes of stray natural gas have high dissolved methane concentrations and low dissolved nitrogen concentrations and δ15N values. Alternatively, groundwater exposed to low volumes of stray gas-phase natural gas have elevated dissolved methane, but the concentration of dissolved nitrogen and its d15N value is atmospheric. A cluster of samples in Parker county have high concentrations of dissolved methane (>10mg/L) with d13Cmethane and alkane ratios (C1/C2+C3) typical of natural gas from the Barnett Shale and the Strawn Formation. Coupling dissolved nitrogen concentrations and δ15N values with these results, we suggest that few of the wells in this cluster preserve large gas to water ratios. Many samples with high dissolved methane concentrations have atmospheric dissolved nitrogen concentrations and δ15N values, providing evidence against high flux natural gas transport into shallow groundwater. These results demonstrate that dissolved nitrogen chemistry, in addition to dissolved alkane and noble gas measurements, may be useful to discern sources of dissolved methane and estimate ratios of stray natural gas-water ratios.

  18. Estimating the health benefits from natural gas use in transport and heating in Santiago, Chile.

    Science.gov (United States)

    Mena-Carrasco, Marcelo; Oliva, Estefania; Saide, Pablo; Spak, Scott N; de la Maza, Cristóbal; Osses, Mauricio; Tolvett, Sebastián; Campbell, J Elliott; Tsao, Tsao Es Chi-Chung; Molina, Luisa T

    2012-07-01

    Chilean law requires the assessment of air pollution control strategies for their costs and benefits. Here we employ an online weather and chemical transport model, WRF-Chem, and a gridded population density map, LANDSCAN, to estimate changes in fine particle pollution exposure, health benefits, and economic valuation for two emission reduction strategies based on increasing the use of compressed natural gas (CNG) in Santiago, Chile. The first scenario, switching to a CNG public transportation system, would reduce urban PM2.5 emissions by 229 t/year. The second scenario would reduce wood burning emissions by 671 t/year, with unique hourly emission reductions distributed from daily heating demand. The CNG bus scenario reduces annual PM2.5 by 0.33 μg/m³ and up to 2 μg/m³ during winter months, while the residential heating scenario reduces annual PM2.5 by 2.07 μg/m³, with peaks exceeding 8 μg/m³ during strong air pollution episodes in winter months. These ambient pollution reductions lead to 36 avoided premature mortalities for the CNG bus scenario, and 229 for the CNG heating scenario. Both policies are shown to be cost-effective ways of reducing air pollution, as they target high-emitting area pollution sources and reduce concentrations over densely populated urban areas as well as less dense areas outside the city limits. Unlike the concentration rollback methods commonly used in public policy analyses, which assume homogeneous reductions across a whole city (including homogeneous population densities), and without accounting for the seasonality of certain emissions, this approach accounts for both seasonality and diurnal emission profiles for both the transportation and residential heating sectors. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Low-Carbon Natural Gas for Transportation: Well-to-Wheels Emissions and Potential Market Assessment in California

    Energy Technology Data Exchange (ETDEWEB)

    Penev, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melaina, Marc [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bush, Brian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Muratori, Matteo [National Renewable Energy Lab. (NREL), Golden, CO (United States); Warner, Ethan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chen, Yuche [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-12-01

    This report improves on the understanding of the long-term technology potential of low-carbon natural gas (LCNG) supply pathways by exploring transportation market adoption potential through 2035 in California. Techno-economic assessments of each pathway are developed to compare the capacity, cost, and greenhouse gas (GHG) emissions of select LCNG production pathways. The study analyzes the use of fuel from these pathways in light-, medium-, and heavy-duty vehicle applications. Economic and life-cycle GHG emissions analysis suggest that landfill gas resources are an attractive and relatively abundant resource in terms of cost and GHG reduction potential, followed by waste water treatment plants and biomass with gasification and methanation. Total LCNG production potential is on the order of total natural gas demand anticipated in a success scenario for future natural gas vehicle adoption by 2035 across light-, medium-, and heavy-duty vehicle markets (110 trillion Btu/year).

  20. Regulatory aspects of the transportation of natural gas coming from marginal fields; Aspectos regulatorios do transporte de gas natural oriundo de campos marginais

    Energy Technology Data Exchange (ETDEWEB)

    Alpire, Ricardo [Universidade Salvador (UNIFACS), BA (Brazil); Tiryaki, Gisele Ferreira [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)

    2010-07-01

    Natural gas is an energy input that only recently began to have greater weight in the Brazilian energy matrix. The share of natural gas in national energy policies grew significantly between 1998 and 2009, reaching almost 10% of energetic participation in the end of this period. Because of this very dynamic and growing market, it is necessary to revisit the existing legislation to assess its relevance in the face of new conflict situations among experienced agents. This article aims to evaluate the existing legislation for the natural gas sector, particularly as to its effectiveness in regulating the conflicting issues in its distribution of this input in the form of compressed natural gas reserves come from marginal, where the final consumer is not located within the pipeline network of state distributor. Will address the standards in the industry, to the most recent law passed, Gas Law No. 11.909/2009, presented a critical review of the subject. (author)

  1. On the Shaker Simulation of Wind-Induced Non-Gaussian Random Vibration

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2016-01-01

    Full Text Available Gaussian signal is produced by ordinary random vibration controllers to test the products in the laboratory, while the field data is usually non-Gaussian. Two methodologies are presented in this paper for shaker simulation of wind-induced non-Gaussian vibration. The first methodology synthesizes the non-Gaussian signal offline and replicates it on the shaker in the Time Waveform Replication (TWR mode. A new synthesis method is used to model the non-Gaussian signal as a Gaussian signal multiplied by an amplitude modulation function (AMF. A case study is presented to show that the synthesized non-Gaussian signal has the same power spectral density (PSD, probability density function (PDF, and loading cycle distribution (LCD as the field data. The second methodology derives a damage equivalent Gaussian signal from the non-Gaussian signal based on the fatigue damage spectrum (FDS and the extreme response spectrum (ERS and reproduces it on the shaker in the closed-loop frequency domain control mode. The PSD level and the duration time of the derived Gaussian signal can be manipulated for accelerated testing purpose. A case study is presented to show that the derived PSD matches the damage potential of the non-Gaussian environment for both fatigue and peak response.

  2. Predicting wind-induced vibrations of high-rise buildings using unsteady CFD and modal analysis

    KAUST Repository

    Zhang, Yue

    2015-01-01

    This paper investigates the wind-induced vibration of the CAARC standard tall building model, via unsteady Computational Fluid Dynamics (CFD) and a structural modal analysis. In this numerical procedure, the natural unsteady wind in the atmospheric boundary layer is modeled with an artificial inflow turbulence generation method. Then, the turbulent flow is simulated by the second mode of a Zonal Detached-Eddy Simulation, and a conservative quadrature-projection scheme is adopted to transfer unsteady loads from fluid to structural nodes. The aerodynamic damping that represents the fluid-structure interaction mechanism is determined by empirical functions extracted from wind tunnel experiments. Eventually, the flow solutions and the structural responses in terms of mean and root mean square quantities are compared with experimental measurements, over a wide range of reduced velocities. The significance of turbulent inflow conditions and aeroelastic effects is highlighted. The current methodology provides predictions of good accuracy and can be considered as a preliminary design tool to evaluate the unsteady wind effects on tall buildings.

  3. Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid.

    Science.gov (United States)

    Roy, James W; Smith, James E

    2007-01-30

    Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.

  4. The Specifics of Legal Regulation of Relations in the Field of Transportation of Oil and Gas by Trunk-Line

    Directory of Open Access Journals (Sweden)

    Ruslana Kramar

    2018-02-01

    Full Text Available The article reveals the specifics of legal regulation of relations in the field of oil and gas transportation by trunk-lines in the context of adaptation of transport legislation of Ukraine to the legislation of the European Union in accordance with the provisions of the Association Agreement. The factors that influence the effectiveness of the organizational and legal mechanism are determined, and measures aimed at improving legal regulation, which will enhance the level of safety and competitiveness of the Ukrainian trunk transport network, are presented.

  5. Applicability of heat and gas trans-port models in biocover design based on a case study from Denmark

    DEFF Research Database (Denmark)

    Nielsen, A. A. F.; Binning, Philip John; Kjeldsen, Peter

    2015-01-01

    . Both models used the heat equation for heat transfer, and the numerical model used advection-diffusion model with dual Monod kinetics for gas transport. The results were validated with data from a Danish landfi The models correlated well with the observed data: the coefficient of determination (R2...

  6. Water transport in the gas diffusion layer of a polymer electrolyte fuel cell : Dynamic Pore-Network Modeling

    NARCIS (Netherlands)

    Qin, C.

    2015-01-01

    The pore-scale modeling is a powerful tool for increasing our understanding of water transport in the fibrous gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). In this work, a new dynamic pore-network model for air-water flow in the GDL is developed. It incorporates water vapor

  7. Vadose zone attenuation of organic compounds at a crude oil spill site - Interactions between biogeochemical reactions and multicomponent gas transport

    Science.gov (United States)

    Molins, S.; Mayer, K.U.; Amos, R.T.; Bekins, B.A.

    2010-01-01

    Contaminant attenuation processes in the vadose zone of a crude oil spill site near Bemidji, MN have been simulated with a reactive transport model that includes multicomponent gas transport, solute transport, and the most relevant biogeochemical reactions. Dissolution and volatilization of oil components, their aerobic and anaerobic degradation coupled with sequential electron acceptor consumption, ingress of atmospheric O2, and the release of CH4 and CO2 from the smear zone generated by the floating oil were considered. The focus of the simulations was to assess the dynamics between biodegradation and gas transport processes in the vadose zone, to evaluate the rates and contributions of different electron accepting processes towards vadose zone natural attenuation, and to provide an estimate of the historical mass loss. Concentration distributions of reactive (O2, CH4, and CO2) and non-reactive (Ar and N2) gases served as key constraints for the model calibration. Simulation results confirm that as of 2007, the main degradation pathway can be attributed to methanogenic degradation of organic compounds in the smear zone and the vadose zone resulting in a contaminant plume dominated by high CH4 concentrations. In accordance with field observations, zones of volatilization and CH4 generation are correlated to slightly elevated total gas pressures and low partial pressures of N2 and Ar, while zones of aerobic CH4 oxidation are characterized by slightly reduced gas pressures and elevated concentrations of N2 and Ar. Diffusion is the most significant transport mechanism for gases in the vadose zone; however, the simulations also indicate that, despite very small pressure gradients, advection contributes up to 15% towards the net flux of CH4, and to a more limited extent to O2 ingress. Model calibration strongly suggests that transfer of biogenically generated gases from the smear zone provides a major control on vadose zone gas distributions and vadose zone carbon

  8. Analysis and characterization of storage, transport and re gasification for distribution of liquid natural gas (LNG); Analise e caracterizacao do armazenamento, transporte e regaseificacao para distribuicao do GNL

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Erica Cristina de; Simoes-Moreira, Jose Roberto [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Mecanica. Lab. de Sistemas Energeticos Alternativos], e-mail: erica.carvalho@poli.usp.br, e-mail: jrsimoes@usp.br; Udaeta, Miguel Edgar Morales [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia], e-mail: udaeta@iee.usp.br

    2008-07-01

    This article approach the evaluation and technical characterization os storage systems, transport and re gasification in the liquid natural gas (LNG). Methodologically the evaluation is performed of each system divided in data assessment and technical evaluation, where evaluations are mainly focused to the technical evaluation of the storage, transport and re gasification of the GNL distribution system in the retail store. The paper presents the re gasification 'cold' retail store, where it is possible to proceed the association with some local industry through the uses of cooling systems.

  9. Large-scale Experiment for Water and Gas Transport in Cementitious Backfill Materials (Phase 1 ): COLEX I

    International Nuclear Information System (INIS)

    Mayer, G.; Wittmann, F.H.; Moetsch, H.A.

    1998-05-01

    In the planned Swiss repository for low- and intermediate-level radioactive waste, the voids between the waste containers will be backfilled with a highly permeable mortar (NAGRA designation: mortar M1 ). As well as providing mechanical stability through filling of voids and sorbing radionuclides, the mortar must divert gases formed in the repository as a result of corrosion into the neighbouring host rock. This will prevent damage which could be caused by excess pressure on the repository structures. Water transport, which is coupled to gas transport, is also of interest. The former is responsible for the migration of radionuclides. Up till now, numerical simulations for a repository situation were carried out using transport parameters determined for small samples in the laboratory. However, the numerical simulations still had to be validated by a large-scale experiment. The investigations presented here should close this gap. Investigations into gas and water transport were carried out using a column (up to 5.4 m high) filled with backfill mortar. The column has a modular construction and can be sealed at the top end with a material of defined permeability (plug or top plug). The possibility to vary the material of the plug allows the influence of the more impermeable cavern lining or possible gas escape vents in the cavern roof to be investigated. A gas supply is connected to the bottom end and is used to simulate different gas generation rates from the waste. A total of 5 experiments were carried out in which the gas generation rate, the column height and the permeability of the plug were varied. Before the start of the experiments, the mortar in the column and the plug were saturated with water to approx. 95 %. In all the experiments, an increase in pressure with time could be observed. The higher the gas generation rate and the lower the permeability of the plug, the more quickly this occurred. At the beginning, only water flow out of the top of the column

  10. Gas transport behavior of mixed-matrix membranes composed of silica nanoparticles in a polymer of intrinsic microporosity (PIM-1)

    KAUST Repository

    Ahn, Juhyeon

    2010-01-01

    Recently, high-free volume, glassy ladder-type polymers, referred to as polymers of intrinsic microporosity (PIM), have been developed and their reported gas transport performance exceeded the Robeson upper bound trade-off for O2/N2 and CO2/CH4. The present work reports the gas transport behavior of PIM-1/silica nanocomposite membranes. The changes in free volume, as well as the presence and volume of the void cavities, were investigated by analyzing the density, thermal stability, and nano-structural morphology. The enhancement in gas permeability (e.g., He, H2, O2, N2, and CO2) with increasing filler content shows that the trend is related to the true silica volume and void volume fraction. Crown Copyright © 2009.

  11. Requirements for gas quality and gas appliances

    NARCIS (Netherlands)

    Levinsky, Howard; Gersen, Sander; Kiewiet, Bert

    2015-01-01

    Introduction The gas transmission network in the Netherlands transports two different qualities of gas, low-calorific gas known as G-gas or L-gas and, high calorific gas (H-gas). These two gas qualities are transported in separate networks, and are connected by means of five blending and conversion

  12. Poly-use multi-level sampling system for soil-gas transport analysis in the vadose zone.

    Science.gov (United States)

    Nauer, Philipp A; Chiri, Eleonora; Schroth, Martin H

    2013-10-01

    Soil-gas turnover is important in the global cycling of greenhouse gases. The analysis of soil-gas profiles provides quantitative information on below-ground turnover and fluxes. We developed a poly-use multi-level sampling system (PMLS) for soil-gas sampling, water-content and temperature measurement with high depth resolution and minimal soil disturbance. It is based on perforated access tubes (ATs) permanently installed in the soil. A multi-level sampler allows extraction of soil-gas samples from 20 locations within 1 m depth, while a capacitance probe is used to measure volumetric water contents. During idle times, the ATs are sealed and can be equipped with temperature sensors. Proof-of-concept experiments in a field lysimeter showed good agreement of soil-gas samples and water-content measurements compared with conventional techniques, while a successfully performed gas-tracer test demonstrated the feasibility of the PMLS to determine soil-gas diffusion coefficients in situ. A field application of the PMLS to quantify oxidation of atmospheric CH4 in a field lysimeter and in the forefield of a receding glacier yielded activity coefficients and soil-atmosphere fluxes well in agreement with previous studies. With numerous options for customization, the presented tool extends the methodological choices to investigate soil-gas transport in the vadose zone.

  13. Pulsatile flow and mass transport over an array of cylinders: gas transfer in a cardiac-driven artificial lung.

    Science.gov (United States)

    Chan, Kit Yan; Fujioka, Hideki; Bartlett, Robert H; Hirschl, Ronald B; Grotberg, James B

    2006-02-01

    The pulsatile flow and gas transport of a Newtonian passive fluid across an array of cylindrical microfibers are numerically investigated. It is related to an implantable, artificial lung where the blood flow is driven by the right heart. The fibers are modeled as either squared or staggered arrays. The pulsatile flow inputs considered in this study are a steady flow with a sinusoidal perturbation and a cardiac flow. The aims of this study are twofold: identifying favorable array geometry/spacing and system conditions that enhance gas transport; and providing pressure drop data that indicate the degree of flow resistance or the demand on the right heart in driving the flow through the fiber bundle. The results show that pulsatile flow improves the gas transfer to the fluid compared to steady flow. The degree of enhancement is found to be significant when the oscillation frequency is large, when the void fraction of the fiber bundle is decreased, and when the Reynolds number is increased; the use of a cardiac flow input can also improve gas transfer. In terms of array geometry, the staggered array gives both a better gas transfer per fiber (for relatively large void fraction) and a smaller pressure drop (for all cases). For most cases shown, an increase in gas transfer is accompanied by a higher pressure drop required to power the flow through the device.

  14. The Integration of a Structural Water Gas Shift Catalyst with a Vanadium Alloy Hydrogen Transport Device

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Thomas; Argyle, Morris; Popa, Tiberiu

    2009-06-30

    This project is in response to a requirement for a system that combines water gas shift technology with separation technology for coal derived synthesis gas. The justification of such a system would be improved efficiency for the overall hydrogen production. By removing hydrogen from the synthesis gas stream, the water gas shift equilibrium would force more carbon monoxide to carbon dioxide and maximize the total hydrogen produced. Additional benefit would derive from the reduction in capital cost of plant by the removal of one step in the process by integrating water gas shift with the membrane separation device. The answer turns out to be that the integration of hydrogen separation and water gas shift catalysis is possible and desirable. There are no significant roadblocks to that combination of technologies. The problem becomes one of design and selection of materials to optimize, or at least maximize performance of the two integrated steps. A goal of the project was to investigate the effects of alloying elements on the performance of vanadium membranes with respect to hydrogen flux and fabricability. Vanadium was chosen as a compromise between performance and cost. It is clear that the vanadium alloys for this application can be produced, but the approach is not simple and the results inconsistent. For any future contracts, large single batches of alloy would be obtained and rolled with larger facilities to produce the most consistent thin foils possible. Brazing was identified as a very likely choice for sealing the membranes to structural components. As alloying was beneficial to hydrogen transport, it became important to identify where those alloying elements might be detrimental to brazing. Cataloging positive and negative alloying effects was a significant portion of the initial project work on vanadium alloying. A water gas shift catalyst with ceramic like structural characteristics was the second large goal of the project. Alumina was added as a

  15. Benefits on public health from transport-related greenhouse gas mitigation policies in Southeastern European cities.

    Science.gov (United States)

    Sarigiannis, D A; Kontoroupis, P; Nikolaki, S; Gotti, A; Chapizanis, D; Karakitsios, S

    2017-02-01

    Climate change is a major environmental threat of our time. Cities have a significant impact on greenhouse gas emissions as most of the traffic, industry, commerce and more than 50% of world population is situated in urban areas. Southern Europe is a region that faces financial turmoil, enhanced migratory fluxes and climate change pressure. The case study of Thessaloniki is presented, one of the only two cities in Greece with established climate change action plans. The effects of feasible traffic policies in year 2020 are assessed and their potential health impact is compared to a business as usual scenario. Two types of measures are investigated: operation of underground rail in the city centre and changes in fleet composition. Potential co-benefits from reduced greenhouse gas emissions on public health by the year 2020 are computed utilizing state-of-the-art concentration response functions for PM x , NO 2 and C 6 H 6 . Results show significant environmental health and monetary co-benefits when the city metro is coupled with appropriate changes in the traffic composition. Monetary savings due to avoided mortality or leukaemia incidence corresponding to the reduction in PM 10 , PM 2.5, NO 2 and C 6 H 6 exposure will be 56.6, 45, 37.7 and 1.0 million Euros respectively. Promotion of 'green' transportation in the city (i.e. the wide use of electric vehicles), will provide monetary savings from the reduction in PM 10 , PM 2.5 , NO 2 and C 6 H 6 exposure up to 60.4, 49.1, 41.2 and 1.08 million Euros. Overall, it was shown that the respective GHG emission reduction policies resulted in clear co-benefits in terms of air quality improvement, public health protection and monetary loss mitigation. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Improving the natural gas transporting based on the steady state simulation results

    International Nuclear Information System (INIS)

    Szoplik, Jolanta

    2016-01-01

    The work presents an example of practical application of gas flow modeling results in the network, that was obtained for the existing gas network and for real data about network load depending on the time of day and air temperature. The gas network load in network connections was estimated based on real data concerning gas consumption by customers and weather data in 2010, based on two-parametric model based on the number of degree-days of heating. The aim of this study was to elaborate a relationship between pressure and gas stream introduced into the gas network. It was demonstrated that practical application of elaborated relationship in gas reduction station allows for the automatic adjustment of gas pressure in the network to the volume of network load and maintenance of gas pressure in the whole network at possibly the lowest level. It was concluded based on the results obtained that such an approach allows to reduce the amount of gas supplied to the network by 0.4% of the annual network load. - Highlights: • Determination of the hourly nodal demand for gas by the consumers. • Analysis of the results of gas flow simulation in pipeline network. • Elaboration of the relationship between gas pressure and gas stream feeding the network. • Automatic gas pressure steering in the network depending on the network load. • Comparison of input gas pressure in the system without and with pressure steering.

  17. A risk analysis for gas transport network planning expansion under regulatory uncertainty in Western Europe

    NARCIS (Netherlands)

    Pelletier, 27736; Wortmann, J.C.; Noteboom, H.J.

    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

  18. Microstructural analysis of mass transport phenomena in gas diffusion media for high current density operation in PEM fuel cells

    Science.gov (United States)

    Kotaka, Toshikazu; Tabuchi, Yuichiro; Mukherjee, Partha P.

    2015-04-01

    Cost reduction is a key issue for commercialization of fuel cell electric vehicles (FCEV). High current density operation is a solution pathway. In order to realize high current density operation, it is necessary to reduce mass transport resistance in the gas diffusion media commonly consisted of gas diffusion layer (GDL) and micro porous layer (MPL). However, fundamental understanding of the underlying mass transport phenomena in the porous components is not only critical but also not fully understood yet due to the inherent microstructural complexity. In this study, a comprehensive analysis of electron and oxygen transport in the GDL and MPL is conducted experimentally and numerically with three-dimensional (3D) microstructural data to reveal the structure-transport relationship. The results reveal that the mass transport in the GDL is strongly dependent on the local microstructural variations, such as local pore/solid volume fractions and connectivity. However, especially in the case of the electrical conductivity of MPL, the contact resistance between carbon particles is the dominant factor. This suggests that reducing the contact resistance between carbon particles and/or the number of contact points along the transport pathway can improve the electrical conductivity of MPL.

  19. Electrification of the transportation sector offers limited country-wide greenhouse gas reductions

    Science.gov (United States)

    Meinrenken, Christoph J.; Lackner, Klaus S.

    2014-03-01

    Compared with conventional propulsion, plugin and hybrid vehicles may offer reductions in greenhouse gas (GHG) emissions, regional air/noise pollution, petroleum dependence, and ownership cost. Comparing only plugins and hybrids amongst themselves, and focusing on GHG, relative merits of different options have been shown to be more nuanced, depending on grid-carbon-intensity, range and thus battery manufacturing and weight, and trip patterns. We present a life-cycle framework to compare GHG emissions for three drivetrains (plugin-electricity-only, gasoline-only-hybrid, and plugin-hybrid) across driving ranges and grid-carbon-intensities, for passenger cars, vans, buses, or trucks (well-to-wheel plus storage manufacturing). Parameter and model uncertainties are quantified via sensitivity analyses. We find that owing to the interplay of range, GHG/km, and portions of country-wide kms accessible to electrification, GHG reductions achievable from plugins (whether electricity-only or hybrids) are limited even when assuming low-carbon future grids. Furthermore, for policy makers considering GHG from electricity and transportation sectors combined, plugin technology may in fact increase GHG compared to gasoline-only-hybrids, regardless of grid-carbon-intensity.

  20. Ab initio phonon thermal transport in monolayer InSe, GaSe, GaS, and alloys

    Science.gov (United States)

    Pandey, Tribhuwan; Parker, David S.; Lindsay, Lucas

    2017-11-01

    We compare vibrational properties and phonon thermal conductivities (κ) of monolayer InSe, GaSe, and GaS systems using density functional theory and Peierls-Boltzmann transport methods. In going from InSe to GaSe to GaS, system mass decreases giving both increasing acoustic phonon velocities and decreasing scattering of these heat-carrying modes with optic phonons, ultimately giving {κ }{InSe}conservation conditions with mode scattering rates and phonon dispersions for each material. We also show that, unlike flat monolayer systems such as graphene, in InSe, GaSe and GaS thermal transport is governed by in-plane vibrations. Alloying of InSe, GaSe, and GaS systems provides an effective method for modulating their κ through intrinsic vibrational modifications and phonon scattering from mass disorder giving reductions ˜2-3.5 times. This disorder also suppresses phonon mean free paths in the alloy systems compared to those in their crystalline counterparts. This work provides fundamental insights of lattice thermal transport from basic vibrational properties for an interesting set of two-dimensional materials.

  1. The potential of natural gas as a bridging technology in low-emission road transportation in Germany

    Directory of Open Access Journals (Sweden)

    Wang-Helmreich Hanna

    2012-01-01

    Full Text Available Greenhouse gas emission reductions are at the centre of national and international efforts to mitigate climate change. In road transportation, many politically incentivised measures focus on increasing the energy efficiency of established technologies, or promoting electric or hybrid vehicles. The abatement potential of the former approach is limited, electric mobility technologies are not yet market-ready. In a case study for Germany, this paper focuses on natural gas powered vehicles as a bridging technology in road transportation. Scenario analyses with a low level of aggregation show that natural gas-based road transportation in Germany can accumulate up to 464 million tonnes of CO2-equivalent emission reductions until 2030 depending on the speed of the diffusion process. If similar policies were adopted EU-wide, the emission reduction potential could reach a maximum of about 2.5 billion tonnes of CO2-equivalent. Efforts to promote natural gas as a bridging technology may therefore contribute to significant emissions reductions.

  2. Purge gas protected transportable pressurized fuel cell modules and their operation in a power plant

    Science.gov (United States)

    Zafred, Paolo R.; Dederer, Jeffrey T.; Gillett, James E.; Basel, Richard A.; Antenucci, Annette B.

    1996-01-01

    A fuel cell generator apparatus and method of its operation involves: passing pressurized oxidant gas, (O) and pressurized fuel gas, (F), into fuel cell modules, (10 and 12), containing fuel cells, where the modules are each enclosed by a module housing (18), surrounded by an axially elongated pressure vessel (64), where there is a purge gas volume, (62), between the module housing and pressure vessel; passing pressurized purge gas, (P), through the purge gas volume, (62), to dilute any unreacted fuel gas from the modules; and passing exhaust gas, (82), and circulated purge gas and any unreacted fuel gas out of the pressure vessel; where the fuel cell generator apparatus is transpatable when the pressure vessel (64) is horizontally disposed, providing a low center of gravity.

  3. Gas Transport Through Porous Strata from Underground Reaction Source; the Influence of the Gas Kind, Temperature and Transport-Pore Size

    Czech Academy of Sciences Publication Activity Database

    Šolcová, Olga; Soukup, Karel; Rogut, J.; Stanczyk, K.; Schneider, Petr

    2009-01-01

    Roč. 90, č. 12 (2009), s. 1495-1501 ISSN 0378-3820 Grant - others:RFCR(XE) CT/2007/00006 Institutional research plan: CEZ:AV0Z40720504 Keywords : underground coal gas ification * diffusion * permeation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.321, year: 2009

  4. Experimental investigation of gas hydrate formation, plugging and transportability in partially dispersed and water continuous systems

    Science.gov (United States)

    Vijayamohan, Prithvi

    As oil/gas subsea fields mature, the amount of water produced increases significantly due to the production methods employed to enhance the recovery of oil. This is true especially in the case of oil reservoirs. This increase in the water hold up increases the risk of hydrate plug formation in the pipelines, thereby resulting in higher inhibition cost strategies. A major industry concern is to reduce the severe safety risks associated with hydrate plug formation, and significantly extending subsea tieback distances by providing a cost effective flow assurance management/safety tool for mature fields. Developing fundamental understanding of the key mechanistic steps towards hydrate plug formation for different multiphase flow conditions is a key challenge to the flow assurance community. Such understanding can ultimately provide new insight and hydrate management guidelines to diminish the safety risks due to hydrate formation and accumulation in deepwater flowlines and facilities. The transportability of hydrates in pipelines is a function of the operating parameters, such as temperature, pressure, fluid mixture velocity, liquid loading, and fluid system characteristics. Specifically, the hydrate formation rate and plugging onset characteristics can be significantly different for water continuous, oil continuous, and partially dispersed systems. The latter is defined as a system containing oil/gas/water, where the water is present both as a free phase and partially dispersed in the oil phase (i.e., entrained water in the oil). Since hydrate formation from oil dispersed in water systems and partially dispersed water systems is an area which is poorly understood, this thesis aims to address some key questions in these systems. Selected experiments have been performed at the University of Tulsa flowloop to study the hydrate formation and plugging characteristics for the partially dispersed water/oil/gas systems as well as systems where the oil is completely dispersed

  5. STP-ECRTS - THERMAL AND GAS ANALYSES FOR SLUDGE TRANSPORT AND STORAGE CONTAINER (STSC) STORAGE AT T PLANT

    Energy Technology Data Exchange (ETDEWEB)

    CROWE RD; APTHORPE R; LEE SJ; PLYS MG

    2010-04-29

    The Sludge Treatment Project (STP) is responsible for the disposition of sludge contained in the six engineered containers and Settler tank within the 105-K West (KW) Basin. The STP is retrieving and transferring sludge from the Settler tank into engineered container SCS-CON-230. Then, the STP will retrieve and transfer sludge from the six engineered containers in the KW Basin directly into a Sludge Transport and Storage Containers (STSC) contained in a Sludge Transport System (STS) cask. The STSC/STS cask will be transported to T Plant for interim storage of the STSC. The STS cask will be loaded with an empty STSC and returned to the KW Basin for loading of additional sludge for transportation and interim storage at T Plant. CH2MHILL Plateau Remediation Company (CHPRC) contracted with Fauske & Associates, LLC (FAI) to perform thermal and gas generation analyses for interim storage of STP sludge in the Sludge Transport and Storage Container (STSCs) at T Plant. The sludge types considered are settler sludge and sludge originating from the floor of the KW Basin and stored in containers 210 and 220, which are bounding compositions. The conditions specified by CHPRC for analysis are provided in Section 5. The FAI report (FAI/10-83, Thermal and Gas Analyses for a Sludge Transport and Storage Container (STSC) at T Plant) (refer to Attachment 1) documents the analyses. The process considered was passive, interim storage of sludge in various cells at T Plant. The FATE{trademark} code is used for the calculation. The results are shown in terms of the peak sludge temperature and hydrogen concentrations in the STSC and the T Plant cell. In particular, the concerns addressed were the thermal stability of the sludge and the potential for flammable gas mixtures. This work was performed with preliminary design information and a preliminary software configuration.

  6. Gas

    International Nuclear Information System (INIS)

    1996-01-01

    The French government has decided to modify the conditions of extension of local natural gas authorities to neighbouring districts. The European Union is studying the conditions of internal gas market with the objective of more open markets although considering public service requirements

  7. New IR-UV gas sensor to energy and transport sector

    DEFF Research Database (Denmark)

    Fateev, Alexander; Clausen, Sønnik

    In situ simultaneous measurements of gas temperature and gas composition are of great interest in combustion research and give useful information about conditions, chemical reactions and gas mixing in many industrial processes. An optically based technique is beneficial because it is non-intrusiv......In situ simultaneous measurements of gas temperature and gas composition are of great interest in combustion research and give useful information about conditions, chemical reactions and gas mixing in many industrial processes. An optically based technique is beneficial because it is non......-intrusive, accurate, fast and can be performed in situ for various extremely hard conditions. In humid and hot gas flows UV technique is more sensitive than FTIR one for fast gas concentration measurements of NO and SO2 and gives a great opportunity for simultaneous measurements of O2 concentration. Analysis...

  8. Detection of leaks for radioactive tracer in marine duct for transport of liquefied petroleum gas

    International Nuclear Information System (INIS)

    Robles P, E. F.; Benitez S, J. A.; Torre O, J. de la; Cruz S, E. de la; Molina, G.; Hernandez C, J. E.; Flores M, J. . e mail: efrp@nuclear.inin.mx

    2008-01-01

    In this work the aplication in the oil industry of the technique of radioactive tracer appears for the detection of internal leaks in a submarine duct that gives service as it lines of receipt of liquefied petroleum gas (Gas LP) located in the Mexican coast of the Pacific Ocean. This system of marine pipe is a consistent arrangement of a duct interior of 0.254 m (10 inches) of nominal diameter (N.D.) of steel to the carbon for cryogenic service ASTM A 333, Grade 6, schedule 30, isolated thermally with foam of polyurethane and shielding in a steel tube to the carbon ASTM A 53 Grade A, of 0.508 m (20 inches) N. D., schedule 20, which is recovered by a ballast encircling of concrete of 0.0508 m (2 inches) of thickness, reinforced with mesh metallic, and that 1315 m runs on the marine stratum to a maximum depth of 12.5 m. For the detection of leaks by radiotracer it was used as tracer the radioactive isotope La-140 produced in the TRIGA Mark III Experimental Reactor of the National Institute of Nuclear Research, starting from stable lanthanum nitrate (La(NO 3 ) 3 6H 2 O), with an activity of 100 mCi, the one which after having been made logistics tasks, given very particular sea maneuvers and due to the conditions of the work place, in the interior tube was injected in two subsequent stages to cover both duct senses; from earth and from the marine end respectively, there being used fresh water like transport way and submergible sodium iodide detectors (NaI) for the rake of the La-140. At the end of the journeys of pursuit of the radiotracer, it was determine the presence of three leaks points located in the break area of the marine surf to 360 m, 450 m and 495 m of distance of a reference point located in the beach section named Trap of Devils. (Author)

  9. Heat and particle transport in a one-dimensional hard-point gas model with on-site potential

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2015-05-01

    Full Text Available Heat and particle transport in a one-dimensional hard-point gas of elastically colliding particles are studied. In the nonequal mass case, due to the presence of on-site potential, the heat conduction of the model obeys the Fourier law and all the transport coefficients asymptotically approach constants in the thermodynamic limit. The thermoelectric figure of merit ZT increases slowly with the system length L and is proportional to the height of the potential barriers H in high H regime. These findings may serve as a guide for future theoretical and experimental studies.

  10. Effects of seasonality, transport pathway, and spatial structure on greenhouse gas fluxes in a restored wetland.

    Science.gov (United States)

    McNicol, Gavin; Sturtevant, Cove S; Knox, Sara H; Dronova, Iryna; Baldocchi, Dennis D; Silver, Whendee L

    2017-07-01

    Wetlands can influence global climate via greenhouse gas (GHG) exchange of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O). Few studies have quantified the full GHG budget of wetlands due to the high spatial and temporal variability of fluxes. We report annual open-water diffusion and ebullition fluxes of CO 2 , CH 4 , and N 2 O from a restored emergent marsh ecosystem. We combined these data with concurrent eddy-covariance measurements of whole-ecosystem CO 2 and CH 4 exchange to estimate GHG fluxes and associated radiative forcing effects for the whole wetland, and separately for open-water and vegetated cover types. Annual open-water CO 2 , CH 4 , and N 2 O emissions were 915 ± 95 g C-CO 2  m -2  yr -1 , 2.9 ± 0.5 g C-CH 4  m -2  yr -1 , and 62 ± 17 mg N-N 2 O m -2  yr -1 , respectively. Diffusion dominated open-water GHG transport, accounting for >99% of CO 2 and N 2 O emissions, and ~71% of CH 4 emissions. Seasonality was minor for CO 2 emissions, whereas CH 4 and N 2 O fluxes displayed strong and asynchronous seasonal dynamics. Notably, the overall radiative forcing of open-water fluxes (3.5 ± 0.3 kg CO 2 -eq m -2  yr -1 ) exceeded that of vegetated zones (1.4 ± 0.4 kg CO 2 -eq m -2  yr -1 ) due to high ecosystem respiration. After scaling results to the entire wetland using object-based cover classification of remote sensing imagery, net uptake of CO 2 (-1.4 ± 0.6 kt CO 2 -eq yr -1 ) did not offset CH 4 emission (3.7 ± 0.03 kt CO 2 -eq yr -1 ), producing an overall positive radiative forcing effect of 2.4 ± 0.3 kt CO 2 -eq yr -1 . These results demonstrate clear effects of seasonality, spatial structure, and transport pathway on the magnitude and composition of wetland GHG emissions, and the efficacy of multiscale flux measurement to overcome challenges of wetland heterogeneity. © 2017 John Wiley & Sons Ltd.

  11. Coupled analysis of multi-impact energy harvesting from low-frequency wind induced vibrations

    Science.gov (United States)

    Zhu, Jin; Zhang, Wei

    2015-04-01

    Energy need from off-grid locations has been critical for effective real-time monitoring and control to ensure structural safety and reliability. To harvest energy from ambient environments, the piezoelectric-based energy-harvesting system has been proven very efficient to convert high frequency vibrations into usable electrical energy. However, due to the low frequency nature of the vibrations of civil infrastructures, such as those induced from vehicle impacts, wind, and waves, the application of a traditional piezoelectric-based energy-harvesting system is greatly restrained since the output power drops dramatically with the reduction of vibration frequencies. This paper focuses on the coupled analysis of a proposed piezoelectric multi-impact wind-energy-harvesting device that can effectively up-convert low frequency wind-induced vibrations into high frequency ones. The device consists of an H-shape beam and four bimorph piezoelectric cantilever beams. The H-shape beam, which can be easily triggered to vibrate at a low wind speed, is originated from the first Tacoma Narrows Bridge, which failed at wind speeds of 18.8 m s-1 in 1940. The multi-impact mechanism between the H-shape beam and the bimorph piezoelectric cantilever beams is incorporated to improve the harvesting performance at lower frequencies. During the multi-impact process, a series of sequential impacts between the H-shape beam and the cantilever beams can trigger high frequency vibrations of the cantilever beams and result in high output power with a considerably high efficiency. In the coupled analysis, the coupled structural, aerodynamic, and electrical equations are solved to obtain the dynamic response and the power output of the proposed harvesting device. A parametric study for several parameters in the coupled analysis framework is carried out including the external resistance, wind speed, and the configuration of the H-shape beam. The average harvested power for the piezoelectric cantilever

  12. A UK portrait of wind-induced undercatch in rainfall measurement

    Science.gov (United States)

    Pollock, Michael; Quinn, Paul; O'Donnell, Greg; Colli, Matteo; Dutton, Mark; Black, Andrew; Wilkinson, Mark; Kilsby, Chris; Stagnaro, Mattia; Lanza, Luca; O'Connell, Enda

    2017-04-01

    Rainfall is vital to life; civilisation depends upon it. Changing local and regional rainfall regimes toward more intense storm events (e.g. in the UK), increases the existing challenge of accurately measuring and modelling rainfall. Data from rain gauges, often considered to provide the most accurate practicable measure of precipitation at a point in space in time, play a critical role. They are used for, inter alia, flood forecasting and flood risk management; radar calibration and numerical weather prediction models; urban planning and drainage; and water resource management and hydrological modelling. Despite the key importance of these measurements, they remain susceptible to fundamental sources of systematic error which are often not considered when rainfall data are used. Inaccuracies in measurements are compounded in modelling applications by producing potentially misleading or incorrect results; it is therefore of great importance to understand and present uncertainty in observations. Standard practice is to mount rain gauges above the ground surface. This configuration obstructs the prevailing wind which causes an acceleration of airflow above the orifice. Precipitation is deflected away from the orifice and lands 'downstream' of the area represented by the gauge measurement, reducing its collection efficiency (CE). This phenomenon is commonly referred to as 'wind-induced undercatch'. The physical shape of a gauge bears a significant impact on its CE. Computational Fluid Dynamics (CFD) simulations are used to investigate how different shapes of precipitation gauge are affected by the wind. CFD modelling is supported by high-resolution field measurements at several exposed 'Hydro-Met' research stations in the UK. These sites are occupied by rain gauges which are scrutinised in the CFD analyses. The reference measurements at all sites are made within a WMO reference pit, where the rain gauge is mounted with its orifice at ground level and surrounded by an

  13. Rehabilitation of the natural gas field Thoense with wet transport of natural gas; Sanierung des Erdgasfeldes Thoense unter Anwendung des Erdgasnasstransports

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, W.; Gerhartz, B.; Schmitt, D.; Uphoff, T. [BEB Erdgas und Erdoel GmbH, Hannover (Germany)

    1998-12-31

    Natural gas has been extracted the gas field of Thoense situated at the Northern fringe of the city of Hannover for over forty years. At all 10 bore sites the gas was dried with glycol dryers. While dealing with the problem of hydrocarbon emissions from the dryers it became evident, that some of the very old plants had to be rehabilitated. BEB operates the Thoense field on behalf of Elwerath/Brigitta/Deutz. An integrated concept, based on wet transport of natural gas, was used to remove the emission of hydrocarbons and rehabilitate the surface plants in order to cut operating costs. The field at Thoense is now economically efficient enough to continue operations for a long time. [Deutsch] Aus dem am nordoestlichen Stadtrand Hannovers liegenden Gasfeld Thoense wird seit ueber vierzig Jahren Erdgas gefoerdert. Die Gastrocknung erfolgte dort in ueblicher Weise mit Glykoltrocknungsanlagen an allen zehn Bohrungen. Bei der Bearbeitung des damit verbundenen Problems der Kohlenwasserstoffemissionen aus den Trocknungsanlagen wurde der Sanierungsbedarf an den z.T. sehr alten Anlagen deutlich. Das Feld Thoense wird von BEB fuer das Konsortium Elwerath/Brigitta/Deutz betrieben. Es wird gezeigt, wie mit einem integrierten Konzept auf der Basis des Erdgasnasstransportes die KW-Emissionen beseitigt wurden und gleichzeitig eine betriebskostensenkende Sanierung der obertaegigen Anlagen durchgefuehrt werden konnte. Damit wurde die wirtschaftliche Voraussetzung geschaffen, die Gasversorgung aus Thoense noch lange aufrecht erhalten zu koennen. (orig.)

  14. The effect of an engineered closure cap on radon gas transport from a shallow land burial site

    International Nuclear Information System (INIS)

    Lindstrom, F.T.; Cawlfield, D.E.; Donahue, M.E.; Emer, D.F.; Shott, G.J.

    1992-01-01

    US Department of Energy (DOE) Order 5820.2A requires performance assessment of all new and existing low level radioactive waste disposal sites. An integral part of performance assessment is estimating the fluxes of radioactive gases such as radon-220 and radon-222. Mathematical models, which in themselves point out data needs and therefore drive site characterization, provide a logical means of performing the required flux estimations. The effects of an engineered closure cap on radon gas transport in a very dry alluvial soil in the southwestern desert are considered in detail in this paper. Our model (Lindstrom, et al. 1992 a ampersand b and Cawlfield et al. 1992 a ampersand b) was constructed in a site specific fashion because the existing mathematical models of noble gas transport from the spatial point of origin in the low level waste repository through the surrounding soil and closure cap with subsequent release to the atmosphere are few in numbers (Nazaroff, 1992)

  15. Knudsen diffusion - The effect of small pore size and low gas pressure on gaseous transport in soil

    Science.gov (United States)

    Clifford, S. M.; Hillel, D.

    1986-01-01

    The analytical principles and applications of the theory of Knudsen diffusion are reviewed, with emphasis on gas transport in the soils of planetary bodies. Knudsen diffusion occurs when the mean free path of diffusing gas molecules surpasses the size of the pores through which diffusion proceeds. The process is then dominated by collisions with the pore walls. Computational techniques for deriving the Knudsen coefficient for soils with a nonreentrant cross-section shape are reviewed, along with methods of deriving a coefficient for soils which permit both Knudsen and bulk diffusion. Sample calculations for three pore-size distributions are provided to illustrate the decrease in transport efficiency with increasingly smaller soil pore sizes.

  16. Modeling lateral gas transport in soil adjacent to an old landfill

    DEFF Research Database (Denmark)

    Poulsen, T.G.; Christophersen, Mette; Moldrup, P.

    2001-01-01

    Lateral migration of landfill gases in soils surrounding old (closed) municipal landfills can lead to explosion hazards and damage to vegetation. Landfill gas production and migration is controlled by microbial activity and soil physical properties such as gas (air) permeability, gas diffusivity...... during the calibration. The model was used to evaluate the sensitivity of landfill gas concentration and flux with respect to a set of governing parameters. The results of the sensitivity analysis indicated that landfill gas migration in the field soil was most sensitive to air permeability and soil...

  17. Interactions of C+(2PJ) with rare gas atoms: incipient chemical interactions, potentials and transport coefficients

    Science.gov (United States)

    Tuttle, William D.; Thorington, Rebecca L.; Viehland, Larry A.; Breckenridge, W. H.; Wright, Timothy G.

    2018-03-01

    Accurate interatomic potentials were calculated for the interaction of a singly charged carbon cation, C+, with a single rare gas atom, RG (RG = Ne-Xe). The RCCSD(T) method and basis sets of quadruple-ζ and quintuple-ζ quality were employed; each interaction energy was counterpoise corrected and extrapolated to the basis set limit. The lowest C+(2P) electronic term of the carbon cation was considered, and the interatomic potentials calculated for the diatomic terms that arise from these: 2Π and 2Σ+. Additionally, the interatomic potentials for the respective spin-orbit levels were calculated, and the effect on the spectroscopic parameters was examined. In doing this, anomalously large spin-orbit splittings for RG = Ar-Xe were found, and this was investigated using multi-reference configuration interaction calculations. The latter indicated a small amount of RG → C+ electron transfer and this was used to rationalize the observations. This is taken as evidence of an incipient chemical interaction, which was also examined via contour plots, Birge-Sponer plots and various population analyses across the C+-RG series (RG = He-Xe), with the latter showing unexpected results. Trends in several spectroscopic parameters were examined as a function of the increasing atomic number of the RG atom. Finally, each set of RCCSD(T) potentials was employed, including spin-orbit coupling to calculate the transport coefficients for C+ in RG, and the results were compared with the limited available data. This article is part of the theme issue `Modern theoretical chemistry'.

  18. Greenhouse gas emissions from Spanish motorway transport: Key aspects and mitigation solutions

    International Nuclear Information System (INIS)

    Pérez-López, Paula; Gasol, Carles M.; Oliver-Solà, Jordi; Huelin, Sagrario; Moreira, Ma Teresa; Feijoo, Gumersindo

    2013-01-01

    The current increasing importance of road transport in the overall greenhouse gas (GHG) emissions has led to the adoption of diverse policies for the mitigation of global warming. These policies focus in two directions, depending on whether they involve the reduction of emissions or the mitigation through carbon dioxide (CO 2 ) sequestration. In this paper, the Tier 3 methodology from the European Monitoring and Evaluation Programme and the Environment Agency (EMEP/EEA) was applied to determine the evolution of Spanish motorway GHG emissions in the period 2005–2010. According to the results, though the average daily traffic (ADT) is the major parameter, the average fleet age and vehicle size also affect the level of emissions. Data analysis also revealed a clear connection between the decrease in European trade volume during the financial crisis and the GHG release, despite its temporary character. Among the three improvement scenarios evaluated, reduced speed limit seems the most direct measure while the consequences of afforestation strongly depend on the traffic density of the stretch of the motorway considered. Finally, technological improvement requires a drastic change in the fleet to obtain substantial decrease. The combination of different policies would allow a more robust strategy with lower GHG emissions. - Highlights: • Three model stretches, representative of Spanish motorway conditions, were evaluated. • Three environmental improvement scenarios were proposed. • Speed limit seemed the easiest measure to implement in a near future. • Afforestation showed limited effectiveness per unit of land surface. • A drastic technological improvement is required to obtain significant reductions

  19. Interactions of C+(2 PJ ) with rare gas atoms: incipient chemical interactions, potentials and transport coefficients.

    Science.gov (United States)

    Tuttle, William D; Thorington, Rebecca L; Viehland, Larry A; Breckenridge, W H; Wright, Timothy G

    2018-03-13

    Accurate interatomic potentials were calculated for the interaction of a singly charged carbon cation, C + , with a single rare gas atom, RG (RG = Ne-Xe). The RCCSD(T) method and basis sets of quadruple-ζ and quintuple-ζ quality were employed; each interaction energy was counterpoise corrected and extrapolated to the basis set limit. The lowest C + ( 2 P ) electronic term of the carbon cation was considered, and the interatomic potentials calculated for the diatomic terms that arise from these: 2 Π and 2 Σ + Additionally, the interatomic potentials for the respective spin-orbit levels were calculated, and the effect on the spectroscopic parameters was examined. In doing this, anomalously large spin-orbit splittings for RG = Ar-Xe were found, and this was investigated using multi-reference configuration interaction calculations. The latter indicated a small amount of RG → C + electron transfer and this was used to rationalize the observations. This is taken as evidence of an incipient chemical interaction, which was also examined via contour plots, Birge-Sponer plots and various population analyses across the C + -RG series (RG = He-Xe), with the latter showing unexpected results. Trends in several spectroscopic parameters were examined as a function of the increasing atomic number of the RG atom. Finally, each set of RCCSD(T) potentials was employed, including spin-orbit coupling to calculate the transport coefficients for C + in RG, and the results were compared with the limited available data.This article is part of the theme issue 'Modern theoretical chemistry'. © 2018 The Author(s).

  20. Onsite well screening with a transportable gas chromatography/mass spectrometer system

    International Nuclear Information System (INIS)

    Rossabi, J.; Eckenrode, B.A.; Owens, B.

    1992-01-01

    The number of hazardous waste site operations continue to multiply. The requirements for efficient chemical assessment and monitoring of these sites become more stringent daily. As more samples are required, the time required for cleanup operations also increases and may make analytical costs prohibitive. Thus improvements in operation efficiency and reduction of cost in evaluating specific sites to minimize or eliminate their toxic effects on the surrounding environment are critical. For many years a formal policy did not exist for the disposal of waste solvents and other chemicals, thus many of these compounds were disposed of ensite. So long as these materials were contained onsite they were not considered to pose a threat to the surrounding environment. We have since determined that many of these compounds found their way into the groundwater. Contaminants such as trichloroethylene and perchloroethylene, which were heavily used for cleaning and degreasing purposes, must be monitored. Groundwater wells can be used to define the location and extent of the migration of any contaminant plume and aid in the determination of required cleanup. The major problem is that monitoring of hundreds of wells may be necessary, requiring several hundred samples on a quarterly basis to characterize the degree and extent of any contamination. Onsite analysis of monitoring wells for this characterization of waste operations could provide time savings and significant cost reduction. Field analyses can provide the required analytical results quickly and at a reduced cost without compromising either sample integrity or data quality. By using onsite analytical instrumentation, such as a field-transportable gas chromatograph/mass spectrometer (GC/MS), screening analyses can be performed to eliminate retturning to the laboratory with meaningless samples. Onsite GC/MS will provide qualitative or semi-quantitative information that can significantly simplify subsequent laboratory analyses

  1. Heat transfer analysis of porous media receiver with different transport and thermophysical models using mixture as feeding gas

    International Nuclear Information System (INIS)

    Wang, Fuqiang; Tan, Jianyu; Wang, Zhiqiang

    2014-01-01

    Highlights: • Using local thermal non-equilibrium model to solve heat transfer of porous media. • CH 4 /H 2 O mixture is adopted as feeding gas of porous media receiver. • Radiative transfer equation between porous strut is solved by Rosseland approximation. • Transport and thermophysical models not included in Fluent are programmed by UDFs. • Variations of model on thermal performance of porous media receiver are studied. - Abstract: The local thermal non-equilibrium model is adopted to solve the steady state heat and mass transfer problems of porous media solar receiver. The fluid entrance surface is subjected to concentrated solar radiation, and CH 4 /H 2 O mixture is adopted as feeding gas. The radiative heat transfer equation between porous strut is solved by Rosseland approximation. The impacts of variation in transport and thermophysical characteristics model of gas mixture on thermal performance of porous media receiver are investigated. The transport and thermophysical characteristics models which are not included in software Fluent are programmed by user defined functions (UDFs). The numerical results indicate that models of momentum source term for porous media receiver have significant impact on pressure drop and static pressure distribution, and the radiative heat transfer cannot be omitted during the thermal performance analysis of porous media receiver

  2. Comparison of pneumatic tube system with manual transport for routine chemistry, hematology, coagulation and blood gas tests.

    Science.gov (United States)

    Pupek, Alex; Matthewson, Beverly; Whitman, Erin; Fullarton, Rachel; Chen, Yu

    2017-08-28

    The pneumatic tube system (PTS) is commonly used in modern clinical laboratories to provide quick specimen delivery. However, its impact on sample integrity and laboratory testing results are still debatable. In addition, each PTS installation and configuration is unique to its institution. We sought to validate our Swisslog PTS by comparing routine chemistry, hematology, coagulation and blood gas test results and sample integrity indices between duplicate samples transported either manually or by PTS. Duplicate samples were delivered to the core laboratory manually by human courier or via the Swisslog PTS. Head-to-head comparisons of 48 routine chemistry, hematology, coagulation and blood gas laboratory tests, and three sample integrity indices were conducted on 41 healthy volunteers and 61 adult patients. The PTS showed no impact on sample hemolysis, lipemia, or icterus indices (all pcoagulation and blood gas (in syringe and capillary tube) laboratory tests.

  3. Transportation Energy Futures Series: Effects of Travel Reduction and Efficient Driving on Transportation: Energy Use and Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D.; Brown, A.; DeFlorio, J.; McKenzie, E.; Tao, W.; Vimmerstedt, L.

    2013-03-01

    Since the 1970s, numerous transportation strategies have been formulated to change the behavior of drivers or travelers by reducing trips, shifting travel to more efficient modes, or improving the efficiency of existing modes. This report summarizes findings documented in existing literature to identify strategies with the greatest potential impact. The estimated effects of implementing the most significant and aggressive individual driver behavior modification strategies range from less than 1% to a few percent reduction in transportation energy use and GHG emissions. Combined strategies result in reductions of 7% to 15% by 2030. Pricing, ridesharing, eco-driving, and speed limit reduction/enforcement strategies are widely judged to have the greatest estimated potential effect, but lack the widespread public acceptance needed to accomplish maximum results. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  4. Transportation Energy Futures Series. Effects of Travel Reduction and Efficient Driving on Transportation. Energy Use and Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); Brown, A. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); DeFlorio, J. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); McKenzie, E. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); Tao, W. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); Vimmerstedt, L. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States)

    2013-03-01

    Since the 1970s, numerous transportation strategies have been formulated to change the behavior of drivers or travelers by reducing trips, shifting travel to more efficient modes, or improving the efficiency of existing modes. This report summarizes findings documented in existing literature to identify strategies with the greatest potential impact. The estimated effects of implementing the most significant and aggressive individual driver behavior modification strategies range from less than 1% to a few percent reduction in transportation energy use and GHG emissions. Combined strategies result in reductions of 7% to 15% by 2030. Pricing, ridesharing, eco-driving, and speed limit reduction/enforcement strategies are widely judged to have the greatest estimated potential effect, but lack the widespread public acceptance needed to accomplish maximum results. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  5. Impacts of pending federal greenhouse gas legislation on the Texas transportation sector.

    Science.gov (United States)

    2010-05-01

    This 2010 study, funded by the Southwest Region University Transportation Center, assesses current regulatory : attempts to mitigate climate change and how such proposed action would impact the Texas transportation sector : economically. Social and p...

  6. Hydrological Regimes of Small Catchments in the High Tatra Mountains Before and After Extraordinary Wind-Induced Deforestation

    Science.gov (United States)

    Holko, Ladislav; Hlavata, Helena; Kostka, Zdenek; Novak, Jan

    2009-01-01

    The paper presents the results of rainfall-runoff data analysis for small catchments of the upper Poprad River affected by wind-induced deforestation in November 2004. Before-event and afterevent measured data were compared in order to assess the impact of deforestation on hydrological regimes. Several characteristics were used including water balance, minimum and maximum runoff, runoff thresholds, number of runoff events, selected characteristics of events, runoff coefficients, and flashiness indices. Despite increased spring runoff minima, which in one catchment (Velick Creek) exceeded previously observed values after deforestation took place, it can be generally concluded that the impact of the deforestation was not clearly manifested in the analyzed hydrological data.

  7. Pure- and Mixed-Gas Transport Study of Nafion® and Its Fe3+-Substituted Derivative for Membrane-Based Natural Gas Applications

    KAUST Repository

    Mukaddam, Mohsin A.

    2016-05-26

    The focus of this research project was to develop a fundamental understanding of the structure-gas transport property relationship in Nafion® to investigate its potential use as a gas separation membrane material for natural gas (NG) applications including carbon dioxide removal from NG, helium recovery, higher-hydrocarbon removal, and nitrogen separation from methane. Separation processes account for ~45% of all energy used in chemical plants and petroleum refineries. As the drive for energy savings and sustainability intensifies, more efficient separation technology becomes increasingly important. Saudi Arabia ranks among the world’s top 5 NG producers. Commercial hydrocarbon-based glassy polymers often lose their gas separation properties in the presence of condensable, highly sorbing NG components such as CO2, ethane, propane, n-butane, and C5+ hydrocarbons. This deterioration in gas separation performance results from penetrant-induced dilation and plasticization of the polymer matrix, leading to significant methane and higher hydrocarbon losses. Polymers that have intrinsically low affinity to high-solubility NG components may be less susceptible to plasticization and therefore offer better performance under actual field conditions. By virtue of their strong carbon-fluorine bonds and chemical inertness, perfluoropolymers exhibit very low affinity for hydrocarbon gases. Nafion®, the prototypical perfluoro-sulfonated ionomer, comprising hydrophilic sulfonate groups phase-separated from a hydrophobic perfluorocarbon matrix, has demonstrated interesting permeability and selectivity relationships for gas pairs relevant to NG applications. Gas transport properties of Nafion® indicated gas solubility behavior similar to rubbery polymers but with sieving properties more commonly observed in low free volume glassy polymers. Nafion® demonstrated very low solubility for CO2 and hydrocarbon gases; the trend-line slope of solubility versus penetrant condensability

  8. Reduction of CO2 emissions from road transport in cities impact of dynamic route guidance system on greenhouse gas emission

    CERN Document Server

    Markiewicz, Michal

    2017-01-01

    Michal Markiewicz presents the outcomes of his research regarding the influence of dynamic route guidance system on overall emission of carbon dioxide from road transport in rural areas. Sustainable transportation in smart cities is a big challenge of our time, but before electric vehicles replace vehicles that burn fossil fuels we have to think about traffic optimization methods that reduce the amount of greenhouse gas emissions. Contents Comparison of Travel Time Measurements Using Floating Car Data and Intelligent Infrastructure Integration of Cellular Automata Traffic Simulator with CO2 Emission Model Impact of Dynamic Route Guidance System on CO2 Emission Naxos Vehicular Traffic Simulator Target Groups Lecturers and students of computer science, transportation and logistics Traffic engineers The Author Dr. Michal Markiewicz defended his PhD thesis in computer science at the University of Bremen,TZI Technologie-Zentrum Informatik und Informationstechnik, Germany. Currently, he is working on commercializat...

  9. Radiation and gas conduction heat transport across a helium dewar multilayer insulation system

    International Nuclear Information System (INIS)

    Green, M.A.

    1994-01-01

    This report describes a method for calculating mixed heat transfer through the multilayer insulation used to insulate a 4 K liquid helium cryostat. The method described here permits one to estimate the insulation potential for a multilayer insulation system from first principles. The heat transfer regimes included are: radiation, conduction by free molecule gas conduction, and conduction through continuum gas conduction. Heat transfer in the transition region between the two gas conduction regimes is also included

  10. Evaluation method of gas leakage rate from transportation casks of radioactive materials (gas leakage rates from scratches on O-ring surface)

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Li Ninghua; Asano, Ryoji; Kawa, Tsunemichi

    2004-01-01

    A sealing function is essential for transportation and/or storage casks of radioactive materials under both normal and accidental operating conditions in order to prevent radioactive materials from being released into the environment. In the safety analysis report, the release rate of radioactive materials into the environment is evaluated using the correlations specified in the ANSI N14.5, 1987. The purposes of the work are to reveal the underlying problems on the correlations specified in the ANSI N14.5 related to gas leakage rates from a scratch on O-ring surface and from multi-leak paths, to offer a data base to study the evaluation method of the leakage rate and to propose the evaluation method. In this paper, the following insights were obtained and clarified: 1. If a characteristic value of a leak path is defined as D 4 /a ('D' is the diameter and 'a' is the length), a scratch on the O-ring surface can be evaluated as a circular tube. 2. It is proper to use the width of O-ring groove on the flange as the leak path length for elastomer O-rings. 3. Gas leakage rates from multi leak paths of the transportation cask can be evaluated in the same manner as a single leak path if an effective D4/a is introduced. (author)

  11. Effect of damage on water retention and gas transport properties geo-materials: Application to geological storage of radioactive waste

    International Nuclear Information System (INIS)

    M'Jahad, S.

    2012-01-01

    In the context of geological disposal of radioactive waste, this work contributes to the characterization of the effect of diffuse damage on the water retention and gas transfer properties of concrete (CEM I and CEM V) selected by Andra, Callovo-Oxfordian argillite (host rock) and argillite / concrete interfaces. This study provides information on the concrete microstructure from Mercury porosimetry intrusion and water retention curves: each concrete has a distinct microstructure, CEM I concrete is characterized by a significant proportion of capillary pores while CEM V concrete has a large proportion of C-S-H pores. Several protocols have been developed in order to damage concrete. The damage reduces water retention capacity of CEM I concrete and increases its gas permeability. Indeed, gas breakthrough pressure decreases significantly for damaged concrete, and this regardless of the type of concrete. For argillite, the sample mass increases gradually at RH = 100%, which creates and increases damage in the material. This reduces its ability to retain water. Otherwise, water retention and gas transport properties of argillite are highly dependent of its initial water saturation, which is linked to its damage. Finally, we observed a clogging phenomenon at the argillite/concrete interfaces, which is first mechanical and then hydraulic (and probably chemical) after water injection. This reduces the gas breakthrough pressure interfaces. (author)

  12. Analysis of selected energy security issues related to US crude oil and natural gas exploration, development, production, transportation and processing

    International Nuclear Information System (INIS)

    1990-10-01

    In July 1989, President Bush directed the Secretary of Energy to initiate the development of a comprehensive National Energy Strategy (NES) built upon a national consensus. The overall principle for the NES, as defined by the President and articulated by the Economic Policy Council (EPC), is the continuation of the successful policy of market reliance, consistent with the following goals: Balancing of energy, economic, and environmental concerns; and reduced dependence by the US and its friends and allies on potentially unreliable energy suppliers. The analyses presented in this report draw upon a large body of work previously conducted for DOE/Office of Fossil Energy, the US Department of Interior/Minerals Management Service (DOI/MMS), and the Gas Research Institute (GRI), referenced throughout the text of this report. This work includes assessments in the following areas: the potential of advanced oil and gas extraction technologies as improved through R ampersand D, along with the successful transfer of these technologies to the domestic petroleum industry; the economic and energy impacts of environmental regulations on domestic oil and gas exploration, production, and transportation; the potential of tax incentives to stimulate domestic oil and gas development and production; the potential environmental costs associated with various options for leasing for US oil and gas resources in the Outer Continental Shelf (OCS); and the economic impacts of environmental regulations affecting domestic crude oil refining

  13. Ozone impacts of gas-aerosol uptake in global chemistry transport models

    Science.gov (United States)

    Stadtler, Scarlet; Simpson, David; Schröder, Sabine; Taraborrelli, Domenico; Bott, Andreas; Schultz, Martin

    2018-03-01

    The impact of six heterogeneous gas-aerosol uptake reactions on tropospheric ozone and nitrogen species was studied using two chemical transport models, the Meteorological Synthesizing Centre-West of the European Monitoring and Evaluation Programme (EMEP MSC-W) and the European Centre Hamburg general circulation model combined with versions of the Hamburg Aerosol Model and Model for Ozone and Related chemical Tracers (ECHAM-HAMMOZ). Species undergoing heterogeneous reactions in both models include N2O5, NO3, NO2, O3, HNO3, and HO2. Since heterogeneous reactions take place at the aerosol surface area, the modelled surface area density (Sa) of both models was compared to a satellite product retrieving the surface area. This comparison shows a good agreement in global pattern and especially the capability of both models to capture the extreme aerosol loadings in east Asia. The impact of the heterogeneous reactions was evaluated by the simulation of a reference run containing all heterogeneous reactions and several sensitivity runs. One reaction was turned off in each sensitivity run to compare it with the reference run. The analysis of the sensitivity runs confirms that the globally most important heterogeneous reaction is the one of N2O5. Nevertheless, NO2, HNO3, and HO2 heterogeneous reactions gain relevance particularly in east Asia due to the presence of high NOx concentrations and high Sa in the same region. The heterogeneous reaction of O3 itself on dust is of minor relevance compared to the other heterogeneous reactions. The impacts of the N2O5 reactions show strong seasonal variations, with the biggest impacts on O3 in springtime when photochemical reactions are active and N2O5 levels still high. Evaluation of the models with northern hemispheric ozone surface observations yields a better agreement of the models with observations in terms of concentration levels, variability, and temporal correlations at most sites when the heterogeneous reactions are

  14. adaptation of natural gas for motor fuels in nigeria transport system

    African Journals Online (AJOL)

    In recent years, as a result of limiting reserve of crude oil and the clamour for the deregulation of the petroleum sector of the nation's economy, there is need to look beyond liquid fuel (gasoline, diesel) as vehicular fuels. The viability of adapting natural gas for motor fuels had been presented. Natural gas as automobile fuel ...

  15. Carrier transport in multi-terminal superconductor/two-dimensional electron gas Josephson junctions

    NARCIS (Netherlands)

    Guzenko, V.A.; Schäpers, Th.; Müller, R.P.; Golubov, Alexandre Avraamovitch; Brinkman, Alexander; Crecelius, G.; Kaluza, A.; Lüth, H.

    2001-01-01

    The critical current in a superconductor/two-dimensional electron gas junction/superconductor junction is controlled by an injection current. In case of a carrier injection from one contact to the semiconductor through the two-dimensional electron gas region of the junction to an ohmic contact at

  16. Gas transport and sub-Ig relaxations in unmodified and nitrated polyarylethersulfones

    NARCIS (Netherlands)

    Kamps, K.M.P.; Teunis, Hermannus A.; Teunis, H.A.; Wessling, Matthias; Smolders, C.A.; Smolders, C.A.

    1992-01-01

    Aromatic nitration has been used to modify the polymer main chain of polysulfone and polyethersulfone. Alteration in the gas separation characteristics of homogeneous membrane made out of these polymers could be observed upon nitration. Generally, separation factors for gas mixtures of CO2/CH4

  17. Effect of Particle Size and Soil Compaction on Gas Transport Parameters in Variably Saturated, Sandy Soils

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken

    2009-01-01

    The soil gas diffusion coefficient (Dp) and air permeability (ka) and their dependency on soil air content ( ) control gas diffusion and advection in soils. This study investigated the effects of average particle size (D50) and dry bulk density ( b) on Dp and ka for six sandy soils under variably...

  18. New IR-UV gas sensor to energy and transport sector

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, A.; Clausen, S.

    2010-12-15

    In situ simultaneous measurements of gas temperature and gas composition are of great interest in combustion research and give useful information about conditions, chemical reactions and gas mixing in many industrial processes. An optically based technique is beneficial because it is non-intrusive, accurate, fast and can be performed in situ for various extremely hard conditions. In humid and hot gas flows UV technique is more sensitive than FTIR one for fast gas concentration measurements of NO and SO{sub 2} and gives a great opportunity for simultaneous measurements of O{sub 2} concentration. Analysis of the fine structure of the UV absorption bands of, for example, NO, SO{sub 2} or O{sub 2} allows also to determine a value of the gas temperature. Absorption cross sections of CO{sub 2}, H{sub 2}O and SO{sub 2} measured using Risoe DTU's hot gas cell facility at elevated temperatures up to 1500 deg. C are reported. Design of a new developed 9-m long water-cooled fiber-optic probe with removable optical head suitable for fast IR/UV local gas absorption/emission measurements is described. The probe performance was successfully tested in several trial measurements on full scale multi-fuel fired boiler. A concept of fast time/spectralresolved measurements has been used in measurements on a large ship engine based on IR and UV broad band spectroscopy. (Author)

  19. Nonlinear Dynamic Analysis on the Rain-Wind-Induced Vibration of Cable Considering the Equilibrium Position of Rivulet

    Directory of Open Access Journals (Sweden)

    Xijun Liu

    2013-01-01

    Full Text Available The nonlinear dynamic behavior of rain-wind-induced vibration of inclined cable is investigated with the consideration of the equilibrium position of the moving rivulet. The partial differential governing equations of three-degree-of-freedom on the model of rain-wind-induced cable vibration are established, which are proposed for describing the nonlinear interactions among the in-plane, out-of-plane vibration of the cable and the oscillation of the moving rivulet. The Galerkin method is applied to discretize the partial differential governing equations. The approximately analytic solution is obtained by using the method of averaging. The unique correspondence between the wind and the equilibrium position of the rivulet is ascertained. The presence of rivulet at certain positions on the surface of cable is then proved to be one of the trigger for wind-rain-induced cable vibration. The nonlinear dynamic phenomena of the inclined cable subjected to wind and rain turbulence are then studied by varying the parameters including mean wind velocity, Coulomb damping force, damping ratio, the span length, and the initial tension of the inclined cable on the model. The jump phenomenon is also observed which occurs when there are multiple solutions in the system.

  20. Control of Wind-Induced Vibration of Transmission Tower-Line System by Using a Spring Pendulum

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2015-01-01

    Full Text Available The high-voltage power transmission tower-line system, which is a high flexible structure, is very susceptible to the wind-induced vibrations. This paper proposes the utilization of the internal resonance feature of the spring pendulum to reduce the wind-induced vibration of a transmission tower. The kinetic expression of the spring pendulum system is obtained through Lagrangian equation. The condition of the internal resonance is verified to be λ = 2, in which λ is the ratio of the spring mode frequency over the pendulum mode frequency. A 55 m tower in the Liaoning province is established in SAP2000 to numerically verify the effectiveness of the proposed device. The spring pendulum is modeled using Link element. The wind speed history is generated based on Kaimal spectrum using harmonic superposition method. Results show that, (1 compared with the suspended mass pendulum, the spring pendulum absorbs more energy and reduces the oscillation more effectively and (2 the vibration control performance of the proposed spring pendulum improves as the external wind load increases.

  1. Measures applicable to transportation sector in order to improve their greenhouse gas emission balance

    International Nuclear Information System (INIS)

    Lamure, C.A.

    1991-01-01

    The greenhouse effect gases emitted by transport vehicles are mainly carbon dioxide, methane and nitrogen dioxide; CO 2 emissions from transport vehicles (automobiles, aircraft) are growing and their relative importance is growing even more due to lowering of other CO 2 sources. Greenhouse gases from thermal engines are assessed as a function of engine and fuel types. Several solutions are proposed in order to reduce pollutant emissions: road traffic control (road pricing), automobile restricted utilization (speed, access areas, traffic and parking regulation), consumption regulation, collective transports (buses, mini buses), urban organization for pedestrian and bicycle transport, fuel substitution, life style modification tele-commuting, etc

  2. Modeling the effect of anisotropy of gas diffusion layer on transport phenomena in a direct methanol fuel cell

    Science.gov (United States)

    Miao, Zheng; He, Ya-Ling; Zou, Jin-Qiang

    Transport phenomena in the gas diffusion layer (GDL) are of vital importance for the operation of direct methanol fuel cells (DMFCs). In this work, a two-phase mass transport model is developed to investigate the effects of anisotropic characteristics of a GDL, including the inherent anisotropy, deformation, and electrical and thermal contact resistances, on the coupled species, charges and thermal transport processes in a DMFC. In this model, methanol crossover and non-equilibrium evaporation/condensation of water and methanol are considered. The multistep electrochemical mechanisms are used to obtain a detailed description of the kinetics of methanol oxidization reaction (MOR) in both the anode and cathode catalyst layers (CLs). The numerical results show that the anisotropy of the GDL has a great effect on the distribution of species concentration, overpotential, local current density, and temperature. The deformation of the GDL depresses the transport of species through the GDL, particularly methanol diffusion in anode GDL, but facilitates the transport of electron and the removal of heat. The electrical contact resistance plays an important role in determining the cell performance.

  3. Modeling the effect of anisotropy of gas diffusion layer on transport phenomena in a direct methanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zheng; He, Ya-Ling; Zou, Jin-Qiang [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2010-06-01

    Transport phenomena in the gas diffusion layer (GDL) are of vital importance for the operation of direct methanol fuel cells (DMFCs). In this work, a two-phase mass transport model is developed to investigate the effects of anisotropic characteristics of a GDL, including the inherent anisotropy, deformation, and electrical and thermal contact resistances, on the coupled species, charges and thermal transport processes in a DMFC. In this model, methanol crossover and non-equilibrium evaporation/condensation of water and methanol are considered. The multistep electrochemical mechanisms are used to obtain a detailed description of the kinetics of methanol oxidization reaction (MOR) in both the anode and cathode catalyst layers (CLs). The numerical results show that the anisotropy of the GDL has a great effect on the distribution of species concentration, overpotential, local current density, and temperature. The deformation of the GDL depresses the transport of species through the GDL, particularly methanol diffusion in anode GDL, but facilitates the transport of electron and the removal of heat. The electrical contact resistance plays an important role in determining the cell performance. (author)

  4. Environmental guidance documents for exploration, development, Production, and transportation of crude oil and natural gas in texas: Quarterly technical report, January 1, 1997-March 31, 1997

    International Nuclear Information System (INIS)

    Savage, L.

    1997-01-01

    The following technical report provides a detailed status report of the DOE grant project entitled ''Environmental Guidance Documents for Exploration, Development, Production, and Transportation of Crude Oil and Natural Gas in Texas.'' The grant funding allocated is for the purpose of provided the Railroad Commission of Texas (Commission) with resources and capabilities to draft, publish and distribute documents that provide guidance to oil and gas operators on issues concerning oil and gas naturally occurring radioactive material (NORM) waste, oil and gas hazardous waste, remediation of crude oil spills, management of non-hazardous oil and gas wastes, and mechanical integrity testing of Class II injection and disposal wells

  5. The effects of gas diffusion layers structure on water transportation using X-ray computed tomography based Lattice Boltzmann method

    Science.gov (United States)

    Jinuntuya, Fontip; Whiteley, Michael; Chen, Rui; Fly, Ashley

    2018-02-01

    The Gas Diffusion Layer (GDL) of a Polymer Electrolyte Membrane Fuel Cell (PEMFC) plays a crucial role in overall cell performance. It is responsible for the dissemination of reactant gasses from the gas supply channels to the reactant sites at the Catalyst Layer (CL), and the adequate removal of product water from reactant sites back to the gas channels. Existing research into water transport in GDLs has been simplified to 2D estimations of GDL structures or use virtual stochastic models. This work uses X-ray computed tomography (XCT) to reconstruct three types of GDL in a model. These models are then analysed via Lattice Boltzmann methods to understand the water transport behaviours under differing contact angles and pressure differences. In this study, the three GDL samples were tested over the contact angles of 60°, 80°, 90°, 100°, 120° and 140° under applied pressure differences of 5 kPa, 10 kPa and 15 kPa. By varying the contact angle and pressure difference, it was found that the transition between stable displacement and capillary fingering is not a gradual process. Hydrophilic contact angles in the region of 60°<θ < 90° showed stable displacement properties, whereas contact angles in the region of 100°<θ < 140° displayed capillary fingering characteristics.

  6. Gas-breakdown effects associated with the self-pinched transport of intense light-ion beams

    International Nuclear Information System (INIS)

    Ottinger, P.F.; Olson, C.L.; Welch, D.R.; Oliver, B.V.

    1997-01-01

    Self-pinched transport (SPT) of intense light-ion beams is being considered for delivering energy to a high-gain, high-yield inertial confinement fusion target. Proton beam SPT experiments are underway on the Gamble II generators at the Naval Research Laboratory. The physics of SPT in low-pressure gas is being analyzed with analytic theory and numerical simulations. A 1-D theory estimates the net current fraction necessary for stable transport as a function of gas density for a given beam profile. SPT simulations using the 3-D hybrid particle-in-cell (PIC) code IPROP determine the beam profile. Important to both theory and simulations is the inclusion of gas-breakdown physics. A comparison between the theory and the self-consistent simulations using IPROP is made. Additional SPT simulations have been carried out using the 2-D hybrid PIC code SOLENZ which assumes a pre-ionized plasma. This simulation model enables the investigation of long time scale beam propagation issues. A comparison between IPROP and SOLENZ will be presented. SOLENZ simulations with the Gamble I beam parameters demonstrate SPT but point to the need to study the injection conditions to improve beam confinement. Simulations examining beam-to-wall distance and injection conditions will be presented

  7. A reactive transport modelling approach to assess the leaching potential of hydraulic fracturing fluids associated with coal seam gas extraction

    Science.gov (United States)

    Mallants, Dirk; Simunek, Jirka; Gerke, Kirill

    2015-04-01

    Coal Seam Gas production generates large volumes of "produced" water that may contain compounds originating from the use of hydraulic fracturing fluids. Such produced water also contains elevated concentrations of naturally occurring inorganic and organic compounds, and usually has a high salinity. Leaching of produced water from storage ponds may occur as a result of flooding or containment failure. Some produced water is used for irrigation of specific crops tolerant to elevated salt levels. These chemicals may potentially contaminate soil, shallow groundwater, and groundwater, as well as receiving surface waters. This paper presents an application of scenario modelling using the reactive transport model for variably-saturated media HP1 (coupled HYDRUS-1D and PHREEQC). We evaluate the fate of hydraulic fracturing chemicals and naturally occurring chemicals in soil as a result of unintentional release from storage ponds or when produced water from Coal Seam Gas operations is used in irrigation practices. We present a review of exposure pathways and relevant hydro-bio-geo-chemical processes, a collation of physico-chemical properties of organic/inorganic contaminants as input to a set of generic simulations of transport and attenuation in variably saturated soil profiles. We demonstrate the ability to model the coupled processes of flow and transport in soil of contaminants associated with hydraulic fracturing fluids and naturally occurring contaminants.

  8. Tritium Transport at the Rulison Site, a Nuclear-stimulated Low-permeability Natural Gas Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    C. Cooper; M. Ye; J. Chapman

    2008-04-01

    The U.S. Department of Energy (DOE) and its predecessor agencies conducted a program in the 1960s and 1970s that evaluated technology for the nuclear stimulation of low-permeability natural gas reservoirs. The second project in the program, Project Rulison, was located in west-central Colorado. A 40-kiltoton nuclear device was detonated 2,568 m below the land surface in the Williams Fork Formation on September 10, 1969. The natural gas reservoirs in the Williams Fork Formation occur in low permeability, fractured sandstone lenses interbedded with shale. Radionuclides derived from residual fuel products, nuclear reactions, and activation products were generated as a result of the detonation. Most of the radionuclides are contained in a cooled, solidified melt glass phase created from vaporized and melted rock that re-condensed after the test. Of the mobile gas-phase radionuclides released, tritium ({sup 3}H or T) migration is of most concern. The other gas-phase radionuclides ({sup 85}Kr, {sup 14}C) were largely removed during production testing in 1969 and 1970 and are no longer present in appreciable amounts. Substantial tritium remained because it is part of the water molecule, which is present in both the gas and liquid (aqueous) phases. The objectives of this work are to calculate the nature and extent of tritium contamination in the subsurface from the Rulison test from the time of the test to present day (2007), and to evaluate tritium migration under natural-gas production conditions to a hypothetical gas production well in the most vulnerable location outside the DOE drilling restriction. The natural-gas production scenario involves a hypothetical production well located 258 m horizontally away from the detonation point, outside the edge of the current drilling exclusion area. The production interval in the hypothetical well is at the same elevation as the nuclear chimney created by the detonation, in order to evaluate the location most vulnerable to

  9. Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport

    Directory of Open Access Journals (Sweden)

    Afrooz Farjoo

    2017-10-01

    Full Text Available Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene was studied within the temperature and pressure ranges of 25–600 °C and 110–160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption–diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

  10. Determinación de restricciones y posibilidades ambientales para la expansion del transporte de gas natural en Colombia

    Directory of Open Access Journals (Sweden)

    Ángel Sanint Enrique

    2011-11-01

    Full Text Available En la línea de la Evaluación Ambiental Estratégica, EAE, se desarrolló un método para la determinación de restricciones y posibilidades ambientales en proyectos de transporte de gas natural por ductos, basado en el uso de herramientas de análisis territorial aplicadas sobre la plataforma SIG (Sistema de Información Geográfica, incorporando criterios ambientales que a escala 1:500.000 apoyarán la toma de decisiones en el nivel de planeación y propiciarán la elaboración del plan de expansión para el transporte de gas natural en Colombia. Para esto, se definió el concepto de ambiente a partir de un Modelo Analítico preexistente; se delimitó un área con posibilidades para la expansión de la red de transporte de gas natural incorporando nuevos trazados; se seleccionaron las variables y factores que complementaban el Modelo Analítico; se definió la estructura de preferencias a partir de una encuesta a expertos; se determinaron las restricciones nacionales y se construyeron superficies numéricas síntesis de critici dad ambiental para cada dimensión. Como resultado, se obtuvieron 5 superficies síntesis, una por cada dimensión, y una superficie final para Colombia, con restricciones y posibilidades ambientales. Además se propusieron análisis complementarios para establecer prioridades en la gestión ambiental.

  11. Effects of Soil Bulk Density on Gas Transport Parameters and Pore-Network Properties across a Sandy Field Site

    DEFF Research Database (Denmark)

    Masis Melendez, Federico; de Jonge, Lis Wollesen; Chamindu, T K K Deepagoda

    2015-01-01

    investigated. Interactions with soil organic matter, sand and clay fractions were also examined. Six parameters including Campbell b, the air entry pressure, the diffusive and convective percolation thresholds, and the diffusivity- and air permeability-based pore connectivity indices were determined......The gas diffusion coefficient, air permeability, and their interrelations with air-filled porosity are crucial for characterization of diffusive and convective transport of gases in soils. Variations in soil bulk density can affect water retention, air-filled pore space, pore tortuosity...

  12. Energy consumption, destruction of exergy and boil off during the process of liquefaction, transport and regasification of liquefied natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Stradioto, Diogo Angelo; Schneider, Paulo Smith [Dept. of Mechanical Engineering. Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)], e-mail: pss@mecanica.ufrgs.br

    2010-07-01

    A supply chain of Liquefied Natural Gas (LNG) is composed by several processes like extraction, purification, liquefaction, storage, transport, regasification and distribution. In all these stages, processes need of energy. The main objective of this work is to quantify the energy consumption, mass loss and exergy destruction occurred throughout the chain. Results show that the process of liquefaction is the largest consumer of energy. Storage and transport by ship are responsible for the bigger mass losses and regasification is the process of larger destruction of exergy. A case study is performed considering a stream of pure methane at the input of a liquefaction plant, and evaluates energy along the chain, ending up at the distribution of NG after its regasification. (author)

  13. The impact of center city economic and cultural vibrancy on greenhouse gas emissions from transportation.

    Science.gov (United States)

    2012-03-01

    Urban planners and scholars have focused a great deal of attention on understanding the relationship between the built environment and transportation behavior. However, other aspects of the urban environment--including the vibrancy and quality of lif...

  14. Analysis of policies to reduce oil consumption and greenhouse-gas emissions from the US transportation sector

    International Nuclear Information System (INIS)

    Ross Morrow, W.; Gallagher, Kelly Sims; Collantes, Gustavo; Lee, Henry

    2010-01-01

    Even as the US debates an economy-wide CO 2 cap-and-trade policy the transportation sector remains a significant oil security and climate change concern. Transportation alone consumes the majority of the US's imported oil and produces a third of total US Greenhouse-Gas (GHG) emissions. This study examines different sector-specific policy scenarios for reducing GHG emissions and oil consumption in the US transportation sector under economy-wide CO 2 prices. The 2009 version of the Energy Information Administration's (EIA) National Energy Modeling System (NEMS), a general equilibrium model of US energy markets, enables quantitative estimates of the impact of economy-wide CO 2 prices and various transportation-specific policy options. We analyze fuel taxes, continued increases in fuel economy standards, and purchase tax credits for new vehicle purchases, as well as the impacts of combining these policies. All policy scenarios modeled fail to meet the Obama administration's goal of reducing GHG emissions 14% below 2005 levels by 2020. Purchase tax credits are expensive and ineffective at reducing emissions, while the largest reductions in GHG emissions result from increasing the cost of driving, thereby damping growth in vehicle miles traveled.

  15. Complex quantum transport in a modulation doped strained Ge quantum well heterostructure with a high mobility 2D hole gas

    Science.gov (United States)

    Morrison, C.; Casteleiro, C.; Leadley, D. R.; Myronov, M.

    2016-09-01

    The complex quantum transport of a strained Ge quantum well (QW) modulation doped heterostructure with two types of mobile carriers has been observed. The two dimensional hole gas (2DHG) in the Ge QW exhibits an exceptionally high mobility of 780 000 cm2/Vs at temperatures below 10 K. Through analysis of Shubnikov de-Haas oscillations in the magnetoresistance of this 2DHG below 2 K, the hole effective mass is found to be 0.065 m0. Anomalous conductance peaks are observed at higher fields which deviate from standard Shubnikov de-Haas and quantum Hall effect behaviour due to conduction via multiple carrier types. Despite this complex behaviour, analysis using a transport model with two conductive channels explains this behaviour and allows key physical parameters such as the carrier effective mass, transport, and quantum lifetimes and conductivity of the electrically active layers to be extracted. This finding is important for electronic device applications, since inclusion of highly doped interlayers which are electrically active, for enhancement of, for example, room temperature carrier mobility, does not prevent analysis of quantum transport in a QW.

  16. Panorama 2015 - Greenhouse gas emissions in the road transport sector: moving towards inclusion in the European system of CO2 allowances?

    International Nuclear Information System (INIS)

    Coussy, Paula; Portenart, Philomene; Afriat, Marion; Alberola, Emilie

    2014-12-01

    In the year 2000, out of 41.8 Gt of global greenhouse gas (GHG) emissions, almost 10% came from transports sector. In Europe, this share of transports GHG emissions rises to 21% and emissions are forecast to rise. Against this background, should the road transport sector be included in the European Union Emissions Trading Scheme and thereby contribute to national GHG emission reduction targets? (authors)

  17. Transport properties of natural gas through polyethylene nanocomposites at high temperature and pressure

    DEFF Research Database (Denmark)

    Adewole, Jimoh K.; Jensen, Lars; Al-Mubaiyedh, Usamah A.

    2012-01-01

    High density polyethylene (HDPE)/clay nanocomposites containing nanoclay concentrations of 1, 2.5, and 5 wt% were prepared by a melt blending process. The effects of various types of nanoclays and their concentrations on permeability, solubility, and diffusivity of natural gas in the nanocomposites...... at constant temperature had little influence on the permeability, whereas increasing the temperature from 30 to 70 degrees C significantly increased the permeability of the gas. Additionally, the effect of crystallinity on permeability, solubility, and diffusivity was investigated. Thus, the permeability...

  18. Natural gas for public and private transportation: Present situation and prospects

    International Nuclear Information System (INIS)

    Gambino, M.; Iannaccone, S.; Unich, A.

    1992-01-01

    In recent years, the use of natural gas as an automotive fuel for private and public vehicles has grown due to its interesting chemical-physical properties which make it an efficient fuel and more environmentally compatible than conventional fuels. This promising consumption trend has led to increased R ampersand D investments in attempts to enhance the fuel's automotive performance and exhaust emission characteristics. This paper reviews the advances in these directions which have been made thus far by research teams around the world and assesses commercialization prospects for natural gas automotive fuels in light of the more stringent air pollution regulations being proposed by the European Communities

  19. A new multi-gas constrained model of trace gas non-homogeneous transport in firn: evaluation and behaviour at eleven polar sites

    Directory of Open Access Journals (Sweden)

    E. Witrant

    2012-12-01

    Full Text Available Insoluble trace gases are trapped in polar ice at the firn-ice transition, at approximately 50 to 100 m below the surface, depending primarily on the site temperature and snow accumulation. Models of trace gas transport in polar firn are used to relate firn air and ice core records of trace gases to their atmospheric history. We propose a new model based on the following contributions. First, the firn air transport model is revised in a poromechanics framework with emphasis on the non-homogeneous properties and the treatment of gravitational settling. We then derive a nonlinear least square multi-gas optimisation scheme to calculate the effective firn diffusivity (automatic diffusivity tuning. The improvements gained by the multi-gas approach are investigated (up to ten gases for a single site are included in the optimisation process. We apply the model to four Arctic (Devon Island, NEEM, North GRIP, Summit and seven Antarctic (DE08, Berkner Island, Siple Dome, Dronning Maud Land, South Pole, Dome C, Vostok sites and calculate their respective depth-dependent diffusivity profiles. Among these different sites, a relationship is inferred between the snow accumulation rate and an increasing thickness of the lock-in zone defined from the isotopic composition of molecular nitrogen in firn air (denoted δ15N. It is associated with a reduced diffusivity value and an increased ratio of advective to diffusive flux in deep firn, which is particularly important at high accumulation rate sites. This has implications for the understanding of δ15N of N2 records in ice cores, in relation with past variations of the snow accumulation rate. As the snow accumulation rate is clearly a primary control on the thickness of the lock-in zone, our new approach that allows for the estimation of the lock-in zone width as a function of accumulation may lead to a better constraint on the age difference between the ice and entrapped gases.

  20. Transport of solutes and gas in soft clay: Experience from the HADES URL[URL = underground research laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Canniere, P. de; Volckaert, G.; Ortiz, L.; Put, M.; Sneyers, A. [Belgian Nuclear Research Centre (SCK-CEN), Geological Waste Disposal, Boeretang 200, 2400 Mol (Belgium); Neerdael, B. [International Atomic Enegy Agency (IAEA), Department of Nuclear Energy, Division of Nuclear Fuel Cycle and Waste Tehnology, Waste Technology Section, Waste Disposal, 2561, IAEA-HQ, Vienna (Austria)

    2007-07-01

    In the absence of water conducting features, low-permeability clay formations provide a low flow environment essential for the very long-term containment of radioactive waste. Comprehensive understanding of the physical and chemical processes that control water, gas, and solute transport through deep argillaceous formations is a key factor for assessing their suitability as host rocks for radioactive waste. Hydraulic tests are carried out at different scales to characterize the in situ hydro-geological conditions and to determine the associated parameters. In parallel, geochemical studies are performed to understand the mechanisms controlling the water-rock interactions and the composition of the Boom Clay pore water. Thermo-hydro-mechanical experiments and large-scale demonstration tests are also conducted to determine the technical feasibility and the Iong-term safety of the repository system. Diffusion is the process dominating the transport of radionuclides in Boom Clay. Good agreement is obtained between model predictions and the results of large-scale migration experiments performed in situ with non-retarded tracers. Small-scale experiments installed at the extremity of boreholes have allowed to successfully measure diffusion profiles for strongly sorbed tracers. After helium injection in multi-piezometers up to gas breakthrough, no preferential pathway is detected for tritiated water. (author)

  1. ASSESSING AS, HG AND SE SPECIATION AND TRANSPORT IN FLUE GAS DESULPHURIZATION MATERIAL AND DRYWALL

    Science.gov (United States)

    The risk associated with the reuse of flue gas desulphurization (FGD) material in drywall manufacture is largely determined by the distribution or mineralogical fractionation of mercury(Hg), arsenic (As) and selenium (Se). During coal combustion, FGD material is enriched in volat...

  2. Cow Power: A Case Study of Renewable Compressed Natural Gas as a Transportation Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mintz, Marianne [Argonne National Lab. (ANL), Argonne, IL (United States); Tomich, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-08-01

    This case study explores the production and use of renewable compressed natural gas (R-CNG)—derived from the anaerobic digestion (AD) of dairy manure—to fuel 42 heavy-duty milk tanker trucks operating in Indiana, Michigan, Tennessee, and Kentucky.

  3. Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms.

    Directory of Open Access Journals (Sweden)

    Chaohua Guo

    Full Text Available Development of unconventional shale gas reservoirs (SGRs has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no systematical work has been conducted considering all reasonable transport mechanisms. And there are very few works on sensitivity studies of uncertain parameters using real parameter ranges. Hence, a detailed and systematic study of reservoir simulation with MsFHW is still necessary. In this paper, a dual porosity model was constructed to estimate the effect of parameters on shale gas production with MsFHW. The simulation model was verified with the available field data from the Barnett Shale. The following mechanisms have been considered in this model: viscous flow, slip flow, Knudsen diffusion, and gas desorption. Langmuir isotherm was used to simulate the gas desorption process. Sensitivity analysis on SGRs' production performance with MsFHW has been conducted. Parameters influencing shale gas production were classified into two categories: reservoir parameters including matrix permeability, matrix porosity; and hydraulic fracture parameters including hydraulic fracture spacing, and fracture half-length. Typical ranges of matrix parameters have been reviewed. Sensitivity analysis have been conducted to analyze the effect of the above factors on the production performance of SGRs. Through comparison, it can be found that hydraulic

  4. Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms.

    Science.gov (United States)

    Guo, Chaohua; Wei, Mingzhen; Liu, Hong

    2018-01-01

    Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no systematical work has been conducted considering all reasonable transport mechanisms. And there are very few works on sensitivity studies of uncertain parameters using real parameter ranges. Hence, a detailed and systematic study of reservoir simulation with MsFHW is still necessary. In this paper, a dual porosity model was constructed to estimate the effect of parameters on shale gas production with MsFHW. The simulation model was verified with the available field data from the Barnett Shale. The following mechanisms have been considered in this model: viscous flow, slip flow, Knudsen diffusion, and gas desorption. Langmuir isotherm was used to simulate the gas desorption process. Sensitivity analysis on SGRs' production performance with MsFHW has been conducted. Parameters influencing shale gas production were classified into two categories: reservoir parameters including matrix permeability, matrix porosity; and hydraulic fracture parameters including hydraulic fracture spacing, and fracture half-length. Typical ranges of matrix parameters have been reviewed. Sensitivity analysis have been conducted to analyze the effect of the above factors on the production performance of SGRs. Through comparison, it can be found that hydraulic fracture

  5. DRFM: A new package for the evaluation of gas-phase transport properties

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.H.

    1997-11-01

    This report describes a complete and modernized procedure to evaluate pure species, binary and mixture transport properties of gases in the low density limit. This includes a description of the relationships used to calculate these quantities and the means used to obtain the necessary input data. The purpose of this work is to rectify certain limitations of previous transport packages, specifically: to employ collision integrals suitable for high temperatures, to modernize the mixture formula, and to modernize the input data base. This report includes a set of input parameters for: the species involved in H{sub 2}-, CO - air combustion, the noble gases, methane and the oxides of nitrogen.

  6. Cost-effectiveness of greenhouse gas mitigation in transport: A review of methodological approaches and their impact

    International Nuclear Information System (INIS)

    Kok, Robert; Annema, Jan Anne; Wee, Bert van

    2011-01-01

    A review is given of methodological practices for ex ante cost-effectiveness analysis (CEA) of transport greenhouse gas (GHG) mitigation measures, e.g. fuel economy and CO 2 standards for road vehicles in the US and EU. Besides the fundamental differences between different types of policies and abatement options which inherently result in different CEA outcomes, differences in methodological choices and assumptions are another important source of variation in CEA outcomes. Fourteen methodological issues clustered into six groups are identified on which thirty-three selected studies are systematically reviewed. The potential variation between lower and upper cost-effectiveness estimates for GHG mitigation measures in transport, resulting from different methodological choices and assumptions, lies in the order of $400 per tonne CO 2 -eq. The practise of using CEA for policy-making could improve considerably by clearly indicating the specific purpose of the CEA and its strengths and limitations for policy decisions. Another improvement is related to the dominant approach in transport GHG mitigation studies: the bottom-up financial technical approach which assesses isolated effects, implying considerable limitations for policy-making. A shift to welfare-economic approaches using a hybrid model has the potential to establish an improved assessment of transport GHG mitigation measures based on realistic market responses and behavioural change. - Highlights: ► We identify fourteen important methodological issues clustered into six groups. ► We systematically review thirty-three selected transport GHG mitigation studies. ► Methodological choices can lead to a difference by up to $400 per tonne CO 2 -eq. ► The dominant bottom-up approach has limitations for policy-making. ► Welfare-economic approaches could improve cost-effectiveness analysis.

  7. Inventory and Policy Reduction Potential of Greenhouse Gas and Pollutant Emissions of Road Transportation Industry in China

    Directory of Open Access Journals (Sweden)

    Ye Li

    2016-11-01

    Full Text Available In recent years, emissions from the road transportation industry in China have been increasing rapidly. To evaluate the reduction potential of greenhouse gas and pollutant emissions of the industry in China, its emission inventory was calculated and scenario analysis was created for the period between 2012 and 2030 in this paper. Based on the Long-range Energy Alternatives Planning System (LEAP model, the development of China’s road transportation industry in two scenarios (the business-as-usual (BAU scenario and the comprehensive-mitigation (CM scenario was simulated. In the Comprehensive Mitigation scenario, there are nine various measures which include Fuel Economy Standards, Auto Emission Standards, Energy-saving Technology, Tax Policy, Eco-driving, Logistics Informatization, Vehicle Liquidation, Electric Vehicles, and Alternative Fuels. The cumulative energy and emission reductions of these specific measures were evaluated. Our results demonstrate that China’s road transportation produced 881 million metric tons of CO2 and emitted 1420 thousand tons of CO, 2150 thousand tons of NOx, 148 thousand tons of PM10, and 745 thousand tons of HC in 2012. The reduction potential is quite large, and road freight transportation is the key mitigation subsector, accounting for 85%–92% of the total emission. For energy conservation and carbon emission mitigation, logistics informatization is the most effective method, potentially reducing 1.80 billion tons of coal equivalent and 3.83 billion tons of CO2 from 2012 to 2030. In terms of air pollutant emission mitigation, the auto emission standards measure performs best with respect to NOx, PM10, and HC emission mitigation, and logistic informatization measure is the best in CO emission reduction. In order to maximize the mitigation potential of China’s road transportation industry, the government needs to implement various measures in a timely and strict fashion.

  8. Development of facilitated transport membranes for the separation of olefins from gas streams; Entwicklung von Carriermembranen zur Olefinabtrennung aus Gasstroemen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Chemie

    2001-07-01

    The current work is concerned with the development of highly selective facilitated transport membranes for olefin/paraffin separation. Adsorption measurements with 7 silver salts showed that silver-perchlorate was the most promising carrier material. This carrier was embedded into two different commercial available polyetherblockamides - Pebax trademark 4011 and Pebax trademark 2533 with up to 41 wt.-% of silver ions. The solubility of the carrier in polymer and the influence of humidity on the separation characteristics of the membranes were studied in detail. The aging of the membrane samples was investigated as well. A composite membrane with a top layer of Pebax trademark 2533/silver-perchlorate showed the best performance. Ethylene permeabilities in the range of 0.1 to 0.4 m{sup 3}/m{sup 2} h bar and gas mixture selectivities of 110 to 400 were measured with an humidified equimolar gas mixture of ethylene and ethane. Best results were obtained with membranes manufactured from proposely aging coating solutions and a sub-surface-structure. These membranes showed a permeability coefficient up to 1000 Barrer for ethylene with a gas mixture selectivity of 400. (orig.)

  9. The regulation of greenhouse gas emissions in the field of transport; La regulation des emissions de gaz a effet de serre dans le domaine du transport

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-03-15

    Since 1990, CO{sub 2} emissions in the transport sector have increased by nearly 20%, mainly because of increased car traffic. Reducing them by 20% between now and 2020, in accordance with the draft law tabled by the Grenelle Environment Forum - and by much more between now and 2050 in the context of reducing European emissions by 75% - presupposes recourse to economic instruments such as the climate-energy contribution envisaged by the Forum. However, the methods of evaluation and implementation remain to be defined. The order of magnitude of such instruments could correspond to the value defined for the socio-economic calculations of public projects by a Centre d'Analyse Strategique mission that was set up at the request of the Prime Minister and chaired by Alain Quinet. It will thus be close to 30 euros per CO{sub 2} ton today, rising to 100 euros in 2030 and between 150 and 350 euros in 2050. However, this value cannot be used as such in the economy - and particularly in the form of a tax - without precautions, both for social reasons and reasons of economic competitiveness. The purpose of this Strategic Newswatch is to contribute to the debate by envisaging, within a European framework, the different forms that the regulation of transport greenhouse gas emissions could take. (author)

  10. Utilizing Non-Equilibrium Thermodynamics and Reactive Transport to Model CH4 Production from the Nankai Trough Gas Hydrate Reservoir

    Directory of Open Access Journals (Sweden)

    Khadijeh Qorbani

    2017-07-01

    Full Text Available The ongoing search for new sources of energy has brought natural gas hydrate (NGH reservoirs to the forefront of attention in both academia and the industry. The amount of gas reserves trapped within these reservoirs surpasses all of the conventional fossil fuel sources explored so far, which makes it of utmost importance to predict their production potential and safety. One of the challenges facing those attempting to analyse their behaviour is that the large number of involved phases make NGHs unable to ever reach equilibrium in nature. Field-scale experiments are expensive and time consuming. However, computer simulations have now become capable of modelling different gas production scenarios, as well as production optimization analyses. In addition to temperature and pressure, independent thermodynamic parameters for hydrate stabilization include the hydrate composition and concentrations for all co-existing phases. It is therefore necessary to develop and implement realistic kinetic models accounting for all significant routes for dissociation and reformation. The reactive transport simulator makes it easy to deploy nonequilibrium thermodynamics for the study of CH4 production from hydrate-bearing sediments by considering each hydrate-related transition as a separate pseudo reaction. In this work, we have used the expanded version of the RetrasoCodeBright (RCB reactive transport simulator to model exploitation of the methane hydrate (MH reservoir located in the Nankai Trough, Japan. Our results showed that higher permeabilities in the horizontal direction dominated the pressure drop propagation throughout the hydrate layers and affected their hydrate dissociation rates. Additionally, the comparison of the vertical well versus the horizontal well pattern indicated that hydrate dissociation was slightly higher in the vertical well scenario compared to the horizontal.

  11. Transportation

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    Here is the decree of the thirtieth of July 1998 relative to road transportation, to trade and brokerage of wastes. It requires to firms which carry out a road transportation as well as to traders and to brokers of wastes to declare their operations to the prefect. The declaration has to be renewed every five years. (O.M.)

  12. Wind-induced single-sided natural ventilation in buildings near a long street canyon: CFD evaluation of street configuration and envelope design

    DEFF Research Database (Denmark)

    Ai, Z.T.; Mak, C.M.

    2018-01-01

    an urban context, this study investigates the wind-induced single-sided natural ventilation in buildings near a long street canyon under a perpendicular wind direction using CFD method. Four aspect ratios (AR) of the street canyon, from 1.0, 2.0, 4.0 to 6.0, are investigated to examine the influence...

  13. Water vapor and gas transport through a poly (butylene terephthalate) poly (ethylene oxide) block copolymer

    NARCIS (Netherlands)

    Metz, S.J.; Potreck, Jens; Mulder, M.H.V.; Wessling, Matthias

    2002-01-01

    In this paper the transport behavior of water vapor and nitrogen in a poly(butylene terephthalate) poly (ethylene oxide) block copolymer is discussed. This polymer has a high solubility for water (300 cm3 (STP)/cm3 polymer at activity 0.9). A new permeation set up has been built to determine the

  14. Shared Freight Transportation and Energy Commodities Phase One: Coal, Crude Petroleum, & Natural Gas Flows

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Shih-Miao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hwang, Ho-Ling [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Diane [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    The Freight Analysis Framework (FAF) integrates data from a variety of sources to create a comprehensive picture of nationwide freight movements among states and major metropolitan areas for all modes of transportation. It provides a national picture of current freight flows to, from, and within the United States, assigns selected flows to the transportation network, and projects freight flow patterns into the future. The latest release of FAF is known as FAF4 with a base year of 2012. The FAF4 origin-destination-commodity-mode (ODCM) matrix is provided at national, state, major metropolitan areas, and major gateways with significant freight activities (e.g., El Paso, Texas). The U.S. Department of Energy (DOE) is interested in using FAF4 database for its strategic planning and policy analysis, particularly in association with the transportation of energy commodities. However, the geographic specification that DOE requires is a county-level ODCM matrix. Unfortunately, the geographic regions in the FAF4 database were not available at the DOE desired detail. Due to this limitation, DOE tasked Oak Ridge National Laboratory (ORNL) to assist in generating estimates of county-level flows for selected energy commodities by mode of transportation.

  15. Trends of greenhouse gas emissions from the road transport sector in India

    International Nuclear Information System (INIS)

    Singh, Anil; Gangopadhyay, S.; Nanda, P.K.; Bhattacharya, S.; Sharma, C.; Bhan, C.

    2008-01-01

    The road transport sector is the largest consumer of commercial fuel energy within the transportation system in India and accounts for nearly 35% of the total liquid commercial fuel consumption by all sectors. Gasoline and diesel consumption for road transportation have quadrupled between 1980 and 2000 due to about nine times increase in the number of vehicles and four-fold increase in freight and passenger travel demands. The paper elaborates the trends of energy consumption and consequent emissions of greenhouse gases such as CO 2 , CH 4 and N 2 O and ozone precursor gases like CO, NO x and NMVOC in the road transport sector in India for the period from 1980 to 2000. For the first time, efforts have been made to apportion the fuels, both diesel and gasoline, across different categories of vehicles operating on the Indian roads. In order to generate more comprehensive and complete emission estimates, additionally, other minor fuel types like light diesel oil and fuel oil along with lubricants have also been taken into account. Emission estimates have revealed that nearly 27 Mt of CO 2 were emitted in 1980, increasing to about 105 Mt in 2000. Similar trends have also been observed for other gases. Further scope for improvements in emission estimation is possible by generating country specific emission factors for different vehicle categories and improvement in documentation of fuel consumption at segregated levels by fuel types and vehicle types

  16. Advective and diffusive contributions to reactive gas transport during pyrite oxidation in the unsaturated zone

    NARCIS (Netherlands)

    Binning, P. J.; POSTMA, D; Russell, T. F.; Wesselingh, J. A.; Boulin, P. F.

    2007-01-01

    [1] Pyrite oxidation in unsaturated mine waste rock dumps and soils is limited by the supply of oxygen from the atmosphere. In models, oxygen transport through the subsurface is often assumed to be driven by diffusion. However, oxygen comprises 23.2% by mass of dry air, and when oxygen is consumed

  17. Advective and diffusive contributions to reactive gas transport during pyrite oxidation in the unsaturated zone

    DEFF Research Database (Denmark)

    Binning, Philip John; Postma, Diederik Jan; Russel, T.F.

    2007-01-01

    Pyrite oxidation in unsaturated mine waste rock dumps and soils is limited by the supply of oxygen from the atmosphere. In models, oxygen transport through the subsurface is often assumed to be driven by diffusion. However, oxygen comprises 23.2% by mass of dry air, and when oxygen is consumed...

  18. Development of Information Support of the Automated System for Monitoring the State of the Gas Transportation System’s Industrial Safety

    Directory of Open Access Journals (Sweden)

    Ruslan Skrynkovskyy

    2017-08-01

    Full Text Available The purpose of the article is to developing the information security of the automated system for monitoring the state of industrial safety of the gas transportation system within the framework of the safety management system, which will enable timely and objective detection of adverse accident hazards (hazardous events and taking the necessary specific measures to eliminate them and operate the gas transport system safely. It is proved that the basis of the information provision of the automated system for monitoring the state of the industrial safety of the gas transmission system is a methodology that includes the following basic procedures: identifying hazards; qualitative and quantitative assessment of emergencies; establishing of unacceptable (unallowable risks and their introduction to the information base (register of unacceptable risks of objects of the gas transportation system; comprehensive assessment and certification of the state of industrial safety of objects of the gas transportation system; identification of effective, productive (efficient risk management measures. The prospect of further research in this area is the development and implementation of an automated system for monitoring the state of industrial safety of the objects of the gas transmission system based on the results of the research (of the submitted information provision.

  19. Rn3D: A finite element code for simulating gas flow and radon transport in variably saturated, nonisothermal porous media

    International Nuclear Information System (INIS)

    Holford, D.J.

    1994-01-01

    This document is a user's manual for the Rn3D finite element code. Rn3D was developed to simulate gas flow and radon transport in variably saturated, nonisothermal porous media. The Rn3D model is applicable to a wide range of problems involving radon transport in soil because it can simulate either steady-state or transient flow and transport in one-, two- or three-dimensions (including radially symmetric two-dimensional problems). The porous materials may be heterogeneous and anisotropic. This manual describes all pertinent mathematics related to the governing, boundary, and constitutive equations of the model, as well as the development of the finite element equations used in the code. Instructions are given for constructing Rn3D input files and executing the code, as well as a description of all output files generated by the code. Five verification problems are given that test various aspects of code operation, complete with example input files, FORTRAN programs for the respective analytical solutions, and plots of model results. An example simulation is presented to illustrate the type of problem Rn3D is designed to solve. Finally, instructions are given on how to convert Rn3D to simulate systems other than radon, air, and water

  20. Growth Dynamics and Gas Transport Mechanism of Nanobubbles in Graphene Liquid Cells

    OpenAIRE

    Shin, Dongha; Park, Jong Bo; Kim, Yong-Jin; Kim, Sang Jin; Kang, Jin Hyoun; Lee, Bora; Cho, Sung-Pyo; Hong, Byung Hee; Novoselov, Konstantin S.

    2014-01-01

    Formation, evolution, and vanishing of bubbles are common phenomena in our nature, which can be easily observed in boiling or falling waters, carbonated drinks, gas-forming electrochemical reactions, etc. However, the morphology and the growth dynamics of the bubbles at nanoscale have not been fully investigated owing to the lack of proper imaging tools that can visualize nanoscale objects in liquid phase. Here we demonstrate, for the first time, that the nanobubbles in water encapsulated by ...

  1. Strategy for monitoring and ensuring safe operation of Russian gas transportation systems

    OpenAIRE

    Dudin Sergey; Bahmat Gennady; Zemenkov Yury; Voronin Konstantin; Shipovalov Anton

    2017-01-01

    The authors examined the legislative framework of the Russian Federation operating in the field of industrial safety, and described how to obtain a license to operate hazardous production facilities. The paper demonstrates that the importance should be given to the quality and completeness of the background information, as well as the choice of inspection strategy in evaluating the technical condition of the line section of main gas pipelines. As a part of a package of measures to ensure indu...

  2. Running on Fumes: A Critical Look at Mexico’s Natural Gas Transportation and Distribution Infrastructure

    Science.gov (United States)

    2011-10-27

    behind existing laws and policies that are hampering growth and development in Mexico’s petrochemical industry. 3 Petroleos Mexicanos ( PEMEX ...is the state-owned company created in 1938 to run the national oil and natural gas monopoly. In the decades that followed, PEMEX often utilized...privatization of PEMEX and its subsidiaries. The PRD has proposed an alternate plan, developed by founding PRD member 4 and adviser to the National

  3. Effect of capillary condensation on gas transport properties in porous media

    Science.gov (United States)

    Yoshimoto, Yuta; Hori, Takuma; Kinefuchi, Ikuya; Takagi, Shu

    2017-10-01

    We investigate the effect of capillary condensation on gas diffusivity in porous media composed of randomly packed spheres with moderate wettability. To simulate capillary phenomena at the pore scale while retaining complex pore networks of the porous media, we employ density functional theory (DFT) for coarse-grained lattice gas models. The lattice DFT simulations reveal that capillary condensations preferentially occur at confined pores surrounded by solid walls, leading to the occlusion of narrow pores. Consequently, the characteristic lengths of the partially wet structures are larger than those of the corresponding dry structures with the same porosities. Subsequent gas diffusion simulations exploiting the mean-square displacement method indicate that while the effective diffusion coefficients significantly decrease in the presence of partially condensed liquids, they are larger than those in the dry structures with the same porosities. Moreover, we find that the ratio of the porosity to the tortuosity factor, which is a crucial parameter that determines an effective diffusion coefficient, can be reasonably related to the porosity even for the partially wet porous media.

  4. Effect of capillary condensation on gas transport properties in porous media.

    Science.gov (United States)

    Yoshimoto, Yuta; Hori, Takuma; Kinefuchi, Ikuya; Takagi, Shu

    2017-10-01

    We investigate the effect of capillary condensation on gas diffusivity in porous media composed of randomly packed spheres with moderate wettability. To simulate capillary phenomena at the pore scale while retaining complex pore networks of the porous media, we employ density functional theory (DFT) for coarse-grained lattice gas models. The lattice DFT simulations reveal that capillary condensations preferentially occur at confined pores surrounded by solid walls, leading to the occlusion of narrow pores. Consequently, the characteristic lengths of the partially wet structures are larger than those of the corresponding dry structures with the same porosities. Subsequent gas diffusion simulations exploiting the mean-square displacement method indicate that while the effective diffusion coefficients significantly decrease in the presence of partially condensed liquids, they are larger than those in the dry structures with the same porosities. Moreover, we find that the ratio of the porosity to the tortuosity factor, which is a crucial parameter that determines an effective diffusion coefficient, can be reasonably related to the porosity even for the partially wet porous media.

  5. Influence of excited molecules on electron swarm transport coefficients and gas discharge kinetics

    International Nuclear Information System (INIS)

    Petrovic, Z.L.; Jovanovic, J.V.; Raspopovic, Z.M.; Bzenic, S.A.; Vrhovac, S.B.

    1997-01-01

    In this paper we study different effects of excited molecules on swarm parameters, electron energy distribution functions and gas discharge modeling. First we discuss a possible experiment in parahydrogen to resolve the discrepancy in hydrogen vibrational excitation cross section data. Negative differential conductivity (NDC) is a kinetic phenomenon which manifests itself in a particular dependence of the drift velocity on E=N and it is affected by superelastic collisions with excited states. A complete kinetic scheme for argon required to model excited state densities in gas discharges is also described. These results are used to explain experiments in capacitively and inductively coupled RF plasmas used for processing. The paper illustrates the application of atomic and molecular collision data, swarm data and the theoretical techniques in modeling of gas discharges with large abundances of excited molecules. It is pointed out that swarm experiments with excited molecules are lacking and that there is a shortage of reliable data, while the numerical procedures are sufficiently developed to include all the important effects. (authors). 59 refs., 12 figs

  6. Investigations on the applicability of pure gases in the transport of nuclear reaction products in a gas jet, and the use of this gas jet for radiochemical separation processes

    International Nuclear Information System (INIS)

    Aumann, D.C.; Presuhn, R.; Weismann, D.

    1975-01-01

    Earlier investigations on the effectivity of the transport of nuclear reaction products in a gas jet were continued where the transporting properties of ethylene and CO 2 in particular were examined in detail. By means of selected measurements, it is shown what influence the temperature of the gas bottle and that of the pressure releaser has on the transport yield. It is attempted from the results to explain the formation of aerosols in pure gases. The fission fragments of the spontaneous fission of Cf-252 are gamma-spectrometrically measured to determine the yields, or the total yield is determined by simple activity measurements. The determination of the isomeric ratio of Cs 138 m/g is described as an example of the possible application of a gas jet. Furthermore, an experiment for the search of super-heavy elements is suggested. (RB/LH) [de

  7. Determination of the potential energy surfaces of refrigerant mixtures and their gas transport coefficients

    Directory of Open Access Journals (Sweden)

    Song Bo

    2017-01-01

    Full Text Available In this work, the inversion scheme was used to determine the potential energy surfaces of five polar refrigerant mixtures. The systems studied here are R123-R134a, R123-R142b, R123-R152a, R142b-R134a, and R142b-R152a. The low density transport coefficients of the refrigerant mixtures were calculated from the new invert potentials by the classical kinetic theory. The viscosity coefficient, binary diffusion coefficient, and thermal diffusion factor were computed for the temperature range from 313.15-973.15 K. The agreement with the NIST viscosity data demonstrates that the present calculated values are accurate enough to supplement experimental data over an extended temperature range. Correlations of the transport properties were also provided for the refrigerant mixtures at equimolar ratios.

  8. The effects of gas-fluid-rock interactions on CO2 injection and storage: Insights from reactive transport modeling

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Y.; Xu, T.; Pruess, K.

    2008-10-15

    Possible means of reducing atmospheric CO{sub 2} emissions include injecting CO{sub 2} in petroleum reservoirs for Enhanced Oil Recovery or storing CO{sub 2} in deep saline aquifers. Large-scale injection of CO{sub 2} into subsurface reservoirs would induce a complex interplay of multiphase flow, capillary trapping, dissolution, diffusion, convection, and chemical reactions that may have significant impacts on both short-term injection performance and long-term fate of CO{sub 2} storage. Reactive Transport Modeling is a promising approach that can be used to predict the spatial and temporal evolution of injected CO{sub 2} and associated gas-fluid-rock interactions. This presentation will summarize recent advances in reactive transport modeling of CO{sub 2} storage and review key technical issues on (1) the short- and long-term behavior of injected CO{sub 2} in geological formations; (2) the role of reservoir mineral heterogeneity on injection performance and storage security; (3) the effect of gas mixtures (e.g., H{sub 2}S and SO{sub 2}) on CO{sub 2} storage; and (4) the physical and chemical processes during potential leakage of CO{sub 2} from the primary storage reservoir. Simulation results suggest that CO{sub 2} trapping capacity, rate, and impact on reservoir rocks depend on primary mineral composition and injecting gas mixtures. For example, models predict that the injection of CO{sub 2} alone or co-injection with H{sub 2}S in both sandstone and carbonate reservoirs lead to acidified zones and mineral dissolution adjacent to the injection well, and carbonate precipitation and mineral trapping away from the well. Co-injection of CO{sub 2} with H{sub 2}S and in particular with SO{sub 2} causes greater formation alteration and complex sulfur mineral (alunite, anhydrite, and pyrite) trapping, sometimes at a much faster rate than previously thought. The results from Reactive Transport Modeling provide valuable insights for analyzing and assessing the dynamic

  9. Transportation

    National Research Council Canada - National Science Library

    Allshouse, Michael; Armstrong, Frederick Henry; Burns, Stephen; Courts, Michael; Denn, Douglas; Fortunato, Paul; Gettings, Daniel; Hansen, David; Hoffman, Douglas; Jones, Robert

    2007-01-01

    .... The ability of the global transportation industry to rapidly move passengers and products from one corner of the globe to another continues to amaze even those wise to the dynamics of such operations...

  10. A liquefied energy chain for transport and utilization of natural gas for power production with CO2 capture and storage - Part 1

    International Nuclear Information System (INIS)

    Aspelund, Audun; Gundersen, Truls

    2009-01-01

    A novel transport chain for stranded natural gas utilized for power production with CO 2 capture and storage is developed. It includes an offshore section, a combined gas carrier, and an onshore integrated receiving terminal. Due to utilization of the cold exergy both in the offshore and onshore processes, and combined use of the gas carrier, the transport chain is both energy and cost effective. In this paper, the liquefied energy chain (LEC) is explained, including novel processes for both the offshore field site and onshore market site. In the offshore section, natural gas (NG) is liquefied to LNG by liquid carbon dioxide (LCO 2 ) and liquid inert nitrogen (LIN), which are used as cold carriers. The LNG is transported in a combined gas carrier to the receiving terminal where it is used as a cooling agent to liquefy CO 2 and nitrogen. The LCO 2 and LIN are transported offshore using the same combined carrier. Pinch and Exergy Analyses are used to determine the optimal offshore and onshore processes and the best transport conditions. The exergy efficiency for a thermodynamically optimized process is 87% and 71% for the offshore and onshore processes, respectively, yielding a total efficiency of 52%. The offshore process is self-supported with power and can operate with few units of rotating equipment and without flammable refrigerants. The loss of natural gas due to power generation for the energy requirements in the LEC processes is roughly one third of the loss in a conventional transport chain for stranded natural gas with CO 2 sequestration. The LEC has several configurations and can be used for small scale ( 5 MTPA LNG) transport. In the example in this paper, the total costs for the simple LEC including transport of natural gas to a 400 MW net power plant and return of 85% of the corresponding carbon as CO 2 for a total sailing distance of 24 h are 58.1 EUR/tonne LNG excluding or including the cost of power. The total power requirements are 319 k

  11. Novel Protic Ionic Liquid Composite Membranes with Fast and Selective Gas Transport Nanochannels for Ethylene/Ethane Separation.

    Science.gov (United States)

    Dou, Haozhen; Jiang, Bin; Xiao, Xiaoming; Xu, Mi; Tantai, Xiaowei; Wang, Baoyu; Sun, Yongli; Zhang, Luhong

    2018-04-25

    Protic ionic liquids (PILs) were utilized for the fabrication of composite membranes containing silver salt as the C 2 H 4 transport carrier to perform C 2 H 4 /C 2 H 6 separation for the first time. The intrinsic nanostructures of PILs were adopted to construct fast and selective C 2 H 4 transport nanochannels. The investigation of structure-performance relationships of composite membranes suggested that transport nanochannels (polar domains of PILs) could be tuned by the sizes of cations, which greatly manipulated activity of the carrier and determined the separation performances of membranes. The role of different carriers in the facilitated transport was studied, which revealed that the PILs were good solvents for dissolution and activation of the carrier due to their hydrogen bond networks and waterlike properties. The operating conditions of separation process were investigated systemically and optimized, confirming C 2 H 4 /C 2 H 6 selectivity was enhanced with the increase of silver salt concentration, the flow rate of sweep gas, and the feed ratio of C 2 H 4 to C 2 H 6 , as well as the decrease of the transmembrane pressure and operating temperature. Furthermore, the composite membranes exhibited long-term stability and obtained very competitive separation performances compared with other results. In summary, PIL composite membranes, which possess good long-term stability, high C 2 H 4 /C 2 H 6 selectivity, and excellent C 2 H 4 permeability, may have a good perspective in industrial C 2 H 4 /C 2 H 6 separation.

  12. Quantifying the loss of methane through secondary gas mass transport (or 'slip') from a micro-porous membrane contactor applied to biogas upgrading.

    Science.gov (United States)

    McLeod, Andrew; Jefferson, Bruce; McAdam, Ewan J

    2013-07-01

    Secondary gas transport during the separation of a binary gas with a micro-porous hollow fibre membrane contactor (HMFC) has been studied for biogas upgrading. In this application, the loss or 'slip' of the secondary gas (methane) during separation is a known concern, specifically since methane possesses the intrinsic calorific value. Deionised (DI) water was initially used as the physical solvent. Under these conditions, carbon dioxide (CO2) and methane (CH4) absorption were dependent upon liquid velocity (V(L)). Whilst the highest CO2 flux was recorded at high V(L), selectivity towards CO2 declined due to low residence times and a diminished gas-side partial pressure, and resulted in slip of approximately 5.2% of the inlet methane. Sodium hydroxide was subsequently used as a comparative chemical absorption solvent. Under these conditions, CO2 mass transfer increased by increasing gas velocity (VG) which is attributed to the excess of reactive hydroxide ions present in the solvent, and the fast conversion of dissolved CO2 to carbonate species reinitiating the concentration gradient at the gas-liquid interface. At high gas velocities, CH4 slip was reduced to 0.1% under chemical conditions. Methane slip is therefore dependent upon whether the process is gas phase or liquid phase controlled, since methane mass transport can be adequately described by Henry's law within both physical and chemical solvents. The addition of an electrolyte was found to further retard CH4 absorption via the salting out effect. However, their applicability to physical solvents is limited since electrolytic concentration similarly impinges upon the solvents' capacity for CO2. This study illustrates the significance of secondary gas mass transport, and furthermore demonstrates that gas-phase controlled systems are recommended where greater selectivity is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Persistent effects of subsoil compaction on pore size distribution and gas transport in a loamy soil

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Keller, T

    2012-01-01

    The ever-increasing weight of agricultural machines exacerbates the risk of subsoil compaction, a condition believed to be persistent and difficult to alleviate by soil tillage and natural loosening processes. However, experimental data on the persistency of subsoil compaction effects on soil pore...... included four repeated wheelings with ∼10 Mg wheel loads. Water retention characteristics (WRC), air permeability (ka) and gas diffusivity (Ds/Do) were measured. A dual-porosity model fitted the WRC well, and there was a reduction in the volume of macropores >30 μm in compacted compared with control soil...

  14. Reaction and Transport Effects in the Heterogeneous Systems for Lean Gas Purification.

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Svoboda, Karel; Pohořelý, Michael; Šyc, Michal; Skoblia, S.; Chyou, Y.-P.

    2017-01-01

    Roč. 71, č. 3 (2017), s. 563-577 ISSN 0366-6352 R&D Projects: GA ČR(CZ) GC14-09692J Grant - others:NSC(TW) 102WBS0300011; NSC(TW) 103-2923-E-042A-001-MY3 Institutional support: RVO:67985858 Keywords : differential reactor * gas chemisorption * alkaline solids Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 1.258, year: 2016

  15. Transport properties of N2 gas at cryogenic temperatures. [computation of viscosity and thermal conductivity

    Science.gov (United States)

    Pearson, W. E.

    1974-01-01

    The viscosity and thermal conductivity of nitrogen gas for the temperature range 5 K - 135 K have been computed from the second Chapman-Enskog approximation. Quantum effects, which become appreciable at the lower temperatures, are included by utilizing collision integrals based on quantum theory. A Lennard-Jones (12-6) potential was assumed. The computations yield viscosities about 20 percent lower than those predicted for the high end of this temperature range by the method of corresponding states, but the agreement is excellent when the computed values are compared with existing experimental data.

  16. Improving sustainability of maritime transport through utilization of Liquefied Natural Gas (LNG) for propulsion

    International Nuclear Information System (INIS)

    Burel, Fabio; Taccani, Rodolfo; Zuliani, Nicola

    2013-01-01

    Today, most merchant vessels use Heavy Fuel Oils (HFOs) for ship propulsion. These fuels are cost effective but they produce significant amounts of noxious emissions. In order to comply with International Maritime Organization (IMO) rules, Liquefied Natural Gas (LNG) is becoming an interesting option for merchant ships. The aim of the research presented in this paper is to analyse the economic upturn that can result from the use of LNG as fuel for merchant ships and to assess the effects of its utilization in terms of environmental impact. In the first part of the study, a statistical analysis of maritime traffic is carried out in order to identify which merchant ship types could most benefit from using LNG as fuel for ship propulsion. Traffic data of world ships related to the months of May 2008, 2009 and 2010 are analysed. Roll-on/Roll-off vessels (RoRo) and tanker ships spend most of their sailing time in Emission Control Areas (ECA) consequently appear to be the best candidates for LNG use. In particular, the use of LNG is most profitable for tanker ships in the range of 10,000–60,000 DWT (deadweight). In the second part of the study, operational costs and pollutant emission reduction, following LNG implementation, are calculated for a 33,000 DWT tanker ship. Results show that LNG leads to a reduction of 35% of operational costs and 25% of CO 2 emissions. The possibility of improving energy efficiency on board is analysed considering that combustion gases, produced by LNG, are cleaner, thus simplifying the introduction of exhaust gas heat recovery. Two options are considered: simple heat recovery and heat recovery to drive a turbine (ORC). The results show that it is possible to achieve a reduction in fuel consumption of up to 15%. - Highlights: • Ship propulsion accounts for a large amount of noxious emissions in costal/harbour areas. • Today price differential between fuel oil and natural gas is increasing. • The use of Liquefied Natural Gas as fuel

  17. Sustainable Transportation Fuels from Natural Gas (H{sub 2}), Coal and Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Huffman, Gerald

    2012-12-31

    This research program is focused primarily on the conversion of coal, natural gas (i.e., methane), and biomass to liquid fuels by Fischer-Tropsch synthesis (FTS), with minimum production of carbon dioxide. A complementary topic also under investigation is the development of novel processes for the production of hydrogen with very low to zero production of CO{sub 2}. This is in response to the nation's urgent need for a secure and environmentally friendly domestic source of liquid fuels. The carbon neutrality of biomass is beneficial in meeting this goal. Several additional novel approaches to limiting carbon dioxide emissions are also being explored.

  18. Mantle rare gas relative abundances in a steady-state mass transport model

    Science.gov (United States)

    Porcelli, D.; Wasserburg, G. J.

    1994-01-01

    A model for He and Xe was presented previously which incorporates mass transfer of rare gases from an undegassed lower mantle (P) and the atmosphere into a degassed upper mantle (D). We extend the model to include Ne and Ar. Model constraints on rare gas relative abundances within P are derived. Discussions of terrestrial volatile acquisition have focused on the rare gas abundance pattern of the atmosphere relative to meteoritic components, and the pattern of rare gases still trapped in the Ear,th is important in identifying volatile capture and loss processes operating during Earth formation. The assumptions and principles of the model are discussed in Wasserburg and Porcelli (this volume). For P, the concentrations in P of the decay/nuclear products 4 He, 21 Ne, 40 Ar, and 136 Xe can be calculated from the concentrations of the parent elements U, Th, K, and Pu. The total concentration of the daughter element in P is proportional to the isotopic shifts in P. For Ar, ((40)Ar/(36)Ar)p - ((40)Ar/(36)Ar)o =Delta (exp 40) p= 40 Cp/(exp 36)C where(i)C(sub j) the concentration of isotope i in j. In D, isotope compositions are the result of mixing rare gases from P, decay/nuclear products generated in the upper mantle, and subducted rare gases (for Ar and Xe).

  19. Strategy for monitoring and ensuring safe operation of Russian gas transportation systems

    Directory of Open Access Journals (Sweden)

    Dudin Sergey

    2017-01-01

    Full Text Available The authors examined the legislative framework of the Russian Federation operating in the field of industrial safety, and described how to obtain a license to operate hazardous production facilities. The paper demonstrates that the importance should be given to the quality and completeness of the background information, as well as the choice of inspection strategy in evaluating the technical condition of the line section of main gas pipelines. As a part of a package of measures to ensure industrial safety and technical reliability of existing gas pipelines it is proposed to carry out conditioning of their line sections. The paper describes general requirements for pipeline inspection, which include: detection efficiency of dangerous damages and major leaks, maximum accuracy of detection of the defect location, continuity of monitoring throughout the entire range of operation modes of the pipeline, cost recovery at the stages of development and operation of control systems, forecasting the state of the pipeline and the effects of accidents. In practice, these parameters have the prevailing significance.

  20. Rent distribution effect of a price reduction in the Dutch gas transport market. A scenario analysis of regulatory policy, market form and rent allocation

    International Nuclear Information System (INIS)

    Van Witteloostuijn, A.; Brakman, S.; Van Marrewijk, C.

    2005-09-01

    As part of the larger energy market deregulation program, the Dutch Office of Energy Regulation (DTe) has developed the habit to force the Dutch gas transport enterprise (Gas Transport Services GTS) to lower its prices. In this report, we simulate the welfare effects of a five per cent transport price reduction. DTe's key argument is that lower gas transport prices will benefit the end-user. Indeed, that might well be the case. However, at least three observations complicate matters substantially: Observation 1: government ownership. GTS is government -owned, and the dominant shipper (Gasunie Trade and Supply) is partly so (50 %). Hence, lost revenues from the gas transport business will all emerge at the debit side of the government's budget, and part of the shippers' rent returns in the government's pockets. Observation 2: imperfect competition. Firms enter into the competitive game to make profits. Shippers are not different. So, apart from in the extreme case of perfect competition (or, more generally, perfect contestability), part of the rents will end up in the pockets of the shippers, rather than the endconsumers. Observation 3: rent export. The Netherlands are not an isolated island in the European gas ocean. Not only is the majority of gas transported in the Netherlands exported to foreign end-users, but apart from that have foreign owners a large stake in Dutch shippers. As a result, given the fact that the Dutch industry is not autarktic, part of the rents will always be distributed, or will always 'leak' away, to foreign consumers and shippers (or their shareholders). These three observations together have three important implications. First, state ownership implies that much rent allocation is simply a matter of circulating money from one government sub-budget to the other (Observation 1). Second, given that the industry is imperfectly competitive, part of the rents will not be passed on to the endconsumers (Observation 2). Third, it is unavoidable

  1. Emissions of Transport Refrigeration Units with CARB Diesel, Gas-to-Liquid Diesel, and Emissions Control Devices

    Energy Technology Data Exchange (ETDEWEB)

    Barnitt, R. A.; Chernich, D.; Burnitzki, M.; Oshinuga, A.; Miyasato, M.; Lucht, E.; van der Merwe, D.; Schaberg, P.

    2010-05-01

    A novel in situ method was used to measure emissions and fuel consumption of transport refrigeration units (TRUs). The test matrix included two fuels, two exhaust configurations, and two TRU engine operating speeds. Test fuels were California ultra low sulfur diesel and gas-to-liquid (GTL) diesel. Exhaust configurations were a stock muffler and a Thermo King pDPF diesel particulate filter. The TRU engine operating speeds were high and low, controlled by the TRU user interface. Results indicate that GTL diesel fuel reduces all regulated emissions at high and low engine speeds. Application of a Thermo King pDPF reduced regulated emissions, sometimes almost entirely. The application of both GTL diesel and a Thermo King pDPF reduced regulated emissions at high engine speed, but showed an increase in oxides of nitrogen at low engine speed.

  2. The tariffs of use of liquefied natural gas transportation networks and facilities; Les tarifs d'utilisation des reseaux de transport et des installations de gaz naturel liquefie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The new tariff proposals for the use of natural gas transportation networks were transmitted to the French Ministry of economy, finances and industry on October 27, 2004 by the commission of energy regulation. These proposals have been adopted and are the object of three legislative texts: the decree no. 2005-607 from May 27 2005 relative to the tariffing rules, the by-law from May 27, 2005 relative to the definition of balancing areas, and the advice from May 27, 2005 relative to the tariffs of use of natural gas transportation networks. In application of article 7 of the law from January 3, 2003, the implementation of the first tariffs of use of natural gas transportation networks and of liquefied natural gas (LNG) facilities is defined in the decree no. 2004-994 from September 21, 2004. On the main transportation network, the tariffing is of 'input-output' type and does not depend on the distance, while at the regional network scale, the tariffing is linked with the distance. The tariff of use of LNG facilities is the sum of 4 terms: a fixed term applied to each batch unloaded at the methane terminal, a term proportional to the unloaded LNG quantities, a term depending on the duration of use of LNG storage facilities and a term covering the gas consumptions of LNG facilities. This document gathers these different legislative texts with their appendixes. (J.S.)

  3. Transport and reaction processes affecting the attenuation of landfill gas in cover soils

    DEFF Research Database (Denmark)

    Molins, S.; Mayer, K.U.; Scheutz, Charlotte

    2008-01-01

    to the atmosphere. Oxygen supply into the soil column is driven exclusively by diffusion, whereas advection outward offsets part of the diffusive contribution. In the reaction zone, methane consumption reduces the pressure gradient, further decreasing the significance of advection near the top of the column....... Simulations suggest that production of water or accumulation of exopolymeric substances due to microbially mediated methane oxidation can significantly reduce diffusive fluxes. Assuming a constant rate of methane production within a landfill, reduction of the diffusive transport properties, primarily due...

  4. Theoretical study and design of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane and intended for cooling of gas transported in a gas-main pipeline

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    This paper describes the construction and performance of a novel combined system intended for natural gas transportation and power production, and for cooling of gas transported in a gas-main pipeline. The proposed system includes a gas turbine compressor, a combined electrogenerating plant and an ejector refrigeration unit operating with a hydrocarbon refrigerant. The combined electrogenerating plant consists of a high-temperature steam-power cycle and a low-temperature hydrocarbon vapor power cycle, which together comprise a binary vapor system. The combined system is designed for the highest possible effectiveness of power generation and could find wide application in gas-transmission systems of gas-main pipelines. Application of the proposed system would enable year-round power generation and provide cooling of natural gas during periods of high ambient temperature operation. This paper presents the main results of a theoretical study and design performance specifications of a low-grade heat-driven pilot ejector refrigeration machine operating with butane and isobutane. © 2010 Elsevier Ltd and IIR. All rights reserved.

  5. Gas production and storage - gas transport and supply. Colloquium 7th conference proceedings; Gasfoerderung und Gasspeicherung - Gastransport und Gasversorgung. Kolloquium 7. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, S. [ed.] [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Bohrtechnik und Fluidbergbau; Koeckritz, V. [comp.

    1999-07-01

    The colloquium papers discuss trends in gas supply engineering, automtion of gas storages, liberalisation of the gas market, and gas management systems in integrated supply systems. Rock-mechanical problems of natural gas storage caverns are mentioned. Further subjects are gas extraction rom coal seams, power generation from gas in fuel cells, a model for blowout calculation of real gases, and vortex tubes in gas pressure reduction systems. 19 contributions have been recorded separately in this database. [German] Die einzelnen Beitraege des Kolloquiums befassen sich mit den Entwicklungen in der Gasversorgungstechnik, mit der Automatisierung von Gasspeichern, mit der Liberalisierung des Gasmarktes sowie mit Gasmanagementsystemen in Verbundnetzen. Neben der Gasspeicherung in Porenspeichern und Salzkavernen, deren Sicherheit und der Soleversenkung, sind Betraege zu gebirgsmechanischen Problemen in Erdgasspeicherkavernen enthalten. Weitere Themen sind die Gasfoerderung aus Steinkohlefloezen, die Energieerzeugung aus Gas in Brennstoffzellen, ein Modell zur Blowout-Berechnung realer Gase sowie Wirbelrohre in Anlagen zur Gasdruckminderung. Fuer die Datenbank Energy wurden 19 Beitraege separat aufgenommen.

  6. Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature

    Science.gov (United States)

    Eckels, David E.; Hass, William J.

    1989-05-30

    A sample transport, sample introduction, and flame excitation system for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses.

  7. CORRELATION BETWEEN POLYMER PACKING AND GAS TRANSPORT PROPERTIES FOR CO2/N2 SEPARATION IN GLASSY FLUORINATED POLYIMIDE MEMBRANE

    Directory of Open Access Journals (Sweden)

    P. C. TAN

    2016-07-01

    Full Text Available Gas separation performance of a membrane highly hinges on its physical properties. In this study, the interplay between polymer packing of a membrane and its gas transport behaviours (permeability and selectivity was investigated through a series of 6FDA-DAM:DABA (3:2 polyimide membranes with different polymer compactness. The chemical structure and the polymer packing of the resulting membrane were characterized using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR and packing density measurement, respectively. CO2/N2 separation efficiency of the membrane was evaluated at 25oC with feed pressure up to 6 bar. N2 permeability was found to rely on the membrane’s packing density, which signified its greater dependence on molecular sieving. In contrast, sorption showed a more vital role in determining the CO2 permeability. In this work, the membrane with a final thickness of 97±2 µm had successfully surpassed the Robeson’s 2008 upper bound plot with a CO2 permeability of 83 Barrer and CO2/N2 selectivity of 97 at 3 bar permeation.

  8. Report of the experts group on the taxation of the access to gas transport and distribution network; Rapport du groupe d'experts sur la tarification de l'acces aux reseaux de transport et de distribution de gaz

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-04-01

    In the framework of a new french gas industry organization (directive of the 22 june 1998), a concerting mission has been realized on prices taxation for the transport and distribution facilities. The following topics have been debated: the integration and competition of the european gas market, the gas market liberalization consistency and the taxation of transport and distribution network access. (A.L.B.)

  9. Deep earthquakes beneath mount st. Helens: evidence for magmatic gas transport?

    Science.gov (United States)

    Weaver, C S; Zollweg, J E; Malone, S D

    1983-09-30

    Small-magnitude earthquakes began beneath Mount St. Helens 40 days before the eruption of 20 March 1982. Unlike earlier preeruption seismicity for this volcano, which had been limited to shallow events (less than 3 kilometers), many of these earthquakes were deep (between 5 and 11 kilometers). The location of these preeruptive events at such depth indicates that a larger volume of the volcanic system was affected prior to the 20 March eruption than prior to any of the earlier dome-building eruptions. The depth-time relation between the deep earthquakes and the explosive onset of the eruption is compatible with the upward migration of magmatic gas released from a separate deep reservoir.

  10. Gas-Transport-Property Performance of Hybrid Carbon Molecular Sieve−Polymer Materials

    KAUST Repository

    Das, Mita

    2010-10-06

    High-performance hybrid materials using carbon molecular sieve materials and 6FDA-6FpDA were produced. A detailed analysis of the effects of casting processes and the annealing temperature is reported. Two existing major obstacles, sieve agglomeration and residual stress, were addressed in this work, and subsequently a new membrane formation technique was developed to produce high-performing membranes. The successfully improved interfacial region of the hybrid membranes allows the sieves to increase the selectivity of the membranes above the neat polymer properties. Furthermore, an additional performance enhancement was seen with increased sieve loading in the hybrid membranes, leading to an actual performance above the upper bound for pure polymer membranes. The membranes were also tested under a mixed-gas environment, which further demonstrated promising results. © 2010 American Chemical Society.

  11. Water retention, gas transport, and pore network complexity during short-term regeneration of soil structure

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Møldrup, Per; Schjønning, Per

    2013-01-01

    Human activities such as mining, grading, and filling results in physical disturbance of soil structure and associated functions, and knowledge on structure recovery after such activities is vital. This study quantifies the newly-formed structure of 22-month field-incubated physically-disturbed (2...... was done using water retention (pore size distribution), soil gas diffusivity, air permeability, and derived pore network complexity parameters. Significant decreases in bulk density (increased total porosity) and increases in pores > 100 1m was observed for incubated samples compared with SR samples......, incubated samples had lower water content, higher air filled porosity, and air permeability than natural intact samples at matric potential of –10 kPa. Despite this, soil pore organization was similar among the two groups but pore network complexity increased in order: SR

  12. Numerical simulation of the environmental impact of hydraulic fracturing of tight/shale gas reservoirs on near-surface groundwater: Background, base cases, shallow reservoirs, short-term gas, and water transport.

    Science.gov (United States)

    Reagan, Matthew T; Moridis, George J; Keen, Noel D; Johnson, Jeffrey N

    2015-04-01

    Hydrocarbon production from unconventional resources and the use of reservoir stimulation techniques, such as hydraulic fracturing, has grown explosively over the last decade. However, concerns have arisen that reservoir stimulation creates significant environmental threats through the creation of permeable pathways connecting the stimulated reservoir with shallower freshwater aquifers, thus resulting in the contamination of potable groundwater by escaping hydrocarbons or other reservoir fluids. This study investigates, by numerical simulation, gas and water transport between a shallow tight-gas reservoir and a shallower overlying freshwater aquifer following hydraulic fracturing operations, if such a connecting pathway has been created. We focus on two general failure scenarios: (1) communication between the reservoir and aquifer via a connecting fracture or fault and (2) communication via a deteriorated, preexisting nearby well. We conclude that the key factors driving short-term transport of gas include high permeability for the connecting pathway and the overall volume of the connecting feature. Production from the reservoir is likely to mitigate release through reduction of available free gas and lowering of reservoir pressure, and not producing may increase the potential for release. We also find that hydrostatic tight-gas reservoirs are unlikely to act as a continuing source of migrating gas, as gas contained within the newly formed hydraulic fracture is the primary source for potential contamination. Such incidents of gas escape are likely to be limited in duration and scope for hydrostatic reservoirs. Reliable field and laboratory data must be acquired to constrain the factors and determine the likelihood of these outcomes. Short-term leakage fractured reservoirs requires high-permeability pathways Production strategy affects the likelihood and magnitude of gas release Gas release is likely short-term, without additional driving forces.

  13. System of large transport containers for waste from dismantling light water and gas-cooled nuclear reactors. Volume 2

    International Nuclear Information System (INIS)

    Price, M.S.T.; Lafontaine, I.

    1985-01-01

    The purpose of this volume is to assess the means of transportation of decommissioning wastes, costs of transport, radiological detriment attributable to transport and develops conceptual designs of large transport containers. The document ends with Conclusions and Recommendations

  14. Multiphase Transport in Porous Media: Gas-Liquid Separation Using Capillary Pressure Gradients International Space Station (ISS) Flight Experiment Development

    Science.gov (United States)

    Wheeler, Richard R., Jr.; Holtsnider, John T.; Dahl, Roger W.; Deeks, Dalton; Javanovic, Goran N.; Parker, James M.; Ehlert, Jim

    2013-01-01

    Advances in the understanding of multiphase flow characteristics under variable gravity conditions will ultimately lead to improved and as of yet unknown process designs for advanced space missions. Such novel processes will be of paramount importance to the success of future manned space exploration as we venture into our solar system and beyond. In addition, because of the ubiquitous nature and vital importance of biological and environmental processes involving airwater mixtures, knowledge gained about fundamental interactions and the governing properties of these mixtures will clearly benefit the quality of life here on our home planet. The techniques addressed in the current research involving multiphase transport in porous media and gas-liquid phase separation using capillary pressure gradients are also a logical candidate for a future International Space Station (ISS) flight experiment. Importantly, the novel and potentially very accurate Lattice-Boltzmann (LB) modeling of multiphase transport in porous media developed in this work offers significantly improved predictions of real world fluid physics phenomena, thereby promoting advanced process designs for both space and terrestrial applications.This 3-year research effort has culminated in the design and testing of a zero-g demonstration prototype. Both the hydrophilic (glass) and hydrophobic (Teflon) media Capillary Pressure Gradient (CPG) cartridges prepared during the second years work were evaluated. Results obtained from ground testing at 1-g were compared to those obtained at reduced gravities spanning Martian (13-g), Lunar (16-g) and zero-g. These comparisons clearly demonstrate the relative strength of the CPG phenomena and the efficacy of its application to meet NASAs unique gas-liquid separation (GLS) requirements in non-terrestrial environments.LB modeling software, developed concurrently with the zero-g test effort, was shown to accurately reproduce observed CPG driven gas-liquid separation

  15. Contribution to internal pressure and flammable gas concentration in RAM transport packages

    International Nuclear Information System (INIS)

    Warrant, M.M.; Brown, N.

    1989-01-01

    Various facilities in the US operated by the US Department of Energy generate wastes contaminated with transuranic (TRU) isotopes (such as plutonium and americium) that decay primarily by emission of alpha particles. The alpha particles lose energy in their passage through matter and change the material chemically in the process called radiolysis. The waste materials consist of a wide variety of commercially available plastics, paper, cloth, and rubber; concreted or sludge wastes containing water; and metals, glass, and other solid inorganic materials. TRU wastes that have surface dose rates of 200 mrem/hr or less are typically packaged in plastic bags placed inside metal drums or boxes that are vented through high efficiency particulate air (HEPA) filters. These wastes are to be transported from waste generation or storage sites to the Waste Isolation Pilot Plant (WIPP) in the TRUPACT-II, a Type B package

  16. Modeling transitions in the California light-duty vehicles sector to achieve deep reductions in transportation greenhouse gas emissions

    International Nuclear Information System (INIS)

    Leighty, Wayne; Ogden, Joan M.; Yang, Christopher

    2012-01-01

    California’s target for reducing economy-wide greenhouse gas (GHG) emissions is 80% below 1990 levels by 2050. We develop transition scenarios for meeting this goal in California’s transportation sector, with focus on light-duty vehicles (LDVs). We explore four questions: (1) what options are available to reduce transportation sector GHG emissions 80% below 1990 levels by 2050; (2) how rapidly would transitions in LDV markets, fuels, and travel behaviors need to occur over the next 40 years; (3) how do intermediate policy goals relate to different transition pathways; (4) how would rates of technological change and market adoption between 2010 and 2050 impact cumulative GHG emissions? We develop four LDV transition scenarios to meet the 80in50 target through a combination of travel demand reduction, fuel economy improvements, and low-carbon fuel supply, subject to restrictions on trajectories of technological change, potential market adoption of new vehicles and fuels, and resource availability. These scenarios exhibit several common themes: electrification of LDVs, rapid improvements in vehicle efficiency, and future fuels with less than half the carbon intensity of current gasoline and diesel. Availability of low-carbon biofuels and the level of travel demand reduction are “swing factors” that influence the degree of LDV electrification required. - Highlights: ► We model change in California LDVs for deep reduction in transportation GHG emissions. ► Reduced travel demand, improved fuel economy, and low-carbon fuels are all needed. ► Transitions must begin soon and occur quickly in order to achieve the 80in50 goal. ► Low-C biofuel supply and travel demand influence the need for rapid LDV electrification. ► Cumulative GHG emissions from LDVs can differ between strategies by up to 40%.

  17. Welfare distribution effect of a price reduction in the Dutch gas transport market: A scenario analysis of regulatory policy, market form and rent allocation

    International Nuclear Information System (INIS)

    Van Witteloostuijn, Arjen; Van Marrewijk, Charles

    2007-01-01

    As part of the larger energy market deregulation program, the Dutch energy authority - DTe - has developed the habit to force the Dutch gas transport enterprise - Gas Transport Services, or GTS - to lower its prices. DTe's key argument is that lower gas transport prices will benefit the end-user. Indeed, that might well be the case. This policy, in general, is in line with European legislation on the liberalization of the gas market. We model and simulate the (domestic) welfare effects of a 5 percent transport price reduction. From this, we conclude that at least three observations complicate matters substantially. First, GTS is government-owned, and the dominant shipper - Gasunie Trade and Supply (or GasTerra, as it was recoined recently) - is partly so (50%). Second, shippers enter into the competitive game to make profits. Third, not only is the majority of gas transported in the Netherlands exported to foreign end-users, but also foreign owners have a large stake in Dutch shippers. As a result, part of the rents will always be distributed, or will 'leak' away, to foreign consumers and shippers (or their shareholders). These three observations together have three important implications. First, state ownership implies that much rent allocation is simply a matter of circulating money from one government sub-budget to the other. Second, given that the industry is imperfectly competitive, part of the rents will not be passed on to the end-consumers. Third, it is unavoidable that a substantial part of the rents are transferred abroad. A general conclusion for policy-makers is that market liberalization might not bring ex post what they expected ex ante. (author)

  18. Welfare distribution effect of a price reduction in the Dutch gas transport market: A scenario analysis of regulatory policy, market form and rent allocation

    Energy Technology Data Exchange (ETDEWEB)

    Van Witteloostuijn, Arjen [University of Antwerpen, Antwerpen (Belgium). Faculty of Applied Economics, Department of Management; Brakman, Steven [University of Groningen (Netherlands); Van Marrewijk, Charles [Erasmus University, Rotterdam (Netherlands)

    2007-12-15

    As part of the larger energy market deregulation program, the Dutch energy authority - DTe - has developed the habit to force the Dutch gas transport enterprise - Gas Transport Services, or GTS - to lower its prices. DTe's key argument is that lower gas transport prices will benefit the end-user. Indeed, that might well be the case. This policy, in general, is in line with European legislation on the liberalization of the gas market. We model and simulate the (domestic) welfare effects of a 5 percent transport price reduction. From this, we conclude that at least three observations complicate matters substantially. First, GTS is government-owned, and the dominant shipper - Gasunie Trade and Supply (or GasTerra, as it was recoined recently) - is partly so (50%). Second, shippers enter into the competitive game to make profits. Third, not only is the majority of gas transported in the Netherlands exported to foreign end-users, but also foreign owners have a large stake in Dutch shippers. As a result, part of the rents will always be distributed, or will 'leak' away, to foreign consumers and shippers (or their shareholders). These three observations together have three important implications. First, state ownership implies that much rent allocation is simply a matter of circulating money from one government sub-budget to the other. Second, given that the industry is imperfectly competitive, part of the rents will not be passed on to the end-consumers. Third, it is unavoidable that a substantial part of the rents are transferred abroad. A general conclusion for policy-makers is that market liberalization might not bring ex post what they expected ex ante. (author)

  19. Welfare distribution effect of a price reduction in the Dutch gas transport market: A scenario analysis of regulatory policy, market form and rent allocation

    Energy Technology Data Exchange (ETDEWEB)

    Witteloostuijn, Arjen van [Faculty of Applied Economics, Department of Management, University of Antwerpen, Prinsstraat 13, 2000 Antwerpen (Belgium)], E-mail: arjen.vanwitteloostuijn@ua.ac.be; Brakman, Steven [University of Groningen (Netherlands); van Marrewijk, Charles [Erasmus University Rotterdam (Netherlands)

    2007-12-15

    As part of the larger energy market deregulation program, the Dutch energy authority-DTe-has developed the habit to force the Dutch gas transport enterprise-Gas Transport Services, or GTS-to lower its prices. DTe's key argument is that lower gas transport prices will benefit the end-user. Indeed, that might well be the case. This policy, in general, is in line with European legislation on the liberalization of the gas market. We model and simulate the (domestic) welfare effects of a 5 percent transport price reduction. From this, we conclude that at least three observations complicate matters substantially. First, GTS is government-owned, and the dominant shipper-Gasunie Trade and Supply (or GasTerra, as it was recoined recently)-is partly so (50%). Second, shippers enter into the competitive game to make profits. Third, not only is the majority of gas transported in the Netherlands exported to foreign end-users, but also foreign owners have a large stake in Dutch shippers. As a result, part of the rents will always be distributed, or will 'leak' away, to foreign consumers and shippers (or their shareholders). These three observations together have three important implications. First, state ownership implies that much rent allocation is simply a matter of circulating money from one government sub-budget to the other. Second, given that the industry is imperfectly competitive, part of the rents will not be passed on to the end-consumers. Third, it is unavoidable that a substantial part of the rents are transferred abroad. A general conclusion for policy-makers is that market liberalization might not bring ex post what they expected ex ante.

  20. Study of wind-induced vibrations in tall buildings with tuned mass dampers taking into account vortices effects

    Science.gov (United States)

    Momtaz, Ali Ajilian; Abdollahian, Mohamadreza Akhavan; Farshidianfar, Anooshiravan

    2017-12-01

    In recent years, construction of tall buildings has been of great interest. Use of lightweight materials in such structures reduces stiffness and damping, making the building more influenced by wind loads. Moreover, tall buildings of more than 30 to 40 stories, depending on the geographical location, the wind effects are more influential than earthquakes. In addition, the complexity of the effects of wind flow on the structure due to the interaction of the fluid flow and solid body results in serious damages to the structure by eliminating them. Considering the importance of the issue, the present study investigates the phenomenon of wind-induced vibration on high-rise buildings, taking into account the effects of vortices created by the fluid flow and the control of this phenomenon. To this end, the governing equations of the structure, the fluid flow and the tuned mass damper (TMD) are first introduced, and their coefficient values are extracted according to the characteristics of ACT skyscraper in Japan. Then, these three coupled equations are solved using a program coded in MATLAB. After validation of the results, the effects of wind loads are analyzed and considered with regard to the effects of vortices and the use of TMD, and are compared with the results of the state where no vortices are considered. Generally, the results of this study point out the significance of vibrations caused by vortices in construction of engineering structures as well as the appropriate performance of a TMD in reducing oscillations in tall buildings.

  1. Investigation of Influence Factors of Wind-Induced Buffeting Response of a Six-Tower Cable-Stayed Bridge

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Zhang

    2016-01-01

    Full Text Available This paper presents an investigation of the wind-induced buffeting responses of the Jiashao Bridge, the longest multispan cable-stayed bridge in the world. A three-dimensional finite element model for the Jiashao Bridge is established using the commercial software package ANSYS and a 3D fluctuating wind field is simulated for both bridge deck and towers. A time-domain procedure for analyzing buffeting responses of the bridge is implemented in ANSYS with the aeroelastic effect included. The characteristics of buffeting responses of the six-tower cable-stayed bridge are studied in some detail, focusing on the effects including the difference in the longitudinal stiffness between the side towers and central towers, partially longitudinal constraints between the bridge deck and part of bridge towers, self-excited aerodynamic forces, and the rigid hinge installed in the middle of the bridge deck. The analytical results can provide valuable references for wind-resistant design of multispan cable-stayed bridges in the future.

  2. Trading greenhouse gas emission benefits from biofuel use in US transportation: Challenges and opportunities

    International Nuclear Information System (INIS)

    Kumarappan, Subbu; Joshi, Satish

    2011-01-01

    Replacing petroleum fuels with biofuels such as ethanol and biodiesel has been shown to reduce greenhouse gas (GHG) emissions. These GHG benefits can potentially be traded in the fledgling carbon markets, and methodologies for quantifying and trading are still being developed. We review the main challenges in developing such carbon trading frameworks and outline a proposed framework for the US, the main features of which include, lifecycle assessment of GHG benefits, a combination of project-specific and standard performance measures, and assigning GHG property rights to biofuel producers. At carbon prices of 10 $ t −1 , estimated monetary benefits from such trading can be 4.5 M$ hm −3 and 17 M$ hm −3 of corn ethanol and cellulosic ethanol respectively. -- Highlights: ▶ Develops a biofuel GHG trading protocol using life-cycle emissions. ▶ Discusses the differences in feedstock and impacts on GHG trading potential. ▶ Compares the developed protocol for biofuels with other existing protocols. ▶ Estimates the market potential, and challenges associated with trading GHG emissions.

  3. Synthesis and gas transport properties of hydroxyl-functionalized polyimides with intrinsic microporosity

    KAUST Repository

    Ma, Xiaohua

    2012-05-08

    A newly designed diamine monomer, 3,3,3′,3′-tetramethyl-1, 1′-spirobisindane-5,5′-diamino-6,6′-diol, was successfully used to synthesize two types of polyimides for membrane-based gas separation applications. The novel polymers integrate significant microporosity and polar hydroxyl groups, showing the combined features of polymers of intrinsic microporosity (PIMs) and functional polyimides (PIs). They possess high thermal stability, good solubility, and easy processability for membrane fabrication; the resulting membranes exhibit good permeability owing to the intrinsic microporosity introduced by the highly contorted PIM segments as well as high CO 2/CH 4 selectivity that arises from the hydroxyl groups. The membranes show CO 2/CH 4 selectivities of >20 when tested with a 1:1 CO 2/CH 4 mixture for feed pressures up to 50 bar. In addition, the incorporation of hydroxyl groups and microporosity in the polymers enhances their affinity to water, leading to remarkable water sorption capacities of up to 22 wt % at 35 °C and 95% relative humidity. © 2012 American Chemical Society.

  4. Analysis of technologies for natural gas transportation in Brazil: results comparison of the application of payback and NPV (Net Present Value) methods; Analise de tecnologias de transporte de gas natural no Brasil: comparacao dos resultados da aplicacao dos metodos 'payback' e VPL (Valor Presente Liquido)

    Energy Technology Data Exchange (ETDEWEB)

    Baioco, Juliana Souza; Santarem, Clarissa Andrade [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Engenharia de Petroleo; Bone, Rosemarie Broeker; Ferreira Filho, Virgilio Jose Martins [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Engenharia Industrial

    2008-07-01

    The increased demand for natural gas leads to global integration of markets, leading to decisions that cover the various technologies of transportation, noting the specific locations. The transport of natural gas considered more traditional (Liquefied Natural Gas and Pipeline) often unviable economically areas of operation due to cost. In this case, there are alternative technologies to reduce those costs. The article is to compare the technologies of transport, using the methodology of the Net Present Value (VPL) to identify one that has more positive VPL, which is the most profitable. Thus, in search of validate the results of SUBERO et al. (2004) for gas transport by Pipelines, Liquefied Natural Gas and Compressed Natural Gas. In addition, they are compared these results with the method of VPL and with the economic analysis presented in using the payback period of CHANG (2001) and SANTAREM et al. (2007). It was found that the results obtained in Brazil were identical to those obtained by CHANG (2001) and SUBERO et al. (2007), saving only some differences in magnitude due to the specific characteristics of the Brazilian economy. In other words, for the Brazilian case, the technology of Compressed Natural Gas (CNG) was the most economically viable with the method of VPL, followed by technology, Pipeline and Liquefied Natural Gas (LNG), regardless of the interest rates of 10% and 6.5% and periods of 20 and 30 years. The contribution of this work is to show that despite of the method, payback or VPL, the various alternatives for transporting natural gas to Brazil have the same ranking and economic viability. (author)

  5. Demonstration of CO{sub 2} Conversion to Synthetic Transport Fuel at Flue Gas Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Dowson, George R. M. [Chemical and Biological Engineering, The University of Sheffield, Sheffield (United Kingdom); Styring, Peter, E-mail: p.styring@sheffield.ac.uk [Chemical and Biological Engineering, The University of Sheffield, Sheffield (United Kingdom); UK Centre for Carbon Dioxide Utilisation, Department of Chemistry, The University of Sheffield, Sheffield (United Kingdom)

    2017-10-12

    A mixture of 1- and 2-butanol was produced using a stepwise synthesis starting with a methyl halide. The process included a carbon dioxide utilization step to produce an acetate salt which was then converted to the butanol isomers by Claisen condensation of the esterified acetate followed by hydrogenation of the resulting ethyl acetoacetate. Importantly, the CO{sub 2} utilization step uses dry, dilute carbon dioxide (12% CO{sub 2} in nitrogen) similar to those found in post-combustion flue gases. The work has shown that the Grignard reagent has a slow rate of reaction with oxygen in comparison to carbon dioxide, meaning that the costly purification step usually associated with carbon capture technologies can be omitted using this direct capture-conversion technique. Butanol isomers are useful as direct drop-in replacement fuels for gasoline due to their high octane number, higher energy density, hydrophobicity, and low corrosivity in existing petrol engines. An energy analysis shows the process to be exothermic from methanol to butanol; however, energy is required to regenerate the active magnesium metal from the halide by-product. The methodology is important as it allows electrical energy, which is difficult to store using batteries over long periods of time, to be stored as a liquid fuel that fits entirely with the current liquid fuels infrastructure. This means that renewable, weather-dependent energy can be stored across seasons, for example, production in summer with consumption in winter. It also helps to avoid new fossil carbon entering the supply chain through the utilization of carbon dioxide that would otherwise be emitted. As methanol has also been shown to be commercially produced from CO{sub 2}, this adds to the prospect of the general decarbonization of the transport fuels sector. Furthermore, as the conversion of CO{sub 2} to butanol requires significantly less hydrogen than CO{sub 2} to octanes, there is a potentially reduced burden on the so

  6. Demonstration of CO2 Conversion to Synthetic Transport Fuel at Flue Gas Concentrations

    Directory of Open Access Journals (Sweden)

    George R. M. Dowson

    2017-10-01

    Full Text Available A mixture of 1- and 2-butanol was produced using a stepwise synthesis starting with a methyl halide. The process included a carbon dioxide utilization step to produce an acetate salt which was then converted to the butanol isomers by Claisen condensation of the esterified acetate followed by hydrogenation of the resulting ethyl acetoacetate. Importantly, the CO2 utilization step uses dry, dilute carbon dioxide (12% CO2 in nitrogen similar to those found in post-combustion flue gases. The work has shown that the Grignard reagent has a slow rate of reaction with oxygen in comparison to carbon dioxide, meaning that the costly purification step usually associated with carbon capture technologies can be omitted using this direct capture-conversion technique. Butanol isomers are useful as direct drop-in replacement fuels for gasoline due to their high octane number, higher energy density, hydrophobicity, and low corrosivity in existing petrol engines. An energy analysis shows the process to be exothermic from methanol to butanol; however, energy is required to regenerate the active magnesium metal from the halide by-product. The methodology is important as it allows electrical energy, which is difficult to store using batteries over long periods of time, to be stored as a liquid fuel that fits entirely with the current liquid fuels infrastructure. This means that renewable, weather-dependent energy can be stored across seasons, for example, production in summer with consumption in winter. It also helps to avoid new fossil carbon entering the supply chain through the utilization of carbon dioxide that would otherwise be emitted. As methanol has also been shown to be commercially produced from CO2, this adds to the prospect of the general decarbonization of the transport fuels sector. Furthermore, as the conversion of CO2 to butanol requires significantly less hydrogen than CO2 to octanes, there is a potentially reduced burden on the so-called hydrogen

  7. Demonstration of CO2 Conversion to Synthetic Transport Fuel at Flue Gas Concentrations

    International Nuclear Information System (INIS)

    Dowson, George R. M.; Styring, Peter

    2017-01-01

    A mixture of 1- and 2-butanol was produced using a stepwise synthesis starting with a methyl halide. The process included a carbon dioxide utilization step to produce an acetate salt which was then converted to the butanol isomers by Claisen condensation of the esterified acetate followed by hydrogenation of the resulting ethyl acetoacetate. Importantly, the CO 2 utilization step uses dry, dilute carbon dioxide (12% CO 2 in nitrogen) similar to those found in post-combustion flue gases. The work has shown that the Grignard reagent has a slow rate of reaction with oxygen in comparison to carbon dioxide, meaning that the costly purification step usually associated with carbon capture technologies can be omitted using this direct capture-conversion technique. Butanol isomers are useful as direct drop-in replacement fuels for gasoline due to their high octane number, higher energy density, hydrophobicity, and low corrosivity in existing petrol engines. An energy analysis shows the process to be exothermic from methanol to butanol; however, energy is required to regenerate the active magnesium metal from the halide by-product. The methodology is important as it allows electrical energy, which is difficult to store using batteries over long periods of time, to be stored as a liquid fuel that fits entirely with the current liquid fuels infrastructure. This means that renewable, weather-dependent energy can be stored across seasons, for example, production in summer with consumption in winter. It also helps to avoid new fossil carbon entering the supply chain through the utilization of carbon dioxide that would otherwise be emitted. As methanol has also been shown to be commercially produced from CO 2 , this adds to the prospect of the general decarbonization of the transport fuels sector. Furthermore, as the conversion of CO 2 to butanol requires significantly less hydrogen than CO 2 to octanes, there is a potentially reduced burden on the so-called hydrogen economy.

  8. Parametric study of a thermoelectric generator system for exhaust gas energy recovery in diesel road freight transportation

    International Nuclear Information System (INIS)

    Vale, S.; Heber, L.; Coelho, P.J.; Silva, C.M.

    2017-01-01

    Highlights: • 1-D numerical TEG model in diesel freight vehicles exhaust pipe. • Over 800 W of electrical power for the heavy-duty vehicle. • Plain fins provide better performance than offset strip fins. • The height of the thermocouple legs plays a significant role. • 2% maximum efficiency needs further improvements. - Abstract: A parametric study and optimization approaches of a thermoelectric generator (TEG) for the recovery of energy from the exhaust gas in Diesel vehicles used in freight transport is reported. The TEG is installed in the tailpipe of a commercial vehicle (3.5 tonnes) and a heavy-duty vehicle (40 tonnes). The exhaust gas is used as the heat source and the cooling water as the heat sink. Two different heat exchanger configurations are considered: plain fins and offset strip fins. The influence of the height, length and spacing of the fins on the electrical and net power is analysed for the fixed width and length of the TEG. The influence of the length and width of the TEG and of the height of the thermocouple legs is also investigated. According to the criteria used in this study, plain fins are the best choice, yielding a maximum electrical power of 188 W for the commercial vehicle and 886 W for the heavy-duty vehicle. The best recovery efficiency is about 2%, with an average thermoelectric material efficiency of approximately 4.4%, for the light-duty vehicle. Accordingly, there is significant room for further improvement and optimisation based on the thermoelectric modules and the system design.

  9. Life cycle greenhouse gas emission assessment of major petroleum oil products for transport and household sectors in India

    International Nuclear Information System (INIS)

    Garg, Amit; Vishwanathan, Saritha; Avashia, Vidhee

    2013-01-01

    Energy security concerns due to high oil import dependence and climate change concerns due to related greenhouse gas emissions are important policy discussions in India. Could life cycle assessment (LCA) of petroleum oil products provide inputs to crude oil sourcing and domestic oil pricing policies to address the two concerns? This paper presents a baseline study on LCA of petroleum products in India from Well to Storage depending on the oil source, type of refinery, product and the selected destinations. The LCA based GHG emissions are found to be higher by 4–12 per cent than GHG emissions from direct fuel consumption alone for LPG, 7–10 per cent for Gasoline, 3–9 per cent for Diesel and 4–10 per cent for Kerosene based on various supply chain routes supplying oil to six largest cities in India. Overall the energy used in oil exploration, refinery and transportation in the LCA have a share of 72–77 per cent, 11–15 per cent and 6–8 per cent, respectively. The paper proposes imposing a relative carbon cess for various oil products in different Indian cities. States could accommodate this additional carbon cess by reducing their respective state taxes without increasing the final delivery price to the consumers. - Highlights: ► LCA emissions are found to be higher by 4–12 per cent than direct fuel consumption emissions. ► Energy used in oil exploration, refinery and transportation in the LCA have a share of 72–77 per cent, 11–15 per cent and 6–8 per cent, respectively. ► Corresponding GHG emission shares are 60–66 per cent, 23–27 per cent and 5–8 per cent, respectively. ► The source of crude oil matters. E and P energy consumption is found highest for African countries. ► Differential carbon cess could be imposed without changing final delivery price to consumers

  10. Assessment of air quality after the implementation of compressed natural gas (CNG) as fuel in public transport in Delhi, India.

    Science.gov (United States)

    Ravindra, Khaiwal; Wauters, Eric; Tyagi, Sushil K; Mor, Suman; Van Grieken, René

    2006-04-01

    Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM(10), CO, SO(2) and NO(x)) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO(2) and CO concentrations, while the NO(x) level was increased in comparison to those before the implementation of CNG. Further, SPM, PM(10), and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.

  11. Ab initio phonon thermal transport in monolayer InSe, GaSe, GaS, and alloys

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Tribhuwan; Parker, David S.; Lindsay, Lucas

    2017-10-17

    We compare vibrational properties and phonon thermal conductivities (κ) of monolayer InSe, GaSe and GaS systems using density functional theory and Peierls-Boltzmann transport methods. In going from InSe to GaSe to GaS, system mass decreases giving both increasing acoustic phonon velocities and decreasing scattering of these heat-carrying modes with optic phonons, ultimately giving κInSe< κGaSe< κGaS. This behavior is demonstrated by correlating the scattering phase space limited by fundamental conservation conditions with mode scattering rates and phonon dispersions for each material. We also show that, unlike flat monolayer systems such as graphene, thermal transport is governed by in-plane vibrations in InSe, GaSe and GaS, similar to buckled monolayer materials such as silicene. Alloying of InSe, GaSe and GaS systems provides an effective method for modulating their κ through intrinsic vibrational modifications and phonon scattering from mass disorder giving reductions ~2-3.5 times. This disorder also suppresses phonon mean free paths in the alloy systems compared to those in their crystalline counterparts. This work provides fundamental insights of lattice thermal transport from basic vibrational properties for an interesting set of two-dimensional materials.

  12. Network transportation model with capacity restrictions for the Bolivia Brazil gas pipeline influence area; Modelo de transporte em rede com restricoes de capacidade para a area de influencia do Gasoduto Bolivia Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Patricia Mannarino; Carpio, Lucio Guido Tapia [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Planejamento Energetico

    2004-07-01

    We present the application of a network transportation model, with capacity restrictions, to determine the minimal cost of supply of a group of markets at the Bolivia Brazil Gas Pipeline influence area, as a function of city gate price. We consider the potential of integration of pipeline transportation at the South Cone, looking forward to supply the Brazilian market. The city gate price consists of the sum of commodity price plus transportation tariffs over every gas pipeline through which the gas passes (except distribution pipelines). There is no distinction related to product quality (e.g. heating value) among suppliers, or among end uses (thermal, thermoelectric or chemical). The model is numerically solved by linear programming. Flow direction alternatives and transportation tariffs alternatives (postal and by zone) are proposed. The model allows, among other applications: identification of the lowest cost supply strategy, identification of network flow capacity bottlenecks, determination of operation and expansion marginal costs using dual solution analysis, investigation of alternative sceneries through sensibility analysis and appreciation of non-optimal solutions that might be attractive. (author)

  13. Rent distribution effect of a price reduction in the Dutch gas transport market. A scenario analysis of regulatory policy, market form and rent allocation

    Energy Technology Data Exchange (ETDEWEB)

    Van Witteloostuijn, A.; Brakman, S. [University of Groningen, Groningen (Netherlands); Van Marrewijk, C. [Erasmus University Rotterdam, Rotterdam (Netherlands)

    2005-09-15

    As part of the larger energy market deregulation program, the Dutch Office of Energy Regulation (DTe) has developed the habit to force the Dutch gas transport enterprise (Gas Transport Services GTS) to lower its prices. In this report, we simulate the welfare effects of a five per cent transport price reduction. DTe's key argument is that lower gas transport prices will benefit the end-user. Indeed, that might well be the case. However, at least three observations complicate matters substantially: Observation 1: government ownership. GTS is government -owned, and the dominant shipper (Gasunie Trade and Supply) is partly so (50 %). Hence, lost revenues from the gas transport business will all emerge at the debit side of the government's budget, and part of the shippers' rent returns in the government's pockets. Observation 2: imperfect competition. Firms enter into the competitive game to make profits. Shippers are not different. So, apart from in the extreme case of perfect competition (or, more generally, perfect contestability), part of the rents will end up in the pockets of the shippers, rather than the endconsumers. Observation 3: rent export. The Netherlands are not an isolated island in the European gas ocean. Not only is the majority of gas transported in the Netherlands exported to foreign end-users, but apart from that have foreign owners a large stake in Dutch shippers. As a result, given the fact that the Dutch industry is not autarktic, part of the rents will always be distributed, or will always 'leak' away, to foreign consumers and shippers (or their shareholders). These three observations together have three important implications. First, state ownership implies that much rent allocation is simply a matter of circulating money from one government sub-budget to the other (Observation 1). Second, given that the industry is imperfectly competitive, part of the rents will not be passed on to the endconsumers (Observation 2

  14. Task 23 - field studies of the occurrence, transport, and fate of mercury at natural gas industry sites. Topical report, May 1, 1992--December 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J.A.; Harju, J.A.; Kuehnel, V.; Charlton, D.S.

    1998-12-31

    The objective of this research project is to define the occurrence, transport, and fate of mercury in air, water, and soil at natural gas production sites that had been instrumented with mercury-based gas flowmeters in the past. The primary focus of this research was initially on determining the potential for mercury contamination in groundwater at these sites. The scope was later broadened to include determinations of the spatial distribution of mercury in soil. Air concentrations were determined solely as a health and safety routine.

  15. Developing a Natural Gas-Powered Bus Rapid Transit Service: A Case Study on Leadership: Roaring Fork Transportation Authority (Presentation); NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, A.

    2015-03-01

    The Roaring Fork Transportation Authority (RFTA) represents a series of unique successes in alternative fuel deployment by pushing the envelope with innovative solutions. In the last year, RFTA demonstrated the ability to utilize compressed natural gas buses at a range of altitudes, across long distances, in extreme weather conditions and in a modern indoor fueling and maintenance facility - allwhile saving money and providing high-quality customer service. This case study will highlight how the leadership of organizations and communities that are implementing advances in natural gas vehicle technology is paving the way for broader participation.

  16. Gas-liquid two-phase flow behavior in terrain-inclined pipelines for gathering transport system of wet natural gas

    DEFF Research Database (Denmark)

    Yang, Yan; Li, Jingbo; Wang, Shuli

    2018-01-01

    The Volume of Fluid method and Re-Normalisation Group (RNG) k-ε turbulence model were employed to predict the gas-liquid two-phase flow in a terrain-inclined pipeline with deposited liquids. The simulation was carried out in a 22.5 m terrain-inclined pipeline with a 150 mm internal diameter...... on the liquid level under the suction force which caused by the negative pressure around the elbow, and then it touched to the top of the pipe. When the liquid blocked the pipe, the pressure drop between the upstream and downstream of the elbow increased with the increase of the gas velocity. At larger gas...

  17. Preliminary technical and economic viability for the implantation of fluvial transport of CNG (Compressed Natural Gas) for barges in Amazon Region; Avaliacao preliminar de viabilidade tecnico-economica para implantacao de transporte fluvial de GNC (Gas Natual Comprimido) por barcacas na Regiao Amazonica

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Marcos C.C. de; Porto, Paulo L. Lemgruber [Interocean Engenharia e Ship Management, Rio de janeiro, RJ (Brazil); Cunha, Rafael H. da [Metro Rio, RJ (Brazil); Garcia, Rafael M. [Pic Brasil (Brazil); Almeida, Marco A.R. de [Universidade Gama Filho (UGF), Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The isolated regions of the Amazon present difficulties for integration with the electrical system which is creating some economic problems due to the consequent costs of electric generation of subsidies as a function of the fossil fuel use as oils diesel and fuel. A viable option is the use of Natural Gas - NG that is Also available in the region. Its modal of transport possible in the Region North they are for gas-lines or barges. The Compressed Natural Gas transport is distinguished that - CNG for barges was still not tested operationally in Brazil. Soon, to develop a Preliminary Study of Viability Technician - Economic - SVTE for the implantation of fluvial transport of CNG between the cities of Coari and Manaus is basic, therefore it is created strategical alternative for the electric generation in this region. The electric sector, the characteristics of the NG and the transport in this region had been analyzed to support to the work. The gas line and the fluvial transport of CNG for barges in this region are not conflicting, and they in a complementary form can act. The SVTE presented a Liquid Present Value and Internal Tax of very attractive Return justifying its implantation. (author)

  18. Coordination of ministerial actions regarding the use of liquefied natural gas (LNG) as fuel. LNG, a European component of the energy transition in road freight transport

    International Nuclear Information System (INIS)

    Maler, Philippe; Erhardt, Jean-Bernard; Ourliac, Jean-Paul

    2015-09-01

    This report is the third of a series dealing with the coordination of ministerial actions in favor of the use of liquefied natural gas (LNG) as fuel in transports. LNG is an important potential substitute to diesel fuel in road transport and would allow significant abatement of nitrogen oxides emissions. Bio-LNG is ten times less polluting than fossil fuel LNG and thus important efforts are to be made in bio-LNG R and D. An important work has been carried out for adapting EU regulations and standards to LNG vehicles and LNG supply developments. This report presents, first, a summary of the report's recommendations and the aim of this coordination study, and, then, treats more thoroughly of the different coordination aspects: 1 - European framework of energy transition in the road freight transport (differences with maritime transport, CO 2 emissions abatement, trucks pollution and fuel quality standards, trucks technical specifications and equipment, fuel taxes in EU countries); 2 - European policy and national actions in favour of LNG development for road transport (LNG as alternate fuel, the Paris agreement, the French national energy plan); 3 - Environmental benefits of LNG in road transport (public health impacts, nitrogen oxides abatement, divergent views and expertise, LNG and CO 2 abatement measures, bio-LNG environmental evaluation; 4 - LNG development actors in road transport and the administrative coordination (professional organizations, public stakeholders, LNG topics information dissemination at the Ministry); 5 - LNG development in road transport at the worldwide, European and national scales; 6 - European regulations and standards allowing trucks LNG fueling and circulation (standard needs, users information, regulation works); 7 - Common rules to define and implement for personnel training; 8 - reflexion on LNG taxation; 9 - support policy for a road transport LNG supply chain (infrastructures, European financing, lessons learnt from maritime

  19. Gas Transport Through Channels

    Science.gov (United States)

    2009-03-25

    CO., permeability of the red blood cell membrane. Proc. Nail . Acad. Sri. U. S. A. 95, 15815-15820 6. Blank, M. E., and Ehmke, H. (2003) Aquaporin-1...Rh50 (21) and the fungal Amt-1 (22) are consistent with the idea that NH3 passes through a pore in each monomer of the homotrimer. Indeed

  20. A pore structure model for the gas transport property changes, initial oxidation rates and cumulative weight loss of AGR moderator graphite

    International Nuclear Information System (INIS)

    Johnson, P.A.V.

    1985-09-01

    A quantitative model has been developed for the gas transport property variation, cumulative weight loss and initial oxidation rates of AGR moderator graphite. The model utilises the theory of dynamic moments of the pore structure to calculate the changes in physical properties brought about by radiolytic corrosion taking place within the graphite porosity. In order to account for the behaviour of the initial rate curves, and the weight loss data obtained it is necessary to invoke the presence of a group of cylindrical pore and a group of small slab-shaped pores. The latter are methane depleted. This is in addition to the pore group involved in gas transport which is best represented by cylinders of mean radius 2.13 μm. The model satisfactorily predicts the experimental weight loss data obtained from experiments in the DIDO 6V3 and BFB loops. (author)

  1. Structural and magnetic ordering of CrNb3S6 single crystals grown by gas transport method

    Science.gov (United States)

    Borisenko, E. B.; Berezin, V. A.; Kolesnikov, N. N.; Gartman, V. K.; Matveev, D. V.; Shakhlevich, O. F.

    2017-07-01

    Paramagnetic layered semiconductor NbS2 doped with some transition metals can transform into ferromagnetic material. That is why such materials are promising candidates for spintronic devices. It is found that only at certain concentrations of a doping metal T crystallographic ordering is possible, which is essential for magnetic ordering of ternary compounds TNbS2. In particular, CrNb3S6 crystals are studied, which form almost completely ordered superstructure with intercalated Cr between NbS2 layers. The main difficulty in crystal growth is reaching stoichiometry of the compound. This problem is solved in the developed method of two-staged gas transport chemical reaction. This new approach provides growth of CrNb3S6 single crystals of several millimeters in diameter and 0.3-0.5 mm thickness. X-ray phase analysis (XRD) of powders is performed to identify all phases involved in synthesis and growth of the crystals. High frequency absorption in external periodic magnetic field as a function of temperature and intensity of magnetic field is used to estimate the temperature of ferromagnetic transition in CrNb3S6 single crystals. The Curie temperature is estimated as 115 K. Growth of CrNb3S6 crystals from vapor phase is studied in detail and full analysis of phase transitions during growth is given. It has been shown that using of high frequency absorption in the crystal provides reliable estimation of the point of ferromagnetic transition in this semiconductor. The authors are grateful to the Physical Science Department of Russian Academy of Sciences for financial support of the studies in the frameworks of the program "Physics of new materials and structures" (project no. 00-12-10).

  2. Future methane emissions from the heavy-duty natural gas transportation sector for stasis, high, medium, and low scenarios in 2035.

    Science.gov (United States)

    Clark, Nigel N; Johnson, Derek R; McKain, David L; Wayne, W Scott; Li, Hailin; Rudek, Joseph; Mongold, Ronald A; Sandoval, Cesar; Covington, April N; Hailer, John T

    2017-12-01

    Today's heavy-duty natural gas-fueled fleet is estimated to represent less than 2% of the total fleet. However, over the next couple of decades, predictions are that the percentage could grow to represent as much as 50%. Although fueling switching to natural gas could provide a climate benefit relative to diesel fuel, the potential for emissions of methane (a potent greenhouse gas) from natural gas-fueled vehicles has been identified as a concern. Since today's heavy-duty natural gas-fueled fleet penetration is low, today's total fleet-wide emissions will be also be low regardless of per vehicle emissions. However, predicted growth could result in a significant quantity of methane emissions. To evaluate this potential and identify effective options for minimizing emissions, future growth scenarios of heavy-duty natural gas-fueled vehicles, and compressed natural gas and liquefied natural gas fueling stations that serve them, have been developed for 2035, when the populations could be significant. The scenarios rely on the most recent measurement campaign of the latest manufactured technology, equipment, and vehicles reported in a companion paper as well as projections of technology and practice advances. These "pump-to-wheels"(PTW) projections do not include methane emissions outside of the bounds of the vehicles and fuel stations themselves and should not be confused with a complete wells-to-wheels analysis. Stasis, high, medium, and low scenario PTW emissions projections for 2035 were 1.32%, 0.67%, 0.33%, and 0.15% of the fuel used. The scenarios highlight that a large emissions reductions could be realized with closed crankcase operation, improved best practices, and implementation of vent mitigation technologies. Recognition of the potential pathways for emissions reductions could further enhance the heavy-duty transportation sectors ability to reduce carbon emissions. Newly collected pump-to-wheels methane emissions data for current natural gas technologies

  3. Effects of surface roughness and cross-sectional distortion on the wind-induced response of bridge cables in dry conditions

    DEFF Research Database (Denmark)

    Matteoni, G.; Georgakis, Christos T.

    2015-01-01

    by local alterations of their inherent surface roughness and shape. Small deviations from ideal circularity result in significant changes in the static drag and lift coefficients with Reynolds number. The present study focuses on the wind-induced response of a full-scale yawed bridge cable section model......, for varying Reynolds numbers and wind angles-of-attack. Using passive-dynamic wind tunnel tests, it is shown that the in-plane aerodynamic damping of a bridge cable section, and the overall dynamic response, is strongly affected by changes in the wind angle-of-attack. Using the drag and lift coefficients...

  4. Pore network modeling to explore the effects of compression on multiphase transport in polymer electrolyte membrane fuel cell gas diffusion layers

    Science.gov (United States)

    Fazeli, Mohammadreza; Hinebaugh, James; Fishman, Zachary; Tötzke, Christian; Lehnert, Werner; Manke, Ingo; Bazylak, Aimy

    2016-12-01

    Understanding how compression affects the distribution of liquid water and gaseous oxygen in the polymer electrolyte membrane fuel cell gas diffusion layer (GDL) is vital for informing the design of improved porous materials for effective water management strategies. Pore networks extracted from synchrotron-based micro-computed tomography images of compressed GDLs were employed to simulate liquid water transport in GDL materials over a range of compression pressures. The oxygen transport resistance was predicted for each sample under dry and partially saturated conditions. A favorable GDL compression value for a preferred liquid water distribution and oxygen diffusion was found for Toray TGP-H-090 (10%), yet an optimum compression value was not recognized for SGL Sigracet 25BC. SGL Sigracet 25BC exhibited lower transport resistance values compared to Toray TGP-H-090, and this is attributed to the additional diffusion pathways provided by the microporous layer (MPL), an effect that is particularly significant under partially saturated conditions.

  5. Sorption of colloids, organics, and metals onto gas-water interfaces: Transport mechanisms and potential remediation technology. 1998 annual progress report

    International Nuclear Information System (INIS)

    Tokunaga, T.K.; Wan, J.

    1998-01-01

    'Although contaminant sorption at mineral surfaces has received much recognition as a major mechanism controlling contaminant behavior in subsurface environments, virtually no attention has been given to the possibility of contaminant sorption at gas-water interfaces. Moreover, no effort has yet been advanced to optimize such interactions for the purpose of facilitating in-situ remediation. Gas-water interfaces, unlike water-solid interfaces, are mobile. Therefore, associations of contaminants with gas-water interfaces can be very important not only in subsurface contaminant distributions, but also in contaminant transport, and potentially in remediation. The first objective of this research is to develop a quantitative understanding of interactions between contaminants and gas-water interfaces. The anticipated results will provide insights into the poorly understood phenomenon of contaminant interactions with the gas-water interface, and improve the current conceptual models of contaminant behavior in subsurface environments. The second purpose of this research is to explore the possibility of using surfactant stabilized microbubbles for in-situ remediation. Both pump-and-treat, and air sparging remediation methods are ineffective at displacing contaminants in zones which are advectively inaccessible. Stable microbubbles can migrate beyond preferential flow pathways and enter lower permeability zones by buoyant rise. The microbubbles can deliver oxygen and nutrients for promoting aerobic degradation of organic contaminants, and also deliver surfactants for emulsifying NAPLs.'

  6. Natural gas marketing II

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book covers all aspects of gas marketing, from the basic regulatory structure to the latest developments in negotiating agreements and locating markets. Topics include: Federal regulation of the gas industry; Fundamentals of gas marketing contracts; FERC actions encouraging competitive markets; Marketing conditions from the pipelines' perspective; State non-utility regulation of natural gas production, transportation, and marketing; Natural gas wellhead agreements and tariffs; Natural gas processing agreements; Effective management of producer's natural gas contracts; Producer-pipeline litigation; Natural gas purchasing from the perspective of industrial gas users; Gas marketing by co-owners: problems of disproportionate sales, gas balancing, and accounting to royalty owners; Alternatives and new directions in marketing

  7. A 3-D functional-structural grapevine model that couples the dynamics of water transport with leaf gas exchange.

    Science.gov (United States)

    Zhu, Junqi; Dai, Zhanwu; Vivin, Philippe; Gambetta, Gregory A; Henke, Michael; Peccoux, Anthony; Ollat, Nathalie; Delrot, Serge

    2017-12-23

    Predicting both plant water status and leaf gas exchange under various environmental conditions is essential for anticipating the effects of climate change on plant growth and productivity. This study developed a functional-structural grapevine model which combines a mechanistic understanding of stomatal function and photosynthesis at the leaf level (i.e. extended Farqhuhar-von Caemmerer-Berry model) and the dynamics of water transport from soil to individual leaves (i.e. Tardieu-Davies model). The model included novel features that account for the effects of xylem embolism (fPLC) on leaf hydraulic conductance and residual stomatal conductance (g0), variable root and leaf hydraulic conductance, and the microclimate of individual organs. The model was calibrated with detailed datasets of leaf photosynthesis, leaf water potential, xylem sap abscisic acid (ABA) concentration and hourly whole-plant transpiration observed within a soil drying period, and validated with independent datasets of whole-plant transpiration under both well-watered and water-stressed conditions. The model well captured the effects of radiation, temperature, CO2 and vapour pressure deficit on leaf photosynthesis, transpiration, stomatal conductance and leaf water potential, and correctly reproduced the diurnal pattern and decline of water flux within the soil drying period. In silico analyses revealed that decreases in g0 with increasing fPLC were essential to avoid unrealistic drops in leaf water potential under severe water stress. Additionally, by varying the hydraulic conductance along the pathway (e.g. root and leaves) and changing the sensitivity of stomatal conductance to ABA and leaf water potential, the model can produce different water use behaviours (i.e. iso- and anisohydric). The robust performance of this model allows for modelling climate effects from individual plants to fields, and for modelling plants with complex, non-homogenous canopies. In addition, the model provides a

  8. The pipeline transportation of natural gas and the regulation of open access in Brazil: historical perspectives and current; Os dutos de transporte do gas natural e a regulacao do livre acesso no Brasil: perspectivas historicas e atuais

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Mariana de; Xavier, Yanko Marcius de Alencar [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The present research, attempting for the economic relevance of the natural gas sector, for the inexistence of a law that disciplines it and, still, for the structural question of the natural gas ducts activity; it analyzes the monopoly of the natural gas ducts activity and the mechanism of competition chosen to brighten up it: the open access. The regulation of the open access and the viability that the insert of this practice has to Brazil nowadays are very important points to be discussed and, in that way, the present research also analyses them. (author)

  9. Waste-to-Fuel: A Case Study of Converting Food Waste to Renewable Natural Gas as a Transportation Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mintz, Marianne [Argonne National Lab. (ANL), Argonne, IL (United States); Tomich, Matthew [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-05-01

    This case study explores the production and use of renewable compressed natural gas (R-CNG)—derived from the anaerobic digestion (AD) of organic waste—to fuel heavy-duty refuse trucks and other natural gas vehicles in Sacramento, California.

  10. System of large transport containers for waste from dismantling light water and gas-cooled nuclear reactors. Volume 2

    International Nuclear Information System (INIS)

    Price, M.S.T.

    1986-09-01

    This report deals with the operational, radiological and economic aspects of transport as well as conceptual designs of large containers for the transport of radioactive decommissioning wastes from nuclear power plants within the member states of the European Economic Community. The means of transport, the costs and radiological detriment are considered, and conceptual designs of containers are described. Recommendations are made for further studies. (U.K.)

  11. Experimental study of gas and water transport processes in the inter-cleat (matrix) system of coal: Anthracite from Qinshui Basin, China

    Energy Technology Data Exchange (ETDEWEB)

    Han, Fengshuang [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, 030001 Taiyuan (China); Graduate University of Chinese Academy of Sciences, 100049 Beijing (China); Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, D-52056 Aachen (Germany); Busch, Andreas; van Wageningen, Niels [Shell International Exploration and Production B.V., 2288 GS Rijswijk-ZH (Netherlands); Yang, Jianli; Liu, Zhenyu [State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, 030001 Taiyuan (China); Krooss, Bernhard M. [Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, D-52056 Aachen (Germany)

    2010-02-01

    The operation and numerical simulation of CO{sub 2}-ECBM processes requires a thorough understanding of the fluid conductivity properties of the coal matrix. Therefore, single phase (water) and two-phase (water and gas) fluid flow tests on a cylindrical anthracite coal matrix plug of 28.5 mm in diameter and about 20 mm in length were conducted in a triaxial flow cell at a confining pressure and axial load of 20 MPa. The absolute permeability coefficient, determined by single phase steady-state water flow tests, was about 2.0 circle 10{sup -} {sup 20} m{sup 2} (20 nDarcy). Two-phase flow tests (''gas breakthrough tests'') were performed by imposing high differential gas pressures (up to 7 MPa) on the water-saturated sample and monitoring the pressure changes over time in closed upstream and downstream reservoirs. Argon (Ar), methane (CH{sub 4}) and carbon dioxide (CO{sub 2}) showed significant differences in their pressure transient curves during gas breakthrough tests, which indicated different controlling processes. The inert gas Ar exhibited capillary pressure-controlled breakthrough behavior. The maximum effective permeability, measured after gas breakthrough at maximum gas saturation, was 1.8 circle 10{sup -} {sup 21} m{sup 2} (1.8 nDarcy); a residual pressure difference referred to as the ''capillary threshold pressure'' was 0.9 MPa for the Ar-water-coal system. The sorbing gas CH{sub 4} exhibited solely diffusion-controlled transport behavior, and no indications of capillary pressure effects. The reactive and sorbing gas CO{sub 2} showed initially capillary pressure-controlled and subsequently diffusion-controlled breakthrough behavior. The mass balance of the gas breakthrough tests indicated that the bulk of CO{sub 2} and CH{sub 4} were taken up by the coal sample. Sorption accounted for the strong uptake of CH{sub 4} by the coal sample, whereas both sorption and, to a lesser extent, CO{sub 2}-water-mineral reactions

  12. A new, fully coupled, reaction-transport-mechanical approach to modeling the evolution of natural gas reservoirs in the Piceance Basin

    Science.gov (United States)

    Payne, Dorothy Frances

    The Piceance Basin is highly compartmented, and predicting the location and characteristics of producible reservoirs is difficult. Gas generation is an important consideration in quality and size of natural gas reserves, but it also may contribute to fracturing, and hence the creation of the reservoirs in which it is contained. The purpose of this dissertation is to use numerical modeling to study the evolution of these unconventional natural gas reservoirs in the Piceance Basin. In order to characterize the scale and structure of compartmentation in the Piceance Basin, a set of in-situ fluid pressure data were interpolated across the basin and the resulting fluid pressure distribution was analyzed. Results show complex basin- and field-scale compartmentation in the Upper Cretaceous units. There are no simple correlations between compartment location and such factors as stratigraphy, basin structure, or coal thickness and maturity. To account for gas generation in the Piceance Basin, a new chemical kinetic approach to modeling lignin maturation is developed, based primarily on structural transformations of the lignin molecule observed in naturally matured samples. This model calculates mole fractions of all species, functional group fractions, and elemental weight percents. Results show reasonable prediction of maturities at other sites in the Piceance Basin for vitrinite reflectance up to about 1.7 %Ro. The flexible design of the model allows it to be modified to account for compositionally heterogeneous source material. To evaluate the role of gas generation in this dynamical system, one-dimensional simulations have been performed using the CIRFB reaction-transport-mechanical (RTM) simulator. CIRFB accounts for compaction, fracturing, hydrocarbon generation, and multi-phase flow. These results suggest that by contributing to overpressure, gas generation has two important implications: (1) gas saturation in one unit affects fracturing in other units, thereby

  13. Coordination of ministerial actions regarding the use of liquefied natural gas (LNG) as fuel. River transport, an asset to LNG use development in the energy transition framework

    International Nuclear Information System (INIS)

    Maler, Philippe; Erhardt, Jean-Bernard

    2016-10-01

    This report is the fourth of a series dealing with the coordination of ministerial actions in favor of the use of liquefied natural gas (LNG) as fuel in transports. LNG is an important potential substitute to diesel fuel in road transport and would allow significant abatement of nitrogen oxides emissions. Bio-LNG is ten times less polluting than fossil fuel LNG and thus important efforts are to be made in bio-LNG R and D. An important work has been carried out for adapting EU regulations and standards to LNG vehicles and LNG supply developments. This report presents, first, a summary of the report's recommendations and the aim of this coordination study, and, then, treats more thoroughly of the different coordination aspects: 1 - Environmental policies undertaken by the EU and by the Central commission of Rhine river navigation, role of LNG (environmental programs, directives, authorizations, technical specifications); 2 - LNG fuel development over the rest of the French river system (projects, subsidies, financing requests, French projects in progress); 3 - differentiated development of LNG as river transport fuel in France (French river transport economical specificities, conditions, geographical differences in the access to the resource); 4 - the 2014/94/UE alternate fuels directive from October 22, 2014 and its potential impacts on LNG development in river transport (directive enforcement, scenarios, project, national guidance scheme)

  14. MODELING OF FLOW AND TRANSPORT INDUCED BY PRODUCTION OF HYDROFRACTURE-STIMULATED GAS WELLS NEAR THE RULISON NUCLEAR TEST

    Energy Technology Data Exchange (ETDEWEB)

    Hodges, Rex A. [Navarro Research and Engineering; Cooper, Clay [Desert Research Inst. (DRI), Reno, NV (United States); Falta, Ronald [Clemson Univ., SC (United States)

    2012-09-17

    The Piceance Basin in western Colorado contains significant reserves of natural gas in poorly connected, low-permeability (tight) sandstone lenses of the Mesaverde Group. The ability to enhance the production of natural gas in this area has long been a goal of the oil and gas industry. The U.S. Atomic Energy Commission, a predecessor agency to the U.S. Department of Energy (DOE) and the U.S. Nuclear Regulatory Commission, participated in three tests using nuclear detonations to fracture tight formations in an effort to enhance gas production. The tests were conducted under Project Plowshare, a program designed to identify peaceful, beneficial uses for nuclear devices. The first, Project Gasbuggy, was conducted in 1967 in the San Juan Basin of New Mexico. The two subsequent tests, Project Rulison in 1969 and Project Rio Blanco in 1973, were in the Piceance Basin. The ability to enhance natural gas production from tight sands has become practical through advances in hydraulic fracturing technology (hydrofracturing). This technology has led to an increase in drilling activity near the Rulison site, raising concerns that contamination currently contained in the subsurface could be released through a gas well drilled too close to the site. As wells are drilled nearer the site, the DOE Office of Legacy Management has taken the approach outlined in the June 2010 Rulison Path Forward document (DOE 2010), which recommends a conservative, staged approach to gas development. Drillers are encouraged to drill wells in areas with a low likelihood of encountering contamination (both distance and direction from the detonation zone are factors) and to collect data from these wells prior to drilling nearer the site’s 40 acre institutional control boundary (Lot 11). Previous modeling results indicate that contamination has been contained within Lot 11 (Figure 1). The Path Forward document couples the model predictions with the monitoring of gas and produced water from the gas wells

  15. Design studies of an electrostatic quadrupole channel for transport of a high-brightness H- beam and comparison with gas focusing

    International Nuclear Information System (INIS)

    Chang, C.R.; Horowitz, E.; Reiser, M.

    1989-01-01

    Transport of low-energy, high-brightness H - beams from the ion source to the radio-frequency quadrupole (RFQ) accelerator requires the solution of several physics and engineering problems to avoid particle losses and emittance growth. The authors developed a conceptual design of an electrostatic quadrupole channel for transport of a 120 keV, 120 mA, H - beam into a 425 MHz RFQ with low emittance growth and high transmission efficiency. This design satisfies several constraints imposed by voltage breakdown and beam optics considerations. The system will consist entirely of electrostatic lenses which prevent plasma build-up and eliminate possible emittance growth from plasma fluctuations. Pertinent design features a worst case non-linear analysis for the electrostatic quadrupole channel, and first results of a particle simulation code used to study beam loss and emittance growth are reported. As an alternative to the electrostatic quadrupole concept, gas focusing is being investigated for transporting low-energy H - beams. Recent results from the numerical simulations of such a gas focussing channel are presented

  16. An assessment of energy and environmental issues related to the use of gas-to-liquid fuels in transportation

    International Nuclear Information System (INIS)

    Greene, D.L.

    1999-01-01

    Recent technological advances in processes for converting natural gas into liquid fuels, combined with a growing need for cleaner, low-sulfur distillate fuel to mitigate the environmental impacts of diesel engines have raised the possibility of a substantial global gas-to-liquids (G-T-L) industry. This report examines the implications of G-T-L supply for U.S. energy security and the environment. It appears that a G-T-L industry would increase competitiveness in world liquid fuels markets, even if OPEC states are major producers of G-T-L's. Cleaner G-T-L distillates would help reduce air pollution from diesel engines. Implications for greenhouse gas (GHG) emissions could be positive or negative, depending on the sources of natural gas, their alternative uses, and the degree of sequestration that can be achieved for CO 2 emissions produced during the conversion process

  17. An assessment of energy and environmental issues related to the use of gas-to-liquid fuels in transportation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D.L.

    1999-11-01

    Recent technological advances in processes for converting natural gas into liquid fuels, combined with a growing need for cleaner, low-sulfur distillate fuel to mitigate the environmental impacts of diesel engines have raised the possibility of a substantial global gas-to-liquids (G-T-L) industry. This report examines the implications of G-T-L supply for U.S. energy security and the environment. It appears that a G-T-L industry would increase competitiveness in world liquid fuels markets, even if OPEC states are major producers of G-T-L's. Cleaner G-T-L distillates would help reduce air pollution from diesel engines. Implications for greenhouse gas (GHG) emissions could be positive or negative, depending on the sources of natural gas, their alternative uses, and the degree of sequestration that can be achieved for CO{sub 2} emissions produced during the conversion process.

  18. An Assessment of Energy and Environmental Issues Related to the Use of Gas-to-Liquid Fuels in Transportation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D.L.

    1999-11-01

    Recent technological advances in processes for converting natural gas into liquid fuels, combined with a growing need for cleaner, low-sulfur distillate fuel to mitigate the environmental impacts of diesel engines have raised the possibility of a substantial global gas-to-liquids (G-T-L) industry. This report examines the implications of G-T-L supply for U.S. energy security and the environment. It appears that a G-T-L industry would increase competitiveness in world liquid fuels markets, even if OPEC states are major producers of G-T-L's. Cleaner G-T-L distillates would help reduce air pollution from diesel engines. Implications for greenhouse gas (GHG) emissions could be positive or negative, depending on the sources of natural gas, their alternative uses, and the degree of sequestration that can be achieved for CO2 emissions produced during the conversion process.

  19. Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms

    OpenAIRE

    Guo, Chaohua; Wei, Mingzhen; Liu, Hong

    2018-01-01

    Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hyd...

  20. Insights into contaminant transport from unconventional oil and gas developments from analog system analysis of methane-bearing thermal springs in the northern Canadian Rocky Mountains

    Science.gov (United States)

    Ferguson, Grant; Grasby, Stephen E.

    2018-03-01

    Natural gas is currently being produced from shales of the Montney and Liard basins in western Canada. Production requires hydraulic fracturing due to the low permeability of the shales in the basins. Stratigraphically equivalent shales are present in the northern Canadian Rocky Mountains. Thermal springs with notable hydrocarbon concentrations occur where large-scale faults intersect the same shale units that are the focus of gas development, indicating that under certain circumstances, connection of deep fractured shales to the land surface is possible. To constrain these conditions, simulations were conducted for the spring with the highest hydrocarbon flux (Toad River Spring), results of which indicate that in order to supply sufficient water to a fault to support measurable advection, the effective permeability of the shales in these structurally deformed areas must be one to four orders of magnitude higher than in areas of active gas production to the east. The spatial scale of enhanced permeability is much greater than that which is achieved by hydraulic fracturing and the mechanism of maintaining high pressures at depth is more persistent in time. Examination of groundwater velocities suggests that upward migration of solutes from hydraulic fracturing may take decades to centuries. Results also indicate that any temperature anomaly will be associated with transport along a fault at such velocities. No such temperature anomaly has been documented in regions with unconventional oil and gas development to date. Such an anomaly would be diagnostic of a deep solute source.

  1. Polymer pipes for distributing mixtures of hydrogen and natural gas. Evolution of their transport and mechanical properties after an ageing under an hydrogen environment

    Energy Technology Data Exchange (ETDEWEB)

    Klopffer, Marie-Helene [IFP (France); Berne, Philippe [CEA (France); Castagnet, Sylvie [ENSMA (France); Weber, Mathilde [Air Liquide (Canada); Hochstetter, Gilles [Arkema (France); Espuche, Eliane [INSA Lyon (France)

    2010-07-01

    With the development of hydrogen as an energy vector, its delivery and transport from the production site to the end user remains an issue. Indeed, the key challenge to overcome is the high hydrogen permeation through existing polymer infrastructures used for natural gas distribution (Polyethylene pipes, components as connecting parts). This high flow rate of hydrogen through polymer has to be taken into account for safety and economical requirements. This 3-year project investigates pure hydrogen gas and mixtures (20% CH4 - 80% H2) in pipelines made of engineering polymers to develop and assess material solutions to cope with today problems for H2 distribution. Materials such as polyethylene (PE100) and polyamide 11 (PA11) have been studied. PE100 is considered as a reference material as it is used today in natural gas distribution pipes. PA11 should allow a higher operating pressure combined with better gas-barrier performances. Test benches and protocols for testing materials in terms of mechanical and barrier properties were first developed. The materials have then been studied in terms of barrier, mechanical properties and on a microstructural point of view. The properties of the raw material and samples after ageing in presence of hydrogen in various conditions were compared to assess the long term behaviour in service. These results as well as the comparison between PA11 and PE are presented. (orig.)

  2. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    Science.gov (United States)

    Ars, Sébastien; Broquet, Grégoire; Yver Kwok, Camille; Roustan, Yelva; Wu, Lin; Arzoumanian, Emmanuel; Bousquet, Philippe

    2017-12-01

    This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping with the distances

  3. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    Directory of Open Access Journals (Sweden)

    S. Ars

    2017-12-01

    Full Text Available This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping

  4. Challenges of conservation agriculture practices on silty soils. Effects on soil pore and gas transport characteristics in North-eastern Italy

    DEFF Research Database (Denmark)

    Piccoli, Ilaria; Schjønning, Per; Lamandé, Mathieu

    2017-01-01

    characteristics. The poor structural stability of Veneto soils, particularly the poor soil organic carbon content, could prevent the exploitation of CA practices firstly on soil structure and in turn on gas exchanges. For these reasons further studies elucidating the mechanisms improving soil structural......Soil air exchange is one of the most important soil functions that directly impacts on crop productivity and environment. Generally, conservation agriculture (CA) practices are expected to provide improved soil aeration but contrasting texture-related effects were found in the literature. The aim...... of this study was to evaluate the effect of CA practices on gas transport characteristics in the silty soils of the Veneto Region (North-Eastern Italy). In 2010, a field experiment comparing CA practices (no-tillage, cover crop and residues retention) to conventional intensive tillage (IT) system...

  5. Development of a equipment to measure gas transport properties: Application to study candidate buffer mixtures for low-medium level waste repositories

    International Nuclear Information System (INIS)

    Martin, P. L.; Barcala, J. M.; Oller, J. C.

    2002-01-01

    This report describes the design, the construction and a testing of a system set-up for the measurement of gas transport, created at CIEMAT, and its application to study mixtures of candidate buffer materials for Low-Medium Level Waste Repertories. The measure of the gas flows is carried on by mass flow meters of several ranges, white the pressure of the applied within the sample is controlled. Two National l Instrument's acquisition system that permits the control and recording of the parameters. A specific application developed for this test, with National Instruments LabWIEW DSC, permits to mange the system. A client interface lets to follow the experiment course from a remote location through Internet. (Author) 21 refs

  6. Development of a Equipment to Measure Gas Transport Properties: Application to Study Mixtures of Candidates Buffer Materials for Low-Medium Level Waste Repositories

    Energy Technology Data Exchange (ETDEWEB)

    Martin, P.L.; Barcala, J.M.; Oller, J.C.

    2002-07-01

    This report describes the design, the construction and a testing of a system set-up for the measurement of gas transport, created at CIEMAT, and its application to study mixtures of candidate buffer materials for Low-Medium Level Waste Repertories. The measure of the gas flows is carried on by mass flow meters of several ranges, white the pressure of the applied within the sample is controlled. Two National l Instrument's acquisition system that permits the control and recording of the parameters. A specific application developed for this test, with National Instruments LabWIEW DSC, permits to mange the system. A client interface lets to follow the experiment course from a remote location through Internet. (Author) 21 refs.

  7. Scenarios of high greenhouse gas emission reduction in transports and buildings by 2050; Scenarios de forte reduction des emissions de gaz a effet de serre dans les transports et les batiments a l'horizon 2050

    Energy Technology Data Exchange (ETDEWEB)

    Teissier, O.; Meunier, L. [Commissariat General au Developpement durable (CGDD/SEEIDD), 75 - Paris (France)

    2008-07-01

    The authors report simulations of different environmental policy measures concerning transports and buildings in France. First, they review measures which may entail a reduction of greenhouse gas emissions, and comment their emission reduction potential and their implementation costs. These measures are then ranked, and only those presenting a significant potential and an economically and technologically feasibility are finally considered. Their impact is then simulated by using different models which are adapted to the both sectors and to time ranges. The obtained results are compared to those obtained with a calibrated trend scenario and with a 'factor 4' scenario.

  8. Proyección de costos de un bus articulado con motor dedicado a gas natural para ser utilizado en los sistemas de transporte masivo de colombia

    OpenAIRE

    MANTILLA, JUAN; ACEVEDO, HELMER; DUQUE, CARLOS; GALEANO, CARLOS; CARRION, SERGIO

    2009-01-01

    El objetivo del presente trabajo es mostrar los resultados del estudio comparativo de costos entre dos buses articulados que operan con diferentes combustibles, gas natural comprimido y diesel. Los resultados se utilizarán para establecer la viabilidad económica de la implementación de flotas de este tipo de buses en los sistemas de transporte masivo de las grandes ciudades colombianas. La proyección se realizó siguiendo las recomendaciones de operación y mantenimiento dadas por los fabricant...

  9. Separation Method for Oxygen Mass Transport Coefficient in Two Phase Porous Air Electrodes - Transport in Gas and Solid Polymer or Liquid Electrolyte Phases

    Science.gov (United States)

    2013-08-06

    of the problem studied Proton exchange membrane fuel cells ( PEMFCs ) are the most promising candidate systems for alternative electricity...characteristic. The limiting current can be used as a tool to study mass transport phenomena in PEMFC because it can provide experimental data for the...coefficient for PEMFCs under in situ conditions based on the galvanostatic discharge of a cell with an interrupted reactant supply. The results indicated

  10. Application of a three-dimensional aeroelastic model to study the wind-induced response of bridge stay cables in unsteady wind conditions

    Science.gov (United States)

    Raeesi, Arash; Cheng, Shaohong; Ting, David S.-K.

    2016-08-01

    The possibility of bridge stay cables experiencing violent dry inclined cable galloping raises great concern in the engineering community. Numerous experimental and analytical studies have been conducted to investigate this phenomenon, most of which were in the context of steady wind past a rigid cylindrical body. Real stay cables however, are generally long and flexible. They are exposed to more "broad" range of atmospheric boundary layer type of wind velocity profile which is also unsteady and turbulent by nature. To better understand the physics underlying this type of wind-induced cable vibration and to elucidate various contributing factors, a more realistic analytical model which is capable of addressing the above elements is imperative. In the current paper, a three-dimensional aeroelastic model is proposed to study the aerodynamic response of an inclined and/or yawed slender flexible cylindrical body subjected to unsteady mean wind, with practical application to wind-induced vibrations of bridge stay cables under no precipitation condition. The non-linear aerodynamic forces derived in the present study are combined with the cable free vibration equations available in literature to obtain the equations of motion for the wind-induced vibration of stay cables, which are solved numerically by an explicit finite difference scheme. The proposed three-dimensional aeroelastic model and numerical solution technique are validated by comparing the predicted cable free vibration responses with existing data in the literature. The mechanism which triggers dry inclined cable galloping and the required conditions for its growth are explored. In addition, the impact of different initial conditions and various unsteady mean wind scenarios on this violent cable motion are investigated. Results show that the occurrence of dry inclined cable galloping is associated with an opposite-phase relation between the relative wind speed and the aerodynamic force along the direction of

  11. Long-term optimization of the transport sector to address greenhouse gas reduction targets under rapid growth. Application of an energy system model for Gauteng province, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Tomaschek, Jan

    2013-12-11

    The transport sector is seen as one of the key factors for driving future energy consumption and greenhouse gas (GHG) emissions. Especially in developing countries, significant growth in transport demand is expected. Gauteng province, as the economic centre of South Africa and transport hub for the whole of southern Africa, is one emerging urban region that faces rapid growth. However, the province is on its way to playing a leading role for supporting ways to adapt to climate change and mitigate GHG emissions. Conversely, there is a lack of scientific research on the promising measures for GHG mitigation in the transport sector. For the rapidly growing transport sector of the province in particular, research is focused primarily on extending and structuring the road infrastructure. Moreover, it is important that the transport sector is considered as part of the whole energy system, as significant contributions to GHG emissions and the associated costs arise from energy supply, provision and conversion. This research is the first application of an integrated energy system model (i.e. the TIMES-GEECO model) for the optimization of the transport sector of Gauteng. Optimizing energy system models allows finding least-cost measures for various scenarios, by considering dependencies and interlinkages in the energy system as well as environmental constraints. To do so, the transport sector and the energy supply sector had to be incorporated into the model application in terms of the characteristics of a developing urban region, which includes all relevant transport modes, vehicle technologies, fuel options, vehicle-to-grid energy storage, the consideration of road types as well as explicit expansions of the public transport system and income-dependent travel demand modelling. Additionally, GHG mitigation options outside the provincial boundaries were incorporated to allow for mitigation at least cost and to consider regional resource availability. Moreover, in TIMES

  12. Long-term optimization of the transport sector to address greenhouse gas reduction targets under rapid growth. Application of an energy system model for Gauteng province, South Africa

    International Nuclear Information System (INIS)

    Tomaschek, Jan

    2013-01-01

    The transport sector is seen as one of the key factors for driving future energy consumption and greenhouse gas (GHG) emissions. Especially in developing countries, significant growth in transport demand is expected. Gauteng province, as the economic centre of South Africa and transport hub for the whole of southern Africa, is one emerging urban region that faces rapid growth. However, the province is on its way to playing a leading role for supporting ways to adapt to climate change and mitigate GHG emissions. Conversely, there is a lack of scientific research on the promising measures for GHG mitigation in the transport sector. For the rapidly growing transport sector of the province in particular, research is focused primarily on extending and structuring the road infrastructure. Moreover, it is important that the transport sector is considered as part of the whole energy system, as significant contributions to GHG emissions and the associated costs arise from energy supply, provision and conversion. This research is the first application of an integrated energy system model (i.e. the TIMES-GEECO model) for the optimization of the transport sector of Gauteng. Optimizing energy system models allows finding least-cost measures for various scenarios, by considering dependencies and interlinkages in the energy system as well as environmental constraints. To do so, the transport sector and the energy supply sector had to be incorporated into the model application in terms of the characteristics of a developing urban region, which includes all relevant transport modes, vehicle technologies, fuel options, vehicle-to-grid energy storage, the consideration of road types as well as explicit expansions of the public transport system and income-dependent travel demand modelling. Additionally, GHG mitigation options outside the provincial boundaries were incorporated to allow for mitigation at least cost and to consider regional resource availability. Moreover, in TIMES

  13. Plasma confinement modification and convective transport suppression in the scrape-off layer using additional gas puffing in the STOR-M tokamak

    International Nuclear Information System (INIS)

    Dreval, M; Hubeny, M; Ding, Y; Onchi, T; Liu, Y; Hthu, K; Elgriw, S; Xiao, C; Hirose, A

    2013-01-01

    The influence of short gas puffing (GP) pulses on the scrape-off layer (SOL) transport is studied. Similar responses of ion saturation current and floating potential measured near the GP injection valve and in the 90° toroidally separated cross-section suggest that the GP influence on the SOL region should be global. A drop in plasma temperature and a decrease in the rotational velocity of the plasma are observed in the SOL region immediately after the GP pulse; however, an unexpected increase in electron and ion temperatures is observed in the second stage of the plasma response. The decrease in floating potential fluctuations indicates that the turbulent transport is dumped immediately after the GP pulse. The GP-induced modification of turbulence properties in the SOL points to a convective transport suppression in the STOR-M tokamak. A substantial decrease in the skewness and kurtosis of ion saturation current fluctuations is observed in the SOL region resulting in the probability distribution function (PDF) getting closer to the Gaussian distribution. The plasma potential reduction, the change in plasma rotation and the suppression of turbulent transport in the SOL region indicate that the plasma confinement is modified after the GP injection. Some features of the H-mode-like confinement in the plasma bulk also accompany the SOL observations after application of the additional sharp GP pulse. (paper)

  14. Monitoring and prediction of geotechnical and environmental risks for security in natural gas transportation; Monitoramento e previsao de riscos geotecnicos e ambientais para seguranca no transporte do gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Chamecki, Paulo R.; Ligocki, Laryssa P.; Andrade, Heber A.C.; Manzolli, Andre; Horbatiuk, Borys W.D. [LACTEC - Instituto de Tecnologia para o Desenvolvimento, Curitiba, PR (Brazil); Strieder, Adelir J.; Quadros, Telmo F.P.; Buffon, Sergio A.; Stupf, Leonardo; Bressani, Luiz A.; Bica, Adriano V. Damiani [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil); Schiafino, Antonio V.; Bastos, Cesar B. [Fundacao Universidade Federal do Rio Grande (FURG), RS (Brazil); Radu, Marcos S.; Nascimento Filho, Lenart P. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Santoro, Alcides [Centro de Tecnologias do Gas (CTGAS), Natal, RN (Brazil); Vasconcellos, Carlos R.A.; Oliveira, Hudson R. [TBG - Transportadora Brasileira Gasoduto Bolivia-Brasil S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    In order to take care of the consumption issues, often the bands of pipelines have to cross regions that do not present ideal conditions in terms of geotechnical and geologic characteristics. The present work describes a research in progress, involving a partnership between LACTEC, UFRGS, RedeGasEnergia and FINEP, that aims the development of a methodology for instrumentation and remote monitoring of places which present risks to the infrastructure of the gas-lines and the environment, due to geological and geotechnical conditions, as well as the definition of these places. The methodology is practically concluded and will be applied in the place defined for the case study in natural gas Bolivia-Brazil gas-line. Satellite images are being used, along whit computational modeling, geophysical methods, exploratory boreholes and field and laboratory tests, for the definition of points of risk. In the remote monitoring, besides a data communication system, residual stress test of the pipelines, strain gauges and automatic instruments, inclinometers, piezometer and pluviometers are being used. (author)

  15. Integration of Wind Energy, Hydrogen and Natural Gas Pipeline Systems to Meet Community and Transportation Energy Needs: A Parametric Study

    Directory of Open Access Journals (Sweden)

    Shahryar Garmsiri

    2014-04-01

    Full Text Available The potential benefits are examined of the “Power-to-Gas” (P2G scheme to utilize excess wind power capacity by generating hydrogen (or potentially methane for use in the natural gas distribution grid. A parametric analysis is used to determine the feasibility and size of systems producing hydrogen that would be injected into the natural gas grid. Specifically, wind farms located in southwestern Ontario, Canada are considered. Infrastructure requirements, wind farm size, pipeline capacity, geographical dispersion, hydrogen production rate, capital and operating costs are used as performance measures. The model takes into account the potential production rate of hydrogen and the rate that it can be injected into the local gas grid. “Straw man” systems are examined, centered on a wind farm size of 100 MW integrating a 16-MW capacity electrolysis system typically producing 4700 kg of hydrogen per day.

  16. Gas transport processes in sea ice: How convection and diffusion processes might affect biological imprints, a challenge for modellers

    DEFF Research Database (Denmark)

    Tison, J.-L.; Zhou, Shaola J. G.; Thomas, D. N.

    2012-01-01

    ice cover. These rates were however obtained surmising that neither convection, nor diffusion had affected the gas concentration profiles in the ice between discrete ice core collections. This paper discusses examples from three different field surveys (the above-mentioned Barrow experiment......, the INTERICE IV tank experiment in Hamburg and a short field survey close to the Kapisilit locality in the South-East Greenland fjords) where convection or diffusion processes have clearly affected the temporal evolution of the gas profiles in the ice, therefore potentially affecting biological signatures....... The INTERICE IV and Barrow experiment show that the initial equilibrium dissolved gas entrapment within the skeletal layer basically governs most of the profiles higher up in the sea ice cover during the active sea ice growth. However, as the ice layers age and cool down under the temperature gradient, bubble...

  17. Open access to natural gas pipeline transportation in North America: Lessons for the European internal energy market

    International Nuclear Information System (INIS)

    Dreyfus, D.A.; Koklauner, A.B.

    1991-01-01

    The North American natural gas industry's experience with deregulation is described, with emphasis on the transition to competition and the conditions for viability under open access. Lessons learned from the North American experience are then examined for relevance to the European situation, which is emphasizing greater access to transmission systems. It is found likely that the European proposal will frequently operate only to facilitate negotiations among players already active in the gas market, and is less likely to introduce a large number of independent transactions or new merchants. Challenges for the system will include: government assurance of reliability to domestic gas users who have made arrangements with foreign suppliers; administration of pipeline grids; resolution of competing claims on available transmission services; planning for future suppliers; and impact on investment. 8 refs., 1 fig

  18. Transportation fuel production from gasified biomass integrated with a pulp and paper mill - Part B: Analysis of economic performance and greenhouse gas emissions

    International Nuclear Information System (INIS)

    Isaksson, Johan; Jansson, Mikael; Åsblad, Anders; Berntsson, Thore

    2016-01-01

    This paper presents a comparison between four gasification-based biorefineries integrated with a pulp and paper mill. It is a continuation of 'Transportation fuel production from gasified biomass integrated with a pulp and paper mill - Part A: Heat integration and system performance'. Synthesis into methanol, Fischer-Tropsch crude or synthetic natural gas, or electricity generation in a gas turbine combined cycle, were evaluated. The concepts were assessed in terms of GHG (greenhouse gas) emissions and economic performance. Net annual profits were positive for all biofuel cases for an annuity factor of 0.1 in the year 2030; however, the results are sensitive to biofuel selling prices and CO 2,eq charge. Additionally, GHG emissions from grid electricity are highly influential on the results since all biofuel processes require external power. Credits for stored CO 2 might be necessary for processes to be competitive, i.e. storage of separated CO 2 from the syngas conditioning has an important role to play. Without CO 2 storage, the gas turbine case is better than, or equal to, biofuels regarding GHG emissions. Efficiency measures at the host mill prior to heat integration of a gasification process are beneficial from the perspective of GHG emissions, while having a negative impact on the economy. - Highlights: • Biomass gasification integrated with a pulp and paper mill was evaluated. • Greenhouse gas emission consequences and economic performance were assessed. • CCS has an important role to play, both in terms of emissions and economy. • Green electricity production is competitive compared to biofuel production in terms of GHG. • All biofuel cases are profitable in 2030 with assumed level of future policy instruments.

  19. The application of the pore population balance method to the calculation of the radiolytic weight loss and gas transport property changes of nuclear graphites

    International Nuclear Information System (INIS)

    Johnson, P.A.V.

    1982-01-01

    A pore population balance equation, previously used to describe the physical property changes of porous carbons during thermal oxidation in carbon dioxide, has been modified to treat the radiolytic oxidation of graphite in CO 2 /CO/CH 4 gas mixtures. Good agreement has been obtained between theory and experiment for the variation in the gas transport coefficients B, K and lambda of gilsonite graphite with absorbed radiation dose. Calculations indicate that the addition of blind pores to the transport porosity, and an allowance for the opening of closed pores with burn-off, do not account for the experimental fractional weight loss curve. An excellent fit is obtained, however, if a small volume of cylindrical pores of a mean radius approximately equal to the diffusion length of oxidising species in the coolant are present in the pore size spectrum. Gilsonite graphite therefore behaves as if the pore size distribution function is trimodal, with mean radii at about 0.5μm, 2.48μm and greater than or equal to 10.57μm. (author)

  20. Performance evaluation of Maxwell and Cercignani-Lampis gas-wall interaction models in the modeling of thermally driven rarefied gas transport

    KAUST Repository

    Liang, Tengfei

    2013-07-16

    A systematic study on the performance of two empirical gas-wall interaction models, the Maxwell model and the Cercignani-Lampis (CL) model, in the entire Knudsen range is conducted. The models are evaluated by examining the accuracy of key macroscopic quantities such as temperature, density, and pressure, in three benchmark thermal problems, namely the Fourier thermal problem, the Knudsen force problem, and the thermal transpiration problem. The reference solutions are obtained from a validated hybrid DSMC-MD algorithm developed in-house. It has been found that while both models predict temperature and density reasonably well in the Fourier thermal problem, the pressure profile obtained from Maxwell model exhibits a trend that opposes that from the reference solution. As a consequence, the Maxwell model is unable to predict the orientation change of the Knudsen force acting on a cold cylinder embedded in a hot cylindrical enclosure at a certain Knudsen number. In the simulation of the thermal transpiration coefficient, although all three models overestimate the coefficient, the coefficient obtained from CL model is the closest to the reference solution. The Maxwell model performs the worst. The cause of the overestimated coefficient is investigated and its link to the overly constrained correlation between the tangential momentum accommodation coefficient and the tangential energy accommodation coefficient inherent in the models is pointed out. Directions for further improvement of models are suggested.

  1. The influence of firn air transport processes and radiocarbon production on gas records from polar firn and ice

    DEFF Research Database (Denmark)

    Buizert, Christo

    in Northern Greenland (77.45 o N 51.06 o W). The depthdiffusivity relationship needs to be reconstructed using reference tracers of known atmospheric history. We present a novel method of characterizing the firn transport using ten tracers simultaneously, thus constraining the effective diffusivity better...... does not vanish completely in the lock-in zone, as is commonly assumed. Six state-of-the-art firn air transport models are tuned to the NEEM site; all models successfully reproduce the data within a 1 Gaussian distribution. We present the first intercomparison study of firn air models, where we...

  2. The Spanish gas industry

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The spanish gas industry has become one of the major actors in the gas sector of the European Economic Community. This paper pictures the spanish gas industry on the basis of a study by Sedigas, the spanish member of the International Gas Union (IGU). The main subjects described are structure of gas companies, natural gas supply, transport and storage, natural gas distribution networks, statistical data on natural gas consumption, manufactured gas and Liquefied Petroleum Gases (LPG) production-consumption in Spain. 7 figs., 10 tabs

  3. Trace gas composition in the free and upper troposphere over Asia: Examining the influence of long-range transport and convection of local pollution

    Science.gov (United States)

    Baker, A. K.; Traud, S.; Brenninkmeijer, C. A.; Hoor, P. M.; Neumaier, M.; Oram, D.; Rauthe-Schöch, A.; Schloegl, S.; Sprung, D.; Slemr, F.; van Velthoven, P.; Wernli, H.; Zahn, A.; Ziereis, H.

    2013-12-01

    Between May 2005 and March 2008 the CARIBIC observatory (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) was deployed to make atmospheric observations during 21 round-trip flights between Frankfurt, Germany and Manila, the Philippines with a stopover in Guangzhou, China. This nearly 3 year flight series provides us with information about atmospheric composition in the free and upper troposphere over Asia during all seasons and was used to investigate seasonal and regional differences in trace gas distributions and the relative influences of long range transport and convected local air masses on composition. The flight route was separated into three different regions having unique characteristics in transport and composition; these were Western Asia (5°E to 70°E), Central Asia (70°E to 100°E) and East Asia (100°E to 125°E). The region over Western Asia was heavily influenced by long range transport of air masses from North America and had elevated levels of NOy and acetone, while the region over East Asia was mostly influenced by convected local (South East Asian) pollution, particularly from biomass/biofuel burning as indicated by high levels of acetonitrile and carbon monoxide. Air masses over Central Asia were found to be influenced by both recently convected air masses from the Indian subcontinent and mid-range transport from Eastern Europe and the Middle East. Elevated levels of propane and other non-methane hydrocarbons, both with and without concommitant elevations in other trace gases (i.e. carbon monoxide, acetonitrile) were a persisent feature of this region in all seasons except summer, and were particularly prominent in fall. Influences on composition over Central Asia were investigated more thoroughly in a case study from a series of flights in October 2006, and elevated levels of pollutants were found to be the result of convective transport of both biomass/biofuel burning and urban emissions from

  4. A liquefied energy chain for transport and utilization of natural gas for power production with CO2 capture and storage - Part 2: The offshore and the onshore processes

    International Nuclear Information System (INIS)

    Aspelund, Audun; Gundersen, Truls

    2009-01-01

    A novel energy and cost effective transport chain for stranded natural gas utilized for power production with CO 2 capture and storage is developed. It includes an offshore section, a combined gas carrier, and an integrated receiving terminal. In the offshore process, natural gas (NG) is liquefied to LNG by liquid carbon dioxide (LCO 2 ) and liquid inert nitrogen (LIN), which are used as cold carriers. The offshore process is self-supported with power, hot and cold utilities and can operate with little rotating equipment and without flammable refrigerants. In the onshore process, the cryogenic exergy in LNG is used to cool and liquefy the cold carriers, which reduces the power requirement to 319 kWh/tonne LNG. Pinch and exergy analyses are used to determine thermodynamically optimized offshore and onshore processes with exergy efficiencies of 87% and 71%, respectively. There are very low emissions from the processes. The estimated specific costs for the offshore and onshore process are 8.0 and 14.6 EUR per tonne LNG, respectively, excluding energy costs. With an electricity price of 100 EUR per MWh, the specific cost of energy in the onshore process is 31.9 EUR per tonne LNG

  5. Co-current air-water flow in downward sloping pipes : Transport of capacity reducing gas pockets in wastewater mains

    NARCIS (Netherlands)

    Pothof, I.W.M.

    2011-01-01

    Air-water flow is an undesired condition in many systems for the transportation of water or wastewater. Air in storm water tunnels may get trapped and negatively affect the system. Air pockets in hydropower tunnels or sewers may cause blow-back events and inadmissible pressure spikes. Water pipes

  6. System of large transport containers for waste from dismantling light water and gas-cooled nuclear reactors. Volume 1

    International Nuclear Information System (INIS)

    Price, M.S.T.; Lafontaine, I.

    1985-01-01

    The purpose of this volume is to introduce the main types of nuclear reactor in the European Community (EC), select reference plants for further study, estimate the waste streams from the reference reactors, survey the transport regulations and assess existing containers

  7. System of large transport containers for waste from dismantling light water and gas-cooled nuclear reactors. Volume 1

    International Nuclear Information System (INIS)

    Price, M.S.T.

    1986-09-01

    General descriptions of the main types of reactors in the European Economic Community are given, a series of reference plants selected for further study. Estimates are made of the radioactive decommissioning wastes for each, including neutron-activated and contaminated materials. Regulations governing the transport of radioactive materials, both international and national, are reviewed. (U.K.)

  8. Drag force and transport property of a small cylinder in free molecule flow: A gas-kinetic theory analysis.

    Science.gov (United States)

    Liu, Changran; Li, Zhigang; Wang, Hai

    2016-08-01

    Analytical expressions are derived for aerodynamic drag force on small cylinders in the free molecule flow using the gas-kinetic theory. The derivation considers the effect of intermolecular interactions between the cylinder and gas media. Two limiting collision models, specular and diffuse scattering, are investigated in two limiting cylinder orientations with respect to the drift velocity. The earlier solution of Dahneke [B. E. Dahneke, J. Aerosol Sci. 4, 147 (1973)10.1016/0021-8502(73)90066-9] is shown to be a special case of the current expressions in the rigid-body limit of collision. Drag force expressions are obtained for cylinders that undergo Brownian rotation and for those that align with the drift velocity. The validity of the theoretical expressions is tested against experimental mobility data available for carbon nanotubes.

  9. Annual and transient signatures of gas exchange and transport in the Castañar de Ibor cave (Spain

    Directory of Open Access Journals (Sweden)

    Fernandez-Cortes A.

    2009-07-01

    Full Text Available The large microclimatic stability is a basic characteristic of the subterranean karst systems and causes a high sensitivity to changesin environmental conditions. High-accuracy monitoring of Castañar de Ibor cave (Spain determined the temporal evolution of theaerodynamic processes and ventilation rate by tracking CO2 and 222Rn levels over a twelve-month period. This cave is characterizedby a very stable microclimate, with high and relatively constant radon content (the mean value is 32200 Bq/m3, roughly, and thestandard deviation is 7600 Bq/m3 and a moderate and quite stable CO2 concentration (the mean value is 3730 ppm and the standarddeviation is 250 ppm. Beside the general patterns of cave microclimate throughout an annual cycle, some particular microclimaticprocesses are described with regard to the gas exchange between the cave and the outside atmosphere. There is a complexmicroclimatic functional relationship between the meteorological and cave microclimate conditions and the diffusion and flow of tracergases from the fractures and the pore system of soil and host rock to cave atmosphere. Transient variations of tracer gas on cave airare controlled by natural barometric fluxes and anthropogenic forced ventilation due to uncontrolled opening of cave entrance. Theshort-term fluctuations of gas levels on cave air reveal distinct patterns during the exhalation process of theses gases from the netof fissures and pores to the cave atmosphere, depending on the isolation effect of soil and host rock.

  10. Integration of the commercial and operational systems for the supply of services related to the transportation of natural gas; Integracao entre sistema comercial e operacional para prestacao de servicos de transporte de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Frisoli, Caetano [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil); Faria, Jose Aurelio Carvalho de; Silva, Mauricio dos Santos [Transportadora Brasileira Gasoduto Bolivia-Brasil, S.A., Rio de Janeiro, RJ (Brazil); Varon, Rene [Energy Solutions International Inc., Houston, TX (United States)

    2003-07-01

    Transportadora Brasileira Gasoduto Bolivia-Brazil S.A. - TBG, In order to perform with efficiency and quality, has always been committed to providing its customers with the best services and support. This commitment has been materialized with the recent implementation of a state-of-the-art technology that allows TBG to automatically manage all of its requests for services and to guarantee the delivery of gas to its customers is done in a safe way, optimizing pipeline capacity. To offer these levels of service, it was necessary to acquire a field proven solution capable of managing all commercial procedures as well as providing the right tools to operation to evaluate the capacity to move gas throughout the pipeline. Therefore the solution also was required to be easily integrated with existing operational and commercial tools such as the SCADA system and SAP R3 software. Reductions of fuel consumption and mitigation of risks against contractual penalties are some of the benefits reached. (author)

  11. Minimizing driving times and greenhouse gas emissions in timber transport with a near-exact solution approach

    DEFF Research Database (Denmark)

    Oberscheider, Marco; Zazgornik, Jan; Henriksen, Christian Bugge

    2013-01-01

    Efficient transport of timber for supplying industrial conversion and biomass power plants is a crucial factor for competitiveness in the forest industry. Throughout the recent years minimizing driving times has been the main focus of optimizations in this field. In addition to this aim the objec......Efficient transport of timber for supplying industrial conversion and biomass power plants is a crucial factor for competitiveness in the forest industry. Throughout the recent years minimizing driving times has been the main focus of optimizations in this field. In addition to this aim...... the objective of reducing environmental impacts, represented by carbon dioxide equivalent (CO(2)e) emissions, is discussed. The underlying problem is formulated as a multi-depot vehicle routing problem with pickup and delivery and time windows (MDVRPPDTW) and a new iterative solution method is proposed...

  12. PRODUT - a pipeline technological program to face the challenges in the oil and gas transportation in Brazil; PRODUT - um programa tecnologico de dutos para enfrentar os desafios do transporte de oleo e gas no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Ney Goncalves [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2003-07-01

    Following the international tendency of the pipeline companies, PETROBRAS has been investing relevant resources in new technologies, with the objective of increasing reliability and life span, and decreasing the cost and the risk of leakage. PETROBRAS created in 1998 the pipeline technological program, PRODUT, to be responsible for coordinating the development of the company R and D projects. This paper will present PRODUT and the good results obtained in order to increase reliability and competitiveness of transportation systems, essential for global performance of the petroleum industry. (author)

  13. Life cycle assessment of urban solid wastes collecting using vehicles of liquefied natural gas and diesel; Analisis del ciclo de vida comparativo de la etapa de recogida y transporte de RSU mediante vehiculos propulsados por gas natural licaudo y gasoleo

    Energy Technology Data Exchange (ETDEWEB)

    Rieradevall, J.; Domenech, X.; Bala, A.; Gazulla, C.; Mila, L. [Universidad de Barcelona (Spain)

    2002-07-01

    This paper shows an environmental comparison using the Life cycle Assessment (LCA)-between two types of duscarts of CESPA Ingenieria Urbana: one of them using Natural Liquid Gas as a fuel and the other using Diesel. Both vehicles are similar in the rest of technical characteristics. The data to make this study has been given by CESPA which made a follow-up of this duscarts while they were working in Barcelona, the first quarter of 2001. the functional unit to make the comparison is: ''Collect and transport one ton of solid urban waste along a urban circuit of 50 kilometres (with a duscart of 18 ton of Maximum Authorizer Weight)''. (Author) 7 refs.

  14. Assessment of potential life-cycle energy and greenhouse gas emission effects from using corn-based butanol as a transportation fuel.

    Science.gov (United States)

    Wu, May; Wang, Michael; Liu, Jiahong; Huo, Hong

    2008-01-01

    Since advances in the ABE (acetone-butanol-ethanol) fermentation process in recent years have led to significant increases in its productivity and yields, the production of butanol and its use in motor vehicles have become an option worth evaluating. This study estimates the potential life-cycle energy and emission effects associated with using bio-butanol as a transportation fuel. It employs a well-to-wheels (WTW) analysis tool: the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The estimates of life-cycle energy use and greenhouse gas (GHG) emissions are based on an Aspen Plus(R) simulation for a corn-to-butanol production process, which describes grain processing, fermentation, and product separation. Bio-butanol-related WTW activities include corn farming, corn transportation, butanol production, butanol transportation, and vehicle operation. In this study, we also analyzed the bio-acetone that is coproduced with bio-butanol as an alternative to petroleum-based acetone. We then compared the results for bio-butanol with those of conventional gasoline. Our study shows that driving vehicles fueled with corn-based butanol produced by the current ABE fermentation process could result in substantial fossil energy savings (39%-56%) and avoid large percentage of the GHG emission burden, yielding a 32%-48% reduction relative to using conventional gasoline. On energy basis, a bushel of corn produces less liquid fuel from the ABE process than that from the corn ethanol dry mill process. The coproduction of a significant portion of acetone from the current ABE fermentation presents a challenge. A market analysis of acetone, as well as research and development on robust alternative technologies and processes that minimize acetone while increase the butanol yield, should be conducted.

  15. Study of the effectiveness of several tree canopy types on roadside green belt in influencing the distribution of NO2 gas emitted from transportation

    Science.gov (United States)

    Desyana, R. D.; Sulistyantara, B.; Nasrullah, N.; Fatimah, I. S.

    2017-03-01

    Transportation is one significant factor which contributes to urban air pollution. One of the pollutants emitted from transportation which affect human’s health is NO2. Plants, especially trees, have high potential in reducing air pollutants from transportation through diffusion, absorbtion, adsorption and deposition. Purpose of this study was to analyze the effectiveness of several tree canopy types on roadside green belt in influencing distribution of NO2 gas emitted from transportation. The study conducted in three plots of tree canopy in Jagorawi Highway: Bungur (Lagerstroemia speciosa), Gmelina (Gmelina arborea) and Tanjung (Mimusops elengi). The tree canopy ability in absorbing pollutant is derived by comparing air quality on vegetated area with ambience air quality at control area (open field). Air sampling was conducted to measure NO2 concentration at elevation 1.5m, 5m and 10m at distance 0m, 10m and 30m, using Air Sampler Impinger. Concentration of NO2 was analyzed with Griess-Saltzman method. From this research, the result of ANOVA showed that tree plot (vegetated area) affected significantly to NO2 concentration. However the effect of distance from road and elevation was not significant. Among the plots, the highest NO2 concentration was found on Control plot (area without tree canopy), while the lowest NO2 concentration was found in Tanjung plot. Tanjung plot with round shape and high density canopy performed better in reducing NO2 than Bungur plot with round shape and medium density canopy, regardless the sampling elevation and distance. Gmelina plot performed the best in reducing horizontal distribution of NO2 concentration at elevation 1.5 and 5m, but the result at elevation 10m was not significant.

  16. An electron conductive polymer, poly-aniline, in gas separation: optimisation of transport properties by alternated acid-base treatment

    International Nuclear Information System (INIS)

    Rebattet, Laurence

    1994-01-01

    The objective of this research thesis is to study the variation of gas permeation properties of poly-aniline during a doping/de-doping/re-doping cycle, and to study the evolution of the separation power of this polymer. Scanning electronic microscopy is used to study the microstructure and more particularly how the doping agent is distributed within the polymer. Permeabilities, diffusion coefficients, sorption solubilities and interaction energies are measured by using coupled permeation and micro-gravimetry-calorimetry methods. A range of gases (H 2 , O 2 , CO 2 , N 2 , CH 4 ) is analysed [fr

  17. Gas transport properties and pervaporation performance of fluoropolymer gel membranes based on pure and mixed ionic liquids

    Czech Academy of Sciences Publication Activity Database

    Jansen, J. C.; Clarizia, G.; Bernardo, P.; Bazzarelli, F.; Friess, K.; Randová, A.; Schauer, Jan; Kubicka, D.; Kačírková, Marie; Izák, Pavel

    2013-01-01

    Roč. 109, 9 May (2013), s. 87-97 ISSN 1383-5866 R&D Projects: GA ČR GA104/08/0600; GA ČR GAP106/10/1194; GA MŠk(CZ) 7C11009 Grant - others:RFCS(XE) RFCR–CT–2010–00009 Institutional research plan: CEZ:AV0Z40720504 Institutional support: RVO:61389013 ; RVO:67985858 Keywords : ionic liquid membrane * gas permeability * pervaporation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.065, year: 2013

  18. Financial and tax risks at implementation of "Chayanda- Lensk" section of "Sila Sibiri" gas transportation system construction project

    Science.gov (United States)

    Sharf, I. V.; Chukhareva, N. V.; Kuznetsova, L. P.

    2014-08-01

    High social and economic importance of large-scale projects on gasification of East Siberian regions of Russia and diversifying gas exports poses the problem of complex risk analysis of the project. This article discusses the various types of risks that could significantly affect the timing of the implementation and effectiveness of the project for the construction of the first line of "Sila Sibiri", the "Chayanda-Lensk" section. Special attention is paid to financial and tax aspects of the project. Graphically presented analysis of the dynamics of financial indicators reflect certain periods of effectiveness in implementing the project. Authors also discuss the possible causes and consequences of risks.

  19. CFD analysis for the hydrogen transport in the primary contention of a BWR using the codes OpenFOAM and Gas-Flow

    International Nuclear Information System (INIS)

    Jimenez P, D. A.

    2014-01-01

    The accidents in Unit 2 of the Three Mile Island Nuclear Power Plant (NPP) in the United States (March 28 th , 1979), the one in Unit 4 of the NPP Chernobyl in Ukraine (April 26 th , 1986) and the explosions in some units of Fukushima NPP in Japan (March 11 th , 2011) boosted the investigations on severe accidents with core damage and, in particular, the threat to the ultimate barrier by an eventual explosion from uncontrolled Hydrogen combustion within the containment was considered of particular relevance. Research programs for analyzing Hydrogen behavior and control during this kind of accidents were early initiated by research and regulatory bodies. Assessment on Hydrogen behavior once it has been postulated to be released on the containment system can be divided into two phases, in the first one, transport and the concentrations of the gas mixtures and steam in each volume or area comprised between the structures of the containment are calculated, in the second one, the propagation of the detonation of the Hydrogen is calculated if there are the conditions to occur. Currently, there are computer programs that can be used in one, or both stages of computation, and they are based on one of the two solution methods in current use, one of them are integrated codes (e.g. MELCOR), which consists in assuming the containment as a network composed of hydraulic tanks or nodes on which the balance equations of mass and energy have to be solved, the network is connected by ducts or connections where the momentum balance equation arise. This methodology relies on the use of semi-empirical relationships and the criteria used to define a geometric pattern, are subjective. The second method, which is having relevance due to the large computing power of modern computers, is the numerical solution of the three-dimensional Navier-Stokes equations in complex geometries. This method of solution is known as Computational Fluid Dynamics (CFD), and offers the advantage of using a

  20. Soil-gas phase transport and structure parameters for soils under different management regimes and at two moisture levels

    DEFF Research Database (Denmark)

    Eden, Marie; Møldrup, Per; Schjønning, Per

    2012-01-01

    at the University of California, Davis. The 18 plots used in this study represented fairly wide ranges in organic carbon (0. 0072-0.0153 kg kg(-1)) and clay (0.30-0.44 kg kg(-1)). Soil-air permeability, k(a), and soil-gas diffusivity, D-P/D-0, were determined at field-moist conditions (fin) and, subsequently, after...... displayed markedly lower D-P/D-0 values at similar air-filled porosity, illustrating soil structure effects on D-P/D-0. The Currie tortuosity-connectivity parameter, X=Log(D-P/D-0)/Log(epsilon), decreased with increasing bulk density in the intact samples at both moisture conditions, suggesting less...... tortuous and well-connected pathways for gas diffusion at higher bulk density. Pore organization, PO = k(a) / epsilon, showed a treatment effect with typically higher values for the organic plots, implying that an improved possibility for formation of organomineral soil aggregates resulted in better...