Arc Interference Behavior during Twin Wire Gas Metal Arc Welding Process

Directory of Open Access Journals (Sweden)

Dingjian Ye

2013-01-01

Full Text Available In order to study arc interference behavior during twin wire gas metal arc welding process, the synchronous acquisition system has been established to acquire instantaneous information of arc profile including dynamic arc length variation as well as relative voltage and current signals. The results show that after trailing arc (T-arc is added to the middle arc (M-arc in a stable welding process, the current of M arc remains unchanged while the agitation increases; the voltage of M arc has an obvious increase; the shape of M arc changes, with increasing width, length, and area; the transfer frequency of M arc droplet increases and the droplet itself becomes smaller. The wire extension length of twin arc turns out to be shorter than that of single arc welding.

Gas-processing profit margin series begins in OGJ

International Nuclear Information System (INIS)

Kovacs, K.J.

1991-01-01

This paper reports on the bases and methods employed by the WK (Wright, Killen and Co, Houston) profit-margin indicator for U.S. gas-processing plants. Additionally, this article reviews the historical profitability of the gas-processing industry and key factors affecting these trends. Texas was selected as the most representative for the industry, reflecting the wide spectrum of gas-processing plants. The profit performance of Texas' gas plants is of special significance because of the large number of plants and high volume of NGL production in the region

Development of high purity CO gas recovery system for BOF gas by modified PSA process

Energy Technology Data Exchange (ETDEWEB)

Sakuraya, Toshikazu; Fujii, Tetsuya; Yaji, Motoyasu; Matsuki, Takao; Matsui, Shigeo; Hayashi, Shigeki

1985-01-01

COPISA process (where two processes for separating CO-adsorptive gases and desorbing desorption-difficult gas are added to conventional PSA gas separation process) is outlined. In two units of PSA, CO/sub 2/ gas is adsorbed and separated in first PSA unit. The gas excluding CO/sub 2/ is fed to second PSA unit, where CO is adsorbed and separated from N/sub 2/ and H/sub 2/, and then desorbed and recovered under reduced pressure. For optimizing the process, a pilot plant was operated for about 1000 hrs. in a half year. The results confirm possibility of simplifying pre-treatment of coal gas. CO-PSA pressure swing pattern suitable for elimination of Co-adsorptive N/sub 2/ is established. Recovery of CO gas is enhanced. Optimization of gas flow pattern between adsorption towers required for reduction in operating cost is performed. (7 figs, 1 tab, 8 refs)

Great gas plants : these five natural gas processing facilities demonstrate decades of top-flight technology

Energy Technology Data Exchange (ETDEWEB)

Byfield, M.

2010-07-15

The natural gas purification and pipeline sector is a major economic driver in Canada. Gas processing facilities are growing in number, and several large gas projects are being planned for future construction in the western provinces. This article outlined 5 gas plants in order to illustrate the sector's history and breadth in Canada. The Shell Jumping Pound gas complex was constructed in 1951 after a sulfur-rich gas discovery near Calgary in 1944. The Empress Straddle plant was built in 1971 in southeastern Alberta and is one of the largest single industrial consumers of electrical power in the province. The Fort Nelson gas processing plant is North America's largest sour gas processing facility. The Shell Caroline complex was built 1993. The Sable offshore energy project is located on the coast of Nova Scotia to handle gas produced from the Thebaud wells. A consortium is now considering the development of new gas fields in the Sable area. 5 figs.

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

International Nuclear Information System (INIS)

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

1993-02-01

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 diffusion. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. CASCADER is a gas-phase, one-space dimensional transport and fate model for M-chain radionuclides in very dry homogeneous or heterogeneous soil. This model contains barometric pressure-induced advection and diffusion together with linear irreversible and linear reversible sorption for each radionuclide. The advection velocity is derived from an embedded air-pumping submodel. The air-pumping submodel is based on an assumption of isothermal conditions, which is driven by barometric pressure. CASCADER allows the concentration of source radionuclides to decay via the classical Bateman chain of simple, first-order kinetic processes. The transported radionuclides also decay via first-order processes while in the soil. A mass conserving, flux-type inlet and exit set of boundary conditions are used. The user must supply the initial distribution for the parent radionuclide in the soil. The initial daughter distribution is found using equilibrium rules. The model is user friendly as it uses a prompt-driven, free-form input. The code is ANSI standard Fortran 77

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

International Nuclear Information System (INIS)

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

1992-06-01

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 as they are advected and/or dispersed. Furthermore, parent and daughter radionuclides may decay as they are transported in the soil. CASCADER is a gas-phase, one space dimensional transport and fate model for an m-chain of radionuclides in very dry soil. This model contains barometric pressure-induced advection and diffusion together with linear irreversible and linear reversible sorption for each radionuclide. The advocation velocity is derived from an embedded air-pumping submodel. The airpumping submodel is based on an assumption of isothermal conditions and is barometric pressure driven. CASCADER allows the concentration of source radionuclides to decay via the classical Bateman chain of simple, first-order kinetic processes. The transported radionuclides also decay via first-order processes while in the soil. A mass conserving, flux-type inlet and exit set of boundary conditions is used. The user must supply the initial distribution for the parent radionuclide in the soil. The initial daughter distribution is found using equilibrium rules. The model is user friendly as it uses a prompt-driven, free-form input. The code is ANSI standard Fortran 77

Impact of pH on hydrogen oxidizing redox processes in aquifers due to gas intrusions

Science.gov (United States)

Metzgen, Adrian; Berta, Marton; Dethlefsen, Frank; Ebert, Markus; Dahmke, Andreas

2017-04-01

Hydrogen production from excess energy and its storage can help increasing the efficiency of solar and wind in the energy mix. Therefore, hydrogen needs large-scale intermediate storage independent of the intended later use as hydrogen gas or as reactant to produce methane in the Sabatier process. A possible storage solution is using the geological subsurface such as caverns built in salt deposits or aquifers that are not used for drinking water production. However, underground storage of hydrogen gas potentially leads to accidental gas leakages into near-surface potable aquifers triggering subsequent geochemical processes. These leakages pose potential risks that are currently not sufficiently understood. To close this gap in knowledge, a high-pressure laboratory column system was used to simulate a hydrogen gas intrusion into a shallow aquifer. Water and sediment were gained from a sandy Pleistocene aquifer near Neumünster, Germany. In the first stage of the experiment, 100% hydrogen gas was used to simulate dissolved hydrogen concentrations between 800 and 4000 µM by varying pH2 between 2 and 15 bars. pH values rose to between 7.9 and 10.4, partly due to stripping CO2 from the groundwater used during H2 gas addition. In a second stage, the pH was regulated in a range of 6.7 to 7.9 by using a gas mixture of 99% H2 and 1% CO2 at 5 bars of total gas pressure. Observed processes included hydrogen oxidation, sulfate reduction, acetogenesis, formate production, and methanogenesis, which were independent of the hydrogen concentration. Hydrogen oxidation and sulfate reduction showed zeroth order reaction rates and rate constants (106 to 412 µM/h and 12 to 33 µM/h, respectively) in the pH range between 8 and 10. At pH levels between 7 and 8, both reactions started out faster near the column's inflow but then seemed limited towards the columns outflow, suggesting the dependence of sulfate reduction on the pH-value. Acetogenesis dominated the pH range between 8 and 10

Investigation of physico-chemical processes in hypervelocity MHD-gas acceleration wind tunnels

International Nuclear Information System (INIS)

Alfyorov, V.I.; Dmitriev, L.M.; Yegorov, B.V.; Markachev, Yu.E.

1995-01-01

The calculation results for nonequilibrium physicochemical processes in the circuit of the hypersonic MHD-gas acceleration wind tunnel are presented. The flow in the primary nozzle is shown to be in thermodynamic equilibrium at To=3400 K, Po=(2∼3)x10 5 Pa, M=2 used in the plenum chamber. Variations in the static pressure due to oxidation reaction of Na, K are pointed out. The channels of energy transfer from the electric field to different degrees of freedom of an accelerated gas with Na, K seeds are considered. The calculation procedure for gas dynamic and kinetic processes in the MHD-channel using measured parameters is suggested. The calculated results are compared with the data obtained in a thermodynamic gas equilibrium assumption. The flow in the secondary nozzle is calculated under the same assumptions and the gas parameters at its exit are evaluated. Particular attention is given to the influence of seeds on flows over bodies. It is shown that the seeds exert a very small influence on the flow behind a normal shock wave. The seeds behind an oblique shock wave accelerate deactivation of vibrations of N 2 , but this effect is insignificant

Gas expanders at M/R Stations in the natural gas distribution network. Pre-project, subreport; Gasexpandere paa distributionsnettets M/R-stationer. Forprojekt, delrapport

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, Niels Bjarne

2010-05-15

Danish Gas Technology Centre has been carrying out a feasibility project to clarify the possibilities of installing gas expanders at M/R-stations (Measuring and Regulating) in the Distribution system of the natural gas grid. A large number of such expanders are installed around the world. The novelty of this project is to use a heat pump to perform the necessary heating of the gas before the expander, and to ''export'' to the electricity grid the remaining electricity from the generator connected to the expander. The present project includes the small M/R-stations at the gas Distribution grid where pressure is reduced from 40 or 20 bar to 4 bar. The preliminary project (year 1 of project) has investigated whether components for such smaller systems can be found, and it has investigated prices for different quantities. A technical feasibility study has been done. Also, preliminary calculations of payback times has been carried out. A large potential of CO{sub 2}-reduction is present with this technology based on saving of natural gas combustion and on new electricity production displacing existing production without any use of primary energy. The main results and conclusions are: 1) There are component suppliers for expander systems suitable to the size of distribution network M/R stations. 2) Pressure regulators provided at the stations are laid out with significant overcapacity, enabling a simplified installation of the expander systems. 3) If the system is being rolled out across the Danish distribution grid, the realistic saving potential is approx. 2.3 million Nm3 of gas per year and a production of almost 40 million kWh of electricity. 4) If the price is 0.60 DKK/kWh for electricity sold, the simple pay-back is 6-7 years on average, covering a variation from 3 to 16 years at the various stations. The smallest stations are omitted. The best stations covering more than half of the gas flow have a pay-back time between 3 and 6 years. 5) The

Process using sorbents for the removal of SOx from flue gas

International Nuclear Information System (INIS)

Pinnavaia, T.J.; Amareskera, J.; Polansky, C.A.

1992-01-01

This patent describes a process for removing the SO x components from a flue gas stream containing oxygen, sulfur dioxide and sulfur trioxide from the combustion of coal from a coal-fired boiler which comprises combusting the coal in the boiler to provide the flue gas stream and contacting the the gas stream with a heated sorbent composition at 400 degrees to 1000 degrees C wherein the the sorbent before being heated is selected from the group consisting of a layered double hydroxide composition of formula: [M 1-x II M x III (OH) 2 ](A n- ) x/n · yH 2 O wherein M II is a divalent metal cation and M III is a trivalent metal cation selected from the group consisting of Group IIA. IIB and IIIA metals as the cation which form metal oxides and which are capable of reacting with SO 2 to form metal sulfites and SO 3 to form metal sulfates, A is an interlayer anion of charge n- which comprises at least one metal atoms selected from the group consisting of main group metals and transition metals which provide oxidation of sulfur dioxide to sulfur trioxide in an amount sufficient that the layered double hydroxide structure promotes the oxidation of the sulfur dioxide to the sulfur trioxide at the combustion conditions within the coal-fired boiler, wherein y is moles of water

Non-equilibrium plasma reactor for natrual gas processing

International Nuclear Information System (INIS)

Shair, F.H.; Ravimohan, A.L.

1974-01-01

A non-equilibrium plasma reactor for natural gas processing into ethane and ethylene comprising means of producing a non-equilibrium chemical plasma wherein selective conversion of the methane in natural gas to desired products of ethane and ethylene at a pre-determined ethane/ethylene ratio in the chemical process may be intimately controlled and optimized at a high electrical power efficiency rate by mixing with a recycling gas inert to the chemical process such as argon, helium, or hydrogen, reducing the residence time of the methane in the chemical plasma, selecting the gas pressure in the chemical plasma from a wide range of pressures, and utilizing pulsed electrical discharge producing the chemical plasma. (author)

Introduction to gas lasers with emphasis on selective excitation processes

CERN Document Server

Willett, Colin S

1974-01-01

Introduction to Gas Lasers: Population Inversion Mechanisms focuses on important processes in gas discharge lasers and basic atomic collision processes that operate in a gas laser. Organized into six chapters, this book first discusses the historical development and basic principles of gas lasers. Subsequent chapters describe the selective excitation processes in gas discharges and the specific neutral, ionized and molecular laser systems. This book will be a valuable reference on the behavior of gas-discharge lasers to anyone already in the field.

Gas processing in the nuclear industry

Energy Technology Data Exchange (ETDEWEB)

Kovach, J.L.

1995-02-01

This article is a brief overview of code requirements in the nuclear air cleaning arena. NRC standards, which employ the various ASME codes, are noted. It is also noted that DOE facilities do not fall under the purview of the NRC and that DOE facilities (especially fuel cycle facilities) typically have broader gas processing activities than for power reactors. The typical differences between DOE facilities` and power reactor facilities` gas processing needs are listed, as are DOE facility components not covered by the ASME AG-1 code.

Microstructure and abrasive wear properties of M(Cr,Fe7C3 carbides reinforced high-chromium carbon coating produced by gas tungsten arc welding (GTAW process

Directory of Open Access Journals (Sweden)

Soner BUYTOZ

2010-01-01

Full Text Available In the present study, high-chromium ferrochromium carbon hypereutectic alloy powder was coated on AISI 4340 steel by the gas tungsten arc welding (GTAW process. The coating layers were analyzed by optical microscopy, X-ray diffraction (XRD, field-emission scanning electron microscopy (FE-SEM, X-ray energy-dispersive spectroscopy (EDS. Depending on the gas tungsten arc welding pa-rameters, either hypoeutectic or hypereutectic microstructures were produced. Wear tests of the coatings were carried out on a pin-on-disc apparatus as function of contact load. Wear rates of the all coating layers were decreased as a function of the loading. The improvement of abrasive wear resistance of the coating layer could be attributed to the high hardness of the hypereutectic M7C3 carbides in the microstruc-ture. As a result, the microstructure of surface layers, hardness and abrasive wear behaviours showed different characteristics due to the gas tungsten arc welding parameters.

Process gas generator feeding internal combustion piston engines

Energy Technology Data Exchange (ETDEWEB)

Iwantscheff, G; Kostka, H; Henkel, H J

1978-10-26

The invention relates to a process gas generator feeding gaseous fuel to internal combustion piston engines. The cylinder linings of the internal combustion engine are enclosed by the catalytic reaction chamber of the process gas generator which contains perforated sintered nozzle bricks as carriers of the catalysts needed for the conversion. The reaction chamber is surrounded by the exhaust gas chamber around which a tube coil is ound which feeds the fuel charge to the reaction chamber after evaporation and mixing with exhaust gas and air. The fuel which may be used for this purpose, e.g., is low-octane gasoline or diesel fuel. In the reaction chamber the fuel is catalytically converted at temperatures above 200/sup 0/C, e.g., into low-molecular paraffins, carbon monoxide and hydrogen. Operation of the internal combustion engine with a process gas generator greatly reduces the pollutant content of the exhaust gases.

Off-gas processing method in reprocessing plant

International Nuclear Information System (INIS)

Kobayashi, Yoshihiro; Seki, Eiji.

1990-01-01

Off-gases containing a radioactive Kr gas generated in a nuclear fuel reprocessing plant are at first sent to a Kr gas separator. Then, the radioactive Kr gas extracted there is introduced to a Kr gas fixing device. A pretreatment and a post-treatment are applied by using a non-radioactive clean inert gas except for the Kr gas as a purge gas. If the radioactive Kr gas is contained in the off-gases discharged from the Kr gas fixing device after applying the post-treatment, the off gases are returned to the Kr gas separator. Accordingly, in a case where the radioactive Kr gas is contained in the off-gases discharged from the Kr gas fixing device, it is not necessary to apply the fixing treatment to all of the off gases. In view of the above, increase of the amount of processing gases can be suppressed and the radioactive Kr gas can be fixed efficiently and economically. (I.N.)

Analysis of an innovative process for landfill gas quality improvement

International Nuclear Information System (INIS)

Lombardi, L.; Carnevale, E.A.

2016-01-01

Low methane content landfill gas is not suitable for feeding engines and is generally flared. This type of landfill gas may be enriched by removing the inert carbon dioxide. An innovative process, based on the carbon dioxide captured by means of accelerated carbonation of bottom ash was proposed and studied for the above purpose. The process was investigated at a laboratory scale, simulating different landfill gas compositions. The enrichment process is able to decrease the carbon dioxide concentration from 70 to 80% in volume to 60% in volume, requiring about 36 kg of bottom ash per Nm"3 of landfill gas. Using this result it was estimated that an industrial scale plant, processing 100–1000 Nm"3/h of low methane content landfill gas requires about 28,760–2,87,600 t of bottom ash for a one year operation. The specific cost of the studied enrichment process was evaluated as well and ranges from 0.052 to 0.241 Euro per Nm"3 of entering landfill gas. The energy balance showed that about 4–6% of the energy entered with the landfill gas is required for carrying out the enrichment, while the use of the enriched landfill gas in the engine producing electricity allows for negative carbon dioxide emission. - Highlights: • The process uses a waste stream as material to capture CO_2. • The process uses a simple gas/solid fixed bed contact reactor at ambient conditions. • The process captures the CO_2 to enrich low-CH4 landfill gas. • The specific cost ranges from 0.052 to 0.241 Euro per Nm"3 of entering landfill gas. • The process consumes about 4–6% of the entering energy and acts as CO_2 sink.

New technological developments in gas processing

International Nuclear Information System (INIS)

Draper, R.C.

1996-01-01

The changes that the natural gas industry has undergone over the last few years was discussed. Low natural gas prices forced companies to react to their high reserves replacements costs. They were forced to downsize and undergo major restructuring because they were losing money due to high operating costs; the future for natural gas prices looked pessimistic. The changes have led to a new kind of business practice, namely 'partnering with third party processor', mid-stream companies known as aggregators, to build and operate facilities as part of a move towards cost effective improvements for gas producers. Besides reducing capital and operating costs, the producer under this arrangements can dedicate his capital to finding new gas which is the basis of growth. Recent technological changes in the gas processing industry were also touched upon. These included enhanced technologies such as increased liquid hydrocarbon recovery, segregation of C3+ and C5+, installation of gas separation membrane systems, small sulphur plants, acid gas injection and selective or mixed solvents. Details of some of these technologies were described. 2 refs., 2 figs

Performance analysis of solar energy integrated with natural-gas-to-methanol process

International Nuclear Information System (INIS)

Yang, Sheng; Liu, Zhiqiang; Tang, Zhiyong; Wang, Yifan; Chen, Qianqian; Sun, Yuhan

2017-01-01

Highlights: • Solar energy integrated with natural-gas-to-methanol process is proposed. • The two processes are modeled and simulated. • Performance analysis of the two processes are conducted. • The proposed process can cut down the greenhouse gas emission. • The proposed process can save natural gas consumption. - Abstract: Methanol is an important platform chemical. Methanol production using natural gas as raw material has short processing route and well developed equipment and technology. However, natural gas reserves are not large in China. Solar energy power generation system integrated with natural-gas-to-methanol (NGTM) process is developed, which may provide a technical routine for methanol production in the future. The solar energy power generation produces electricity for reforming unit and system consumption in solar energy integrated natural-gas-to-methanol system (SGTM). Performance analysis of conventional natural-gas-to-methanol process and solar energy integrated with natural-gas-to-methanol process are presented based on simulation results. Performance analysis was conducted considering carbon efficiency, production cost, solar energy price, natural gas price, and carbon tax. Results indicate that solar energy integrated with natural-gas-to-methanol process is able to cut down the greenhouse gas (GHG) emission. In addition, solar energy can replace natural gas as fuel. This can reduce the consumption of natural gas, which equals to 9.2% of the total consumed natural gas. However, it is not economical considering the current technology readiness level, compared with conventional natural-gas-to-methanol process.

Contracting out gas processing : the pros and cons

International Nuclear Information System (INIS)

Stout, D.L.

1999-01-01

The impact of competition within the energy industry on the midstream infrastructure was discussed. It was demonstrated that it is no longer necessary to own all or a portion of a processing facility to be a successful exploration company. It is now possible for midstream operators to manage the transmission business, the gas storage sector and the gas processing segment of the industry. Contract options and issues that should be addressed by natural gas producers in determining risks involved in contracting out were summarized. Changes in the industry has greatly expanded the options and opportunities for companies, both upstream and midstream. The industry has been contracting out gas processing for many years. However, the entry into the business of the specialized midstream player should further enhance the producer's options. The ultimate goal for the producer should be to benefit from lower costs, long term offerings, and a reduced need to invest potential exploration capital into non-core processing facilities

Mathematical simulation of the process of condensing natural gas

Science.gov (United States)

Tastandieva, G. M.

2015-01-01

Presents a two-dimensional unsteady model of heat transfer in terms of condensation of natural gas at low temperatures. Performed calculations of the process heat and mass transfer of liquefied natural gas (LNG) storage tanks of cylindrical shape. The influence of model parameters on the nature of heat transfer. Defined temperature regimes eliminate evaporation by cooling liquefied natural gas. The obtained dependence of the mass flow rate of vapor condensation gas temperature. Identified the possibility of regulating the process of "cooling down" liquefied natural gas in terms of its partial evaporation with low cost energy.

Process development report: 0.20-m secondary burner system

International Nuclear Information System (INIS)

Rickman, W.S.

1977-09-01

HTGR fuel reprocessing consists of crushing the spent fuel elements to a size suitable for burning in a fluidized bed to remove excess graphite; separating, crushing, and reburning the fuel particles to remove the remainder of the burnable carbon; dissolution and separation of the particles from insoluble materials; and solvent extraction separation of the dissolved uranium and thorium. Burning the crushed fuel particles is accomplished in a secondary burner. This is a batch fluidized-bed reactor with in-vessel, off-gas filtration. Process heat is provided by an induction heater. This report documents operational tests performed on a commercial size 0.20-m secondary burner using crushed Fort St. Vrain type TRISO fuel particles. Analysis of a parametric study of burner process variables led to recommending lower bed superficial velocity (0.8 m/s), lower ignition temperature (600 0 C), lower fluid bed operating temperature (850 0 C), lower filter blowback frequency (1 cycle/minute), and a lower fluid bed superficial velocity during final bed burnout

Using Noble Gas Measurements to Derive Air-Sea Process Information and Predict Physical Gas Saturations

Science.gov (United States)

Hamme, Roberta C.; Emerson, Steven R.; Severinghaus, Jeffrey P.; Long, Matthew C.; Yashayaev, Igor

2017-10-01

Dissolved gas distributions are important because they influence oceanic habitats and Earth's climate, yet competing controls by biology and physics make gas distributions challenging to predict. Bubble-mediated gas exchange, temperature change, and varying atmospheric pressure all push gases away from equilibrium. Here we use new noble gas measurements from the Labrador Sea to demonstrate a technique to quantify physical processes. Our analysis shows that water-mass formation can be represented by a quasi steady state in which bubble fluxes and cooling push gases away from equilibrium balanced by diffusive gas exchange forcing gases toward equilibrium. We quantify the rates of these physical processes from our measurements, allowing direct comparison to gas exchange parameterizations, and predict the physically driven saturation of other gases. This technique produces predictions that reasonably match N2/Ar observations and demonstrates that physical processes should force SF6 to be ˜6% more supersaturated than CFC-11 and CFC-12, impacting ventilation age calculations.

Gas processing at DOE nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Jacox, J.

1995-02-01

The term {open_quotes}Gas Processing{close_quotes} has many possible meanings and understandings. In this paper, and panel, we will be using it to generally mean the treatment of gas by methods other than those common to HVAC and Nuclear Air Treatment. This is only a working guideline not a rigorous definition. Whether a rigorous definition is desirable, or even possible is a question for some other forum. Here we will be discussing the practical aspects of what {open_quotes}Gas Processing{close_quotes} includes and how existing Codes, Standards and industry experience can, and should, apply to DOE and NRC Licensed facilities. A major impediment to use of the best engineering and technology in many nuclear facilities is the administrative mandate that only systems and equipment that meet specified {open_quotes}nuclear{close_quotes} documents are permissible. This paper will highlight some of the limitations created by this approach.

Sulfur oxides and nitrogen oxides gas treating process

International Nuclear Information System (INIS)

Forbes, J. T.

1985-01-01

A process is disclosed for treating particle-containing gas streams by removing particles and gaseous atmospheric pollutants. Parallel passage contactors are utilized to remove the gaseous pollutants. The minimum required gas flow rate for effective operation of these contactors is maintained by recycling a variable amount of low temperature gas which has been passed through a particle removal zone. The recycled gas is reheated by heat exchange against a portion of the treated gas

Mathematical simulation of the process of condensing natural gas

Directory of Open Access Journals (Sweden)

Tastandieva G.M.

2015-01-01

Full Text Available Presents a two-dimensional unsteady model of heat transfer in terms of condensation of natural gas at low temperatures. Performed calculations of the process heat and mass transfer of liquefied natural gas (LNG storage tanks of cylindrical shape. The influence of model parameters on the nature of heat transfer. Defined temperature regimes eliminate evaporation by cooling liquefied natural gas. The obtained dependence of the mass flow rate of vapor condensation gas temperature. Identified the possibility of regulating the process of “cooling down” liquefied natural gas in terms of its partial evaporation with low cost energy.

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

International Nuclear Information System (INIS)

Girish Srinivas; Steven C. Gebhard; David W. DeBerry

2001-01-01

This first quarter report of 2001 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H(sub 2)S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf(trademark) (service mark of Gas Research Institute) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H(sub 2)S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H(sub 2)S in the natural gas is first oxidized to SO(sub 2) at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H(sub 2)S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. During this reporting periods new catalyst formulations were tested. The experiments showed that the newest catalyst has slightly better performance, but catalyst TDA No.2 is still superior overall for use with the hybrid CrystaSulf process due to lower costs. Plans for catalyst pelletization and continued testing are described

Methanation process utilizing split cold gas recycle

Science.gov (United States)

Tajbl, Daniel G.; Lee, Bernard S.; Schora, Jr., Frank C.; Lam, Henry W.

1976-07-06

In the methanation of feed gas comprising carbon monoxide and hydrogen in multiple stages, the feed gas, cold recycle gas and hot product gas is mixed in such proportions that the mixture is at a temperature sufficiently high to avoid carbonyl formation and to initiate the reaction and, so that upon complete reaction of the carbon monoxide and hydrogen, an excessive adiabatic temperature will not be reached. Catalyst damage by high or low temperatures is thereby avoided with a process that utilizes extraordinarily low recycle ratios and a minimum of investment in operating costs.

Tax issues in structuring gas process arrangements

International Nuclear Information System (INIS)

Iverach, R.J.

1999-01-01

The current status of various tax issues regarding ownership, operation and financing of gas processing facilities in Canada was discussed. Frequently, energy companies are not taxed because of their large pools of un-depreciated capital cost and other resource related accounts. In addition, their time horizons for taxability are being extended in line with the expansion of their businesses. However, other investors are fully taxable, hence they wish to shelter their income through the use of tax efficient investment arrangements. This paper provides a detailed description of the tax treatment of gas processing facilities, tax implications of various structures between the producer and the investor such as lease, processing fee arrangements etc., and use of 'Canadian Renewable and Conservation Expense' (CRCE) for cogeneration projects within processing plants. All these need to be considered before completing a financing transaction involving a gas processing facility, since the manner in which the transaction is completed will determine the advantages and benefits from an income tax perspective. The accounting and legal aspects must be similarly scrutinized to ensure that the intended results for all parties are achieved. 8 figs

Cooling process in separation devices of krypton gas

Energy Technology Data Exchange (ETDEWEB)

Kimura, S; Sugimoto, K

1975-06-11

To prevent entry of impurities into purified gases and to detect leaks of heat exchanger in a separation and recovering device of krypton gas by means of liquefaction and distillation, an intermediate refrigerant having the same or slightly higher boiling point than that of gas to be cooled is used between the gas to be cooled (process gas) and refrigerant (nitrogen), and the pressure of the gas to be cooled is controlled to have a pressure higher than the intermediate refrigerant to cool the gas to be cooled.

Method of optimization of the natural gas refining process

Energy Technology Data Exchange (ETDEWEB)

Sadykh-Zade, E.S.; Bagirov, A.A.; Mardakhayev, I.M.; Razamat, M.S.; Tagiyev, V.G.

1980-01-01

The SATUM (automatic control system of technical operations) system introduced at the Shatlyk field should assure good quality of gas refining. In order to optimize the natural gas refining processes and experimental-analytical method is used in compiling the mathematical descriptions. The program, compiled in Fortran language, in addition to parameters of optimal conditions gives information on the yield of concentrate and water, concentration and consumption of DEG, composition and characteristics of the gas and condensate. The algorithm for calculating optimum engineering conditions of gas refining is proposed to be used in ''advice'' mode, and also for monitoring progress of the gas refining process.

THE CHARACTERISTICS OF THE PRODUCTION AND PROCESSING OF OIL AND NATURAL GAS IN CROATIA FROM 2000 TO 2014

Directory of Open Access Journals (Sweden)

Josipa Velić

2016-06-01

Full Text Available This research analyzes the characteristics of the production and processing of oil, condensates and natural gas in the Republic of Croatia starting from 2000, until the end of 2014. Amounts of balance sheet (exploitable reserves of oil and condensates ranges from 9330,92 × 103 m3 in 2005, to 13 471,08 × 103 m3 in 2013, while extracted amounts are gradually declining from 1332,61 × 103 m3 to 639,96 × 103 m3. The ratio of extracted amounts and reserves is gradually declining, meaning that a slight increase in reserves does not affect the extracted amounts. Exploitable reserves of natural gas during the observed period fluctuate greatly. Being peaked in 2007, at 40,919.70 × 106 m3, they reached a low in 2014, at 17,932.98 × 106 m3. Unlike liquid hydrocarbons, the ratio of extracted and exploitable amounts is growing and peaked in 2014. Overall energy demands for oil in Croatia (shown as total consumption of crude oil amounted to 3032,8 × 103 m3 in 2013, while demands for natural gas amounted to 2809,90 × 106 m3. It is interesting to note that the consumption of oil is rapidly declining, which is a favorable trend from the standpoint of reducing emissions of greenhouse gases. While needs are partly covered by domestic exploitation, the dependence on imports of oil and natural gas is still evident and ranges from 75% to 84% for oil and 28% to 46% for natural gas, without major changes to the trend. The amounts of processed hydrocarbons are declining gradually, especially motor gasoline and fuel oil, while diesel fuel amounts remain mostly the same. Further research as well as development of the exploitation of oil and natural gas is of paramount importance, especially by investing in cadre education and new technologies.

Mechanistic Processes Controlling Gas Sorption in Shale Reservoirs

Science.gov (United States)

Schaef, T.; Loring, J.; Ilton, E. S.; Davidson, C. L.; Owen, T.; Hoyt, D.; Glezakou, V. A.; McGrail, B. P.; Thompson, C.

2014-12-01

Utilization of CO2 to stimulate natural gas production in previously fractured shale-dominated reservoirs where CO2 remains in place for long-term storage may be an attractive new strategy for reducing the cost of managing anthropogenic CO2. A preliminary analysis of capacities and potential revenues in US shale plays suggests nearly 390 tcf in additional gas recovery may be possible via CO2 driven enhanced gas recovery. However, reservoir transmissivity properties, optimum gas recovery rates, and ultimate fate of CO2 vary among reservoirs, potentially increasing operational costs and environmental risks. In this paper, we identify key mechanisms controlling the sorption of CH4 and CO2 onto phyllosilicates and processes occurring in mixed gas systems that have the potential of impacting fluid transfer and CO2 storage in shale dominated formations. Through a unique set of in situ experimental techniques coupled with molecular-level simulations, we identify structural transformations occurring to clay minerals, optimal CO2/CH4 gas exchange conditions, and distinguish between adsorbed and intercalated gases in a mixed gas system. For example, based on in situ measurements with magic angle spinning NMR, intercalation of CO2 within the montmorillonite structure occurs in CH4/CO2 gas mixtures containing low concentrations (hydrocarbon recovery processes.

METHODS FOR ORGANIZATION OF WORKING PROCESS FOR GAS-DIESEL ENGINE

Directory of Open Access Journals (Sweden)

G. A. Vershina

2017-01-01

Full Text Available Over the past few decades reduction in pollutant emissions has become one of the main directions for further deve- lopment of engine technology. Solution of such problems has led to implementation of catalytic post-treatment systems, new technologies of fuel injection, technology for regulated phases of gas distribution, regulated turbocharger system and, lately, even system for variable compression ratio of engine. Usage of gaseous fuel, in particular gas-diesel process, may be one of the means to reduce air pollution caused by toxic substances and meet growing environmental standards and regulations. In this regard, an analysis of methods for organization of working process for a gas-diesel engine has been conducted in the paper. The paper describes parameters that influence on the nature of gas diesel process, it contains graphics of specific total heat consumption according to ignition portion of diesel fuel and dependence of gas-diesel indices on advance angle for igni-tion portion injection of the diesel fuel. A modern fuel system of gas-diesel engine ГД-243 has been demonstrated in the pa- per. The gas-diesel engine has better environmental characteristics than engines running on diesel fuel or gasoline. According to the European Natural & bio Gas Vehicle Association a significant reduction in emissions is reached at a 50%-substitution level of diesel fuel by gas fuel (methane and in such a case there is a tendency towards even significant emission decrease. In order to ensure widespread application of gaseous fuel as fuel for gas-diesel process it is necessary to develop a new wor- king process, to improve fuel equipment, to enhance injection strategy and fuel supply control. A method for organization of working process for multi-fuel engine has been proposed on the basis of the performed analysis. An application has been submitted for a patent.

FY 1999 report on the results of the R and D of the substituting gas system and the substituting process of the etching gas used in the electronic device production process; 1999 nendo denshi device seizo process de shiyosuru etching gas no daitai gas system oyobi daitai process no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

As to the dry etching process and the wiring process where PFC gas and electric power are required most in the electronic device production process, an investigational study was conducted with the aim of PFC saving and energy saving, and the FY 1999 results were summed up. In the study, high efficiency etching process analysis equipment was developed, and three kinds of PFC gas quantitative analysis method were comparatively studied. Relating to the substitution of global environmental warming gas, it was found that C{sub x}F{sub y} type gas was effective which includes no oxygen, has a lot of carbon element numbers, and has double unsaturated bond. Further, in the study of the technology of PFC decomposition by plasma, it was indicated that PFC of 98.7% at maximum in exhaust gas could be removed on ideal conditions. In the dry etching technology by non-PFC gas of the organic insulating film, it was found out that NH{sub 3} base gas is more excellent in both shape and speed of etching than the existing O{sub 2} base one. As to the future wiring technology, new concepts of the optical wiring inside chip, etc. were proposed. (NEDO)

Heat-reactivatable adsorbent gas fractionator and process

International Nuclear Information System (INIS)

Verrando, M.G.

1982-01-01

A process and apparatus are provided for removing a first polar gas from a mixture thereof with a second gas. The gas mixture is passed through a sorbent bed having a preferential affinity for the first polar gas and the first polar gas is sorbed thereon so as to produce a gaseous effluent which has a concentration of first polar gas therein below a predetermined maximum. Then the polar gas sorbed on the sorbent bed is removed therefrom by application of microwave energy, at a temperature at which the sorbent is transparent to such energy, while passing a purge flow of gas in contact with the bed to flush out desorbed first polar gas from the bed. The bed is allowed to cool to a relatively efficient temperature for adsorption. The gas mixture is then again passed in contact with the bed. If two beds are used, one bed can be desorbed while the other is on-stream thereby maintaining a substantially continuous flow of effluent gas. The apparatus of the invention provides a sorbent bed assembly having a microwave energy generator positioned to direct such energy into the sorbent bed for desorption of first polar gas from the bed

Diagnostic significance of lung ventilation study with sup(81m)Kr gas

International Nuclear Information System (INIS)

Narabayashi, Isamu; Ito, Yasuhiko; Ohtsuka, Nobuaki; Muranaka, Akira; Yokobayashi, Tsuneo

1979-01-01

Lung ventilation study was performed on 43 patients by the continuous inhalation of sup(81m)Kr gas from a 81 Rb-sup(81m)Kr generator (Nihon Mediphysics Inc. Hyogo Japan). The patients were measured in a sitting position using a scintillation camera in conjunction with a data processor. In 37 cases, scintigraphic findings were compared with those of sup(99m)Tc-MAA images. We discussed the ventilation/perfusion mismatching cases, especially in those of the pulmonary arterial abnormarity and lung cancer. In some of the discrepancy between ventilation and perfusion, nuclear angiography with sup(99m)Tc-HSA was performed. The following results were obtained by those studies. 1) The distribution of sup(81m)Kr gas within the lung is considered proportional to regional ventilation because of a short half life of sup(81m)Kr (13 seconds). 2) The ventilation image with sup(81m)Kr gas was clearly visualized because of the lower gamma-ray energy and much accumulation of activity. 3) Combined use of ventilation-perfusion scintigraphy and nuclear angiography often gave us new additional informations about the pathophysiological condition of lung. 4) In mismatching cases of lung cancer, perfusion was usually more impaired than ventilation. (author)

Process for selected gas oxide removal by radiofrequency catalysts

Science.gov (United States)

Cha, Chang Y.

1993-01-01

This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

Gas-cooled reactor thermal-hydraulics using CAST3M and CRONOS2 codes

International Nuclear Information System (INIS)

Studer, E.; Coulon, N.; Stietel, A.; Damian, F.; Golfier, H.; Raepsaet, X.

2003-01-01

The CEA R and D program on advanced Gas Cooled Reactors (GCR) relies on different concepts: modular High Temperature Reactor (HTR), its evolution dedicated to hydrogen production (Very High Temperature Reactor) and Gas Cooled Fast Reactors (GCFR). Some key safety questions are related to decay heat removal during potential accident. This is strongly connected to passive natural convection (including gas injection of Helium, CO 2 , Nitrogen or Argon) or forced convection using active safety systems (gas blowers, heat exchangers). To support this effort, thermal-hydraulics computer codes will be necessary tools to design, enhance the performance and ensure a high safety level of the different reactors. Accurate and efficient modeling of heat transfer by conduction, convection or thermal radiation as well as energy storage are necessary requirements to obtain a high level of confidence in the thermal-hydraulic simulations. To achieve that goal a thorough validation process has to ve conducted. CEA's CAST3M code dedicated to GCR thermal-hydraulics has been validated against different test cases: academic interaction between natural convection and thermal radiation, small scale in-house THERCE experiments and large scale High Temperature Test Reactor benchmarks such as HTTR-VC benchmark. Coupling with neutronics is also an important modeling aspect for the determination of neutronic parameters such as neutronic coefficient (Doppler, moderator,...), critical position of control rods...CEA's CAST3M and CRONOS2 computer codes allow this coupling and a first example of coupled thermal-hydraulics/neutronics calculations has been performed. Comparison with experimental data will be the next step with High Temperature Test Reactor experimental results at nominal power

Economics of natural gas conversion processes

International Nuclear Information System (INIS)

Gradassi, M.J.; Green, N.W.

1995-01-01

This paper examines the potential profitability of a selected group of possible natural gas conversion processes from the perspective of a manufacturing entity that has access to substantial low cost natural gas reserves, capital to invest, and no allegiance to any particular product. The analysis uses the revenues and costs of conventional methanol technology as a framework to evaluate the economics of the alternative technologies. Capital requirements and the potential to enhance cash margins are the primary focus of the analysis. The basis of the analysis is a world-scale conventional methanol plant that converts 3.2 Mm 3 per day (120 MMSCFD) of natural gas into 3510 metric tonnes (3869 shorts tons) per day of methanol. Capital and operating costs are for an arbitrary remote location where natural gas is available at 0.47 US dollars per GJ (0.50 US dollars per MMBtu). Other costs include ocean freight to deliver the product to market at a US Gulf Coast location. Payout time, which is the ratio of the total capital investment to cash margin (revenue less total operating expenses), is the economic indicator for the analysis. Under these conditions, the payout time for the methanol plant is seven years. The payout time for the alternative natural gas conversion technologies is generally much higher, which indicates that they currently are not candidates for commercialization without consideration of special incentives. The analysis also includes an evaluation of the effects of process yields on the economics of two potential technologies, oxidative coupling to ethylene and direct conversion to methanol. This analysis suggests areas for research focus that might improve the profitability of natural gas conversion. 29 refs., 14 figs., 5 tabs

Gas phase decontamination of gaseous diffusion process equipment

International Nuclear Information System (INIS)

Bundy, R.D.; Munday, E.B.; Simmons, D.W.; Neiswander, D.W.

1994-01-01

D ampersand D of the process facilities at the gaseous diffusion plants (GDPs) will be an enormous task. The EBASCO estimate places the cost of D ampersand D of the GDP at the K-25 Site at approximately $7.5 billion. Of this sum, nearly $4 billion is associated with the construction and operation of decontamination facilities and the dismantlement and transport of contaminated process equipment to these facilities. In situ long-term low-temperature (LTLT) gas phase decontamination is being developed and demonstrated at the K-25 site as a technology that has the potential to substantially lower these costs while reducing criticality and safeguards concerns and worker exposure to hazardous and radioactive materials. The objective of gas phase decontamination is to employ a gaseous reagent to fluorinate nonvolatile uranium deposits to form volatile LJF6, which can be recovered by chemical trapping or freezing. The LTLT process permits the decontamination of the inside of gas-tight GDP process equipment at room temperature by substituting a long exposure to subatmospheric C1F for higher reaction rates at higher temperatures. This paper outlines the concept for applying LTLT gas phase decontamination, reports encouraging laboratory experiments, and presents the status of the design of a prototype mobile system. Plans for demonstrating the LTLT process on full-size gaseous diffusion equipment are also outlined briefly

Process gas solidification system

International Nuclear Information System (INIS)

1980-01-01

A process for withdrawing gaseous UF 6 from a first system and directing same into a second system for converting the gas to liquid UF 6 at an elevated temperature, additionally including the step of withdrawing the resulting liquid UF 6 from the second system, subjecting it to a specified sequence of flash-evaporation, cooling and solidification operations, and storing it as a solid in a plurality of storage vessels. (author)

Union Gas and Ontario gas production

International Nuclear Information System (INIS)

Cameron, C.

2001-01-01

A step-by-step review of the tie-in process of new production wells into the Union Gas System is described. Requirements of the producer and those of Union Gas are explained. Also described are the choices available to the producer to sell his gas. He can sell either to Union Gas directly at an agreed upon price, or the producer has the option to have what is called an M13 contract which allows him to sell his gas at Dawn, where it can be stored within parameters of the contract, and sold to any buyer at Dawn at a negotiated rate. This arrangement, while entailing a much greater administrative load than direct sale to Union Gas, nevertheless, allows the producer to take advantage of market fluctuations. A third option provided by Union Gas is to make available to the producer storage space greater than the provisions of the M13 contract at current market rate, thereby opening up the opportunity to the producer to capture additional value in later winter months (when gas is in greater demand)

Thermodynamic and Process Modelling of Gas Hydrate Systems in CO2 Capture Processes

DEFF Research Database (Denmark)

Herslund, Peter Jørgensen

A novel gas separation technique based on gas hydrate formation (solid precipitation) is investigated by means of thermodynamic modeling and experimental investigations. This process has previously been proposed for application in post-combustion carbon dioxide capture from power station flue gases...... formation may be performed at pressures of approximately 20 MPa and temperatures below 280 K. Thermodynamic promoters are needed, to reduce the pressure requirement of the process, thereby making it competitive to existing capture technologies. A literature study is presented focusing mainly...... on thermodynamic gas hydrate promotion by hydrate formers stabilising the classical gas clathrate hydrate structures (sI, sII and sH) at low to moderate pressures. Much literature is available on this subject. Both experimental and theoretical studies presented in the literature have pointed out cyclopentane...

Gas treatment processes for keeping the environment of nuclear plants free from gas-borne activity

International Nuclear Information System (INIS)

Schiller, H.

1977-01-01

The separation processes in gas treatment steps for the decontamination of circuit or offgas streams are described and their practicability is evaluated. Examples of the effectiveness of gas separation plants for keeping the environment within and without nuclear plants free from harmful gas-borne activity are presented. (orig.) [de

A Rapid Process for Fabricating Gas Sensors

Directory of Open Access Journals (Sweden)

Chun-Ching Hsiao

2014-07-01

Full Text Available Zinc oxide (ZnO is a low-toxicity and environmentally-friendly material applied on devices, sensors or actuators for “green” usage. A porous ZnO film deposited by a rapid process of aerosol deposition (AD was employed as the gas-sensitive material in a CO gas sensor to reduce both manufacturing cost and time, and to further extend the AD application for a large-scale production. The relative resistance change (△R/R of the ZnO gas sensor was used for gas measurement. The fabricated ZnO gas sensors were measured with operating temperatures ranging from 110 °C to 180 °C, and CO concentrations ranging from 100 ppm to 1000 ppm. The sensitivity and the response time presented good performance at increasing operating temperatures and CO concentrations. AD was successfully for applied for making ZnO gas sensors with great potential for achieving high deposition rates at low deposition temperatures, large-scale production and low cost.

Detection of solvent losses (entrainment) in gas streams of process vessels using radioisotope tracing techniques

International Nuclear Information System (INIS)

Wan Zakaria Wan Muhamad Tahir; Juhari Mohd Yusof

2002-01-01

Liquid droplets (MDEA aqueous solution) entrained in the gas streams can cause severe problems on chemical plants. On-line detection of liquid entrainment (carry over) into gas streams from process vessel is investigated using radioisotope iodine ( 131 I). In order to obtain information on whether there is any carry-over of MDEA in the vapour space leaving from the process system, a number of test and calibration injections involving the released of certain amount of tracer activity (mCi) at the inlet and overhead lines of the process vessels were made using a special injection device. MDEA solvent- tagged tracer in the overhead line of the designated process vessels was monitored using radiation scintillation detectors mounted externally at specified locations of the vessels. Output pulses (response curves) with respect to time of measurements from all detectors were plotted and analysed for the finger prints of solvent losses leaving the vessels. From this study, no distinguishable peaks were detected at the outlet vessels of the overhead lines. Thus, no significant MDEA solvent losses in the form of vapour being discovered along the gas streams due to the process taking place in the system. (Author)

Process for generating substitute natural gas. Verfahren zur Erzeugung von Erdgasersatzgas

Energy Technology Data Exchange (ETDEWEB)

Messerschmidt, D

1984-09-13

The invention deals with a process for the production of a substitute for natural gas from coal gas or other feed gases containing hydrogen and methane. For a simpler and economically more efficient process it is suggested to separate the feed gas, purified or unpurified, by selection of the molar sieve in a PSA plant so that the sweep gas of the PSA plant can reach the quality of a substitute gas. (orig.).

Integrated approach to gas accumulation identification in Field M

International Nuclear Information System (INIS)

Malyshevskaya, K; Rukavishnikov, V; Belozerov, B; Podnebesnikh, A

2015-01-01

The given paper describes how the integration of different methods, such as core data, well logs, production logging, seismic data and well test analysis, was used to solve the problem of determining gas accumulation boundaries in sediment complex PK1-3 of Field M. This paper is devoted to the block with wells 2, 36, 49, 85, 127, 148 of the field, since it is characterized by high uncertainty, sc. recently drilled wells 1V, 2V and 120 have produced oil, although according to the present-day geological concept they were considered to be gas saturated in the intervals investigated with production logging. Besides, well 127 that was presumably oil saturated has produced gas. By accounting mismatching production data and the geological concept, the authors have supposed that PK1-3 gas accumulation is characterized by a more complex structure than it was supposed by the predecessors and it is represented by reservoir compartmentalization and high heterogeneity. Therefore, the main goal of the work was to revise the distribution of gas saturated reservoir within the PK1-3 sediment complex. To achieve this goal, the authors have set the following tasks: to revise the geological correlation and gas oil contact; to carry out fault interpretation by means of seismic and well test data; to determine areal facies distribution on the basis of integrated core, perform a log motifs and seismic facies analysis. Thus, the estimation of the gas saturated reservoir portion was implemented in two stages: defining the boundary of gas accumulation in depth on the basis of well logs, production data and fault interpretation; reservoir distribution determination on the basis of the seismic facies analysis within the derived gas accumulation boundary

Treatment of gas from an in situ conversion process

Science.gov (United States)

Diaz, Zaida [Katy, TX; Del Paggio, Alan Anthony [Spring, TX; Nair, Vijay [Katy, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX

2011-12-06

A method of producing methane is described. The method includes providing formation fluid from a subsurface in situ conversion process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. At least the olefins in the first gas stream are contacted with a hydrogen source in the presence of one or more catalysts and steam to produce a second gas stream. The second gas stream is contacted with a hydrogen source in the presence of one or more additional catalysts to produce a third gas stream. The third gas stream includes methane.

The evolution of gasification processes and reactors and the utilization of the coal gas. A proposition for the implementation of the gasification technology

International Nuclear Information System (INIS)

Pasculete, E.; Iorgulescu, S.

1996-01-01

Thermochemical treatment of coal by gasification, considered as a non-polluting technology to turn the coal highly-profitably is one of the alternative ways to produce gas with a high effective caloric capacity. Due to its advantages, the gasification has made through the last few decades significant advances from the point of view of the process efficiency (chemical, thermal), of motor outputs (in m 3 producer gas / m 2 reactor cross section x hour), of the solutions of supplying energy to support the endothermic reactions implied by the process, and especially of the reactors. Reactors have been developed from gas generators. Starting from gas generators various advanced reactors (of 1 st to 3 rd generation) have been developed to produce air gas, water gas or mixed gas. Applications of the producer gas were developed using it either as fuel or as synthesis gas in chemical industry or else as a substitute to the natural gas in combined cycle gas turbines where the gasification plant was integrated. In Romania there are projects in the field of coal gasification, namely at ICPET-RESEARCH, that can offer advanced technologies. One of these projects deals with the construction of the first demonstrative gasification plant based on a highly efficient process and equipped with a 10 G cal/h reactor. (author). 1 tab., 12 refs

System evaluation of offshore platforms with gas liquefaction processes

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; de Oliveira Júnior, Silvio

2018-01-01

Abstract Floating, production, storage and offloading plants are facilities used for offshore processing of hydrocarbons in remote locations. At present, the produced gas is injected back into the reservoir instead of being exported. The implementation of refrigeration processes offshore for liqu......Abstract Floating, production, storage and offloading plants are facilities used for offshore processing of hydrocarbons in remote locations. At present, the produced gas is injected back into the reservoir instead of being exported. The implementation of refrigeration processes offshore...... improvements are discussed based on an energy and exergy analysis. Compared to a standard platform where gas is directly injected into the reservoir, the total power consumption increases by up to 50%, and the exergy destruction within the processing plant doubles when a liquefaction system is installed....... It is therefore essential to conduct a careful analysis of the trade-off between the capital costs and operating revenues for such options....

Application of Module System for Processing a Large Capacity of Coal Steam Power Plant Flue gas by Electron Beam Machine

International Nuclear Information System (INIS)

Rukijatmo; Munawir Z, M.

2003-01-01

Conceptual design of SOx dan NOx flue gas treatment base on 25% of 400 M We capacity and 90% efficiency reduction of SOx, the electron beam machine will be utilized to performed the environment quality standard of air pollution. The technical specification of electron beam machine, processing system and chamber dimension should conformed to the regulation. The discussion is focused on the selection of electron beam machine type and the dimension of radiation vessel for perfect reaction and exact time processing. The design calculation is indicated that we need two electron beam machines of 500 mA, 800 kV installed in parallel and 3 up to 3.4 metres diameter, the speed of flue gas in the vessel around 16.4 up to 18.14 metre per second, 80% treatment of 0,7% sulphur content coal is conform to regulation on emission of flue gas environment, and only 50% of flue gas needed to be treated by 4 modular. (author)

The Integration Of Process Heat Applications To High Temperature Gas Reactors

International Nuclear Information System (INIS)

McKellar, Michael G.

2011-01-01

A high temperature gas reactor, HTGR, can produce industrial process steam, high-temperature heat-transfer gases, and/or electricity. In conventional industrial processes, these products are generated by the combustion of fossil fuels such as coal and natural gas, resulting in significant emissions of greenhouse gases such as carbon dioxide. Heat or electricity produced in an HTGR could be used to supply process heat or electricity to conventional processes without generating any greenhouse gases. Process heat from a reactor needs to be transported by a gas to the industrial process. Two such gases were considered in this study: helium and steam. For this analysis, it was assumed that steam was delivered at 17 MPa and 540 C and helium was delivered at 7 MPa and at a variety of temperatures. The temperature of the gas returning from the industrial process and going to the HTGR must be within certain temperature ranges to maintain the correct reactor inlet temperature for a particular reactor outlet temperature. The returning gas may be below the reactor inlet temperature, ROT, but not above. The optimal return temperature produces the maximum process heat gas flow rate. For steam, the delivered pressure sets an optimal reactor outlet temperature based on the condensation temperature of the steam. ROTs greater than 769.7 C produce no additional advantage for the production of steam.

Elimination of methane in exhaust gas from biogas upgrading process by immobilized methane-oxidizing bacteria.

Science.gov (United States)

Wu, Ya-Min; Yang, Jing; Fan, Xiao-Lei; Fu, Shan-Fei; Sun, Meng-Ting; Guo, Rong-Bo

2017-05-01

Biogas upgrading is essential for the comprehensive utilization of biogas as substitute of natural gas. However, the methane in the biogas can be fully recovered during the upgrading process of biogas, and the exhaust gas produced during biogas upgrading may contain a very low concentration of methane. If the exhaust gas with low concentration methane releases to atmosphere, it will be harmful to environment. In addition, the utilization of large amounts of digestate produced from biogas plant is another important issue for the development of biogas industry. In this study, solid digestate was used to produce active carbon, which was subsequently used as immobilized material for methane-oxidizing bacteria (MOB) in biofilter. Biofilter with MOB immobilized on active carbon was used to eliminate the methane in exhaust gas from biogas upgrading process. Results showed porous active carbon was successfully made from solid digestate. The final methane elimination capacity of immobilized MOB reached about 13molh -1 m -3 , which was more 4 times higher than that of MOB without immobilization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Process development report: 0.20-m primary burner system

International Nuclear Information System (INIS)

Rickman, W.S.

1978-09-01

HTGR reprocessing consists of crushing the spent fuel elements to a size suitable for burning in a fluidized bed to remove excess graphite, separating the fissile and fertile particles, crushing and burning the SiC-coated fuel particles to remove the remainder of the carbon, dissolution and separation of the particles from insoluble materials, and solvent extraction separation of the dissolved uranium and thorium. Burning the crushed fuel elements is accomplished in a primary burner. This is a batch-continuous, fluidized-bed process utilizing above-bed gravity fines recycle. In gas-solid separation, a combination of a cyclone and porous metal filters is used. This report documents operational tests performed on a 0.20-m primary burner using crushed fuel representative of both Fort St. Vrain and large high-temperature gas-cooled reactor cores. The burner was reconstructed to a gravity fines recycle mode prior to beginning these tests. Results of two separate and successful 48-hour burner runs and several short-term runs have indicated the operability of this concept. Recommendations are made for future work

Significant Variables in the Combustion Process of Natural Gas

OpenAIRE

Villaflor, Gloria; Morales, Graciela V; Velasco, Jorge

2008-01-01

Se determinan las variables significativas del proceso de combustión de gas natural, aquellas más sensibles para producir cambios importantes desde punto de vista económico y medioambiental. Con este fin se realiza la simulación del proceso de combustión de gas natural, utilizando el simulador comercial HYSYS. Se determina que las variables de operación más sensibles para este proceso son la temperatura del aire, la temperatura de los gases de combustión y el exceso de aire usado en la combus...

Mathematical simulation of the process of condensing natural gas

OpenAIRE

Tastandieva G.M.

2015-01-01

Presents a two-dimensional unsteady model of heat transfer in terms of condensation of natural gas at low temperatures. Performed calculations of the process heat and mass transfer of liquefied natural gas (LNG) storage tanks of cylindrical shape. The influence of model parameters on the nature of heat transfer. Defined temperature regimes eliminate evaporation by cooling liquefied natural gas. The obtained dependence of the mass flow rate of vapor condensation gas temperature. Identified the...

Gasoline from natural gas by sulfur processing

Energy Technology Data Exchange (ETDEWEB)

Erekson, E.J.; Miao, F.Q. [Institute of Gas Technology, Des Plaines, IL (United States)

1995-12-31

The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process, called the HSM (Hydrogen Sulfide-Methane) Process, consists of two steps that each utilize a catalyst and sulfur-containing intermediates: (1) converting natural gas to CS{sub 2} and (2) converting CS{sub 2} to gasoline range liquids. Catalysts have been found that convert methane to carbon disulfide in yields up to 98%. This exceeds the target of 40% yields for the first step. The best rate for CS{sub 2} formation was 132 g CS{sub 2}/kg-cat-h. The best rate for hydrogen production is 220 L H{sub 2} /kg-cat-h. A preliminary economic study shows that in a refinery application hydrogen made by the HSM technology would cost $0.25-R1.00/1000 SCF. Experimental data will be generated to facilitate evaluation of the overall commercial viability of the process.

Floating natural gas processing plants. Technical ideal or feasible technology

Energy Technology Data Exchange (ETDEWEB)

Backhaus, H

1977-04-01

Realizability of floating natural gas processing plants is decisively influenced by the economy of the system. Illustrated by the example of the natural gas product LPG (liquefied petroleum gas), a model cost calculation is carried out. It is demonstrated that the increase in the price level during the 1973/1974 energy crisis is an important factor for the realiability in terms of economy of such complicated technical systems. Another aspect which the model calculation revealed is that the economy of floating natural gas processing plants and storage systems can only be estimated in connection with other system components.

Uranium enrichment in Europe by the gas centrifuge process

International Nuclear Information System (INIS)

Severin, D.J.E.

1975-01-01

To begin with, this lesson gives an outline of the expected energy demand of the Western World and the concentration of the European companies participating in uranium enrichment by the gas centrifuge method. Next, a) the principles of the gas centrifuge method are outlined, b) its advantages over other industrial processes are stressed, and c) the characteristic data of complete plants are given. The existing German, Dutch, and British pilot plants are mentioned as examples for the perfected state of the process. The Capenhurst (UK) and Almedo (NL) demonstration plants, each with a capacity of 200 t SW/a, will have been extended to 2 x 1.000 t SW/a by 1982. Finally, economic data of the gas centrifuge process are given. The term 'separative work' is explained in an annex. (GG) [de

Overview of gas processing fee practices in Canada

International Nuclear Information System (INIS)

Swenson, R.W.

1999-01-01

The negotiation of gas processing fees from the perspective of the natural gas producer are summarized. Some of the topics discussed are: evaluation of fee proposals, capital cost estimates, pipeline capital fees, compressor capital fees, plant capital fees, upper and lower limits on fees, (JP-90 and JP-95), negotiation options, operating costs, production allocation, and processing agreements. Several case studies involving one or more of these items were reviewed by way of illustration. The importance of documentation of all agreements, changes to agreements, commitments, etc., was stressed

Method and apparatus for rapid adjustment of process gas inventory in gaseous diffusion cascades

International Nuclear Information System (INIS)

1980-01-01

A method is specified for the operation of a gaseous diffusion cascade wherein electrically driven compressors circulate a process gas through a plurality of serially connected gaseous diffusion stages to establish first and second countercurrently flowing cascade streams of process gas, one of the streams being at a relatively low pressure and enriched in a component of the process gas and the other being at a higher pressure and depleted in the same, and wherein automatic control systems maintain the stage process gas pressures by positioning process gas flow control valve openings at values which are functions of the difference between reference-signal inputs to the systems, and signal inputs proportional to the process gas pressures in the gaseous diffusion stages associated with the systems, the cascade process gas inventory being altered, while the cascade is operating, by simultaneously directing into separate process-gas freezing zones a plurality of substreams derived from one of the first and second streams at different points along the lengths thereof to solidify approximately equal weights of process gas in the zone while reducing the reference-signal inputs to maintain the positions of the control valves substantially unchanged despite the removal of process gas inventory via the substreams. (author)

Study of Catalyst Variation Effect in Glycerol Conversion Process to Hydrogen Gas by Steam Reforming

Science.gov (United States)

Widayat; Hartono, R.; Elizabeth, E.; Annisa, A. N.

2018-04-01

Along with the economic development, needs of energy being increase too. Hydrogen as alternative energy has many usages. Besides that, hydrogen is one source of energy that is a clean fuel, but process production of hydrogen from natural gas as a raw material has been used for a long time. Therefore, there is need new invention to produce hydrogen from the others raw material. Glycerol, a byproduct of biodiesel production, is a compound which can be used as a raw material for hydrogen production. By using glycerol as a raw material of hydrogen production, we can get added value of glycerol as well as an energy source solution. The process production of hydrogen by steam reforming is a thermochemical process with efficiency 70%. This process needs contribution of catalyst to improve its efficiency and selectivity of the process. In this study will be examined the effect variation of catalyst for glycerol conversion process to hydrogen by steam reforming. The method for catalyst preparation was variation of catalyst impregnation composition, catalyst calcined with difference concentration of hydrochloric acid and calcined with difference hydrochloric acid ratio. After that, all of catalyst which have been prepared, used for steam reforming process for hydrogen production from glycerol as a raw material. From the study, the highest yield of hydrogen gas showed in the process production by natural zeolite catalyst with 1:15 Hydrochloric acid ratio was 42.28%. Hydrogen yield for 2M calcined natural zeolite catalyst was 38.37%, for ZSM-5 catalyst was 15.83%, for 0.5M calcined natural zeolite was 13.09% and for ultrasonic natural zeolite was 11.43%. The lowest yield of hydrogen gas showed in catalyst 2Zn/ZSM-5 with 11.22%. This result showed that hydrogen yield product was affected by catalyst variation because of the catalyst has difference characteristic and difference catalytic activity after the catalyst preparation process.

Portable spectrometer monitors inert gas shield in welding process

Science.gov (United States)

Grove, E. L.

1967-01-01

Portable spectrometer using photosensitive readouts, monitors the amount of oxygen and hydrogen in the inert gas shield of a tungsten-inert gas welding process. A fiber optic bundle transmits the light from the welding arc to the spectrometer.

Process Investigation of Tube Expansion by Gas Detonation

OpenAIRE

Bach, F.-W.; Beerwald, C.; Brosius, A.; Gershteyn, G.; Hermes, M.; Kleiner, M.; Olivier, H.; Weber, M.

2006-01-01

The present paper deals with the expansion of tubes by direct application of gas detonation waves, i.e. the gas is both pressure medium and energy source. After an introduction to gas detonation forming, measurements of the motion process and the internal pressures are presented. Results of free expansion and of forming into a die are thoroughly studied and compared to the results of quasi-static burst tests and hydroforming. Using pure aluminum Al99.5 and a medium strength alloy AlMgSi1, ...

Technical characterization and economic evaluation of recovery of flare gas in various gas-processing plants

International Nuclear Information System (INIS)

Zolfaghari, Mohabbat; Pirouzfar, Vahid; Sakhaeinia, Hossein

2017-01-01

Today in the worldwide quest for production and economic preference, only industries will survive that have proper solutions for waste disposal and environmental pollution. In industrial applications, a blow down network of gases is used in order to control system pressure and safety instruments. At the end of this network, the excess gases are burnt in the flare tower, which have severe consequences on the environment. Different methods have been proposed and several alternatives have been introduced for reduction and recovery of flaring gases. In this paper, three methods including gas to liquid (GTL), gas turbines generation (GTG) and gas to ethylene (GTE) are introduced and compared with the best method from economic point of view being identified. For this purpose, a natural gas sample is taken from Asalloyeh Refinery Plant and the process has been simulated using Aspen HYSYS. Meanwhile, estimation of the capital and operating costs and evaluation of the processes involved were made using Aspen Capital Cost Estimator. According to the results obtained, production of the electric power from flaring gases is one of the most economical methods. GTG method, with an annual profit of about 480e+006 $, has a greater ROR percent. - Highlights: • Three methods including GTL, GTG and GTE are developed for flare gas recovery. • The processes has been simulated using Aspen HYSYS. • Estimation of the capital and operating costs of the processes were made. • According to the results obtained, GTG is one of the most economical methods. • GTE method has the highest annual benefit, it has the lowest ROR percent.

H/sub 2/S-removal processes for low-Btu coal gas

Energy Technology Data Exchange (ETDEWEB)

Edwards, M. S.

1979-01-01

Process descriptions are provided for seven methods of removing H/sub 2/S from a low-Btu coal-derived gas. The processes include MDEA, Benfield, Selexol, Sulfinol, Stretford, MERC Iron Oxide, and Molecular Sieve. Each of these processes was selected as representing a particular category of gas treating (e.g., physical solvent systems). The open literature contains over 50 processes for H/sub 2/S removal, of which 35 were briefly characterized in the literature survey. Using a technical evaluation of these 35 processes, 21 were eliminated as unsuitable for the required application. The remaining 14 processes represent six categories of gas treating. A seventh category, low-temperature solid sorption, was subsequently added. The processes were qualitatively compared within their respective categories to select a representative process in each of the seven categories.

Process for producing synthetic ammonia gas. Verfahren zur Erzeugung von Ammoniak-Synthesegas

Energy Technology Data Exchange (ETDEWEB)

Meckel, J F; Messerschmidt, D; Wagener, D

1984-01-12

The invention refers to a process for producing synthetic ammonia gas from gases containing hydrocarbons, which is reformed catalytically and autothermally with a synthesis gas containing oxygen and then subjected to conversion to synthesis gas containing carbon dioxide and hydrogen. In order to simplify the plant required for such a process, the invention provides that part of the gas main flow is subjected to a multistage alternating pressure absorption plant (PSA plant) in a bypass of the gas main flow and the separated hydrogen is returned to the remaining gas main flow, in order to set the required H/sub 2/N/sub 2/ ratio and that the fission gas is subject to carbon dioxide washing and methanizing after conversion. This process therefore does not need a pipe splitting furnace and enrichment of the air with oxygen.

mRNA processing in yeast

International Nuclear Information System (INIS)

Stevens, A.

1982-01-01

Investigations in this laboratory center on basic enzymatic reactions of RNA. Still undefined are reactions involved in the conversion of precursors of mRA (pre-mRNA) to mRNA in eukaryotes. The pre-mRNA is called heterogeneous nuclear RNA and is 2 to 6 times larger than mRNA. The conversion, called splicing, involves a removal of internal sequences called introns by endoribonuclease action followed by a rejoining of the 3'- and 5'-end fragments, called exons, by ligating activity. It has not been possible yet to study the enzymes involved in vitro. Also undefined are reactions involved in the turnover or discarding of certain of the pre-mRNA molecules. Yeast is a simple eukaryote and may be expected to have the same, but perhaps simpler, processing reactions as the higher eukaryotes. Two enzymes involved in the processing of pre-mRNA and mRNA in yeast are under investigation. Both enzymes have been partially purified from ribonucleoprotein particles of yeast. The first is a unique decapping enzyme which cleaves [ 3 H]m 7 Gppp [ 14 C]RNA-poly (A) of yeast, yielding [ 3 H]m 7 GDP and is suggested by the finding that the diphosphate product, m 7 GpppA(G), and UDP-glucose are not hydrolyzed. The second enzyme is an endoribonuclease which converts both the [ 3 H] and [ 14 C] labels of [ 3 H]m 7 Gppp[ 14 C]RNA-poly(A) from an oligo(dT)-cellulose bound form to an unbound, acid-insoluble form. Results show that the stimulation involves an interaction of the labeled RNA with the small nuclear RNA. The inhibition of the enzyme by ethidium bromide and its stimulation by small nuclear RNA suggest that it may be a processing ribonuclease, requiring specific double-stranded features in its substrate. The characterization of the unique decapping enzyme and endoribonuclease may help to understand reactions involved in the processing of pre-mRNA and mRNA in eukaryotes

Laboratory modelling of the physico-chemical processes in the cosmic gas-dust clouds

International Nuclear Information System (INIS)

Bakulina, I.N.; Blashenkov, N.M.; Varshalovich, D.A.; Lavrent'ev, G.Ya.; Shustrov, B.N.

1980-01-01

The preliminary results of an experiment on the complex laboratory modelling of the physico-chemical processes proceeding in the interstellar gas clouds are presented. The purpose of the modelling is an analysis of the molecule formation and dissociation processes kinetics. The basic component of the modelling system is 10 cm diameter spherical container with cooled walls (the dust particles surface analogue). The high frequency discharger (the discharge region - the H 2 zone analogue) is placed in the central part of the container. The container contains the mixture of simple gases: 10 -1 Tor of H 2 and He, 10 -2 Tor of CO, O 2 and N 2 and 0.5x10 -2 Tor of H 2 S (an analogue of the H 1 zone). The reactions are induced by the electrodeless high-frequency discharge (f=20 MHz) with the discharge power of 0.1-1 W. The resulting mixture has been analyzed by the high-resolution magnetic resonance mass spectrometer. (M/ΔM=2x10 4 ) with an electron impact source. It is shown that, in the reactions of the formation of many on the interstellar molecules, the on the cold dust surface reactions rather than the gas-phase reactions may play the dominant role

HYBRID SULFUR RECOVERY PROCESS FOR NATURAL GAS UPGRADING

International Nuclear Information System (INIS)

Girish Srinivas; Steven C. Gebhard; David W. DeBerry

2002-01-01

This first quarter report of 2002 describes progress on a project funded by the U.S. Department of Energy (DOE) to test a hybrid sulfur recovery process for natural gas upgrading. The process concept represents a low cost option for direct treatment of natural gas streams to remove H(sub 2)S in quantities equivalent to 0.2-25 metric tons (LT) of sulfur per day. This process is projected to have lower capital and operating costs than the competing technologies, amine/aqueous iron liquid redox and amine/Claus/tail gas treating, and have a smaller plant footprint, making it well suited to both on-shore and offshore applications. CrystaSulf(sup SM) (service mark of CrystaTech, Inc.) is a new nonaqueous sulfur recovery process that removes hydrogen sulfide (H(sub 2)S) from gas streams and converts it into elemental sulfur. CrystaSulf features high sulfur recovery similar to aqueous-iron liquid redox sulfur recovery processes, but differs from the aqueous processes in that CrystaSulf controls the location where elemental sulfur particles are formed. In the hybrid process, approximately 1/3 of the total H(sub 2)S in the natural gas is first oxidized to SO(sub 2) at low temperatures over a heterogeneous catalyst. Low temperature oxidation is done so that the H(sub 2)S can be oxidized in the presence of methane and other hydrocarbons without oxidation of the hydrocarbons. The project involves the development of a catalyst using laboratory/bench-scale catalyst testing, and then demonstration of the catalyst at CrystaTech's pilot plant in west Texas. In a previous reporting period tests were done to determine the effect of hydrocarbons such as n-hexane on catalyst performance with and without H(sub 2)S present. The experiments showed that hexane oxidation is suppressed when H(sub 2)S is present. Hexane represents the most reactive of the C1 to C6 series of alkanes. Since hexane exhibits low reactivity under H(sub 2)S oxidation conditions, and more importantly, does not change

Gas permeation process for post combustion CO2 capture

International Nuclear Information System (INIS)

Pfister, Marc

2017-01-01

CO 2 Capture and Storage (CCS) is a promising solution to separate CO 2 from flue gas, to reduce the CO 2 emissions in the atmosphere, and hence to reduce global warming. In CCS, one important constraint is the high additional energy requirement of the different capture processes. That statement is partly explained by the low CO 2 fraction in the inlet flue gas and the high output targets in terms of CO 2 capture and purity (≥90%). Gas permeation across dense membrane can be used in post combustion CO 2 capture. Gas permeation in a dense membrane is ruled by a mass transfer mechanism and separation performance in a dense membrane are characterized by component's effective permeability and selectivity. One of the newest and encouraging type of membrane in terms of separation performance is the facilitated transport membrane. Each particular type of membrane is defined by a specific mass transfer law. The most important difference to the mass transfer behavior in a dense membrane is related to the facilitated transport mechanism and the solution diffusion mechanism and its restrictions and limitations. Permeation flux modelling across a dense membrane is required to perform a post combustion CO 2 capture process simulation. A CO 2 gas permeation separation process is composed of a two-steps membrane process, one drying step and a compression unit. Simulation on the energy requirement and surface area of the different membrane modules in the global system are useful to determine the benefits of using dense membranes in a post combustion CO 2 capture technology. (author)

Mixing process of a binary gas in a density stratified layer

Energy Technology Data Exchange (ETDEWEB)

Takeda, Tetsuaki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

1997-09-01

This study is to investigate the effect of natural convection on the mixing process by molecular diffusion in a vertical stratified layer of a binary fluid. There are many experimental and analytical studies on natural convection in the vertical fluid layer. However, there are few studies on natural convection with molecular diffusion in the vertical stratified layer of a binary gas. Experimental study has been performed on the combined phenomena of molecular diffusion and natural convection in a binary gas system to investigate the mixing process of the binary gas in a vertical slot consisting of one side heated and the other side cooled. The range of Rayleigh number based on the slot width was about 0 < Ra{sub d} < 7.5 x 10{sup 4}. The density change of the gas mixture and the temperature distribution in the slot was obtained and the mixing process when the heavier gas ingress into the vertical slot filled with the lighter gas from the bottom side of the slot was discussed. The experimental results showed that the mixing process due to molecular diffusion was affected significantly by the natural convection induced by the slightly temperature difference between both vertical walls even if a density difference by the binary gas is larger than that by the temperature difference. (author). 81 refs.

Measurements of gas parameters in plasma-assisted supersonic combustion processes using diode laser spectroscopy

International Nuclear Information System (INIS)

Bolshov, Mikhail A; Kuritsyn, Yu A; Liger, V V; Mironenko, V R; Leonov, S B; Yarantsev, D A

2009-01-01

We report a procedure for temperature and water vapour concentration measurements in an unsteady-state combustion zone using diode laser absorption spectroscopy. The procedure involves measurements of the absorption spectrum of water molecules around 1.39 μm. It has been used to determine hydrogen combustion parameters in M = 2 gas flows in the test section of a supersonic wind tunnel. The relatively high intensities of the absorption lines used have enabled direct absorption measurements. We describe a differential technique for measurements of transient absorption spectra, the procedure we used for primary data processing and approaches for determining the gas temperature and H 2 O concentration in the probed zone. The measured absorption spectra are fitted with spectra simulated using parameters from spectroscopic databases. The combustion-time-averaged (∼50 ms) gas temperature and water vapour partial pressure in the hot wake region are determined to be 1050 K and 21 Torr, respectively. The large signal-to-noise ratio in our measurements allowed us to assess the temporal behaviour of these parameters. The accuracy in our temperature measurements in the probed zone is ∼40 K. (laser applications and other topics in quantum electronics)

Integrated process for synthetic natural gas production from coal and coke-oven gas with high energy efficiency and low emission

International Nuclear Information System (INIS)

Man, Yi; Yang, Siyu; Qian, Yu

2016-01-01

Highlights: • A novel coal and coke-oven gas to SNG (CGtSNG) process is proposed. • Energy efficiency of CGtSNG increases 8% compared to coal-to-SNG process. • CGtSNG reduces 60% CO_2 emission and 72% effluent discharge. • CGtSNG proposes an idea of using redundant coke-oven gas for producing SNG production. - Abstract: There was a rapid development of coal to synthetic natural gas (SNG) projects in the last few years in China. The research from our previous work and some other researchers have found coal based SNG production process has the problems of environmental pollution and emission transfer, including CO_2 emission, effluent discharge, and high energy consumption. This paper proposes a novel co-feed process of coal and coke-oven gas to SNG process by using a dry methane reforming unit to reduce CO_2 emissions, more hydrogen elements are introduced to improve resource efficiency. It is shown that the energy efficiency of the co-feed process increases by 4%, CO_2 emission and effluent discharge is reduced by 60% and 72%, whereas the production cost decreases by 16.7%, in comparison to the conventional coal to SNG process. As coke-oven gas is a waste gas in most of the coking plant, this process also allows to optimize the allocation of resources.

A Systematic Procedure to Describe Shale Gas Permeability Evolution during the Production Process

Science.gov (United States)

Jia, B.; Tsau, J. S.; Barati, R.

2017-12-01

Gas flow behavior in shales is complex due to the multi-physics nature of the process. Pore size reduces as the in-situ stress increases during the production process, which will reduce intrinsic permeability of the porous media. Slip flow/pore diffusion enhances gas apparent permeability, especially under low reservoir pressures. Adsorption not only increases original gas in place but also influences gas flow behavior because of the adsorption layer. Surface diffusion between free gas and adsorption phase enhances gas permeability. Pore size reduction and the adsorption layer both have complex impacts on gas apparent permeability and non-Darcy flow might be a major component in nanopores. Previously published literature is generally incomplete in terms of coupling of all these four physics with fluid flow during gas production. This work proposes a methodology to simultaneously take them into account to describe a permeability evolution process. Our results show that to fully describe shale gas permeability evolution during gas production, three sets of experimental data are needed initially: 1) intrinsic permeability under different in-situ stress, 2) adsorption isotherm under reservoir conditions and 3) surface diffusivity measurement by the pulse-decay method. Geomechanical effects, slip flow/pore diffusion, adsorption layer and surface diffusion all play roles affecting gas permeability. Neglecting any of them might lead to misleading results. The increasing in-situ stress during shale gas production is unfavorable to shale gas flow process. Slip flow/pore diffusion is important for gas permeability under low pressures in the tight porous media. They might overwhelm the geomechanical effect and enhance gas permeability at low pressures. Adsorption layer reduces the gas permeability by reducing the effective pore size, but the effect is limited. Surface diffusion increases gas permeability more under lower pressures. The total gas apparent permeability might

Optimal design issues of a gas-to-liquid process

Energy Technology Data Exchange (ETDEWEB)

Rafiee, Ahmad

2012-07-01

Interests in Fischer-Tropsch (FT) synthesis is increasing rapidly due to the recent improvements of the technology, clean-burning fuels (low sulphur, low aromatics) derived from the FT process and the realization that the process can be used to monetize stranded natural gas resources. The economy of GTL plants depends very much on the natural gas price and there is a strong incentive to reduce the investment cost and in addition there is a need to improve energy efficiency and carbon efficiency. A model is constructed based on the available information in open literature. This model is used to simulate the GTL process with UNISIM DESIGN process simulator. In the FT reactor with cobalt based catalyst, Co2 is inert and will accumulate in the system. Five placements of Co2 removal unit in the GTL process are evaluated from an economical point of view. For each alternative, the process is optimized with respect to steam to carbon ratio, purge ratio of light ends, amount of tail gas recycled to syngas and FT units, reactor volume, and Co2 recovery. The results show that carbon and energy efficiencies and the annual net cash flow of the process with or without Co2 removal unit are not significantly different and there is not much to gain by removing Co2 from the process. It is optimal to recycle about 97 % of the light ends to the process (mainly to the FT unit) to obtain higher conversion of CO and H2 in the reactor. Different syngas configurations in a gas-to-liquid (GTL) plant are studied including auto-thermal reformer (ATR), combined reformer, and series arrangement of Gas Heated Reformer (GHR) and ATR. The Fischer-Tropsch (FT) reactor is based on cobalt catalyst and the degrees of freedom are; steam to carbon ratio, purge ratio of light ends, amount of tail gas recycled to synthesis gas (syngas) and Fischer-Tropsch (FT) synthesis units, and reactor volume. The production rate of liquid hydrocarbons is maximized for each syngas configuration. Installing a steam

Finite Element Modeling of Adsorption Processes for Gas Separation and Purification

International Nuclear Information System (INIS)

Humble, Paul H.; Williams, Richard M.; Hayes, James C.

2009-01-01

Pacific Northwest National Laboratory (PNNL) has expertise in the design and fabrication of automated radioxenon collection systems for nuclear explosion monitoring. In developing new systems there is an ever present need to reduce size, power consumption and complexity. Most of these systems have used adsorption based techniques for gas collection and/or concentration and purification. These processes include pressure swing adsorption, vacuum swing adsorption, temperature swing adsorption, gas chromatography and hybrid processes that combine elements of these techniques. To better understand these processes, and help with the development of improved hardware, a finite element software package (COMSOL Multiphysics) has been used to develop complex models of these adsorption based operations. The partial differential equations used include a mass balance for each gas species and adsorbed species along with a convection conduction energy balance equation. These equations in conjunction with multicomponent temperature dependent isotherm models are capable of simulating separation processes ranging from complex multibed PSA processes, and multicomponent temperature programmed gas chromatography, to simple two component temperature swing adsorption. These numerical simulations have been a valuable tool for assessing the capability of proposed processes and optimizing hardware and process parameters.

Electro-membrane processes for flue gas cleaning

Energy Technology Data Exchange (ETDEWEB)

Larsen, T. F.

1997-12-31

Various techniques for NO removal in Membrane Contactor were considered. However the NO absorption in a liquid adsorbent with chemical enhancement and its ease for regeneration, was selected as the most practicable choice. Various different compounds for chemical enhancement were studied and Fe(II)-chelate enhanced adsorbent was selected for further studies. The technical feasibility of Fe(II)-chelate enhanced adsorbent for obtaining greater than 80% NO removal have been successfully established. Even though the membrane area required for greater than 80% NO removal has been found to be about 500 m{sup 2}/MW{sub c} (compared to 50 - 150 m{sup 2}/MW{sub c}, for 95% SO{sub 2} removal, depending on the membrane characteristics), suitable Membrane Contactor design has been proposed for carrying out the process at an acceptable gas side pressure drop. The electro-membrane processes for the regeneration of adsorbents have been studied both theoretically and experimentally. The theoretical studies have concerned the study of basic functions of both the bipolar membranes and charge laden (anion/cation) membranes. Suitable experimental techniques have been devised for studying of these basic parameters (e.g. charge transport number, salt diffusion through membranes, current-voltage characteristics of bipolar membranes and electrical resistance of charge laden membranes). These parameters have further been utilized in the mechanistic model of combined membranes in an ED cell (electrodialysis). Based on these fundamental studies and analysis of process requirements, suitable configuration of ED cell has been developed and verified by experimental studies. The effect of both the stack design parameters (e.g. number of cells, membrane type and spacer design) and the operational parameters (e.g. temperature, electrolyte concentration, liquid velocity and current density) have been studied for optimization of energy consumption for regeneration of loaded adsorbents. As a result

Electron beam flue gas treatment process. Review

International Nuclear Information System (INIS)

Honkonen, V.A.

1996-01-01

The basis of the process for electron beam flue gas treatment are presented in the report. In tabular form the history of the research is reviewed. Main dependences of SO 2 and NO x removal efficiencies on different physico-chemical parameters are discussed. Trends concerning industrial process implementation are presented in the paper,finally. (author). 74 refs, 11 figs, 1 tab

WAG (water-alternating-gas) process design: an update review

Energy Technology Data Exchange (ETDEWEB)

Zahoor, M.K. [University of Engineering and Technology, Lahore (Pakistan). Dept. of Petroleum and Gas Engineering], e-mail: mkzahoor@uet.edu.pk; Derahman, M.N.; Yunan, M.H. [Universiti Teknologi Malaysia, Johor (Malaysia). Dept. of Petroleum Engineering

2011-04-15

The design and implementation of water-alternating-gas (WAG) process in an improved and cost-effective way are still under process. Due to the complexities involved in implementing the process and the lack of information regarding fluid and reservoir properties, the water-alternating-gas process has not yet been as successful as initially expected. This situation can be overcome by better understanding the fluid distribution and flow behavior within the reservoir. The ultimate purpose can be achieved with improved knowledge on wettability and its influence on fluid distribution, capillary pressure, relative permeability, and other design parameters. This paper gives an insight on the WAG process design and the recently developed correlations which are helpful in incorporating the effects of wettability variations on fluid dynamics within the reservoir. (author)

Modifications to Langley 0.3-m TCT adaptive wall software for heavy gas test medium, phase 1 studies

Science.gov (United States)

Murthy, A. V.

1992-01-01

The scheme for two-dimensional wall adaptation with sulfur hexafluoride (SF6) as test gas in the NASA Langley Research Center 0.3-m Transonic Cryogenic Tunnel (0.3-m TCT) is presented. A unified version of the wall adaptation software has been developed to function in a dual gas operation mode (nitrogen or SF6). The feature of ideal gas calculations for nitrogen operation is retained. For SF6 operation, real gas properties have been computed using the departure function technique. Installation of the software on the 0.3-m TCT ModComp-A computer and preliminary validation with nitrogen operation were found to be satisfactory. Further validation and improvements to the software will be undertaken when the 0.3-m TCT is ready for operation with SF6 gas.

Process and system for removing impurities from a gas

Science.gov (United States)

Henningsen, Gunnar; Knowlton, Teddy Merrill; Findlay, John George; Schlather, Jerry Neal; Turk, Brian S

2014-04-15

A fluidized reactor system for removing impurities from a gas and an associated process are provided. The system includes a fluidized absorber for contacting a feed gas with a sorbent stream to reduce the impurity content of the feed gas; a fluidized solids regenerator for contacting an impurity loaded sorbent stream with a regeneration gas to reduce the impurity content of the sorbent stream; a first non-mechanical gas seal forming solids transfer device adapted to receive an impurity loaded sorbent stream from the absorber and transport the impurity loaded sorbent stream to the regenerator at a controllable flow rate in response to an aeration gas; and a second non-mechanical gas seal forming solids transfer device adapted to receive a sorbent stream of reduced impurity content from the regenerator and transfer the sorbent stream of reduced impurity content to the absorber without changing the flow rate of the sorbent stream.

Gas Migration Processes through the Gas Hydrate Stability Zone at Four-Way Closure Ridge Offshore SW Taiwan

Science.gov (United States)

Kunath, P.; Chi, W. C.; Berndt, C.; Liu, C. S.

2016-12-01

We have used 3D P-Cable seismic data from Four-Way-Closure Ridge, a NW-SE trending anticlinal ridge within the lower slope domain of accretionary wedge, to investigate the geological constraints influencing the fluid migration pattern in the shallow marine sediments. In the seismic data, fluid migration feature manifests itself as high reflection layers of dipping strata, which originate underneath a bottom simulating reflector (BSR) and extend towards the seafloor. Shoaling of the BSR near fluid migration pathways indicates a focused fluid flux, perturbing the temperature field. Furthermore, seafloor video footage confirmed the presence of recent methane seepage above seismically imaged fluid migration pathways. We plan to test two hypotheses for the occurrence of these fluid migration pathways: 1) the extensional regime under the anticlinal ridge crest caused the initiation of localized fault zones, acting as fluid conduits in the gas hydrate stability zone (GHSZ). 2) sediment deformation induced by focused fluid flow and massive growth and dissolution of gas hydrate, similar to processes controlling the evolution of pockmarks on the Nigerian continental margin. We suggest that these processes may be responsible for the formation of a massive hydrate core in the crest of the anticline, as inferred from other geophysical datasets. Triggering process for fluid migration cannot be clearly defined. However, the existence of blind thrust faults may help to advect deep-seated fluids. This may be augmented by biogenic production of shallow gas underneath the ridge, where the excess of gas enables the coexistence of gas, water, and gas hydrate within the GHSZ. Fluid migration structures may exists because of the buoyancy of gas-bearing fluids. This study shows a potential model on how gas-bearing fluids migrate upward towards structural highs, which might occur in other anticlinal structures around the world. Keywords: P-Cable, gas-hydrate, fluid flow, fault-related fold

Investigation of the gas formation in dissolution process of nuclear reactor fuel

International Nuclear Information System (INIS)

Zhang Qinfen; Liao Yuanzhong; Chen Yongqing; Sun Shuyun; Fan Yincheng

1987-12-01

The gas formation in dissolution process of two kinds of nuclear fuels was studied. The results shows that the maximum volume flow released from dissolution system is composed of two parts. One of them is air remained in dissolver and pushed out by acid vapor. The other is produced in dissolution reaction. The procedure of calculating the gas amount produced in dissolution process has been given. It is based on variation of components of dissolution solution. The gas amount produced in dissolution process of spent UO 2 fuel elements was calculated. The condenser system and loading volume of disposal system of tail gas of dissolution of spent fuel were discussed

Review on biofuel oil and gas production processes from microalgae

International Nuclear Information System (INIS)

Amin, Sarmidi

2009-01-01

Microalgae, as biomass, are a potential source of renewable energy, and they can be converted into energy such as biofuel oil and gas. This paper presents a brief review on the main conversion processes of microalgae becoming energy. Since microalgae have high water content, not all biomass energy conversion processes can be applied. By using thermochemical processes, oil and gas can be produced, and by using biochemical processes, ethanol and biodiesel can be produced. The properties of the microalgae product are almost similar to those of offish and vegetable oils, and therefore, it can be considered as a substitute of fossil oil.

Implementing process safety management in gas processing operations

International Nuclear Information System (INIS)

Rodman, D.L.

1992-01-01

The Occupational Safety and Health Administration (OSHA) standard entitled Process Safety Management of Highly Hazardous Chemicals; Explosives and Blasting Agents was finalized February 24, 1992. The purpose of the standard is to prevent or minimize consequences of catastrophic releases of toxic, flammable, or explosive chemicals. OSHA believes that its rule will accomplish this goal by requiring a comprehensive management program that integrates technologies, procedures, and management practices. Gas Processors Association (GPA) member companies are significantly impacted by this major standard, the requirements of which are extensive and complex. The purpose of this paper is to review the requirements of the standard and to discuss the elements to consider in developing and implementing a viable long term Process Safety Management Program

A catalytic distillation process for light gas oil hydrodesulfurization

Energy Technology Data Exchange (ETDEWEB)

Vargas-Villamil, F.D.; Marroquin, J.O.; Paz, C. de la; Rodriguez, E. [Prog. de Matematicas Aplicadas y Computacion, Prog. de Tratamiento de Crudo Maya, Instituto Mexicano del Petroleo, Mexico City, DF (Mexico)

2004-07-01

A light gas oil hydrodesulfurization process via catalytic distillation is developed and compared to a conventional process. By integrating the separation and reaction into a single unit, the catalytic distillation may produce a diesel with low concentration of sulfur compounds at a lower cost than the traditional reaction/separation process. The process proposed in this work is compared to an optimised conventional hydrodesulfurization unit which represents fairly well a plant that belongs to the National System of Refineries. During the optimisation of the conventional process, a compromise is established among the production of diesel and naphtha and the operating costs. The results show that the light gas oil hydrodesulfurization via catalytic distillation is as or more efficient than the conventional process. However, the removal of the sulfur compounds is carried out under less rigorous conditions. This design reduces the fix and operational costs. (author)

30 CFR 206.181 - How do I establish processing costs for dual accounting purposes when I do not process the gas?

Science.gov (United States)

2010-07-01

... accounting purposes when I do not process the gas? 206.181 Section 206.181 Mineral Resources MINERALS... Processing Allowances § 206.181 How do I establish processing costs for dual accounting purposes when I do not process the gas? Where accounting for comparison (dual accounting) is required for gas production...

Acoustic Emission Characteristics of Gas-Containing Coal during Loading Dilation Process

Directory of Open Access Journals (Sweden)

Z. Q. Yin

2015-12-01

Full Text Available Raw coal was used as the study object in this paper to identify the evolution characteristics of acoustic emission (AE during the dilation process of gas-containing coal. The coal specimens were stored in gas seal devices filled with gas at different pressures (0, 0.5, 1.0, and 1.5 MPa for 24 h prior to testing. Then, the specimens were tested in a rock-testing machine, and the deformation and crack fracture patterns were recorded by using strain gauges and an AE system. The axial and volumetric strains–stress curves were analyzed in relation to the AE and the failure mode. Results show that as gas pressure increases, the uniaxial compression strength and elasticity modulus of gas-containing coal decreases, whereas the Poisson’s ratio increases. In all the coal specimens, the dilation initiation stress decreases, and the dilation degree increases. During the dilation process, before the loaded coal specimens reach peak stress, and as the load increases, the changes in the specimens and in the AE energy parameter of specimens can be divided into four phases: crack closure deformation, elastic deformation, stable crack propagation, and unstable crack propagation (dilation process. Across the four phases, the AE energy increases evidently during crack closure and elastic deformation but decreases during stable crack propagation. As the gas pressure increases, the AE signal frequency increases from 4.5 KHz to 8.1 KHz during the dilation process. Thus, the gas presence in coal specimens exerts a significant influence on the closure of sample cracks and dilation damage.

Shell launches its Claus off-gas desulfurization process

Energy Technology Data Exchange (ETDEWEB)

Groenendaal, W; van Meurs, H C.A.

1972-01-01

The Shell Flue Gas Desulfurization (SFGD) Process was developed for removal of sulfur oxides from flue gases originating from oil-fired boilers or furnaces. It can also be used to remove sulfur dioxide from Claus sulfur recovery tail gases if they are combined with boiler/furnace flue gases. For Claus tail gas only, the Shell Claus off-gas desulfurization process was developed. Claus unit operation and desulfurization by low temperature Claus processes and conversion/concentration processes are discussed. The new Shell process consists of a conversion/concentration process involving a reduction section and an amine absorption section. In the reduction section, all sulfur compounds and free sulfur are completely reduced to hydrogen sulfide with hydrogen, or hydrogen plus carbon monoxide, over a cobalt/molybdenum-on-alumina catalyst at a temperature of about 300/sup 0/C. Extensive bench scale studies on the reduction system have been carried out. A life test of more than 4000 hr showed a stable activity of the reduction catalyst, which means that in commercial units, very long catalyst lives can be expected. The commercial feasibility of the reduction section was further demonstrated in the Godorf refinery of Deutsche Shell AG. More than 80 absorption units using alkanolamine (AIDP) solutions have been installed. Bench scale studies of the ADIP absorption units were compared to commercial experience.The total capital investment of the new Shell process is 0.7, 2.0, and 3.2 $ times 10 to the 6th power for 100, 500, and 1000 tons of sulfur/sd capacity Claus units, respectively. The total operating costs for these units are, respectively, 610, 1930 and 3310 $/stream day. The capital investment corresponds to about 75% of the capital investment of the preceding Claus unit.

A novel process for small-scale pipeline natural gas liquefaction

International Nuclear Information System (INIS)

He, T.B.; Ju, Y.L.

2014-01-01

Highlights: • A novel process was proposed to liquefy natural gas by utilizing the pressure exergy. • The process is zero energy consumption. • The maximum liquefaction rate of the process is 12.61%. • The maximum exergy utilization rate is 0.1961. • The economic analysis showed that the payback period of the process is quit short. - Abstract: A novel process for small-scale pipeline natural gas liquefaction is designed and presented. The novel process can utilize the pressure exergy of the pipeline to liquefy a part of natural gas without any energy consumption. The thermodynamic analysis including mass, energy balance and exergy analysis are adopted in this paper. The liquefaction rate and exergy utilization rate are chosen as the objective functions. Several key parameters are optimized to approach the maximum liquefaction rate and exergy utilization rate. The optimization results showed that the maximum liquefaction rate is 12.61% and the maximum exergy utilization rate is 0.1961. What is more, the economic performances of the process are also discussed and compared by using the maximum liquefaction rate and exergy utilization rate as indexes. In conclusion, the novel process is suitable for pressure exergy utilization due to its simplicity, zero energy consumption and short payback period

Gas retorts: gas manufacture, process for distillation, destructive

Energy Technology Data Exchange (ETDEWEB)

Bell, J

1874-05-23

In apparatus for distilling shale, coal, etc. for making oil and gas, tubular retorts are supported horizontally in a chamber by plates from a brick setting and are heated partly by jets of gas from a pipe supplied through a cock from a gas holder, and partly by the waste gases from a furnace, which heats gas retorts placed in a chamber, air being supplied beneath the grate by a fan.

[Contamination levels to room air arising from the use of 99mTc-gas and prevention from the contamination].

Science.gov (United States)

Komatani, A; Akutsu, T; Yamaguchi, K; Onodera, Y; Manaka, Y; Takahashi, K

1996-04-01

99mTc-gas (TECHNEGAS) is a 99mTc-labeled micro-aerosol which is considered to have different behavior from 133Xe or 81mKr gas. In order to estimate contamination levels to room air arising from the use of 99mTc-gas, filtered expired air during administration and 1, 2, 3, 5, 10 min after the administration were collected in each polyethylene bag. Radioactivities of the polyethylene bags, used filter and the lung were measured with 3-head scintillation camera. The activity of the expired air diminished within 6-10 min and about 5% of whole discharged 99mTc-gas was released to room air. The activity of the used filter was two times of the lung. According to these results, it is recommended that the 99mTc-gas may be administrated in a exclusive room. The administrated patient and used filter must be remain in the exclusive room.

HIGH RESOLUTION PREDICTION OF GAS INJECTION PROCESS PERFORMANCE FOR HETEROGENEOUS RESERVOIRS

Energy Technology Data Exchange (ETDEWEB)

Franklin M. Orr, Jr.

2004-05-01

This final technical report describes and summarizes results of a research effort to investigate physical mechanisms that control the performance of gas injection processes in heterogeneous reservoirs and to represent those physical effects in an efficient way in simulations of gas injection processes. The research effort included four main lines of research: (1) Efficient compositional streamline methods for 3D flow; (2) Analytical methods for one-dimensional displacements; (3) Physics of multiphase flow; and (4) Limitations of streamline methods. In the first area, results are reported that show how the streamline simulation approach can be applied to simulation of gas injection processes that include significant effects of transfer of components between phases. In the second area, the one-dimensional theory of multicomponent gas injection processes is extended to include the effects of volume change as components change phase. In addition an automatic algorithm for solving such problems is described. In the third area, results on an extensive experimental investigation of three-phase flow are reported. The experimental results demonstrate the impact on displacement performance of the low interfacial tensions between the gas and oil phases that can arise in multicontact miscible or near-miscible displacement processes. In the fourth area, the limitations of the streamline approach were explored. Results of an experimental investigation of the scaling of the interplay of viscous, capillary, and gravity forces are described. In addition results of a computational investigation of the limitations of the streamline approach are reported. The results presented in this report establish that it is possible to use the compositional streamline approach in many reservoir settings to predict performance of gas injection processes. When that approach can be used, it requires substantially less (often orders of magnitude) computation time than conventional finite difference

Development of energy-efficient processes for natural gas liquids recovery

International Nuclear Information System (INIS)

Yoon, Sekwang; Binns, Michael; Park, Sangmin; Kim, Jin-Kuk

2017-01-01

A new NGL (natural gas liquids) recovery process configuration is proposed which can offer improved energy efficiency and hydrocarbon recovery. The new process configuration is an evolution of the conventional turboexpander processes with the introduction of a split stream transferring part of the feed to the demethanizer column. In this way additional heat recovery is possible which improves the energy efficiency of the process. To evaluate the new process configuration a number of different NGL recovery process configurations are optimized and compared using a process simulator linked interactively with external optimization methods. Process integration methodology is applied as part of the optimization to improve energy recovery during the optimization. Analysis of the new process configuration compared with conventional turbo-expander process designs demonstrates the benefits of the new process configuration. - Highlights: • Development of a new energy-efficient natural gas liquids recovery process. • Improving energy recovery with application of process integration techniques. • Considering multiple different structural changes lead to considerable energy savings.

Gas stripping and recirculation process in heavy water separation plant

International Nuclear Information System (INIS)

Nazzer, D.B.; Thayer, V.R.

1976-01-01

Hydrogen sulfide is stripped from hot effluent, in a heavy water separation plant of the dual temperature isotope separation type, by taking liquid effluent from the hot tower before passage through the humidifier, passing the liquid through one or more throttle devices to flash-off the H 2 S gas content, and feeding the gas into an absorption tower containing incoming feed water, for recycling of the gas through the process

Gas prices and price process

International Nuclear Information System (INIS)

Groenewegen, G.G.

1992-01-01

On a conference (Gas for Europe in the 1990's) during the Gasexpo '91 the author held a speech of which the Dutch text is presented here. Attention is paid to the current European pricing methods (prices based on the costs of buying, transporting and distributing the natural gas and prices based on the market value, which is deducted from the prices of alternative fuels), and the transparency of the prices (lack of information on the way the prices are determined). Also attention is paid to the market signal transparency and gas-gas competition, which means a more or less free market of gas distribution. The risks of gas-to-gas competition for a long term price stability, investment policies and security of supply are discussed. Opposition against the Third Party Access (TPA), which is the program to implement gas-to-gas competition, is caused by the fear of natural gas companies for lower gas prices and lower profits. Finally attention is paid to government regulation and the activities of the European Commission (EC) in this matter. 1 fig., 6 ills., 1 tab

High-resolution structural and functional assessments of cerebral microvasculature using 3D Gas ΔR2*-mMRA.

Science.gov (United States)

Huang, Chien-Hsiang; Chen, Chiao-Chi V; Siow, Tiing-Yee; Hsu, Sheng-Hsiou S; Hsu, Yi-Hua; Jaw, Fu-Shan; Chang, Chen

2013-01-01

The ability to evaluate the cerebral microvascular structure and function is crucial for investigating pathological processes in brain disorders. Previous angiographic methods based on blood oxygen level-dependent (BOLD) contrast offer appropriate visualization of the cerebral vasculature, but these methods remain to be optimized in order to extract more comprehensive information. This study aimed to integrate the advantages of BOLD MRI in both structural and functional vascular assessments. The BOLD contrast was manipulated by a carbogen challenge, and signal changes in gradient-echo images were computed to generate ΔR2* maps. Simultaneously, a functional index representing the regional cerebral blood volume was derived by normalizing the ΔR2* values of a given region to those of vein-filled voxels of the sinus. This method is named 3D gas ΔR2*-mMRA (microscopic MRA). The advantages of using 3D gas ΔR2*-mMRA to observe the microvasculature include the ability to distinguish air-tissue interfaces, a high vessel-to-tissue contrast, and not being affected by damage to the blood-brain barrier. A stroke model was used to demonstrate the ability of 3D gas ΔR2*-mMRA to provide information about poststroke revascularization at 3 days after reperfusion. However, this technique has some limitations that cannot be overcome and hence should be considered when it is applied, such as magnifying vessel sizes and predominantly revealing venous vessels.

1991 worldwide refining and gas processing directory

International Nuclear Information System (INIS)

Anon.

1990-01-01

This book ia an authority for immediate information on the industry. You can use it to find new business, analyze market trends, and to stay in touch with existing contacts while making new ones. The possibilities for business applications are numerous. Arranged by country, all listings in the directory include address, phone, fax and telex numbers, a description of the company's activities, names of key personnel and their titles, corporate headquarters, branch offices and plant sites. This newly revised edition lists more than 2000 companies and nearly 3000 branch offices and plant locations. This east-to-use reference also includes several of the most vital and informative surveys of the industry, including the U.S. Refining Survey, the Worldwide Construction Survey in Refining, Sulfur, Gas Processing and Related Fuels, the Worldwide Refining and Gas Processing Survey, the Worldwide Catalyst Report, and the U.S. and Canadian Lube and Wax Capacities Report from the National Petroleum Refiner's Association

Process for water-gas generation from degassed combustibles

Energy Technology Data Exchange (ETDEWEB)

1906-05-23

A process for water-gas generation in a continuous operation from degassed combustibles in the lower part of a vertical exterior-heated retort, whose middle part can serve to degas the combustibles, is described. It is characterized in that the water vapor employed is obtained by vaporizing water in the upper part of the retort by means of the waste heat from the heating gases, which had effected the coking of the combustibles before the water-gas recovery or after the latter.

The GAS5/miR-222 Axis Regulates Proliferation of Gastric Cancer Cells Through the PTEN/Akt/mTOR Pathway.

Science.gov (United States)

Li, Yanhua; Gu, Junjiao; Lu, Hong

2017-12-01

Several lines of evidence have indicated that growth arrest-specific transcript 5 (GAS5) functions as a tumor suppressor and is aberrantly expressed in multiple cancers. GAS5 was found to be downregulated in gastric cancer (GC) tissues, and ectopic expression of GAS5 inhibited GC cell proliferation. The present study aimed to explore the underlying mechanisms of GAS5 involved in GC cell proliferation. GAS5 and miR-222 expressions in GC cell lines were estimated by quantitative real-time polymerase chain reaction. The effects of GAS5 and miR-222 on GC cell proliferation were assessed by MTT assay and 5-bromo-2-deoxyuridine (BrdU) incorporation assays. The interaction between GAS5 and miR-222 was confirmed by luciferase reporter assay and RNA immunoprecipitation assay. The protein levels of the phosphatase and tensin homolog (PTEN), phosphorylated protein kinase B (Akt) (p-Akt), Akt, phosphorylated mammalian target of rapamycin (mTOR) (p-mTOR), and mTOR were determined by western blot. GAS5 was downregulated and miR-222 was upregulated in GC cells. GAS5 directly targeted and suppressed miR-222 expression. GAS5 overexpression and miR-222 inhibition suppressed cell proliferation, increased PTEN protein level and decreased p-Akt and p-mTOR protein levels in GC cells while GAS5 knockdown and miR-222 overexpression exhibited the opposite effects. Moreover, mechanistic analyses revealed that GAS5 regulated GC cell proliferation through the PTEN/Akt/mTOR pathway by negatively regulating miR-222. GAS5/miR-222 axis regulated proliferation of GC cells through the PTEN/Akt/mTOR pathway, which facilitated the development of lncRNA-directed therapy against this deadly disease.

Effect of ring rotation upon gas adsorption in SIFSIX-3-M (M = Fe, Ni) pillared square grid networks.

Science.gov (United States)

Elsaidi, Sameh K; Mohamed, Mona H; Simon, Cory M; Braun, Efrem; Pham, Tony; Forrest, Katherine A; Xu, Wenqian; Banerjee, Debasis; Space, Brian; Zaworotko, Michael J; Thallapally, Praveen K

2017-03-01

Dynamic and flexible metal-organic frameworks (MOFs) that respond to external stimuli, such as stress, light, heat, and the presence of guest molecules, hold promise for applications in chemical sensing, drug delivery, gas separations, and catalysis. A greater understanding of the relationship between flexible constituents in MOFs and gas adsorption may enable the rational design of MOFs with dynamic moieties and stimuli-responsive behavior. Here, we detail the effect of subtle structural changes upon the gas sorption behavior of two "SIFSIX" pillared square grid frameworks, namely SIFSIX-3-M (M = Ni, Fe). We observe a pronounced inflection in the Xe adsorption isotherm in the Ni variant. With evidence from X-ray diffraction studies, density functional theory, and molecular simulations, we attribute the inflection to a disordered to ordered transition of the rotational configurations of the pyrazine rings induced by sorbate-sorbent interactions. We also address the effect of cage size, temperature, and sorbate on the guest-induced ring rotation and the adsorption isotherms. The absence of an inflection in the Xe adsorption isotherm in SIFSIX-3-Fe and in the Kr, N 2 , and CO 2 adsorption isotherms in SIFSIX-3-Ni suggest that the inflection is highly sensitive to the match between the size of the cage and the guest molecule.

Horizontal drilling in a natural gas storage horizon of 4 m thickness using reservoir navigation technology

Energy Technology Data Exchange (ETDEWEB)

Bastert, Thomas [E.ON Gas Storage GmbH, Essen (Germany); Liewert, Mathias; Rohde, Uwe [Baker Hughes INTEQ GmbH, Celle (Germany); Haberland, Joachim

2010-09-15

With a working gas capacity of 1,44 billion m{sup 3} (Vn) the natural gas storage facility at Bierwang is one of the largest storage facilities of E.ON Gas Storage (in Germany) and also one of the largest porous rock storages in Germany. The natural gas is stored in the tertiary storage horizons of the Chattian Hauptsand and Nebensand. To increase the storage capacity a second development well was planned for the Chattian Nebensand II (approx. 1680 m below ground). Following a comprehensive technical investigation the BW 502 well was planned as a horizontal well intended to provide a 300 m exposed section length through the reservoir. In a first step a pilot well was drilled to examine the Nebensand II which had been explored only to a limited extent before; the pilot well was also to provide accurate data on depth, thickness and dip. The results obtained indicated that the Nebensand II was only 4 m thick instead of 6 m as originally assumed. An azimuthal LWD resistivity tool was therefore used for reservoir navigation to allow horizontal drilling despite the lower thickness found. The technology allowed drilling of the horizontal well over its entire length of 315 m within a max. 1.5 m corridor relative to the reservoir top. Drilling confirmed that the actual formation found corresponded to the reservoir formation plan. Drilling operations were completed successfully. The well has been commissioned in the spring of 2010. (orig.)

Corrosion And Thermal Processing In Cold Gas Dynamic Spray Deposited Austenitic Stainless Steel Coatings

Science.gov (United States)

2016-06-01

Champagne have demonstrated this use of the cold spray technique in the repair of helicopter mast supports in U.S. Army aircraft, with over 50...Process: Fundamentals and Applications, Champagne , V. K., Ed., Woodhead, Boca Raton, FL Chap. 3. [3] Schiel, J. F., 2014, “The cold gas-dynamic spray... Champagne , V. K., Ed., Woodhead, Boca Raton, FL Chap. 2. [15] Han, W., Meng, X. M., Zhang, J. B., and Zhao, J., 2012, “Elastic modulus of 304 stainless

Partial oxidation process for producing a stream of hot purified gas

Science.gov (United States)

Leininger, T.F.; Robin, A.M.; Wolfenbarger, J.K.; Suggitt, R.M.

1995-03-28

A partial oxidation process is described for the production of a stream of hot clean gas substantially free from particulate matter, ammonia, alkali metal compounds, halides and sulfur-containing gas for use as synthesis gas, reducing gas, or fuel gas. A hydrocarbonaceous fuel comprising a solid carbonaceous fuel with or without liquid hydrocarbonaceous fuel or gaseous hydrocarbon fuel, wherein said hydrocarbonaceous fuel contains halides, alkali metal compounds, sulfur, nitrogen and inorganic ash containing components, is reacted in a gasifier by partial oxidation to produce a hot raw gas stream comprising H{sub 2}, CO, CO{sub 2}, H{sub 2}O, CH{sub 4}, NH{sub 3}, HCl, HF, H{sub 2}S, COS, N{sub 2}, Ar, particulate matter, vapor phase alkali metal compounds, and molten slag. The hot raw gas stream from the gasifier is split into two streams which are separately deslagged, cleaned and recombined. Ammonia in the gas mixture is catalytically disproportionated into N{sub 2} and H{sub 2}. The ammonia-free gas stream is then cooled and halides in the gas stream are reacted with a supplementary alkali metal compound to remove HCl and HF. Alkali metal halides, vaporized alkali metal compounds and residual fine particulate matter are removed from the gas stream by further cooling and filtering. The sulfur-containing gases in the process gas stream are then reacted at high temperature with a regenerable sulfur-reactive mixed metal oxide sulfur sorbent material to produce a sulfided sorbent material which is then separated from the hot clean purified gas stream having a temperature of at least 1000 F. 1 figure.

Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems

International Nuclear Information System (INIS)

Soelberg, Nick; Enneking, Joe

2011-01-01

Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absorption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

Method for treating a nuclear process off-gas stream

International Nuclear Information System (INIS)

Pence, D.T.; Chou, C.-C.

1981-01-01

A method is described for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. The method involves a sequence of adsorption and desorption steps which are specified. Particular reference is made to the separation of xenon and krypton from the off-gas stream, and to the use of silver-exchanged mordenite as the adsorbent. (U.K.)

TIG (Tungsten Inert Gas) welding

International Nuclear Information System (INIS)

Anon.

2010-01-01

After having recalled the Tungsten Inert Gas process principle and the different alternative TIG processes, the author explains the advantages and limits of this process. The applications and recent developments are given. (O.M.)

The s-process enrichment of the globular clusters M4 and M22

Energy Technology Data Exchange (ETDEWEB)

Shingles, Luke J.; Karakas, Amanda I.; Fishlock, Cherie K.; Yong, David; Da Costa, Gary S.; Marino, Anna F. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Hirschi, Raphael, E-mail: luke.shingles@anu.edu.au [Institute for the Physics and Mathematics of the Universe (WPI), University of Tokyo, 5-1-5 Kashiwanoha, 277-8583 Kashiwa (Japan)

2014-11-01

We investigate the enrichment in elements produced by the slow neutron-capture process (s-process) in the globular clusters M4 (NGC 6121) and M22 (NGC 6656). Stars in M4 have homogeneous abundances of Fe and neutron-capture elements, but the entire cluster is enhanced in s-process elements (Sr, Y, Ba, Pb) relative to other clusters with a similar metallicity. In M22, two stellar groups exhibit different abundances of Fe and s-process elements. By subtracting the mean abundances of s-poor from s-rich stars, we derive s-process residuals or empirical s-process distributions for M4 and M22. We find that the s-process distribution in M22 is more weighted toward the heavy s-peak (Ba, La, Ce) and Pb than M4, which has been enriched mostly with light s-peak elements (Sr, Y, Zr). We construct simple chemical evolution models using yields from massive star models that include rotation, which dramatically increases s-process production at low metallicity. We show that our massive star models with rotation rates of up to 50% of the critical (break-up) velocity and changes to the preferred {sup 17}O(α, γ){sup 21}Ne rate produce insufficient heavy s-elements and Pb to match the empirical distributions. For models that incorporate asymptotic giant branch yields, we find that intermediate-mass yields (with a {sup 22}Ne neutron source) alone do not reproduce the light-to-heavy s-element ratios for M4 and M22, and that a small contribution from models with a {sup 13}C pocket is required. With our assumption that {sup 13}C pockets form for initial masses below a transition range between 3.0 and 3.5 M {sub ☉}, we match the light-to-heavy s-element ratio in the s-process residual of M22 and predict a minimum enrichment timescale of between 240 and 360 Myr. Our predicted value is consistent with the 300 Myr upper limit age difference between the two groups derived from isochrone fitting.

Essentials of water systems design in the oil, gas, and chemical processing industries

CERN Document Server

Bahadori, Alireza; Boyd, Bill

2013-01-01

Essentials of Water Systems Design in the Oil, Gas and Chemical Processing Industries provides valuable insight for decision makers by outlining key technical considerations and requirements of four critical systems in industrial processing plants—water treatment systems, raw water and plant water systems, cooling water distribution and return systems, and fire water distribution and storage facilities. The authors identify the key technical issues and minimum requirements related to the process design and selection of various water supply systems used in the oil, gas, and chemical processing industries. This book is an ideal, multidisciplinary work for mechanical engineers, environmental scientists, and oil and gas process engineers.

Gas manufacture, processes for: condensers

Energy Technology Data Exchange (ETDEWEB)

Young, W

1876-11-29

In the production of illuminating gas from coal, shale, hydrocarbon oil, or other substance used in the production of gas, the volatile products inside the retort are agitated by means of moving pistons or jets of compressed gas, steam, or vapor in order to decompose them into permanent gases, and in some cases to increase the volume of gas by the decomposition of the injected gas, etc. or by blending or carburetting this gas with the decomposition products of the volatile matters. To separate the condensible hydrocarbons from the crude gas it is passed through heated narrow tortuous passages or is caused to impinge on surfaces. If the crude gases are cold these surfaces are heated and vice versa.

Emergency gas processing device

International Nuclear Information System (INIS)

Taruishi, Yoshiaki; Sasaki, Susumu.

1984-01-01

Purpose: To enable the reduction of radioactive substances released out of reactor buildings irrespective of the aging change in the buildings. Constitution: There are provided an exhaust gas flow channel for cleaning contaminated airs within a reactor building by way of a series of filters and exhausting the cleaned airs by means of exhaust fans to the outside and a gas recycling flow channel having a cooler in connection with the exhaust gas flow channel at a position downstream of the exhaust fans for returning the cleaned airs in the exhaust gas flow channel to the inside of the reactor buildings. The pressure difference between the outside and the inside of the reactor buildings is made constant by controlling the air flow channel within the gas recycling flow channel by a flow control valve. The airs cleaned by the series of the filters are recycled to the inside of the buildings to decrease the radioactive substance within the buildings. (Horiuchi, T.)

Coke battery with 51-m{sup 3} furnace chambers and lateral supply of mixed gas

Energy Technology Data Exchange (ETDEWEB)

V.I. Rudyka; N.Y. Chebotarev; O.N. Surenskii; V.V. Derevich [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

2009-07-15

The basic approaches employed in the construction of coke battery 11A at OAO Magnitogorskii Metallurgicheskii Kombinat are outlined. This battery includes 51.0-m{sup 3} furnaces and a dust-free coke-supply system designed by Giprokoks with lateral gas supply; it is heated exclusively by low-calorific mixed gas consisting of blast-furnace gas with added coke-oven gas. The 82 furnaces in the coke battery are divided into two blocks of 41. The gross coke output of the battery (6% moisture content) is 1140000 t/yr.

The influence of process parameters on Gas Assisted Mechanical Expression (GAME) of cocoa nibs

NARCIS (Netherlands)

Venter, M.J.; Hink, R.; Kuipers, N.J.M.; de Haan, A.B.

2007-01-01

It is known that increased cocoa butter yields can be achieved with Gas Assisted Mechanical Expression (GAME) of cocoa nibs when compared to conventional expression of cocoa nibs [Venter, M.J., Willems, P., Kuipers, N.J.M. & de Haan, A.B. (2006). Gas Assisted Mechanical Expression of cocoa butter

The influence of process parameters on gas assisted mechanical expression (GAME) of cocoa nibs

NARCIS (Netherlands)

Venter, M.J.; Hink, R.; Kuipers, N.J.M.; Haan, de A.B.

2007-01-01

It is known that increased cocoa butter yields can be achieved with Gas Assisted Mechanical Expression (GAME) of cocoa nibs when compared to conventional expression of cocoa nibs [Venter, M.J., Willems, P., Kuipers, N.J.M. & de Haan, A.B. (2006). Gas Assisted Mechanical Expression of cocoa butter

Fission gas bubble identification using MATLAB's image processing toolbox

Energy Technology Data Exchange (ETDEWEB)

Collette, R. [Colorado School of Mines, Nuclear Science and Engineering Program, 1500 Illinois St, Golden, CO 80401 (United States); King, J., E-mail: kingjc@mines.edu [Colorado School of Mines, Nuclear Science and Engineering Program, 1500 Illinois St, Golden, CO 80401 (United States); Keiser, D.; Miller, B.; Madden, J.; Schulthess, J. [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

2016-08-15

Automated image processing routines have the potential to aid in the fuel performance evaluation process by eliminating bias in human judgment that may vary from person-to-person or sample-to-sample. This study presents several MATLAB based image analysis routines designed for fission gas void identification in post-irradiation examination of uranium molybdenum (U–Mo) monolithic-type plate fuels. Frequency domain filtration, enlisted as a pre-processing technique, can eliminate artifacts from the image without compromising the critical features of interest. This process is coupled with a bilateral filter, an edge-preserving noise removal technique aimed at preparing the image for optimal segmentation. Adaptive thresholding proved to be the most consistent gray-level feature segmentation technique for U–Mo fuel microstructures. The Sauvola adaptive threshold technique segments the image based on histogram weighting factors in stable contrast regions and local statistics in variable contrast regions. Once all processing is complete, the algorithm outputs the total fission gas void count, the mean void size, and the average porosity. The final results demonstrate an ability to extract fission gas void morphological data faster, more consistently, and at least as accurately as manual segmentation methods. - Highlights: •Automated image processing can aid in the fuel qualification process. •Routines are developed to characterize fission gas bubbles in irradiated U–Mo fuel. •Frequency domain filtration effectively eliminates FIB curtaining artifacts. •Adaptive thresholding proved to be the most accurate segmentation method. •The techniques established are ready to be applied to large scale data extraction testing.

Powder-Metallurgy Process And Product

Science.gov (United States)

Paris, Henry G.

1988-01-01

Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

Flue Gas Cleaning With Alternative Processes and Reaction Media

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Huang, Jun; Riisager, Anders

2007-01-01

Alternative methods to the traditional industrial NOX and SOXflue gas cleaning processes working at lower temperatures and/orleading to useful products are desired. In this work we presentour latest results regarding the use of molten ionic media inelectrocatalytic membrane separation, ionic liquid...... reversibleabsorption and supported ionic liquid deNOX catalysis. Furtherdevelopment of the methods will hopefully make them suitable forinstallation in different positions in the flue gas duct ascompared to the industrial methods available today....

Application of gas hydrate formation in separation processes: A review of experimental studies

International Nuclear Information System (INIS)

Eslamimanesh, Ali; Mohammadi, Amir H.; Richon, Dominique; Naidoo, Paramespri; Ramjugernath, Deresh

2012-01-01

Highlights: ► Review of gas hydrate technology applied to separation processes. ► Gas hydrates have potential to be a future sustainable separation technology. ► More theoretical, simulation, and economic studies needed. - Abstract: There has been a dramatic increase in gas hydrate research over the last decade. Interestingly, the research has not focussed on only the inhibition of gas hydrate formation, which is of particular relevance to the petroleum industry, but has evolved into investigations on the promotion of hydrate formation as a potential novel separation technology. Gas hydrate formation as a separation technology shows tremendous potential, both from a physical feasibility (in terms of effecting difficult separations) as well as an envisaged lower energy utilization criterion. It is therefore a technology that should be considered as a future sustainable technology and will find wide application, possibly replacing a number of current commercial separation processes. In this article, we focus on presenting a brief description of the positive applications of clathrate hydrates and a comprehensive survey of experimental studies performed on separation processes using gas hydrate formation technology. Although many investigations have been undertaken on the positive application of gas hydrates to date, there is a need to perform more theoretical, experimental, and economic studies to clarify various aspects of separation processes using clathrate/semi-clathrate hydrate formation phenomena, and to conclusively prove its sustainability.

Gas atomization processing of tin and silicon modified LaNi₅ for nickel-metal hydride battery applications

Energy Technology Data Exchange (ETDEWEB)

Ting, Jason [Iowa State Univ., Ames, IA (United States)

1999-02-12

Numerous researchers have studied the relevant material properties of so-called AB₅ alloys for battery applications. These studies involved LaNi₅ substituted alloys which were prepared using conventional cast and crush alloying techniques. While valuable to the understanding of metal hydride effects, the previous work nearly ignored the potential for alternative direct powder production methods, like high pressure gas atomization (HPGA). Thus, there is a need to understand the relationship between gas atomization processes, powder particle solidification phases, and hydrogen absorption properties of ultra fine (< 25 μm) atomized powders with high surface area for enhanced battery performance. Concurrently, development of a gas atomization nozzle that is more efficient than all current designs is needed to increase the yield of ultrafine AB₅ alloy powder for further processing advantage. Gas atomization processing of the AB₅ alloys was demonstrated to be effective in producing ultrafine spherical powders that were resilient to hydrogen cycling for the benefit of improving corrosion resistance in battery application. These ultrafine powders benefited from the rapid solidification process by having refined solute segregation in the microstructure of the gas atomized powders which enabled a rapid anneal treatment of the powders. The author has demonstrated the ability to produce high yields of ultrafine powder efficiently and cost effectively, using the new HPGA-III technology. Thus, the potential benefits of processing AB₅ alloys using the new HPGA technology could reduce manufacturing cost of nickel-metal hydride powder. In the near future, the manufacture of AB₅ alloy powders could become a continuous and rapid production process. The economic benefit of an improved AB₅ production process may thereby encourage the use of nickel-metal hydride rechargeable batteries in electrical vehicle

Developing an equitable fee structure for gas processing services: JP-90 and beyond

International Nuclear Information System (INIS)

Kingsbury, J.D.; Moller, I.

1996-01-01

The Joint Industry Gas Processing Fee Task Force Report, JP-90, was designed to promote negotiation of gas processing fees that are based on principles of equity and fairness for both natural gas producers and processors. Another purpose of the JP-90 was to develop an effective dispute resolution process for use in those cases where negotiations have failed. At its inception, JP-90 was the only guideline for unregulated fee practices in the oil and gas sector in North America. Today PJVA-95, the revised version of JP-90, is in its final draft. It addresses the changing focus of the gas processing business, and changing regulatory roles in Alberta and British Columbia. A number of other fee mechanisms also have been described, such as the jumping pound formula, fixed fees, fees based on price, wellhead purchases, and others. These mechanisms developed over time to allow the processor and the producer to share the price risk. The changing role of regulatory agencies in fee dispute resolution was also discussed briefly

Gas recovery process

International Nuclear Information System (INIS)

Schmidt, W.B.; Lewis, W.W.; Edmiston, A.; Klauser, G.

1980-01-01

In order to decontaminate a gas stream containing radioactive krypton, a preliminary step of removing oxygen and oxides of nitrogen by catalytic reaction with hydrogen is performed. The gas stream is then passed serially through a drier, a carbon dioxide adsorber and a xenon adsorber to remove sequentially water, CO 2 and xenon therefrom. The gas exiting the xenon adsorber is passed to a krypton recovery plant wherein krypton is concentrated to a first level in a primary distillation column by contact with a reflux liquid in a packed section of the column. The liquid and vapour collecting at the bottom of the column is passed to a separator in which the liquid is separated from the vapour. The liquid is partially evaporated in a vessel to increase concentration thereof and is brought to a concentration of approximately 90 mole % or greater in a second distillation column thereby enabling efficient storage of a radioactive krypton product. (author)

Natural gas processing optimization in Espirito Santo plant; Sistema de otimizacao aplicado ao processamento de gas natural no Espirito Santo

Energy Technology Data Exchange (ETDEWEB)

Nunes, Carlos Henrique de Oliveira; Costa, Fernando Lourenco Pinho da; Mazzini, Filipe Ferreira; Campos, Flavia Schittine [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Oliveira, Fabricio Carlos; Hamacher, Silvio [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

2008-07-01

This work introduces the MODEP system, which was developed by PETROBRAS in association with PUC-Rio. The system objective is to support the gas processing and flow planning for the Espirito Santo PETROBRAS. The MODEP core is a non linear optimization model that allows the user to optimize the production of gas as well as to optimize the net present value. In addition, the system offers to the user a comprehensive asset of the gas network since its production fields until the products selling points. The development of this system was motivated by the sharp increase of the Espirito Santo gas production capacity as well as the increase in the number of its processing units. (author)

The comparison of greenhouse gas emissions in sewage treatment plants with different treatment processes.

Science.gov (United States)

Masuda, Shuhei; Sano, Itsumi; Hojo, Toshimasa; Li, Yu-You; Nishimura, Osamu

2018-02-01

Greenhouse gas emissions from different sewage treatment plants: oxidation ditch process, double-circulated anoxic-oxic process and anoxic-oxic process were evaluated based on the survey. The methane and nitrous oxide characteristics were discussed based on the gaseous and dissolved gas profiles. As a result, it was found that methane was produced in the sewer pipes and the primary sedimentation tank. Additionally, a ventilation system would promote the gasification of dissolved methane in the first treatment units. Nitrous oxide was produced and emitted in oxic tanks with nitrite accumulation inside the sewage treatment plant. A certain amount of nitrous oxide was also discharged as dissolved gas through the effluent water. If the amount of dissolved nitrous oxide discharge is not included, 7-14% of total nitrous oxide emission would be overlooked. Based on the greenhouse gas calculation, electrical consumption and the N 2 O emission from incineration process were major sources in all the plants. For greenhouse gas reduction, oxidation ditch process has an advantage over the other advanced systems due to lower energy consumption, sludge production, and nitrogen removal without gas stripping. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gas inflow in oil base fluids; Influxo de gas em fluidos a base de oleo

Energy Technology Data Exchange (ETDEWEB)

Lazaro, Welmar [PETROBRAS, Rio de Janeiro (Brazil). Dept. de Perfuracao. Div. de Fluidos de Perfuracao; Boas, Mario Barbosa V [PETROBRAS, Rio de Janeiro (Brazil). Centro de Pesquisas. Div. de Explotacao

1990-12-31

One of the major problems related to the use of oil base fluids is the dissolution of the natural gas in the fluid. This paper attempts initially at making a bibliographical review of all that was written on the subject of drilling fluids up to now. It also mentions some theoretical aspects regarding the process of gas dissolution in diesel oils, in order to produce an understanding of how the dissolution mechanism is processed. For a same increase in measured volume on the surface, the amount of gas incorporated into the fluid is significantly larger if the gas is dissolved in the oil phase than if it is emulsified in the fluid, as occurs when the fluid is water base. A rig team used to working with water-base fluids may be surprised with the fact that an increase of 20 bbl of fluid on the surface of a 5000 m well can mean the incorporation of about 1800 m{sup 3} of gas, if the fluid is oil-base and all the gas is in solution instead of the incorporation of 900 m{sup 3} if the fluid is water base. This paper has the goal of warning drilling engineers and technicians about this problem, as well as presenting charts and equations that allow for a more realistic evaluation of the amount of gas incorporated into oil fluids. (author) 16 refs., 7 figs., 2 tabs.

The Flakt-Hydro process: flue gas desulfurization by use of seawater

Energy Technology Data Exchange (ETDEWEB)

Xia, W.Z. [ABB China Limited, Shanghai (China)

1999-07-01

ABB's seawater scrubbing process (the Flakt-Hydro process) for flue gas desulfurization has recently triggered interest among power producers because of its simple operating principle and high reliability. The process uses seawater to absorb and neutralize sulfur dioxide in flue gases. The absorbed gas is oxidized and returned to the ocean in the form it originated in the first place, namely as dissolved sulfate salts. The process uses the seawater downstream of the power plant condensers. This paper gives an introduction to the basic principle of the process and presents some of the recent power plant applications, namely at the Paiton Private Power Project; Phase 1 (2 x 670 MWe) in Indonesia and at the Shenzhen West Power Plant, Unit 2 (300 MWe) in China.

Producing hydrogen from coke-oven gas: the Solmer project. [PSA process

Energy Technology Data Exchange (ETDEWEB)

Bernard, G; Vidal, J

1984-05-01

After presenting the energy situation at the Solmer plant, where coke-oven gas is produced to excess, the authors examine the technical and economic possibilities of utilizing this gas for hydrogen extraction. They describe a project (based on the PSA process) for producing some 65 t/d of hydrogen and present the technical features of the scheme. An evaluation of the energy and financial costs of producing the hydrogen confirms the competitive status of the process.

Flue gas cleanup using the Moving-Bed Copper Oxide Process

Energy Technology Data Exchange (ETDEWEB)

Pennline, Henry W; Hoffman, James S

2013-10-01

The use of copper oxide on a support had been envisioned as a gas cleanup technique to remove sulfur dioxide (SO{sub 2}) and nitric oxides (NO{sub x}) from flue gas produced by the combustion of coal for electric power generation. In general, dry, regenerable flue gas cleanup techniques that use a sorbent can have various advantages, such as simultaneous removal of pollutants, production of a salable by-product, and low costs when compared to commercially available wet scrubbing technology. Due to the temperature of reaction, the placement of the process into an advanced power system could actually increase the thermal efficiency of the plant. The Moving-Bed Copper Oxide Process is capable of simultaneously removing sulfur oxides and nitric oxides within the reactor system. In this regenerable sorbent technique, the use of the copper oxide sorbent was originally in a fluidized bed, but the more recent effort developed the use of the sorbent in a moving-bed reactor design. A pilot facility or life-cycle test system was constructed so that an integrated testing of the sorbent over absorption/regeneration cycles could be conducted. A parametric study of the total process was then performed where all process steps, including absorption and regeneration, were continuously operated and experimentally evaluated. The parametric effects, including absorption temperature, sorbent and gas residence times, inlet SO{sub 2} and NO{sub x} concentration, and flyash loadings, on removal efficiencies and overall operational performance were determined. Although some of the research results have not been previously published because of previous collaborative restrictions, a summary of these past findings is presented in this communication. Additionally, the potential use of the process for criteria pollutant removal in oxy-firing of fossil fuel for carbon sequestration purposes is discussed.

Stripping of gas and dust from the elliptical galaxy M86

International Nuclear Information System (INIS)

White, D.A.; Fabian, A.C.; Forman, W.; Jones, C.; Stern, C.

1990-01-01

Past observations of the x ray morphology of M86 have revealed that the galaxy is experiencing ram-pressure stripping due to its large velocity (1500 km s(-1)) relative to the intracluster medium of Virgo (Forman et al. 1979, Fabian, Schwartz, and Forman 1980). Observations indicate that the x ray emitting gas in the plume of M86 is still being produced from the continual heating of gas and dust stripped from nearer the galaxy's center. Researchers obtained two-dimensional Infrared Astronomy Satellite (IRAS) images of M86 which have revealed that there are two spatially separated regions of emission, one at 60 microns and the other at 100 microns of the IRAS wavebands. The 100 microns emission, presumably from cool dust (at approximately 20 K), appears to be located near the center of the galaxy together with HI (detected by Bregman, Roberts and Giovanelli 1988), while the 60 microns emission appears to lie more than 3 arcminutes away from the optical center in a direction slightly south of the center of the plume. Optical images produced by scanning U.K. Schmidt plates, reveal asymmetric isophotal contours along the major axis of the galaxy (first reported by Nulsen and Carter in 1987, which they propose as excess emission due to star formation). This excess optical emission is co-incident with the direction of the 60 micron infra-red emission

Experimental investigation about attachment processes of atoms and ions in the size range < 0.1 μm

International Nuclear Information System (INIS)

Porstendoerfer, J.; Mercer, T.T.

1977-01-01

Results of an investigation of the attachment process of atoms and ion in the size range between 0.009 to 4 μm on a particle or droplet surface are presented. It is again shown that the experimental values are adequately predicted by the diffusion attachment theory under gas kinetic consideration, if the sticking probability of Rn and Tn decay products is S = 1. 12 references

Process design analyses of co/sub 2/ capture from natural gas by polymer membrane

Energy Technology Data Exchange (ETDEWEB)

Hussain, A.; Nasir, H.; Ahsan, M. [National Univ. of Science and Technology, Islamabad (Pakistan). Dept. of Chemical Engineering

2014-06-15

Membrane-based natural gas separation has become one of the promising technologies due to its compactness, energy efficiency, environment friendliness and economic advantages. In this work, a three stage membrane process for the separation of CO/sub 2//CH/sub 4/ is proposed based on a novel fixed site carrier membrane which has the potential to meet the CO/sub 2//CH/sub 4/ separation and durability requirement. A simulation analysis, which utilizes the Aspen Hysys capabilities to calculate and couple energy balances in the process model, has been conducted to investigate the effect of process parameters on the gas processing cost. Two different natural gas mixtures containing 9.5% and 2.9% CO/sub 2/ have been simulated for various process conditions. This fixed site carrier membrane performs well when wetted with water. Therefore, natural gas feed streams are saturated with water. It is evident from the analysis that it is possible to maintain 2% CO/sub 2/ in retentate and methane loss in permeate below 2% by optimizing the process conditions. The analysis shows that fixed site carrier membrane offers a viable solution for natural gas sweetening. (author)

Process design analyses of co/sub 2/ capture from natural gas by polymer membrane

International Nuclear Information System (INIS)

Hussain, A.; Nasir, H.; Ahsan, M.

2014-01-01

Membrane-based natural gas separation has become one of the promising technologies due to its compactness, energy efficiency, environment friendliness and economic advantages. In this work, a three stage membrane process for the separation of CO/sub 2//CH/sub 4/ is proposed based on a novel fixed site carrier membrane which has the potential to meet the CO/sub 2//CH/sub 4/ separation and durability requirement. A simulation analysis, which utilizes the Aspen Hysys capabilities to calculate and couple energy balances in the process model, has been conducted to investigate the effect of process parameters on the gas processing cost. Two different natural gas mixtures containing 9.5% and 2.9% CO/sub 2/ have been simulated for various process conditions. This fixed site carrier membrane performs well when wetted with water. Therefore, natural gas feed streams are saturated with water. It is evident from the analysis that it is possible to maintain 2% CO/sub 2/ in retentate and methane loss in permeate below 2% by optimizing the process conditions. The analysis shows that fixed site carrier membrane offers a viable solution for natural gas sweetening. (author)

Method and apparatus for rapid adjustment of process gas inventory in gaseous diffusion cascades

International Nuclear Information System (INIS)

Dyer, R.H.; Fowler, A.H.; Vanstrum, P.R.

1977-01-01

The invention relates to an improved method and system for making relatively large and rapid adjustments in the process gas inventory of an electrically powered gaseous diffusion cascade in order to accommodate scheduled changes in the electrical power available for cascade operation. In the preferred form of the invention, the cascade is readied for a decrease in electrical input by simultaneously withdrawing substreams of the cascade B stream into respective process-gas-freezing and storage zones while decreasing the datum-pressure inputs to the positioning systems for the cascade control valves in proportion to the weight of process gas so removed. Consequently, the control valve positions are substantially unchanged by the reduction in invention, and there is minimal disturbance of the cascade isotopic gradient. The cascade is readied for restoration of the power cut by simultaneously evaporating the solids in the freezing zones to regenerate the process gas substreams and introducing them to the cascade A stream while increasing the aforementioned datum pressure inputs in proportion to the weight of process gas so returned. In the preferred form of the system for accomplishing these operations, heat exchangers are provided for freezing, storing, and evaporating the various substreams. Preferably, the heat exchangers are connected to use existing cascade auxiliary systems as a heat sink. A common control is employed to adjust and coordinate the necessary process gas transfers and datum pressure adjustments

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

Design and analysis of siloxanes removal by adsorption from landfill gas for waste-to-energy processes.

Science.gov (United States)

Elwell, Anthony C; Elsayed, Nada H; Kuhn, John N; Joseph, Babu

2018-03-01

Separation of volatile methyl siloxanes from landfill gas using fixed adsorption beds was modeled with the objective of identifying appropriate technology and the economics associated with this purification step. A general adsorption model assuming plug flow and radial symmetry was developed and used to conduct a parametric sweep of 162 unique cases. The varied parameters were adsorbent type (activated carbon and silica gel), bed height (3.05-9.15 m/10-30 ft), inlet siloxane concentration (5-15 mg/m 3 ), moisture content (0-100% relative humidity at STP or RH), and siloxane tolerance limit (0.094-9.4 mg/m 3 ) that correlated to three distinct energy conversion technologies (electricity production using engines or fuels cells or catalytic conversion to liquid hydrocarbon fuels). Due to the detrimental effect of RH on siloxane absorption, the maximum allowable moisture content of LFG before purification is 50% RH and moisture removal processes are also required. The design calculations using a selected case study show that the adsorption bed height required needed for 6 months minimum breakthrough time for catalytic fuel production is twice that for engine applications. Fuel cell applications require 3 times the bed height compared to engine applications. However, the purification costs amounted to 94%, 16% and 52% of recovered product value for engine, liquefaction, and fuel cell applications, respectively indicating the need for a high value product to justify purification costs. The approaches and conclusions can be extended to specific process conditions for landfill gas purification and to other processes that use biogas produced from waste as a feedstock. Copyright © 2017 Elsevier Ltd. All rights reserved.

The world economy: Its impact on the gas processing industry

International Nuclear Information System (INIS)

Teleki, A.

1994-01-01

Gas processors are in the business of extracting C 2-7 hydrocarbons from natural gas streams and converting them to commercial grade gas liquids, valued at or slightly below oil product prices. If the margin of oil prices over gas prices is higher, the gas processing business is more profitable. An approximate index of profitability is the ratio of the price of a bbl of oil divided by the price of a million Btu of gas (the oil-gas ratio). Since the mid-1980s, by which time both the oil and gas markets had been largely deregulated, the oil-gas ratio fluctuated in the 10-12 range then peaked to over 15 in 1990-91. The recent fall in oil prices has driven the ratio to historically low levels of 6-7, which leads to gas processors curtailing ethane recovery. Various aspects of the world economy and the growth of oil consumption are discussed to forecast their effect on gas processors. It is expected that oil demand should grow at least 4% annually over 1994-98, due to factors including world economic growth and low energy prices. Oil prices are forecast to bottom out in late 1995 and rise thereafter to the mid-20 dollar range by the end of the 1990s. A close supply-demand balance could send short-term prices much higher. Some widening of the gas-oil ratio should occur, providing room for domestic natural gas prices to rise, but with a lag. 8 figs

Spiral Structure and Global Star Formation Processes in M 51

Science.gov (United States)

Gruendl, Robert A.

1994-12-01

The nearby grand design spiral galaxy, M 51, is an obvious proving ground for studies of spiral structure and large scale star formation processes. New near--infrared observations of M 51 made with COB (Cryogenic Optical Bench) on the Kitt Peak 1.3m allow us to examine the stellar distribution and the young star formation regions as well as probe regions of high extinction such as dust lanes. We also present an analysis of the kinematics of the ionized gas observed with the Maryland--Caltech Imaging Fabry Perot. The color information we derive from the near--infrared bands provides a more accurate tracer of extinction than optical observations. We find that the dust extinction and CO emission in the arms are well correlated. Our kinematic data show unambiguously that these dense gas concentrations are associated with kinematic perturbations. In the inner disk, these perturbations are seen to be consistent with the streaming motions predicted by classical density wave theory. The dust lanes, and presumably the molecular arms, form a narrow ridge that matches these velocity perturbations wherever the viewing angle is appropriate. This interpretation requires that the corotation radius be inward of the outer tidal arms. The outer tidal arms however show streaming velocities of the sign that would be expected interior to the corotation point. This can be reconciled if the outer arms are part of a second spiral pattern, most likely due to the interaction with the companion NGC 5195. The near--infrared observations also show emission from the massive star forming regions. These observations are less affected by extinction than optical observations of H II regions and show clearly that the sites of massive star formation are correlated with but downstream from the concentrations of dense molecular material. This provides clear evidence that the ISM has been organized by the streaming motions which have in turn triggered massive star formation.

Infrared photodissociation spectroscopy of M(N2)n(+) (M = Y, La, Ce; n = 7-8) in the gas phase.

Science.gov (United States)

Xie, Hua; Shi, Lei; Xing, Xiaopeng; Tang, Zichao

2016-02-14

M(N2)n(+) (M = Y, La, Ce; n = 7-8) complexes have been studied by infrared photodissociation (IRPD) spectroscopy and density functional theory (DFT) calculations. The experimental results indicate that the N-N stretching vibrational frequencies are red-shifted from the gas-phase N2 value. The π back-donation is found to be a main contributor in these systems. IRPD spectra and DFT calculations reveal the coexistence of two isomers in the seven-coordinate M(N2)7(+) and eight-coordinate M(N2)8(+) complexes, respectively. The present studies on these metal-nitrogen complexes shed light on the interactions and coordinations toward N2 with transition and lanthanide metals.

Low background gas flow beta counting system [Paper No.:M2

International Nuclear Information System (INIS)

Abani, M.C.; Anilkumar, S.; Bhende, D.R.; Krishnan, Narayani; Babu, D.A.R.

1993-01-01

It is difficult to count beta samples of low specific activity in conventional types of counting systems which have inherently high background. This is specially true in case of environmental samples. A gas flow type beta counter has been developed which have the twin advantage of high efficiency and low background. This system uses a gas flow type main counter and another gas flow type guard counter working on the same principle in anticoincidence mode. Both counters are operated in G.M. region. With this anticoincidence arrangement and lead shielding of 3 inch, the system has the background of the order of 1 cpm and efficiency of 40% for 40 K beta and 14% for 14 C beta. The electronics developed includes a quenching cum coincidence-anticoincidence unit, EHT and a counter timer. This paper describes in detail the development and operational experience with the system. A number of units are already operational at BARC and at Environmental Survey Laboratories set up by Department of Atomic Energy and at various other institutions. (author). 4 refs., 2 figs

A preliminary analysis of floating production storage and offloading facilities with gas liquefaction processes

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; Carranza-Sánchez, Yamid Alberto; Junior, Silvio de Oliveira

2016-01-01

Floating, production, storage and offloading (FPSO) plants are facilities used in upstream petroleum processing. They have gained interest because they are more flexible than conventional plants and can be used for producing oil and gas in deep-water fields. In general, gas export is challenging...... because of the lack of infrastructure in remote locations. The present work investigates the possibility of integrating liquefaction processes on such facilities, considering two mixed-refrigerant and two expansion-based processes suitable for offshore applications. Two FPSO configurations are considered...... in this work, and they were suggested by Brazilian operators for fields processing natural gas with moderate to high content of carbon dioxide. The performance of the combined systems is analysed by conducting energy and exergy analyses. The integration of gas liquefaction results in greater power consumption...

Hanford gas dispersion analysis

International Nuclear Information System (INIS)

Fujita, R.K.; Travis, J.R.

1994-01-01

An analysis was performed to verify the design of a waste gas exhauster for use in support of rotary core sampling activities at the Westinghouse Hanford Waste Tank Farm. The exhauster was designed to remove waste gases from waste storage tanks during the rotary core drilling process of the solid materials in the tank. Some of the waste gases potentially are very hazardous and must be monitored during the exhauster's operation. If the toxic gas concentrations in specific areas near the exhauster exceed minimum Threshold Limit Values (TLVs), personnel must be excluded from the area. The exhauster stack height is of interest because an increase in stack height will alter the gas concentrations at the critical locations. The exhaust stack is currently ∼4.6 m (15 ft) high. An equipment operator will be located within a 6.1 m (20 ft) radius of the exhaust stack, and his/her head will be at an elevation 3.7 m (12 ft) above ground level (AGL). Therefore, the maximum exhaust gas concentrations at this location must be below the TLV for the toxic gases. Also, the gas concentrations must be within the TLV at a 61 m (200 ft) radius from the stack. If the calculated gas concentrations are above the TLV, where the operator is working below the stack at the 61 m (200 ft) radius location, the stack height may need to be increased

Recent natural gas mergers/alliances and their impact on processing

International Nuclear Information System (INIS)

Kovacs, K.; Schwenker, C.

1997-01-01

Recent mergers and acquisitions have dramatically changed the competitive landscape for companies in the oil, gas and energy services businesses. One measure of this change is the number of publicly traded oil and gas producers in the US. Prior to 1991 the Oil and Gas Journal listed 400 publicly traded producers. This list shrank in 1991 to 300, and as of 1996, the list is now down to 200 in their annual survey. The purpose of this paper is to: briefly review some of the underlying factors or events that have shaped or driven the rush to consolidate; discuss how these changes have impacted gas processing; finally, make some observations on the types of consolidations and opportunities that could occur in the future

Analysis on discharge process of a plasma-jet triggered gas spark switch

Science.gov (United States)

Weihao, TIE; Cui, MENG; Yuting, ZHANG; Zirang, YAN; Qiaogen, ZHANG

2018-01-01

The plasma-jet triggered gas switch (PJTGS) could operate at a low working coefficient with a low jitter. We observed and analyzed the discharge process of the PJTGS at the lowest working coefficient of 47% with the trigger voltage of 40 kV and the pulse energy of 2 J to evaluate the effect of the plasma jet. The temporal and spatial evolution and the optical emission spectrum of the plasma jet were captured. And the spraying delay time and outlet velocity under different gas pressures were investigated. In addition, the particle in cell with Monte Carlo collision was employed to obtain the particle distribution of the plasma jet varying with time. The results show that, the plasma jet generated by spark discharge is sprayed into a spark gap within tens of nanoseconds, and its outlet velocity could reach 104 m s-1. The plasma jet plays a non-penetrating inducing role in the triggered discharge process of the PJTGS. On the one hand, the plasma jet provides the initial electrons needed by the discharge; on the other hand, a large number of electrons focusing on the head of the plasma jet distort the electric field between the head of the plasma jet and the opposite electrode. Therefore, a fast discharge originated from the plasma jet is induced and quickly bridges two electrodes.

Method of processing radioactive gas

International Nuclear Information System (INIS)

Saito, Masayuki.

1978-01-01

Purpose: To reduce the quantity of radioactive gas discharged at the time of starting a nuclear power plant. Method: After the stoppage of a nuclear power plant air containing a radioactive gas is extracted from a main condenser by operating an air extractor. The air is sent into a gaseous waste disposal device, and then introduced into the activated carbon adsorptive tower of a rare gas holdup device where xenon and krypton are trapped. Thereafter, the air passes through pipelines and returned to the main condenser. In this manner, the radioactive gas contained in air within the main condenser is removed during the stoppage of the operation of the nuclear power plant. After the plant has been started, when it enters the normal operation, a flow control valve is closed and another valve is opened, and a purified gas exhausted from the rare gas holdup device is discharged into the atmosphere through an exhaust cylinder. (Aizawa, K.)

Simulation, integration, and economic analysis of gas-to-liquid processes

International Nuclear Information System (INIS)

Bao, Buping; El-Halwagi, Mahmoud M.; Elbashir, Nimir O.

2010-01-01

Gas-to-liquid (GTL) involves the chemical conversion of natural gas into synthetic crude that can be upgraded and separated into different useful hydrocarbon fractions including liquid transportation fuels. Such technology can also be used to convert other abundant natural resources such as coal and biomass to fuels and value added chemicals (referred to as coal-to-liquid (CTL) and biomass-to-liquid (BTL)). A leading GTL technology is the Fischer-Tropsch (FT) process. The objective of this work is to provide a techno-economic analysis of the GTL process and to identify optimization and integration opportunities for cost saving and reduction of energy usage while accounting for the environmental impact. First, a base-case flowsheet is synthesized to include the key processing steps of the plant. Then, a computer-aided process simulation is carried out to determine the key mass and energy flows, performance criteria, and equipment specifications. Next, energy and mass integration studies are performed to address the following items: (a) heating and cooling utilities, (b) combined heat and power (process cogeneration), (c) management of process water, (c) optimization of tail gas allocation, and (d) recovery of catalyst-supporting hydrocarbon solvents. Finally, these integration studies are conducted and the results are documented in terms of conserving energy and mass resources as well as providing economic impact. Finally, an economic analysis is undertaken to determine the plant capacity needed to achieve the break-even point and to estimate the return on investment for the base-case study. (author)

Behaviour of CaO coating of gas atomized Mg powders using mechanical milling process

International Nuclear Information System (INIS)

Kim, Sun-Mi; Kim, Yong Hwan; Kim, Young Do; Kim, Taek-Soo

2011-01-01

Highlights: → This work is very new, since behaviour of CaO coating with milling time as desulfurizer is not frequently reported. → The manuscript reports the new manner of Mg powders desulfurizer development by the innovative process. - Abstract: In order to synthesize a thermally stable Mg powder as a desulfurizer of iron, pure Mg was gas atomized to powders and coated by CaO powders, to produce a thermally stable desulfurizer using a mechanical milling process. Since the effect of desulfurization is dependent on the degree of surface modification, coating behaviours such as the size, morphology and layer thickness were investigated as a function of milling condition. As the milling conducted from 10 min to 30 min, 1 h, 3 h, 6 h, 12 h, CaO particles began to stick on the surface of Mg powders. The layer of CaO formed from 1 h milling was about 17 μm thick and gradually thickened to be 28 μm, 32 μm and 37 μm with increasing the milling time to 3 h, 6 h and 12 h, respectively. The shape of coated powder became more spherical after 1 h milling, being mostly spherical after 6 h. Desulfurization rate and uniformity were evaluated for the various thickness of the coating layer.

The behaviour of radionuclides in gas adsorption chromatographic processes with superimposed chemical reactions (chlorides)

International Nuclear Information System (INIS)

Eichler, B.

1996-01-01

Thermochemical relationships are derived describing the gas adsorption chromatographic transport of carrier-free radionuclides. Especially, complex adsorption processes such as dissociative, associative and substitutive adsorption are dealt with. The comparison of experimental with calculated data allows the determination of the type of adsorption reaction, which is the basis of the respective gas chromatographic process. The behaviour of carrier-free radionuclides of elements Pu, Ce, Ru, Co and Cr in thermochromatographic experiments with chlorinating carrier gases can be described as dissociative adsorption of chlorides in higher oxidation states. The gas adsorption chromatographic transport of Zr with oxygen and chlorine containing carrier gas is shown to be a substitutive adsorption process. The consequences of superimposed chemical reactions on the interpretation of results and the conception of gas adsorption chromatographic experiments with carrier-free radionuclides in isothermal columns and in temperature gradient tubes is discussed. (orig.)

Hysec Process: production of high-purity hydrogen from coke oven gas

Energy Technology Data Exchange (ETDEWEB)

Nishida, S

1984-01-01

An account is given of the development of the Hysec Process by the Kansai Netsukagaku and Mitsubishi Kakoki companies. The process is outlined and its special features noted. The initial development aim was to obtain high-purity hydrogen from coke oven gas by means of PSA. To achieve this, ways had to be found for removing the impurities in the coke oven gas and the trace amounts of oxygen which are found in the product hydrogen. The resulting hydrogen is 99.9999% pure. 3 references.

Experimental substantiation of combined methods for designing processes for the commercial preparation of gas at gas condensate fields

Energy Technology Data Exchange (ETDEWEB)

Gurevich, G R; Karlinskii, E D; Posypkina, T V

1977-04-01

An analysis is made of the possibility of using two analytical methods for studying vapor--liquid equilibrium of hydrocarbon mixtures that are used in designing the separation of natural gas and the stabilization of condensate--the Chao and Sider method, which uses computations by equilibrium constants. A combined computational method is proposed for describing a unified process of natural gas separation and condensate stabilization. The method of preparing the original data for the computation of the separation and stabilization processes can be significantly simplified. 10 references, 1 table.

Absorption process for removing krypton from the off-gas of an LMFBR fuel reprocessing plant

International Nuclear Information System (INIS)

Stephenson, M.J.; Dunthorn, D.I.; Reed, W.D.; Pashley, J.H.

1975-01-01

The Oak Ridge Gaseous Diffusion Plant selective absorption process for the collection and recovery of krypton and xenon is being further developed to demonstrate, on a pilot scale, a fluorocarbon-based process for removing krypton from the off-gas of an LMFBR fuel reprocessing plant. The new ORGDP selective absorption pilot plant consists of a primary absorption-stripping operation and all peripheral equipment required for feed gas preparation, process solvent recovery, process solvent purification, and krypton product purification. The new plant is designed to achieve krypton decontamination factors in excess of 10 3 with product concentration factors greater than 10 4 while processing a feed gas containing typical quantities of common reprocessing plant off-gas impurities, including oxygen, carbon dioxide, nitrogen oxides, water, xenon, iodine, and methyl iodide. Installation and shakedown of the facility were completed and some short-term tests were conducted early this year. The first operating campaign using a simulated reprocessing plant off-gas feed is now underway. The current program objective is to demonstrate continuous process operability and performance for extended periods of time while processing the simulated ''dirty'' feed. This year's activity will be devoted to routine off-gas processing with little or no deliberate system perturbations. Future work will involve the study of the system behavior under feed perturbations and various plant disturbances. (U.S.)

Natural gas. The LNG trade exceeds the 100 billions of m3 limit

International Nuclear Information System (INIS)

Anon.

1997-01-01

1996 has been a particularly favourable year for the international natural gas industry with a 10% increase of the international trade. The worldwide commercialized production of natural gas (2310 billions of m 3 ) has shown a 5% increase with respect to the previous year, with a strong increase in the OECD countries (+15.5%), in particular in the North Sea. High growing rates were recorded also in Latin America (9.5%) and Middle East (8%). Natural gas production in the CIS (Community of Independent States) reached 714 Gm 3 in 1996 with 600 Gm 3 from the Russian federation. The international trade has shown a 10% increase and reached 429.3 Gm 3 . The methane tanker ship trade has shown a 10 Gm 3 increase mainly in the Asian market (Japan and South Korea). Natural gas consumption growth has been high too (+4.9%) and reached 11.6% in Europe due to the climate conditions and to an increasing electric power demand. (J.S.)

Process for the gas extraction of coal

Energy Technology Data Exchange (ETDEWEB)

Urquhart, D B

1976-05-20

The object of the invention is a process for the hydroextraction of coal is treated with water and carbon monoxide at a temperature in the region of 300 - 380/sup 0/C. After treatment is completed, the gases are separated from the treated gas; the treated coal is then extracted with an extraction medium during the gas phase at a temperature of at least 400/sup 0/C, the remainder is separated from the gas phase and the coal extract is obtained from the extraction medium. Hydrogenation is preferably carried out at a temperature in the region of 320 - 370/sup 0/C and at a pressure of 200 - 400 at. The time required for treatment with carbon monoxide and water is 1/4 - 2 hours, and in special cases 3/4 - 1 1/2 hours. The coal material itself is nutty slack, of which more than 95% of the coal particles pass through a 1.5 mm mesh sieve. After the hydrogenation the extraction is carried out at a temperature in the region of 400 - 450/sup 0/C. The patent claims relate to the types of extraction media used.

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

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

Gas-assisted gravity drainage (GAGD) process for improved oil recovery

Science.gov (United States)

Rao, Dandina N [Baton Rouge, LA

2012-07-10

A rapid and inexpensive process for increasing the amount of hydrocarbons (e.g., oil) produced and the rate of production from subterranean hydrocarbon-bearing reservoirs by displacing oil downwards within the oil reservoir and into an oil recovery apparatus is disclosed. The process is referred to as "gas-assisted gravity drainage" and comprises the steps of placing one or more horizontal producer wells near the bottom of a payzone (i.e., rock in which oil and gas are found in exploitable quantities) of a subterranean hydrocarbon-bearing reservoir and injecting a fluid displacer (e.g., CO.sub.2) through one or more vertical wells or horizontal wells. Pre-existing vertical wells may be used to inject the fluid displacer into the reservoir. As the fluid displacer is injected into the top portion of the reservoir, it forms a gas zone, which displaces oil and water downward towards the horizontal producer well(s).

Experimental and theoretical investigations on the carbon dioxide gas hydrate formation kinetics at the onset of turbidity regarding CO2 capture and sequestration processes

International Nuclear Information System (INIS)

ZareNezhad, Bahman; Mottahedin, Mona; Varaminian, Farshad

2013-01-01

The carbon dioxide gas hydrate formation kinetics at the onset of turbidity is experimentally and theoretically investigated. It is shown that the time-dependent heterogeneous nucleation and growth kinetics are simultaneously governing the hydrate formation process at the onset of turbidity. A new approach is also presented for determination of gas hydrate-liquid interfacial tension. The CO 2 hydrate-liquid interfacial tension according to the suggested heterogeneous nucleation mechanism is found to be about 12.7 mJ/m 2 . The overall average absolute deviation between predicted and measured CO 2 molar consumption is about 0.61%, indicating the excellent accuracy of the proposed model for studying the hydrate-based CO 2 capture and sequestration processes over wide ranges of pressures and temperatures

Numerical simulations of rarefied gas flows in thin film processes

NARCIS (Netherlands)

Dorsman, R.

2007-01-01

Many processes exist in which a thin film is deposited from the gas phase, e.g. Chemical Vapor Deposition (CVD). These processes are operated at ever decreasing reactor operating pressures and with ever decreasing wafer feature dimensions, reaching into the rarefied flow regime. As numerical

Landfill gas (LFG) processing via adsorption and alkanolamine absorption

Energy Technology Data Exchange (ETDEWEB)

Gaur, Ankur; Park, Jin-Won; Song, Ho-Jun; Park, Jong-Jin [Department of Chemical and Biomolecular Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea); Maken, Sanjeev [Department of Chemistry, Deenbandhu Chhotu Ram University of Science and Technology, Murthal-131 039, Haryana (India)

2010-06-15

Landfill gas (LFG) was upgraded to pure methane using the adsorption and absorption processes. Different toxic compounds like aromatics and chlorinated compounds were removed using granular activated carbon. The activated carbon adsorbed toxic trace components in the following order: carbon tetrachloride > toluene > chloroform > xylene > ethylbenzene > benzene > trichloroethylene {approx} tetrachloroethylene. After removing all trace components, the gas was fed to absorption apparatus for the removal of carbon dioxide (CO{sub 2}). Two alkanolamines, monoethanol amine (MEA) and diethanol amine (DEA) were used for the removal of CO{sub 2} from LFG. The maximum CO{sub 2} loading is obtained for 30 wt.% MEA which is around 2.9 mol L{sup -} {sup 1} of absorbent solution whereas for same concentration of DEA it is around 1.66 mol L {sup -} {sup 1} of solution. 30 wt% MEA displayed a higher absorption rate of around 6.64 x 10{sup -} {sup 5} mol L{sup -} {sup 1} min{sup -} {sup 1}. DEA displayed a higher desorption rate and a better cyclic capacity as compared to MEA. Methane obtained from this process can be further used in the natural gas network for city. (author)

Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas

Energy Technology Data Exchange (ETDEWEB)

Kaaeid Lokhandwala

2005-12-22

The original proposal described the construction and operation of a 1 MMscfd treatment system to be operated at a Butcher Energy gas field in Ohio. The gas produced at this field contained 17% nitrogen. During pre-commissioning of the project, a series of well tests showed that the amount of gas in the field was significantly smaller than expected and that the nitrogen content of the wells was very high (25 to 30%). After evaluating the revised cost of the project, Butcher Energy decided that the plant would not be economical and withdrew from the project. Since that time, Membrane Technology and Research, Inc. (MTR) has signed a marketing and sales partnership with ABB Lummus Global, a large multinational corporation. MTR will be working with the company's Randall Gas Technology Group, a supplier of equipment and processing technology to the natural gas industry. Randall's engineering group first found a new site for the project at a North Texas Exploration (NTE) gas processing plant. The plant produced about 1 MMscfd of gas containing 24% nitrogen. The membrane unit was built to bring this gas to 4% nitrogen for delivery to the pipeline. The membrane skid was built by ABB. NTE ordered the required compressor and MTR made the membrane modules for a December 2004 delivery. However, the gas supply was not steady enough for field testing, and MTR/ABB have now located other sites for field testing and commercial development.

Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas

Energy Technology Data Exchange (ETDEWEB)

Kaaeid Lokhandwala

2005-12-15

The original proposal described the construction and operation of a 1 MMscfd treatment system to be operated at a Butcher Energy gas field in Ohio. The gas produced at this field contained 17% nitrogen. During pre-commissioning of the project, a series of well tests showed that the amount of gas in the field was significantly smaller than expected and that the nitrogen content of the wells was very high (25 to 30%). After evaluating the revised cost of the project, Butcher Energy decided that the plant would not be economical and withdrew from the project. Since that time, Membrane Technology and Research, Inc. (MTR) has signed a marketing and sales partnership with ABB Lummus Global, a large multinational corporation. MTR is now working with the company's Randall Gas Technology Group, a supplier of equipment and processing technology to the natural gas industry. Randall's engineering group first found a new site for the project at a North Texas Exploration (NTE) gas processing plant. The plant produced about 1 MMscfd of gas containing 24% nitrogen. The membrane unit was built to bring this gas to 4% nitrogen for delivery to the pipeline. The membrane skid was built by ABB. NTE ordered the required compressor and MTR made the membrane modules for a December 2004 delivery. However, the gas supply was not steady enough for field testing, and MTR/ABB have now located other sites for field testing and commercial development.

Coupled Thermo-Hydro-Mechanical-Chemical Modeling of Water Leak-Off Process during Hydraulic Fracturing in Shale Gas Reservoirs

Directory of Open Access Journals (Sweden)

Fei Wang

2017-11-01

Full Text Available The water leak-off during hydraulic fracturing in shale gas reservoirs is a complicated transport behavior involving thermal (T, hydrodynamic (H, mechanical (M and chemical (C processes. Although many leak-off models have been published, none of the models fully coupled the transient fluid flow modeling with heat transfer, chemical-potential equilibrium and natural-fracture dilation phenomena. In this paper, a coupled thermo-hydro-mechanical-chemical (THMC model based on non-equilibrium thermodynamics, hydrodynamics, thermo-poroelastic rock mechanics, and non-isothermal chemical-potential equations is presented to simulate the water leak-off process in shale gas reservoirs. The THMC model takes into account a triple-porosity medium, which includes hydraulic fractures, natural fractures and shale matrix. The leak-off simulation with the THMC model involves all the important processes in this triple-porosity medium, including: (1 water transport driven by hydraulic, capillary, chemical and thermal osmotic convections; (2 gas transport induced by both hydraulic pressure driven convection and adsorption; (3 heat transport driven by thermal convection and conduction; and (4 natural-fracture dilation considered as a thermo-poroelastic rock deformation. The fluid and heat transport, coupled with rock deformation, are described by a set of partial differential equations resulting from the conservation of mass, momentum, and energy. The semi-implicit finite-difference algorithm is proposed to solve these equations. The evolution of pressure, temperature, saturation and salinity profiles of hydraulic fractures, natural fractures and matrix is calculated, revealing the multi-field coupled water leak-off process in shale gas reservoirs. The influences of hydraulic pressure, natural-fracture dilation, chemical osmosis and thermal osmosis on water leak-off are investigated. Results from this study are expected to provide a better understanding of the

Experimental and theoretical analysis of the combustion process at low loads of a diesel natural gas dual-fuel engine

International Nuclear Information System (INIS)

Li, Weifeng; Liu, Zhongchang; Wang, Zhongshu

2016-01-01

To construct an effective method to analyze the combustion process of dual fuel engines at low loads, effects of combustion boundaries on the combustion process of an electronically controlled diesel natural gas dual-fuel engine at low loads were investigated. Three typical combustion modes, including h, m and n, appeared under different combustion boundaries. In addition, the time-sequenced characteristic and the heat release rate-imbalanced characteristic were found in the dual fuel engine combustion process. To quantify these characteristics, two quantitative indicators, including the TSC (time-sequenced coefficient) and the HBC (HRR-balanced coefficient) were defined. The results show that increasing TSC and HBC can decrease HC (hydrocarbon) emissions and improve the BTE (brake thermal efficiency) significantly. The engine with the n combustion mode can obtain the highest BTE and the lowest HC emissions, followed by m, and then h. However, the combustion process of the engine will deteriorate sharply if boundary conditions are not strictly controlled in the n combustion mode. Based on the n combustion mode, advancing the start of diesel injection significantly, using large EGR (exhaust gas recirculation) rate and appropriately intake throttling can effectively reduce HC emissions and improve the BTE of dual fuel engines at low loads with relatively high natural gas PES (percentage energy substitution). - Highlights: • We reported three typical combustion modes of a dual-fuel engine at low loads. • Time-sequenced characteristic was put forward and qualified. • HRR-imbalanced characteristic was put forward and qualified. • Three combustion modes appeared as equivalence ratio/diesel injection timing varied. • The engine performance varied significantly with different combustion mode.

Effective energy management by combining gas turbine cycles and forward osmosis desalination process

International Nuclear Information System (INIS)

Park, Min Young; Shin, Serin; Kim, Eung Soo

2015-01-01

Highlights: • Innovative gas turbine system and FO integrated system was proposed. • The feasibility of the integrated system was analyzed thermodynamically. • GOR of the FO–gas turbine system is 17% higher than those of MED and MSF. • Waste heat utilization of the suggested system is 85.7%. • Water production capacity of the suggested system is 3.5 times higher than the MSF–gas turbine system. - Abstract: In the recent years, attempts to improve the thermal efficiency of the gas turbine cycles have been made. In order to enhance the energy management of the gas turbine cycle, a new integration concept has been proposed; integration of gas turbine cycle and forward osmosis desalination process. The combination of the gas turbine cycle and the forward osmosis (FO) desalination process basically implies the coupling of the waste heat from the gas turbine cycle to the draw solute recovery system in the FO process which is the most energy consuming part of the whole FO process. By doing this, a strong system that is capable of producing water and electricity with very little waste heat can be achieved. The feasibility of this newly proposed system was analyzed using UNISIM program and the OLI property package. For the analysis, the thermolytic draw solutes which has been suggested by other research groups have been selected and studied. Sensitivity analysis was conducted on the integration system in order to understand and identify the key parameters of the integrated system. And the integrated system was further evaluated by comparing the gain output ratio (GOR) values with the conventional desalination technologies such as multi stage flash (MSF) and multi effect distillation (MED). The suggested integrated system was calculated to have a GOR of 14.8, while the MSF and MED when integrated to the gas turbine cycle showed GOR value of 12. It should also be noted that the energy utilization of the suggested integrated system is significantly higher by 27

Metalurgia de alabes móviles con banda integrada de turbinas de gas y su influencia sobre el comportamiento de los alabes

Directory of Open Access Journals (Sweden)

Mazur, Z.

1999-02-01

Full Text Available The influence of the microstructure of the gas turbine blades with integral shroud on the blades performance is presented. The analysis of the solidification process of the gas turbine blades during conventionally casting process (equiaxed grains with all elements which has influence on the mode of its solidification and variation of the microstructure is carried out. Also, the evaluation of the failure of the gas turbine blade is presented. A detailed analysis of the blade tip shroud microstructure (presence of the equiaxed and columnar grains and its influence on the failure initiation and propagation is carried out. Finally, conclusions and some necessary improvements of the blades casting process to prevent blades failures are presented.

Se presenta la influencia de la microestructura en el comportamiento de los alabes móviles con banda integrada de turbinas de gas bajo condiciones reales de trabajo. Para el proceso de vaciado convencional (granos equiaxiales de los alabes de turbinas de gas se lleva a cabo el análisis del proceso de solidificación presentando todos los elementos que influyen al modo de solidificación de un alabe y en la variación de la microestructura resultante. Se hace la evaluación de la falla de un alabe con la banda integrada de turbina de gas presentando el mecanismo de la falla y la influencia de la microestructura de la banda del alabe al inicio y propagación de la falla. Finalmente, se presentan las conclusiones determinando los elementos principales de la microestructura que influyen en el comportamiento de los alabes y las medidas preventivas para adecuar la microestructura a las condiciones de trabajo de los alabes.

Investigation of a Gas-Solid Separation Process for Cement Raw Meal

DEFF Research Database (Denmark)

Maarup, Claus; Hjuler, Klaus; Clement, Karsten

2015-01-01

The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation efficienc......The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation...

Heat recovery from flue gas of coal fired installations with reduced pollutant emission - the Zittau process

Energy Technology Data Exchange (ETDEWEB)

Mueller, H; Strauss, R; Hofmann, K -D; Suder, M; Hultsch, T; Wetzel, W; Gabrysch, H; Jung, J [Technische Hochschule, Zittau (German Democratic Republic)

1988-12-01

Reviews the technology applied in the Zittau process for flue gas heat recovery and flue gas desulfurization in small brown coal fired power plants. Steam generators have a capacity of 6.5 or 10 t/h, low grade fuel with 8.2 MJ/kg calorific value is combusted. Technology has been developed on an experimental 10 t/h steam generator since 1986; an industrial 6.5 t/h prototype steam generator is now in operation achieving 95% SO{sub 2} removal from flue gas with 5600 to 7800 mg SO{sub 2} per m{sup 3} of dry flue gas. The Zittau technology is available in 3 variants: with maximum waste heat recovery, with partial waste heat recovery or without waste heat recovery and only wet flue gas scrubbing. Two flowsheets of flue gas and suspension circulation are provided. The first variant recovers 25.7% of nominal heat capacity (1.1 thermal MW from a 4.2 MW steam generator with 6.5 t/h steam capacity), the second variant recovers 6.5% of waste heat by reducing heat exchangers to 20% of the size of the first variant. Flue gas suspension scrubbing utilizes power plant ash, which is capable of absorbing 50 to 70% of SO{sub 2}, additional 25% SO{sub 2} removal is achieved by providing either 40% ash from another power plant or limestone for suspensions. Various technological details are included. 5 refs.

Process for catalytic flue gas denoxing

International Nuclear Information System (INIS)

Woldhuis, A.; Goudriaan, F.; Groeneveld, M.; Samson, R.

1991-01-01

With the increasing concern for the environment, stringency of legislation and industry's awareness of its own environmental responsibility, the demand for the reduction of emission levels of nitrogen oxides is becoming increasingly urgent. This paper reports that Shell has developed a low temperature catalytic deNOx system for deep removal of nitrogen oxides, which includes a low-pressure-drop reactor. This process is able to achieve over 90% removal of nitrogen oxides and therefore can be expected to meet legislation requirements for the coming years. The development of a low-temperature catalyst makes it possible to operate at temperatures as low as 120 degrees C, compared to 300-400 degrees C for the conventional honeycomb and plate-type catalysts. This allows an add-on construction, which is most often a more economical solution than the retrofits in the hot section required with conventional deNOx catalysts. The Lateral Flow Reactor (LFR), which is used for dust-free flue gas applications, and the Parallel Passage Reactor (PPR) for dust-containing flue gas applications, have been developed to work with pressure drops below 10 mbar

Downstream gas processing opportunities arising from the 1990's quest for a quality environment

International Nuclear Information System (INIS)

Geren, P.M.

1992-01-01

Over the last several years the former wart on your favorite daughter's nose (gas liquids processing) has become a most cherished body part, to paraphrase 1991 remarks of a U.S. gas processing leader. The dramatic recent spreads between liquids prices and the cost of feedstock natural gas have provided spectacular performance for processors. However, market prices for liquids will probably track petroleum. One day soon natural gas's inherent value will rise to parity with petroleum on a heating value basis. As petroleum demands will probably be flat in the foreseeable term, and natural gas prices will rise, something must be done to preserve gas processors' margins. Radical change in the formulation of U.S. gasoline presents many opportunities for gas processor to diversify into synthesis of upgraded derivatives of natural gas and liquids, which derivatives have high value-added characteristics. Issues relating to the selection of derivatives, the required technology, and capital project considerations are discussed in this paper

Method and apparatus for manufacturing gas tags

International Nuclear Information System (INIS)

Gross, K.C.; Laug, M.T.

1996-01-01

For use in the manufacture of gas tags employed in a gas tagging failure detection system for a nuclear reactor, a plurality of commercial feed gases each having a respective noble gas isotopic composition are blended under computer control to provide various tag gas mixtures having selected isotopic ratios which are optimized for specified defined conditions such as cost. Using a new approach employing a discrete variable structure rather than the known continuous-variable optimization problem, the computer controlled gas tag manufacturing process employs an analytical formalism from condensed matter physics known as stochastic relaxation, which is a special case of simulated annealing, for input feed gas selection. For a tag blending process involving M tag isotopes with N distinct feed gas mixtures commercially available from an enriched gas supplier, the manufacturing process calculates the cost difference between multiple combinations and specifies gas mixtures which approach the optimum defined conditions. The manufacturing process is then used to control tag blending apparatus incorporating tag gas canisters connected by stainless-steel tubing with computer controlled valves, with the canisters automatically filled with metered quantities of the required feed gases. 4 figs

Electric power generation and LNG evaporation with the aid of gas turbines within a closed-cycle process. [In German

Energy Technology Data Exchange (ETDEWEB)

Weber, D

1978-01-01

LNG, after being pumped to customary pipeline pressure, has a high working potential which can be technically utilized. Thus, in a modern large-size terminal, a power potential in the order of magnitude of several hundred MW is available. In the course of rising power prices the question becomes important if this potential continues to be wasted or if conversion to electric power is economical. In the proposed process the working fluid of a gas turbine plant with a closed circuit is cooled to -140/sup 0/C with LNG before entering the compressor and heated to +720/sup 0/C before entering the turbine by means of external heat gained by burning natural gas. With a 1 million m/sup 3//h throughput of LNG in its normal state, 237 MW of electric power can be generated with 53% efficiency with this simple circuit, which can be further developed. In a combination of closed gas turbine and diesel generator, almost 289 MW of electric power can be produced per 1 million m/sup 3//h LNG with an efficiency of 60%.

Aqueous process for recovering sulfur from hydrogen sulfide-bearing gas

Science.gov (United States)

Basu, Arunabha

2015-05-05

A process for recovering sulfur from a hydrogen sulfide-bearing gas utilizes an aqueous reaction medium, a temperature of about 110-150.degree. C., and a high enough pressure to maintain the aqueous reaction medium in a liquid state. The process reduces material and equipment costs and addresses the environmental disadvantages associated with known processes that rely on high boiling point organic solvents.

A Theoretical and Experimental Analysis of Post-Compression Water Injection in a Rolls-Royce M250 Gas Turbine Engine

Science.gov (United States)

2015-05-18

ROLLS-ROYCE M250 GAS TURBINE ENGINE by Midshipman 1/C Brian R. He United States Naval Academy Annapolis, Maryland...Injection in a Rolls- Royce M250 Gas Turbine Engine 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) He...output, efficiency, operating conditions, and emissions of injecting water at the compressor discharge of a Rolls-Royce M250 . The results

Natural gas industry in Bulgaria

International Nuclear Information System (INIS)

Mashkin, L.

1994-01-01

An overview of the Bulgarian natural gas industry is presented. The starting point was the discovery of the indigenous Chiren gas-field in 1967. The first agreement with the ex-USSR for supply of natural gas and construction of main pipelines was signed in 1968. The state gas company BULGARGAZ is responsible for transportation, storage, distribution, processing and marketing of the gas to over 150 industrial companies in the country, as well as for the transportation services to gas importers in neighboring Turkey. The GAZSTROJMONTAZH company accomplish the construction of the local and transit pipelines to Turkey and Greece, as well as of some objects in Iran, Syria, Ukraine and Germany. In the past 20 years, 87890 million m 3 natural gas from Russia are supplied and 846 million m 3 - from domestic sources. The share of natural gas in the overall energy balance is 13.6% for 1992. The restructuring and further development of gas industry require to take into account some factors as: security in supply; investments for technical assurance; pricing policy for natural gas; development of private business. Some administrative problems are also mentioned. 2 tabs., 1 fig

Ceramic membranes for gas processing in coal gasification

Energy Technology Data Exchange (ETDEWEB)

Smart, S.; Lin, C.X.C.; Ding, L.; Thambimuthu, K.; da Costa, J.C.D. [University of Queensland, Brisbane, Qld. (Australia)

2010-07-01

Pre-combustion options via coal gasification, especially integrated gasification combined cycle (IGCC) processes, are attracting the attention of governments, industry and the research community as an attractive alternative to conventional power generation. It is possible to build an IGCC plant with CCS with conventional technologies however; these processes are energy intensive and likely to reduce power plant efficiencies. Novel ceramic membrane technologies, in particular molecular sieving silica (MSS) and pervoskite membranes, offer the opportunity to reduce efficiency losses by separating gases at high temperatures and pressures. MSS membranes can be made preferentially selective for H{sub 2}, enabling both enhanced production, via a water-gas shift membrane reactor, and recovery of H{sub 2} from the syngas stream at high temperatures. They also allow CO{sub 2} to be concentrated at high pressures, reducing the compression loads for transportation and enabling simple integration with CO{sub 2} storage or sequestration operations. Perovskite membranes provide a viable alternative to cryogenic distillation for air separation by delivering the tonnage of oxygen required for coal gasification at a reduced cost. In this review we examine ceramic membrane technologies for high temperature gas separation and discuss the operational, mechanical, design and process considerations necessary for their successful integration into IGCC with CCS systems.

Radiological considerations of the reactor cover gas processing system at the FFTF

International Nuclear Information System (INIS)

Prevo, P.R.

1987-01-01

Radiological and environmental protection experience associated with the reactor cover gas processing system at the Fast Flux Test Facility (FFTF) has been excellent. Personnel radiation exposures received from operating and maintaining the reactor cover gas processing system have been very low, the system has remained free of radioactive particulate contamination through the first seven operating cycles (cesium contamination was detected at the end of Cycle 8A), and releases of radioactivity to the environment have been very low, well below environmental standards. This report discusses these three aspects of fast reactor cover gas purification over the first eight operating cycles of the FFTF (a duration of a little more than four years, from April 1982 through July 1986). (author)

A novel Kr-83m tracer method for characterizing xenon gas and cryogenic distillation systems

Czech Academy of Sciences Publication Activity Database

Rosendahl, S.; Bokeloh, K.; Brown, E.; Cristescu, R.; Fieguth, A.; Huhmann, C.; Lebeda, Ondřej; Levy, C.; Murra, M.; Schneider, S.; Vénos, Drahoslav; Weinheimer, C.

2014-01-01

Roč. 9, OCT (2014), p10010 ISSN 1748-0221 R&D Projects: GA ČR(CZ) GAP203/12/1896; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : photon detectors for UV * visible and IR photons (gas) * gas systems and purification * scintillators, scintillation and light emission processes (solid, gas and liquid scintillators) * very low-energy charged particle detectors Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.399, year: 2014

Energy consumption estimation for greenhouse gas separation processes by clathrate hydrate formation

International Nuclear Information System (INIS)

Tajima, Hideo; Yamasaki, Akihiro; Kiyono, Fumio

2004-01-01

The process energy consumption was estimated for gas separation processes by the formation of clathrate hydrates. The separation process is based on the equilibrium partition of the components between the gaseous phase and the hydrate phase. The separation and capturing processes of greenhouse gases were examined in this study. The target components were hydrofluorocarbon (HFC-134a) from air, sulfur hexafluoride (SF 6 ) from nitrogen, and CO 2 from flue gas. Since these greenhouse gases would form hydrates under much lower pressure and higher temperature conditions than the accompanying components, the effective capturing of the greenhouse gases could be achieved by using hydrate formation. A model separation process for each gaseous mixture was designed from the basis of thermodynamics, and the process energy consumption was estimated. The obtained results were then compared with those for conventional separation processes such as liquefaction separation processes. For the recovery of SF 6 , the hydrate process is preferable to liquefaction process in terms of energy consumption. On the other hand, the liquefaction process consumes less energy than the hydrate process for the recovery of HFC-134a. The capturing of CO 2 by the hydrate process from a flue gas will consume a considerable amount of energy; mainly due to the extremely high pressure conditions required for hydrate formation. The influences of the operation conditions on the heat of hydrate formation were elucidated by sensitivity analysis. The hydrate processes for separating these greenhouse gases were evaluated in terms of reduction of global warming potential (GWP)

Simulating gas-aerosol-cirrus interactions: Process-oriented microphysical model and applications

Directory of Open Access Journals (Sweden)

B. Kärcher

2003-01-01

Full Text Available This work describes a process-oriented, microphysical-chemical model to simulate the formation and evolution of aerosols and ice crystals under the conditions prevailing in the upper troposphere and lower stratosphere. The model can be run as a box model or along atmospheric trajectories, and considers mixing, gas phase chemistry of aerosol precursors, binary homogeneous aerosol nucleation, homogeneous and heterogeneous ice nucleation, coagulation, condensation and dissolution, gas retention during particle freezing, gas trapping in growing ice crystals, and reverse processes. Chemical equations are solved iteratively using a second order implicit integration method. Gas-particle interactions and coagulation are treated over various size structures, with fully mass conserving and non-iterative numerical solution schemes. Particle types include quinternary aqueous solutions composed of H2SO4, HNO3, HCl, and HBr with and without insoluble components, insoluble aerosol particles, and spherical or columnar ice crystals deriving from each aerosol type separately. Three case studies are discussed in detail to demonstrate the potential of the model to simulate real atmospheric processes and to highlight current research topics concerning aerosol and cirrus formation near the tropopause. Emphasis is placed on how the formation of cirrus clouds and the scavenging of nitric acid in cirrus depends on small-scale temperature fluctuations and the presence of efficient ice nuclei in the tropopause region, corroborating and partly extending the findings of previous studies.

Measuring gas temperature during spin-exchange optical pumping process

Science.gov (United States)

Normand, E.; Jiang, C. Y.; Brown, D. R.; Robertson, L.; Crow, L.; Tong, X.

2016-04-01

The gas temperature inside a Spin-Exchange Optical Pumping (SEOP) laser-pumping polarized 3He cell has long been a mystery. Different experimental methods were employed to measure this temperature but all were based on either modelling or indirect measurement. To date there has not been any direct experimental measurement of this quantity. Here we present the first direct measurement using neutron transmission to accurately determine the number density of 3He, the temperature is obtained using the ideal gas law. Our result showed a surprisingly high gas temperature of 380°C, compared to the 245°C of the 3He cell wall temperature and 178°C of the optical pumping oven temperature. This experiment result may be used to further investigate the unsolved puzzle of the "X-factor" in the SEOP process which places an upper bound to the 3He polarization that can be achieved. Additional spin relaxation mechanisms might exist due to the high gas temperature, which could explain the origin of the X-factor.

Aircraft Flight Modeling During the Optimization of Gas Turbine Engine Working Process

Science.gov (United States)

Tkachenko, A. Yu; Kuz'michev, V. S.; Krupenich, I. N.

2018-01-01

The article describes a method for simulating the flight of the aircraft along a predetermined path, establishing a functional connection between the parameters of the working process of gas turbine engine and the efficiency criteria of the aircraft. This connection is necessary for solving the optimization tasks of the conceptual design stage of the engine according to the systems approach. Engine thrust level, in turn, influences the operation of aircraft, thus making accurate simulation of the aircraft behavior during flight necessary for obtaining the correct solution. The described mathematical model of aircraft flight provides the functional connection between the airframe characteristics, working process of gas turbine engines (propulsion system), ambient and flight conditions and flight profile features. This model provides accurate results of flight simulation and the resulting aircraft efficiency criteria, required for optimization of working process and control function of a gas turbine engine.

Hydrogen enriched gas production in a multi-stage downdraft gasification process

International Nuclear Information System (INIS)

Dutta, A.; Jarungthammachote, S.

2009-01-01

To achieve hydrogen enriched and low-tar producer gas, multi-stage air-blown and air-steam gasification were studied in this research. Results showed that the tar content from multi-stage air-blown and air-steam gasification was lower compared to the average value of that from downdraft gasification. It was also seen that an air-steam gasification process could potentially increase the hydrogen concentration in the producer gas in the expense of carbon monoxide; however, the summation of hydrogen and carbon monoxide in the producer gas was increased. (author)

Analysis of Off Gas From Disintegration Process of Graphite Matrix by Electrochemical Method

International Nuclear Information System (INIS)

Tian Lifang; Wen Mingfen; Chen Jing

2010-01-01

Using electrochemical method with salt solutions as electrolyte, some gaseous substances (off gas) would be generated during the disintegration of graphite from high-temperature gas-cooled reactor fuel elements. The off gas is determined to be composed of H 2 , O 2 , N 2 , CO 2 and NO x by gas chromatography. Only about 1.5% graphite matrix is oxidized to CO 2 . Compared to the direct burning-graphite method, less off gas,especially CO 2 , is generated in the disintegration process of graphite by electrochemical method and the treatment of off gas becomes much easier. (authors)

Method for treating a nuclear process off-gas stream

International Nuclear Information System (INIS)

Pence, D.T.; Chou, C.C.

1984-01-01

Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO /SUB x/ , hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140 0 to -160 0 C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140 0 to -160 0 C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton

Method for treating a nuclear process off-gas stream

Science.gov (United States)

Pence, Dallas T.; Chou, Chun-Chao

1984-01-01

Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO.sub.x, hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140.degree. to -160.degree. C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140.degree. to -160.degree. C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton.

Methods for Organization of Working Process for Gas-Diesel Engine

OpenAIRE

Вершина, Г. А.; Быстренков, О. С.

2017-01-01

Over the past few decades reduction in pollutant emissions has become one of the main directions for further deve- lopment of engine technology. Solution of such problems has led to implementation of catalytic post-treatment systems, new technologies of fuel injection, technology for regulated phases of gas distribution, regulated turbocharger system and, lately, even system for variable compression ratio of engine. Usage of gaseous fuel, in particular gas-diesel process, may be one of the me...

Process for preparing a normal lighting and heating gas etc

Energy Technology Data Exchange (ETDEWEB)

Becker, J

1910-12-11

A process for preparing a normal lighting and heating gas from Australian bituminous shale by distillation and decomposition in the presence of water vapor is characterized by the fact that the gasification is suitably undertaken with gradual filling of a retort and with simultaneous introduction of water vapor at a temperature not exceeding 1,000/sup 0/ C. The resulting amount of gas is heated in the same or a second heated retort with freshly supplied vapor.

Separation of krypton from dissolver off-gas of a reprocessing plant using preparative gas chromatography

International Nuclear Information System (INIS)

Matoni, M.

1984-02-01

Kr-85 can be separated from the pre-purified purge air in the final processing step of the purification phase for dissolver off-gases of a reprocessing plant with the aid of preparative gas chromatography. Activated carbon adsorbers in combination with helium as carrier gas permits maximum gas mixture through-flow. A separation temperature of 30 0 C is considered optimal. An adsorbent volume of 40 dm 3 is necessary for processing the residual gas flow of 2.5 Nm 3 /h; the adsorbent is divided between 2 columns linked in series each of which are 2 m long with an internal diameter of 100 mm. The helium flow required is five times greater than the off-gas flow. The degree of purity for krypton is greater than 90% for a decontamination factor of greater than 1000. (orig./HP) [de

The current investment climate for midstream gas processing assets

International Nuclear Information System (INIS)

Brouwer, R.J.

1999-01-01

Topics discussed in this paper dealing with the current investment climate for midstream gas processing assets include: (1) strategic reasons to retain or divest midstream assets, (2) available options for midstream asset divestment, (3) midstream market fundamentals, and (4) financial performance of midstream companies. There are some 700 gas plants in Alberta at present, of which about 20 per cent are owned by midstream companies . About one half of the plants are smaller than 12.5 MMCFD which represent inefficient use of resources; a clear indication that there are substantial opportunities for consolidation. 1 tab., 4 figs

Fiscal 2000 achievement report on the investigation of alternative gas system and process technologies for dry etching in electronic device manufacturing; 2000 nendo denshi device seizo process de shiyosuru etching gas no daitai gas system oyobi daitai process no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Efforts are made to develop technologies for saving PFC (perfluoro-compound) and conserving energy in semiconductor manufacturing processes, in particular, in the layer insulation film (SiO{sub 2}) dry etching process. Activities are conducted in the five fields of (1) research and development of technologies for reducing the amount of etching gas consumption, (2) development of a dry etching technology using alternative gas, (3) development of a dry etching technology using a low dielectric constant layer insulation film, (4) research and development of novel wiring structures and a method for fabricating the same, and (5) re-entrusted studies. Conducted in field (5) are studies of novel alternative gas - solid sources to substitute PFC, theory design technologies for low dielectric constant organic macromolecules, low dielectric constant material film fabrication by CVD (chemical vapor deposition), and technology for optical wiring inside chips. In field (2), studies are conducted of low GWP (global warming potential) alternative PFC gas aided etching and decomposition prevention technologies for reduction in PFC emissions, and it is made clear that C{sub 4}F{sub 6} performs excellently as an etchant. (NEDO)

Process for removal of hydrogen halides or halogens from incinerator gas

Science.gov (United States)

Huang, H.S.; Sather, N.F.

1987-08-21

A process for reducing the amount of halogens and halogen acids in high temperature combustion gas and through their removal, the formation of halogenated organics at lower temperatures, with the reduction being carried out electrochemically by contacting the combustion gas with the negative electrode of an electrochemical cell and with the halogen and/or halogen acid being recovered at the positive electrode.

Hanford Low-Activity Waste Processing: Demonstration of the Off-Gas Recycle Flowsheet - 13443

Energy Technology Data Exchange (ETDEWEB)

Ramsey, William G.; Esparza, Brian P. [Washington River Protection Solutions, LLC, Richland, WA 99532 (United States)

2013-07-01

Vitrification of Hanford Low-Activity Waste (LAW) is nominally the thermal conversion and incorporation of sodium salts and radionuclides into borosilicate glass. One key radionuclide present in LAW is technetium-99. Technetium-99 is a low energy, long-lived beta emitting radionuclide present in the waste feed in concentrations on the order of 1-10 ppm. The long half-life combined with a high solubility in groundwater results in technetium-99 having considerable impact on performance modeling (as potential release to the environment) of both the waste glass and associated secondary waste products. The current Hanford Tank Waste Treatment and Immobilization Plant (WTP) process flowsheet calls for the recycle of vitrification process off-gas condensates to maximize the portion of technetium ultimately immobilized in the waste glass. This is required as technetium acts as a semi-volatile specie, i.e. considerable loss of the radionuclide to the process off-gas stream can occur during the vitrification process. To test the process flowsheet assumptions, a prototypic off-gas system with recycle capability was added to a laboratory melter (on the order of 1/200 scale) and testing performed. Key test goals included determination of the process mass balance for technetium, a non-radioactive surrogate (rhenium), and other soluble species (sulfate, halides, etc.) which are concentrated by recycling off-gas condensates. The studies performed are the initial demonstrations of process recycle for this type of liquid-fed melter system. This paper describes the process recycle system, the waste feeds processed, and experimental results. Comparisons between data gathered using process recycle and previous single pass melter testing as well as mathematical modeling simulations are also provided. (authors)

Evaluation of process costs for small-scale nitrogen removal from natural gas. Topical report, January 1989-December 1989

International Nuclear Information System (INIS)

Echterhoff, L.W.; Pathak, V.K.

1991-08-01

The report establishes the cost of producing pipeline quality gas on a small scale from high nitrogen subquality natural gas. Three processing technologies are evaluated: cryogenic, Nitrotec Engineering Inc.'s pressure swing adsorption (PSA), and lean oil absorption. Comparison of the established costs shows that the cryogenic process exhibits the lowest total plant investment for nitrogen feed contents up to about 22%, above which the PSA process exhibits the lowest investment cost. The lean oil process exhibits the highest total plant investment at the 25% nitrogen feed studied. Opposite to the total plant investment for the cryogenic process, the total plant investment for the PSA process decreases with increasing nitrogen content primarily due to increasing product gas compression requirements. The cryogenic process exhibits the lowest gas processing costs for the nitrogen content range under study. However, the difference between the gas processing costs for the PSA and cryogenic processes narrows as the nitrogen content approaches 15-25%. The lean oil gas processing cost is very high compared to both the cryogenic and PSA processes. The report verifies that nitrogen removal from natural gas is expensive, especially for small-scale applications, and several avenues are identified for improving the cryogenic and PSA technologies

Large scale gas injection test (Lasgit): Results from two gas injection tests

International Nuclear Information System (INIS)

Cuss, R. J.; Harrington, J. F.; Noy, D. J.; Wikman, A.; Sellin, P.

2011-01-01

This paper describes the initial results from a large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory (Sweden)). Lasgit is a full-scale field-scale experiment based on the Swedish KBS-3V repository concept, examining the processes controlling gas and water flow in compact buffer bentonite. The first 2 years of the test focused on the artificial hydration of the bentonite buffer. This was followed by a programme of hydraulic and gas injection tests which ran from day 843 to 1110. A further period of artificial hydration occurred from day 1110 to 1385, followed by a more complex programme of gas injection testing which remains on going (day 1385+). After 2 years of hydration, hydraulic conductivity and specific storage values in the lower filter array were found to range from 9 x 10 -14 to 1.6 x 10 -13 m/s and 5.5 x 10 -5 to 4.4 x 10 -4 m -1 respectively, with the injection filter FL903 yielding values of 7.5 x 10 -14 m/s and 2.5 x 10 -5 m -1 . A second set of hydraulic measurements were performed over 1 year and a half later yielding similar values, in the range 7.8 x 10 -14 m/s and 1.3 x 10 -13 m/s. The hydraulic conductivity of FL903 had reduced slightly to 5.3 x 10 -14 m/s while specific storage had increased to 4.0 x 10 -5 m -1 . Both datasets agree with laboratory values performed on small-scale saturated samples. Two sets of gas injection tests were performed over a 3 year period. During the course of testing, gas entry pressure was found to increase from around 650 kPa to approximately 1.3 MPa, indicative of the maturation of the clay. The sequential reduction in volumetric flow rate and lack of correlation between the rate of gas inflow and the gas pressure gradient observed during constant pressure steps prior to major gas entry, is suggestive of a reduction in gas permeability of the buffer and indicates only limited quantities of gas can be injected into the clay without interacting with the continuum stress field. Major gas

Gas from waste materials

Energy Technology Data Exchange (ETDEWEB)

Leroux, H

1943-01-01

Various efforts to produce fuel gas from waste materials by fermentation are reviewed. Although the thermal yield appears to be attractive (60%) in the formation of CH/sub 4/ + CO/sub 2/ from cellulose the process requires very large equipment owing to the slowness of the reaction. From 1 ton of waste, a daily production of 1 m/sup 2/ of gas (7700 cal) is obtained for 50 days.

Adsorption process to recover hydrogen from feed gas mixtures having low hydrogen concentration

Science.gov (United States)

Golden, Timothy Christopher; Weist, Jr., Edward Landis; Hufton, Jeffrey Raymond; Novosat, Paul Anthony

2010-04-13

A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

Current gas storage R and D programmes at Gas Research Institute

International Nuclear Information System (INIS)

Shikari, Y.A.

1990-01-01

The Gas Research Institute (GRI) is currently involved in the development of concepts aimed at an enhancement of natural gas service to the consumer. In order to maintain the attractiveness of the gas options to industrial consumers and to reinforce the ''value-in-use'' of natural gas to residential as well as commercial customers, it is essential to develop efficient, economical, and safe means of reducing the ''cost-of-service'', including that of natural gas storage in underground formations. Specifically, research and development (R and D) is needed to explore ways to better utilize existing storage fields and also to develop new storage facilities at minimum cost. GRI is currently sponsoring research projects aimed at controlling gas migration in underground gas storage reservoirs, reducing base (or cushion) gas requirements, understanding the gas-gas phase mixing behaviour via laboratory experiments and reservoir models, developing cost-effective gas separation processes using membranes, and optimizing the operation and maintenance (O and M) costs of underground gas storage operations. This paper provides an overview of the GRI's Gas Storage R and D Programme and highlights key results achieved to date for selected research projects. (author). 16 refs, 6 figs, 3 tabs

Infrared Spectroscopy of Gas-Phase M+(CO2)n (M = Co, Rh, Ir) Ion-Molecule Complexes.

Science.gov (United States)

Iskra, Andreas; Gentleman, Alexander S; Kartouzian, Aras; Kent, Michael J; Sharp, Alastair P; Mackenzie, Stuart R

2017-01-12

The structures of gas-phase M + (CO 2 ) n (M = Co, Rh, Ir; n = 2-15) ion-molecule complexes have been investigated using a combination of infrared resonance-enhanced photodissociation (IR-REPD) spectroscopy and density functional theory. The results provide insight into fundamental metal ion-CO 2 interactions, highlighting the trends with increasing ligand number and with different group 9 ions. Spectra have been recorded in the region of the CO 2 asymmetric stretch around 2350 cm -1 using the inert messenger technique and their interpretation has been aided by comparison with simulated infrared spectra of calculated low-energy isomeric structures. All vibrational bands in the smaller complexes are blue-shifted relative to the asymmetric stretch in free CO 2 , consistent with direct binding to the metal center dominated by charge-quadrupole interactions. For all three metal ions, a core [M + (CO 2 ) 2 ] structure is identified to which subsequent ligands are less strongly bound. No evidence is observed in this size regime for complete activation or insertion reactions.

The experiment of the elemental mercury was removed from natural gas by 4A molecular sieve

Science.gov (United States)

Jiang, Cong; Chen, Yanhao

2018-04-01

Most of the world's natural gas fields contain elemental mercury and mercury compounds, and the amount of mercury in natural gas is generally 1μg/m3 200μg/m3. This paper analyzes the mercury removal principle of chemical adsorption process, the characteristics and application of mercury removal gent and the factors that affect the efficiency of mercury removal. The mercury in the natural gas is adsorbed by the mercury-silver reaction of the 4 molecular sieve after the manned treatment. The limits for mercury content for natural gas for different uses and different treatment processes are also different. From the environmental protection, safety and other factors, it is recommended that the mercury content of natural gas in the pipeline is less than 28μg / m3, and the mercury content of the raw material gas in the equipment such as natural gas liquefaction and natural gas condensate recovery is less than 0.01μg/m3. This paper mainly analyzes the existence of mercury in natural gas, and the experimental research process of using 4A molecular sieve to absorb mercury in natural gas.

Power-generating process of obtaining gas-energy carrier and reducer from coal

International Nuclear Information System (INIS)

Tleugabulov, S.; Duncheva, E.; Zubkevich, M.

1999-01-01

The manufacture of power-generating gas has the important economic value for Kazakhstan having large territory, raw and fuel resources especially power coal and clean coal wastes. The technology of reception of gas-energy carrier and reducer from power coal is developed. The basic product of technological process is heated reducing gas. Reducing potential of the gas is characterized by a volumetric share of components (CO+H 2 )-RC in relation to volume of whole mix of gases received with gasification of coal. The value of parameter RC is regulated by a degree of enrichment of air by oxygen r 0 , and the temperature - by the charge of a parity of endothermic reaction in the chamber of gas regeneration. The dependence of the gas structure and temperature on the degree of enrichment of air by oxygen is shown and the circuit of the gas generator is given. (author)

Integration of High-Temperature Gas-Cooled Reactors into Industrial Process Applications

International Nuclear Information System (INIS)

Nelson, Lee

2009-01-01

This report is a preliminary comparison of conventional and potential HTGR-integrated processes in several common industrial areas: (1) Producing electricity via a traditional power cycle; (2) Producing hydrogen; (3) Producing ammonia and ammonia-derived products, such as fertilizer; (4) Producing gasoline and diesel from natural gas or coal; (5) Producing substitute natural gas from coal; and (6) Steam-assisted gravity drainage (extracting oil from tar sands).

Construction and Arena Simulation of Grid M-Commerce Process

OpenAIRE

Danqing Li; Dan Chang

2012-01-01

With the rapid development and the wide use of mobile technology, m-commerce research has gradually become the focus of scholars. Difficulties exist in m-commerce, such as information sharing, business collaboration, and process reengineering. Grid management, a new managerial concept, has the potential of being a powerful weapon that affects the study on m-commerce process. This study systematically analyzes the traditional m-commerce process and its problems. On that basis, this paper const...

Biological flue gas desulfurization

Energy Technology Data Exchange (ETDEWEB)

Buisman, C.J.N.; Dijkman, H.; Wijte, G.; Prins, W.L.; Verbraak, P.; Hartog, H.A.J. den [Paper B.V. Blak (Netherlands)

1995-08-01

A new biological flue gas desulfurization process (BIO-FGD) producing sulphur as a by-product was invented by Paques BV and Hoogens Technical Services in 1993. Sulphur dioxide is absorbed from flue gas using a combination of a sodium based scrubber and two biological reactors, an anaerobic and an aerobic biological reactor. The article describes the process and its evaluation in a pilot plant at 2 MW scale, designed to remove 6 kg/hr SO{sub 2} of the 2 million m{sup 3}/hr of flue gas produced at the 600 MW coal fired power station Amer-8 situated in Geertruidenberg in the south of the Netherlands. Research so far has proved the process works successfully and at low cost. A second pilot plant due to start-up in May 1995 will provide data on scale up and further information on sulphur recovery. 5 refs., 5 figs.

Co-processing of standard gas oil and biocrude oil to hydrocarbon fuels

International Nuclear Information System (INIS)

Agblevor, Foster A.; Mante, O.; McClung, R.; Oyama, S.T.

2012-01-01

The major obstacle in thermochemical biomass conversion to hydrocarbon fuels using pyrolysis has been the high oxygen content and the poor stability of the product oils, which cause them to solidify during secondary processing. We have developed a fractional catalytic pyrolysis process to convert biomass feedstocks into a product termed “biocrude oils” (stable biomass pyrolysis oils) which are distinct from unstable conventional pyrolysis oils. The biocrude oils are stable, low viscosity liquids that are storable at ambient conditions without any significant increases in viscosity; distillable at both atmospheric pressure and under vacuum without char or solid formation. About 15 wt% biocrude oils containing 20–25% oxygen were blended with 85 wt% standard gas oil and co-cracked in an Advanced Catalyst Evaluation (ACE™) unit using fluid catalytic cracking (FCC) catalysts to produce hydrocarbon fuels that contain negligible amount of oxygen. For the same conversion of 70% for both the standard gas oil and the biocrude oil/gas oil blends, the product gasoline yield was 44 wt%, light cycle oil (LCO) 17 wt%, heavy cycle oil (HCO) 13 wt%, and liquefied petroleum gas (LPG) 16 wt%. However, the coke yield for the standard gas oil was 7.06 wt% compared to 6.64–6.81 wt% for the blends. There appeared to be hydrogen transfer from the cracking of the standard gas oil to the biocrude oil which subsequently eliminated the oxygen in the fuel without external hydrogen addition. We have demonstrated for the first time that biomass pyrolysis oils can be successfully converted into hydrocarbons without hydrogenation pretreatment. -- Highlights: ► The co-processed product had less than 1% oxygen content and contained biocarbons determined by 14 C analysis. ► The co-processing did not affect the yields of gasoline, LCO, and HCO. ► First demonstration of direct conversion of pyrolysis oils into drop-in hydrocarbon fuels.

Electron-beam flue gas treatment

International Nuclear Information System (INIS)

Aoki, Shinji

1990-01-01

A new flue gas treatment process (EBA process) using an electron beam will be discussed. This EBA process is attracting worldwide attention as a new effective measure for solving acid rain problems and jointly developed by Ebara Corporation and the Japan Atomic Energy Research Institute. This process has many advantages: a) a dry process capable of removing high level SO x and NO x simultaneously, b) a process simple and easy to operate, c) production of agricultural fertilizers as salable by-products, and d) minimal installation space. Test results from the demonstration plant (max. gas flow rate of 24,000 m 3 N/h) which was erected in a coal-fired power station in Indianapolis, Indiana, U.S.A. will be presented. (author)

Statistical dynamics of transient processes in a gas discharge plasma

International Nuclear Information System (INIS)

Smirnov, G.I.; Telegin, G.G.

1991-01-01

The properties of a gas discharge plasma to a great extent depend on random processes whose study has recently become particularly important. The present work is concerned with analyzing the statistical phenomena that occur during the prebreakdown stage in a gas discharge. Unlike other studies of breakdown in the discharge gap, in which secondary electron effects and photon processes at the electrodes must be considered, here the authors treat the case of an electrodeless rf discharge or a laser photoresonant plasma. The analysis is based on the balance between the rates of electron generation and recombination in the plasma. The fluctuation kinetics for ionization of atoms in the hot plasma may also play an important role when the electron temperature changes abruptly, as occurs during adiabatic pinching of the plasma or during electron cyclotron heating

TIG (Tungsten Inert Gas) welding; Le soudage TIG

Energy Technology Data Exchange (ETDEWEB)

Anon.

2010-09-15

After having recalled the Tungsten Inert Gas process principle and the different alternative TIG processes, the author explains the advantages and limits of this process. The applications and recent developments are given. (O.M.)

Demonstration of a bronchopleural communication by inhalation of Kr-81m gas

International Nuclear Information System (INIS)

Vincken, W.; Schandevyl, W.; Sonstabo, R.; Bossuyt, A.

1981-01-01

Suspicion of a persisting communication between the bronchial tree and the pleural space in a patient with surgically drained pneumothorax was confirmed by the inhalation of Kr-81m gas. Compared to other diagnostic methods, this technique is harmless and repeatable, and hence very convenient for the assessment and follow-up of persisting pneumothorax due to air-leaks and of bronchopleural fistulas of any cause

Continuous chemical cold traps for reprocessing off-gas purification

International Nuclear Information System (INIS)

Henrich, E.; Bauder, U.; Steinhardt, H.J.; Bumiller, W.

1985-01-01

Absorption of nitrogen oxides and iodine from simulated reprocessing plant off-gas streams has been studied using nitric acid and nitric acid/hydrogen peroxide mixtures at low temperatures. The experiments were carried out at the laboratory and on the engineering scale. The pilot plant scale column has 0.8 m diameter and 16 absorption plates at 0.2 m spacing. Cooling coils on the plates allow operating temperatures down to -60 0 C. The NO concentration in the feed gas usually has been 1% by volume and the flow rate 4-32 m 3 (STP) per hour. The iodine behavior has been studied using I-123 tracer. Results of the study are presented. The chemistry of the processes and the advantages and disadvantages in correlation to the various applications for an off-gas purification in a reprocessing plant are compared and discussed. The processes are compatible with the PUREX process and do not produce additional waste

Pilot-scale tests for EB flue gas treatment process in Japan

International Nuclear Information System (INIS)

Sato, S.; Tokunaga, O.; Namba, H.

1994-01-01

A review of electron beam applications for flue gas treatment in Japan has been done. Several pilot plants are being performed for commercial use of electron beams process for cleaning of flue gas from low-sulfur coal burning boiler, a municipal waste incinerator and for removal of NO x from a ventilation exhaust of a highway tunnel. Outlines of three pilot-scale tests are introduced. 9 refs, 4 figs

EQUATIONS FOR GAS RELEASING PROCESS FROM PRESSURIZED VESSELS IN ODH EVALUATION

International Nuclear Information System (INIS)

JIA, L.X.; WANG, L.

2001-01-01

IN THE EVALUATION OF ODH, THE CALCULATION OF THE SPILL RATE FROM THE PRESSURIZED VESSEL IS THE CENTRAL TASK. THE ACCURACY OF THE ENGINEERING ESTIMATION BECOMES ONE OF THE SAFETY DESIGN ISSUES. THIS PAPER SUMMARIZES THE EQUATIONS FOR THE OXYGEN CONCENTRATION CALCULATION IN DIFFERENT CASES, AND DISCUSSES THE EQUATIONS FOR THE GAS RELEASE PROCESS CALCULATION BOTH FOR THE HIGH-PRESSURE GAS TANK AND THE LOW-TEMPERATURE LIQUID CONTAINER

Treatment of exhaust gas from the semiconductor manufacturing process. 3; Handotai seizo sochi kara no hai gas shori. 3

Energy Technology Data Exchange (ETDEWEB)

Fukunaga, A. [Ebara Research Co. Ltd., Kanagawa (Japan); Mori, Y.; Osato, M.; Tsujimura, M. [Ebara Corp., Tokyo (Japan)

1995-10-20

Demand has been building up for an individual dry type scrubber for treating exhaust gas from the semiconductor manufacturing process. Some factors for the wide acceptance of such a scrubber would be the capability for complete treatment, easy maintenance and safety features, etc. Practical gas analysis and optimum scrubbing techniques would have to be applied, as well as effective monitoring, alarm, and fail-safe techniques. The overall exhaust gas line, i.e. the line connecting the scrubber system and the upstream process, including that extending to pump system, has to be fully considered for enabling effective scrubbing performance. Such factors, which have until now not been given any priority, would have to be fully studied for the development of a practical, individual dry type scrubber. Cooperation on this matter from the semiconductor manufacturing industry would also be essential. 6 refs., 3 figs., 5 tabs.

Process for purification of gas mixtures

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, S Z; Letitschevskij, V I; Maergojz, I I; Michailov, L A; Puschkarev, L I

1977-06-23

The process relates to the purification of gas mixtures of N, H, and Ar, or N and H, or N and O which contain CO, CO/sub 2/ and water vapour. Single-stage adsorption occurs under standard pressure at temperatures from -40 to +4/sup 0/C up to the point of CO penetration through the zeolite layer. Zeolite is of type A or X combined with Ca, Na, Ag, Cd, Co, Ni, Mn or a natural zeolite of the type klinoptilolite. Regeneration is achieved at constant temperature and pressure of 1-5x10/sup -1/ Torr or by heating to 120-600/sup 0/C.

Plasmachemical oxidation processes in a hybrid gas-liquid electrical discharge reactor

Energy Technology Data Exchange (ETDEWEB)

Lukes, Petr; Locke, Bruce R [Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Florida State University, 2525 Pottsdamer Street, Tallahassee, Florida (United States)

2005-11-21

Oxidation processes induced in water by pulsed electrical discharges generated simultaneously in the gas phase in close proximity to the water surface and directly in the liquid were investigated in a hybrid series gas-liquid electrical discharge reactor. The mechanism of phenol degradation was studied through its dependence on the gas phase and liquid phase compositions using pure argon and oxygen atmospheres above the liquid and different initial pH values in the aqueous solution. Phenol degradation was significantly enhanced in the hybrid-series reactor compared with the phenol removal by the single-liquid phase discharge reactor. Under an argon atmosphere the mechanism of phenol degradation was mainly caused by the electrophilic attack of OH{center_dot} radicals produced by the liquid phase discharge directly in water and OH{center_dot} radicals produced by the gas phase discharge at the gas-liquid interface. Under an oxygen atmosphere the formation of gaseous ozone dominated over the formation of OH{center_dot} radicals, and the contribution of the gas phase discharge in this case was determined mainly by the dissolution of gaseous ozone into the water and its subsequent interaction with phenol. At high pH phenol was degraded, in addition to the direct attack by ozone, also through indirect reactions of OH{center_dot} radicals formed via a peroxone process by the decomposition of dissolved ozone by hydrogen peroxide produced by the liquid phase discharge. Such a mechanism was proved by the detection of cis,cis-muconic acid and pH-dependent degradation of phenol, which resulted in significantly higher removal of phenol from alkaline solution observed under oxygen atmosphere than in argon.

Plasmachemical oxidation processes in a hybrid gas-liquid electrical discharge reactor

International Nuclear Information System (INIS)

Lukes, Petr; Locke, Bruce R

2005-01-01

Oxidation processes induced in water by pulsed electrical discharges generated simultaneously in the gas phase in close proximity to the water surface and directly in the liquid were investigated in a hybrid series gas-liquid electrical discharge reactor. The mechanism of phenol degradation was studied through its dependence on the gas phase and liquid phase compositions using pure argon and oxygen atmospheres above the liquid and different initial pH values in the aqueous solution. Phenol degradation was significantly enhanced in the hybrid-series reactor compared with the phenol removal by the single-liquid phase discharge reactor. Under an argon atmosphere the mechanism of phenol degradation was mainly caused by the electrophilic attack of OH· radicals produced by the liquid phase discharge directly in water and OH· radicals produced by the gas phase discharge at the gas-liquid interface. Under an oxygen atmosphere the formation of gaseous ozone dominated over the formation of OH· radicals, and the contribution of the gas phase discharge in this case was determined mainly by the dissolution of gaseous ozone into the water and its subsequent interaction with phenol. At high pH phenol was degraded, in addition to the direct attack by ozone, also through indirect reactions of OH· radicals formed via a peroxone process by the decomposition of dissolved ozone by hydrogen peroxide produced by the liquid phase discharge. Such a mechanism was proved by the detection of cis,cis-muconic acid and pH-dependent degradation of phenol, which resulted in significantly higher removal of phenol from alkaline solution observed under oxygen atmosphere than in argon

Theoretical test of Jarzynski's equality for reversible volume-switching processes of an ideal gas system.

Science.gov (United States)

Sung, Jaeyoung

2007-07-01

We present an exact theoretical test of Jarzynski's equality (JE) for reversible volume-switching processes of an ideal gas system. The exact analysis shows that the prediction of JE for the free energy difference is the same as the work done on the gas system during the reversible process that is dependent on the shape of path of the reversible volume-switching process.

Dense gas and star formation in individual Giant Molecular Clouds in M31

Science.gov (United States)

Viaene, S.; Forbrich, J.; Fritz, J.

2018-04-01

Studies both of entire galaxies and of local Galactic star formation indicate a dependency of a molecular cloud's star formation rate (SFR) on its dense gas mass. In external galaxies, such measurements are derived from HCN(1-0) observations, usually encompassing many Giant Molecular Clouds (GMCs) at once. The Andromeda galaxy (M31) is a unique laboratory to study the relation of the SFR and HCN emission down to GMC scales at solar-like metallicities. In this work, we correlate our composite SFR determinations with archival HCN, HCO+, and CO observations, resulting in a sample of nine reasonably representative GMCs. We find that, at the scale of individual clouds, it is important to take into account both obscured and unobscured star formation to determine the SFR. When correlated against the dense-gas mass from HCN, we find that the SFR is low, in spite of these refinements. We nevertheless retrieve an SFR-dense-gas mass correlation, confirming that these SFR tracers are still meaningful on GMC scales. The correlation improves markedly when we consider the HCN/CO ratio instead of HCN by itself. This nominally indicates a dependency of the SFR on the dense-gas fraction, in contradiction to local studies. However, we hypothesize that this partly reflects the limited dynamic range in dense-gas mass, and partly that the ratio of single-pointing HCN and CO measurements may be less prone to systematics like sidelobes. In this case, the HCN/CO ratio would importantly be a better empirical measure of the dense-gas content itself.

Reactor modeling and process analysis for partial oxidation of natural gas

NARCIS (Netherlands)

Albrecht, B.A.

2004-01-01

This thesis analyses a novel process of partial oxidation of natural gas and develops a numerical tool for the partial oxidation reactor modeling. The proposed process generates syngas in an integrated plant of a partial oxidation reactor, a syngas turbine and an air separation unit. This is called

Inhalation scan using sup(81m)Kr-gas

International Nuclear Information System (INIS)

Kobayashi, Hidetoshi; Sasaki, Tsuneo; Senda, Kohei; Ohara, Ken; Kaii, Osamu

1979-01-01

Inhalation scan using sup(81m) Kr-gas was performed in the various pulmonary diseases, in order to examine the ventilatory function of the lung after the measurement of ratio of expiratory ratio in the normal and diseased lung field. Inhalation scan is applied to the various pulmonary diseases such as lung cancer, radiation pulmonary fibrosis and chronic obstructive pulmonary disease. In cases of lung cancer, there is disturbance of respiratory function at the site of lesion when compared to the remainder of the normal lung fields. In cases of chronic obstructive pulmonary disease, the inhalation scan is performed at three states such as pre-, in- and post-attack of the disease. During the asthma attack the respiratory function is disturbed considerably when compared to the pre- and post-attack states. In each pulmonary disease, the ratio of expiratory ratio is measured from the histogram and pulmonary function is evaluated. (author)

Radioactive waste gas processing systems

International Nuclear Information System (INIS)

Kita, Kaoru; Minemoto, Masaki; Takezawa, Kazuaki.

1981-01-01

Purpose: To effectively separate and remove only hydrogen from hydrogen gas-containing radioactive waste gases produced from nuclear power plants without using large scaled facilities. Constitution: From hydrogen gas-enriched waste gases which contain radioactive rare gases (Kr, Xe) sent from the volume control tank of a chemical volume control system, only the hydrogen is separated in a hydrogen separator using palladium alloy membrane and rare gases are concentrated, volume-decreased and then stored. In this case, an activated carbon adsorption device is connected at its inlet to the radioactive gas outlet of the hydrogen separator and opened at its outlet to external atmosphere. In this system, while only the hydrogen gas permeates through the palladium alloy membrane, other gases are introduced, without permeation, into the activated carbon adsorption device. Then, the radioactive rare gases are decayed by the adsorption on the activated carbon and then released to the external atmosphere. (Furukawa, Y.)

Design and analysis of liquefaction process for offshore associated gas resources

International Nuclear Information System (INIS)

Li, Q.Y.; Ju, Y.L.

2010-01-01

Liquefaction is the key section on floating platform. Some experts and designers selected mixed refrigerant process for floating platform, while some recommended expander cycle. However, few of them compared the two types of processes systemically before making a choice. In this paper, the liquefaction processes of propane pre-cooled mixed refrigerant cycle (C 3 /MRC), mixed refrigerant cycle (MRC) and nitrogen expander cycle (N 2 expander) for the special offshore associated gases in South China Sea have been designed and studied. These processes have been analyzed and compared systematically considering the main factors including the performance parameters, economic performance, layout, sensitivity to motion, suitability to different gas resources, safety and operability, accounting for the features of the floating production, storage and offloading unit for liquefied natural gas (LNG-FPSO) in marine environment. The results indicated that N 2 expander has higher energy consumption and poorer economic performance, while it has much more advantages than C 3 /MRC and MRC for offshore application because it is simpler and more compact and thus requiring less deck area, less sensitive to LNG-FPSO motion, has better suitability for other gas resources, has higher safety and is easier to operate. Therefore, N 2 expander is the most suitable offshore liquefaction process. In addition, the exergy analysis is conducted for N 2 expander and the results indicate that the compression equipments and after coolers, expanders and LNG heat exchangers are the main contribution to the total exergy losses. The measures to decrease the losses for these equipments are then discussed.

The role of process intensification in cutting greenhouse gas emissions

International Nuclear Information System (INIS)

Reay, David

2008-01-01

Between 1900 and 1955 the average rate of global energy use rose from about 1 TW to 2 TW. Between 1955 and 1999 energy use rose from 2 TW to about 12 TW, and to 2006 a further 16% growth in primary energy use was recorded world-wide. There are recommendations by the UK Royal Commission on Environmental Pollution, subsequently supported by others in the UK, that we need to reduce CO 2 emissions by over 50% in order to stabilise their impact on global warming (CO 2 being the principal gas believed to be contributing to this phenomenon). One way in which we can address this is by judicious use of process intensification technology. Process intensification may be defined as: 'Any engineering development that leads to a substantially smaller, cleaner, safer and more energy-efficient technology.' It is most often characterised by a huge reduction in plant volume - orders of magnitude - but its contribution to reducing greenhouse gas emissions may also be significant. Potential energy savings due to investment in process intensification were studied by several UK organisations in the mid 1990s, to assist the UK Government in formulating a strategy on intensification. It is relevant to the themes of the PRES 07 Conference that process integration features in these analyses. Overall plant intensification in the UK was identified as having a technical potential of 40 PJ/year (about 1 million tonnes of oil equivalent/annum). The total potential energy savings due to investment in process intensification in a range of process unit operations were predicted to be over 74 PJ/year (1 PJ = 10 15 J). Projections for The Netherlands suggest that savings of 50-100 PJ/year should be achieved across chemicals and food processing by 2050. Substantial benefits to industry in the USA are highlighted by US Department of Energy studies. This paper relates by discussion and example process intensification to the main themes of the PRES 07 Conference, including process integration. It also

Optimization of pulsed current GTAW process parameters for sintered hot forged AISI 4135 P/M steel welds by simulated annealing and genetic algorithm

International Nuclear Information System (INIS)

Joseph, Joby; Muthukumaran, S.

2016-01-01

Abundant improvements have occurred in materials handling, especially in metal joining. Pulsed current gas tungsten arc welding (PCGTAW) is one of the consequential fusion techniques. In this work, PCGTAW of AISI 4135 steel engendered through powder metallurgy (P/M) has been executed, and the process parameters have been highlighted applying Taguchi's L9 orthogonal array. The results show that the peak current (Ip), gas flow rate (GFR), welding speed (WS) and base current (Ib) are the critical constraints in strong determinant of the Tensile strength (TS) as well as percentage of elongation (% Elong) of the joint. The practical impact of applying Genetic algorithm (GA) and Simulated annealing (SA) to PCGTAW process has been authenticated by means of calculating the deviation between predicted and experimental welding process parameters

Optimization of pulsed current GTAW process parameters for sintered hot forged AISI 4135 P/M steel welds by simulated annealing and genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Joseph, Joby; Muthukumaran, S. [National Institute of Technology, Tamil Nadu (India)

2016-01-15

Abundant improvements have occurred in materials handling, especially in metal joining. Pulsed current gas tungsten arc welding (PCGTAW) is one of the consequential fusion techniques. In this work, PCGTAW of AISI 4135 steel engendered through powder metallurgy (P/M) has been executed, and the process parameters have been highlighted applying Taguchi's L9 orthogonal array. The results show that the peak current (Ip), gas flow rate (GFR), welding speed (WS) and base current (Ib) are the critical constraints in strong determinant of the Tensile strength (TS) as well as percentage of elongation (% Elong) of the joint. The practical impact of applying Genetic algorithm (GA) and Simulated annealing (SA) to PCGTAW process has been authenticated by means of calculating the deviation between predicted and experimental welding process parameters.

Gas turbine with two circuits and intermediate fuel conversion process

International Nuclear Information System (INIS)

Bachl, H.

1978-01-01

The combination of a fuel conversion process with a thermal process saves coolant and subsequent separation plant, in order to achieve the greatest possible use of the mechanical or electrical energy. The waste heat of a thermal circuit is taken to an endothermal chemical fuel conversion process arranged before a second circuit. The heat remaining after removal of the heat required for the chemical process is taken to a second thermal circuit. The reaction products of the chemical process which condense out during expansion in the second thermal process are selectively separated from the remaining gas mixture in the individual turbine stages. (HGOE) [de

Study on incineration technology of oil gas generated during the recovery process of oil spill

International Nuclear Information System (INIS)

Hou, Shuhn-Shyurng; Ko, Yung-Chang; Lin, Ta-Hui

2011-01-01

The objective of this study is to design, set up and operate an incinerator system capable of providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in Taiwan. In this study, we successfully develop a vertical-type incinerator, which consists of five oil gas burners with entrained primary air, a pilot burner, and an auxiliary burner. The incinerator system is equipped with necessary control units in order to achieve safe, easy, fast, and efficient operation. Flame appearance, flue gas temperature and CO emission of the incinerator system for burning oil gas are reported and discussed. Under the long-term operation, it is found that the new designed incinerator is satisfactory for burning oil gas with low supply pressure at various compositions and supply rates during the recovery process of oil spill. It is noteworthy that the results obtained herein are of great significance to provide a good guidance for those who need to design, set up and operate an incinerator system providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in a polluted site with a large area.

Study on incineration technology of oil gas generated during the recovery process of oil spill

Energy Technology Data Exchange (ETDEWEB)

Hou, Shuhn-Shyurng [Department of Mechanical Engineering, Kun Shan University, Tainan 71003 (China); Ko, Yung-Chang [China Steel Corporation, Kaohsiung 81233 (China); Lin, Ta-Hui [Department of Mechanical Engineering, National Cheng Kung University, Tainan 70101 (China)

2011-03-15

The objective of this study is to design, set up and operate an incinerator system capable of providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in Taiwan. In this study, we successfully develop a vertical-type incinerator, which consists of five oil gas burners with entrained primary air, a pilot burner, and an auxiliary burner. The incinerator system is equipped with necessary control units in order to achieve safe, easy, fast, and efficient operation. Flame appearance, flue gas temperature and CO emission of the incinerator system for burning oil gas are reported and discussed. Under the long-term operation, it is found that the new designed incinerator is satisfactory for burning oil gas with low supply pressure at various compositions and supply rates during the recovery process of oil spill. It is noteworthy that the results obtained herein are of great significance to provide a good guidance for those who need to design, set up and operate an incinerator system providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in a polluted site with a large area. (author)

Recombining processes in a cooling plasma by mixing of initially heated gas

International Nuclear Information System (INIS)

Furukane, Utaro; Sato, Kuninori; Takiyama, Ken; Oda, Toshiatsu.

1992-03-01

A numerical investigation of recombining process in a high temperature plasma in a quasi-steady state is made in a gas contact cooling, in which the initial temperature effect of contact gas heated up by the hot plasma is considered as well as the gas cooling due to the surrounding neutral particles freely coming into the plasma. The calculation has shown that the electron temperature relaxes in accord with experimental results and that the occurrence of recombining region and the inverted populations almost agree with the experimental ones. (author)

Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

OpenAIRE

Orlov Alexey; Ushakov Anton; Sovach Victor

2016-01-01

This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge casca...

HERSCHEL-SPIRE IMAGING SPECTROSCOPY OF MOLECULAR GAS IN M82

Energy Technology Data Exchange (ETDEWEB)

Kamenetzky, J.; Glenn, J.; Rangwala, N.; Maloney, P. [Center for Astrophysics and Space Astronomy, 389-UCB, University of Colorado, Boulder, CO 80303 (United States); Bradford, M. [NASA Jet Propulsion Laboratory, Pasadena, CA 91109 (United States); Wilson, C. D.; Schirm, M. R. P. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1 (Canada); Bendo, G. J. [UK ALMA Regional Centre Node, Jordell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Baes, M. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, 9000 Gent (Belgium); Boselli, A. [Laboratoire d' Astrophysique de Marseille, UMR6110 CNRS, 38 rue F. Joliot-Curie, 13388 Marseille (France); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Isaak, K. G. [ESA Astrophysics Missions Division, ESTEC, P.O. Box 299, 2200 AG Noordwijk (Netherlands); Lebouteiller, V.; Madden, S.; Panuzzo, P.; Wu, R. [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, 91191 Gif-sur-Yvette (France); Spinoglio, L. [Istituto di Fisica dello Spazio Interplanetario, INAF, Via del Fosso del Cavaliere 100, 00133 Roma (Italy)

2012-07-01

We present new Herschel-SPIRE imaging spectroscopy (194-671 {mu}m) of the bright starburst galaxy M82. Covering the CO ladder from J = 4 {yields} 3 to J = 13 {yields} 12, spectra were obtained at multiple positions for a fully sampled {approx}3 Multiplication-Sign 3 arcmin map, including a longer exposure at the central position. We present measurements of {sup 12}CO, {sup 13}CO, [C I], [N II], HCN, and HCO{sup +} in emission, along with OH{sup +}, H{sub 2}O{sup +}, and HF in absorption and H{sub 2}O in both emission and absorption, with discussion. We use a radiative transfer code and Bayesian likelihood analysis to model the temperature, density, column density, and filling factor of multiple components of molecular gas traced by {sup 12}CO and {sup 13}CO, adding further evidence to the high-J lines tracing a much warmer ({approx}500 K), less massive component than the low-J lines. The addition of {sup 13}CO (and [C I]) is new and indicates that [C I] may be tracing different gas than {sup 12}CO. No temperature/density gradients can be inferred from the map, indicating that the single-pointing spectrum is descriptive of the bulk properties of the galaxy. At such a high temperature, cooling is dominated by molecular hydrogen. Photon-dominated region (PDR) models require higher densities than those indicated by our Bayesian likelihood analysis in order to explain the high-J CO line ratios, though cosmic-ray-enhanced PDR models can do a better job reproducing the emission at lower densities. Shocks and turbulent heating are likely required to explain the bright high-J emission.

Modelling of tetrahydrofuran promoted gas hydrate systems for carbon dioxide capture processes

DEFF Research Database (Denmark)

Herslund, Peter Jørgensen; Thomsen, Kaj; Abildskov, Jens

2014-01-01

A thermodynamic study of a novel gas hydrate based CO2 capture process is presented.•Model predicts this process unsuitable for CO2 capture from power station flue gases. A thermodynamic modelling study of both fluid phase behaviour and hydrate phase behaviour is presented for the quaternary system...... of water, tetrahydrofuran, carbon dioxide and nitrogen. The applied model incorporates the Cubic-Plus-Association (CPA) equation of state for the fluid phase description and the van der Waals-Platteeuw hydrate model for the solid (hydrate) phase. Six binary pairs are studied for their fluid phase behaviour...... accurate descriptions of both fluid- and hydrate phase equilibria in the studied system and its subsystems. The developed model is applied to simulate two simplified, gas hydrate-based processes for post-combustion carbon dioxide capture from power station flue gases. The first process, an unpromoted...

Optical methods to study the gas exchange processes in large diesel engines

Energy Technology Data Exchange (ETDEWEB)

Gros, S.; Hattar, C. [Wartsila Diesel International Oy, Vaasa (Finland); Hernberg, R.; Vattulainen, J. [Tampere Univ. of Technology, Tampere (Finland). Plasma Technology Lab.

1996-12-01

To be able to study the gas exchange processes in realistic conditions for a single cylinder of a large production-line-type diesel engine, a fast optical absorption spectroscopic method was developed. With this method line-of-sight UV-absorption of SO{sub 2} contained in the exhaust gas was measured as a function of time in the exhaust port area in a continuously fired medium speed diesel engine type Waertsilae 6L20. SO{sub 2} formed during the combustion from the fuel contained sulphur was used as a tracer to study the gas exchange as a function of time in the exhaust channel. In this case of a 4-stroke diesel engine by assuming a known concentration of SO{sub 2} in the exhaust gas after exhaust valve opening and before inlet and exhaust valve overlap period, the measured optical absorption was used to determine the gas density and further the instantaneous exhaust gas temperature during the exhaust cycle. (author)

Glovebox atmosphere detritiation process using gas separation membranes

International Nuclear Information System (INIS)

Le Digabel, M.; Truan, P.A.; Ducret, D.; Laquerbe, C.; Perriat, P.; Niepce, J.C.; Pelletier, T.

2003-01-01

The use of gas separation membranes in atmospheric detritiation systems has been studied. The main advantage of this new process is to reduce the number and/or the size of the equipment in comparison to conventional tritium removal systems. Owing to the constraints linked to tritium handling, the separation performances of several commercial hollow fiber organic membranes have been analyzed, under various operating conditions, with hydrogen/nitrogen or deuterium/nitrogen mixtures. The experiments are performed with small quantities of hydrogen or deuterium (5000 ppm). The experimental results allow to evaluate the separation efficiency of these membranes and to determine the appropriate operating conditions to apply to a membrane detritiation process

Novel design of LNG (liquefied natural gas) reliquefaction process

Energy Technology Data Exchange (ETDEWEB)

Baek, S., E-mail: s.baek@kaist.ac.kr [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Hwang, G.; Lee, C. [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Jeong, S., E-mail: skjeong@kaist.ac.kr [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Choi, D. [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Ship/Plant System R and D Team, Daewoo Shipbuilding and Marine Engineering Co., Ltd., 1, Ajoo, Koje, Kyungnam 656-714 (Korea, Republic of)

2011-08-15

Highlights: {yields} We performed experiments with LN2 to mock up the new LNG reliquefaction process. {yields} Subcooled liquid goes to heat exchanger, heater, and phase separator. {yields} Reliquefaction occurs when vapor enters heat exchanger and verified by experiments. {yields} Reliquefaction ratio increases when subcooling degree or system pressure increases. - Abstract: This paper presents an investigation of novel LNG reliquefaction process where the cold exergy of subcooled LNG is utilized to recondense the vaporized light component of LNG after it is separated from the heavier component in a phase separator. The regeneration of cold exergy is especially effective as well as important in thermodynamic sense when a cryogenic process is involved. To verify the proposed idea, we performed an experimental study by facilitating liquid nitrogen apparatus to mock up the LNG reliquefaction process. Subcooled liquid nitrogen is produced for a commercial transportation container with a house-made atmospheric liquid nitrogen heat exchanger and then, having subooled degree of up to 19 K, it simulates the behavior of subcooled LNG in the lab-scale reliquefaction experiment. Recondensation of the vaporized gas is possible by using the cold exergy of subcooled liquid in a properly fabricated heat exchanger. Effect of heat exchanger performance factor and degree of subcooling on recondensation portion has been discussed in this paper. It is concluded that utilizing pressurized subcooled liquid that is obtained by liquid pump can surely reduce the pumping power of the vaporized natural gas and save the overall energy expenditure in LNG reliquefaction process.

Novel design of LNG (liquefied natural gas) reliquefaction process

International Nuclear Information System (INIS)

Baek, S.; Hwang, G.; Lee, C.; Jeong, S.; Choi, D.

2011-01-01

Highlights: → We performed experiments with LN2 to mock up the new LNG reliquefaction process. → Subcooled liquid goes to heat exchanger, heater, and phase separator. → Reliquefaction occurs when vapor enters heat exchanger and verified by experiments. → Reliquefaction ratio increases when subcooling degree or system pressure increases. - Abstract: This paper presents an investigation of novel LNG reliquefaction process where the cold exergy of subcooled LNG is utilized to recondense the vaporized light component of LNG after it is separated from the heavier component in a phase separator. The regeneration of cold exergy is especially effective as well as important in thermodynamic sense when a cryogenic process is involved. To verify the proposed idea, we performed an experimental study by facilitating liquid nitrogen apparatus to mock up the LNG reliquefaction process. Subcooled liquid nitrogen is produced for a commercial transportation container with a house-made atmospheric liquid nitrogen heat exchanger and then, having subooled degree of up to 19 K, it simulates the behavior of subcooled LNG in the lab-scale reliquefaction experiment. Recondensation of the vaporized gas is possible by using the cold exergy of subcooled liquid in a properly fabricated heat exchanger. Effect of heat exchanger performance factor and degree of subcooling on recondensation portion has been discussed in this paper. It is concluded that utilizing pressurized subcooled liquid that is obtained by liquid pump can surely reduce the pumping power of the vaporized natural gas and save the overall energy expenditure in LNG reliquefaction process.

Thermodynamic models to predict gas-liquid solubilities in the methanol synthesis, the methanol-higher alcohol synthesis, and the Fischer-Tropsch synthesis via gas-slurry processes

NARCIS (Netherlands)

Breman, B.B; Beenackers, A.A C M

1996-01-01

Various thermodynamic models were tested concerning their applicability to predict gas-liquid solubilities, relevant for synthesis gas conversion to methanol, higher alcohols, and hydrocarbons via gas-slurry processes. Without any parameter optimization the group contribution equation of state

The method of predicting the process of condensation of moisture and hydrate formation in the gas pipeline

OpenAIRE

Хвостова, Олена Вікторівна

2014-01-01

The problem of ensuring the required value of one of the natural gas quality indicators during its transportation to the consumer - moisture content is considered in the paper. The method for predicting possible moisture condensation and hydrate formation processes in gas pipelines considering mixing gas flows with different moisture content was developed.Predicting the moisture condensation and hydrate formation in gas pipelines is an actual task since a timely prevention of these processes ...

Gas leak characteristics of inner packaging components used in the D0T-Spec 6M container

International Nuclear Information System (INIS)

Taylor, J.M.

1985-09-01

A test program was conducted by Pacific Northwest Laboratory to determine the gas leak characteristics of metal food pack cans and 2R vessels used to package radioactive material in a D0T 6M specification container. It can be concluded from the tests performed that the inner packaging components (2R vessel, metal product cans) used with a 6M container can be sealed so that they will be gas tight ( -5 cc/sec) under elevated temperature and pressure and impact conditions. To maintain gas tight seals under accident conditions, the metal cans must be sealed with a properly adjusted can-sealing machine; the threads of the 2R vessel must be luted with a sealing compound such as a silicone rubber compound; and the metal cans must be protected inside the 2R vessel with spacer plates and impact absorbers. 4 refs., 37 figs

Conceptual design of coke-oven gas assisted coal to olefins process for high energy efficiency and low CO2 emission

International Nuclear Information System (INIS)

Man, Yi; Yang, Siyu; Zhang, Jun; Qian, Yu

2014-01-01

Highlights: • A novel coke-oven gas assisted coal to olefins (GaCTO) process is proposed. • GaCTO has higher energy efficiency and emits less CO 2 compared to coal-to-olefins process. • GaCTO proposes an idea of using redundant coke-oven gas for producing value added products. - Abstract: Olefins are one of the most important platform chemicals. Developing coal-to-olefins (CTO) processes is regarded as one of promising alternatives to oil-to-olefins process. However, CTO suffers from high CO 2 emission due to the high carbon contents of coal. In China, there is 7 × 10 10 m 3 coke-oven gas (COG) produced in coke plants annually. However, most of the hydrogen-rich COG is utilized as fuel or discharged directly into the air. Such situation is a waste of precious hydrogen resource and serious economic loss, which causes serious environmental pollution either. This paper proposes a novel co-feed process of COG assist CTO in which CH 4 of COG reacts with CO 2 in a Dry Methane Reforming unit to reduce emissions, while the Steam Methane Reforming unit produces H 2 -rich syngas. H 2 of COG can adjust the H/C ratio of syngas. The analysis shows that the energy efficiency of the co-feed process increases about 10%, while at the same time, life cycle carbon footprint is reduced by around 85% in comparison to the conventional CTO process. The economic sustainability of the co-feed process will be reached when the carbon tax would be higher than 150 CNY/t CO 2

High Resolution CH4 Emissions and Dissolved CH4 Measurements Elucidate Surface Gas Exchange Processes in Toolik Lake, Arctic Alaska

Science.gov (United States)

Del Sontro, T.; Sollberger, S.; Kling, G. W.; Shaver, G. R.; Eugster, W.

2013-12-01

Approximately 14% of the Alaskan North Slope is covered in lakes of various sizes and depths. Diffusive carbon emissions (CH4 and CO2) from these lakes offset the tundra sink by ~20 %, but the offset would substantially increase if ebullitive CH4 emissions were also considered. Ultimately, arctic lake CH4 emissions are not insignificant in the global CH4 budget and their contribution is bound to increase due to impacts from climate change. Here we present high resolution CH4 emission data as measured via eddy covariance and a Los Gatos gas analyzer during the ice free period from Toolik Lake, a deep (20 m) Arctic lake located on the Alaskan North Slope, over the last few summers. Emissions are relatively low (Gatos gas analyzer. Thus, having both the flux and the CH4 gradient across the air-water interface measured directly, we can calculate k and investigate the processes influencing CH4 gas exchange in this lake. Preliminary results indicate that there are two regimes in wind speed that impact k - one at low wind speeds up to ~5 m s-1 and another at higher wind speeds (max ~10 m s-1). The differential wind speeds during night and day may compound the effect of convective mixing and cause the diurnal variation in observed fluxes.

Mathematical model of nonstationary hydraulic processes in gas centrifuge cascade for separation of multicomponent isotope mixtures

OpenAIRE

Orlov, Aleksey Alekseevich; Ushakov, Anton; Sovach, Victor

2017-01-01

The article presents results of development of a mathematical model of nonstationary hydraulic processes in gas centrifuge cascade for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of silicon isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary hydraulic processes in gas centrifuge cascades for separation...

Development and evaluation of a collection apparatus for recoil products for study of the deexcitation process of "2"3"5"mU

International Nuclear Information System (INIS)

Shigekawa, Y.; Kasamatsu, Y.; Shinohara, A.

2016-01-01

The nucleus "2"3"5"mU is an isomer with extremely low excitation energy (76.8 eV) and decays dominantly through the internal conversion (IC) process. Because outer-shell electrons are involved in the IC process, the decay constant of "2"3"5"mU depends on its chemical environment. We plan to study the deexcitation process of "2"3"5"mU by measuring the energy spectra of IC electrons in addition to the decay constants for various chemical forms. In this paper, the preparation method of "2"3"5"mU samples from "2"3"9Pu by using alpha-recoil energy is reported. A Collection Apparatus for Recoil Products was fabricated, and then collection efficiencies under various conditions were determined by collecting "2"2"4Ra recoiling out of "2"2"8Th electrodeposited and precipitated sources. The pressure in the apparatus (vacuum or 1 atm of N_2 gas) affected the variations of the collection efficiencies depending on the negative voltage applied to the collector. The maximum values of the collection efficiencies were mainly affected by the thickness of the "2"2"8Th sources. From these results, the suitable conditions of the "2"3"9Pu sources for preparation of "2"3"5"mU were determined. In addition, dissolution efficiencies were determined by washing collected "2"2"4Ra with solutions. When "2"2"4Ra was collected in 1 atm of N_2 gas and dissolved with polar solutions such as water, the dissolution efficiencies were nearly 100%. The method of rapid dissolution of recoil products would be applicable to rapid preparation of short-lived "2"3"5"mU samples for various chemical forms.

Process for dehydration of oregano using propane gas as fuel

Directory of Open Access Journals (Sweden)

Carlos O. Velásquez-Santos

2014-08-01

Full Text Available The article describes two important issues, the first is the process to design, implement and validate a mechanical dryer of oregano, using propane gas as fuel, and the second is the cost of the process of dehydrated, taking into account the cost of electric energy consumption by the fan and the cost of propane gas consumption by the heat exchanger. To achieve this, it was necessary review the state of the art and the study of the raw material (oregano, were established as premises of design the necessary technical specifications and the variables involved in the process, using conceptual methods and simulation to ensure that it complies with the ISO standard 7925:1999, which defines the requirements for the marketing of dried oregano and processed. Emphasis was made on the percentage of moisture that is 10%, the moisture of the product was found by the azeotropic distillation method, subsequently was validated the functionality and efficiency, comparing the results from an experimental design, then it was obtained the drying curve of oregano with the prototype of drying and it was checked if it meets ISO 7925:1999 standard and the NTC 4423 standard in order to obtain a final product dehydrated with the percentage of humidity appropriate.

The constitutive distributed parameter model of multicomponent chemical processes in gas, fluid and solid phase

International Nuclear Information System (INIS)

Niemiec, W.

1985-01-01

In the literature of distributed parameter modelling of real processes is not considered the class of multicomponent chemical processes in gas, fluid and solid phase. The aim of paper is constitutive distributed parameter physicochemical model, constructed on kinetics and phenomenal analysis of multicomponent chemical processes in gas, fluid and solid phase. The mass, energy and momentum aspects of these multicomponent chemical reactions and adequate phenomena are utilized in balance operations, by conditions of: constitutive invariance for continuous media with space and time memories, reciprocity principle for isotropic and anisotropic nonhomogeneous media with space and time memories, application of definitions of following derivative and equation of continuity, to the construction of systems of partial differential constitutive state equations, in the following derivative forms for gas, fluid and solid phase. Couched in this way all physicochemical conditions of multicomponent chemical processes in gas, fluid and solid phase are new form of constitutive distributed parameter model for automatics and its systems of equations are new form of systems of partial differential constitutive state equations in sense of phenomenal distributed parameter control

The Ispra flue gas desulphurization process: research, development and marketing aspects

Energy Technology Data Exchange (ETDEWEB)

Velzen, D. van (JRC, Ispra (Italy))

1993-01-01

The most widely used method of reducing sulphur dioxide emission is flue gas desulphurisation (FGD). The combustion gases produced by large combustion units (for example power stations) are in contact with a liquid or a slurry containing a reactant for SO[sub 2]. This operation produces a waste gas which is essentially free of sulphur dioxide. This paper describes the steps involved in the research and development of the new Ispra FGD process. Details of market consideration are also given.

Numerical analysis of exhaust gas flow during the gas exchange process and the design optimization; Haiki manihorudonai no hiteijo nagare kaiseki gijutsu to sono oyo

Energy Technology Data Exchange (ETDEWEB)

Yoshizawa, K; Takeyama, S; Sakai, E; Tanzawa, K [Nissan Motor Co. Ltd., Tokyo (Japan)

1997-10-01

A simulation method was developed to estimate exhaust gas flow during the gas exchange process. In this simulation, one dimensional in-cylinder gas flow calculation and three dimensional exhaust gas flow calculation were combined. Gas flow inside the exhaust manifold catalyst during gas exchange was agreed in experiments. A simulation method was applied to select oxygen sensor location. A prediction of the oxygen sensor sensitivity of each cylinder gas was presented. The possibility of selecting oxygen sensor location in the exhaust manifold using calculation was proved. 5 refs., 10 figs., 1 tab.

Methods of natural gas liquefaction and natural gas liquefaction plants utilizing multiple and varying gas streams

Science.gov (United States)

Wilding, Bruce M; Turner, Terry D

2014-12-02

A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO.sub.2 from a liquid NG process stream and processing the CO.sub.2 to provide a CO.sub.2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.

Optimizing Location of Bulk Metallic Minerals Processing Based on Greenhouse Gas Avoidance

Directory of Open Access Journals (Sweden)

Benjamin C. McLellan

2011-12-01

Full Text Available The bulk minerals iron ore and bauxite cause significant greenhouse emissions in their processing to steel and aluminum respectively. The level of these emissions is highly dependent on the source of electrical and thermal energy. However, they also cause significant greenhouse gas emissions from their transportation across the globe for processing. This study examines these minerals from the perspective of greenhouse gas avoidance, examining the location of processing as an option for reducing transportation-based and process-based emissions. The analysis proposes a “radius of reduction” to define the potential for transporting ore to reduce emissions by offshore processing. Overall scenarios for localized steel production indicate potential for 85% reduction of transport emissions in the steel industry and 14% of overall industry emissions. Local high-carbon electricity grids and inefficient production mean that the benefit of reduced transportation is partially counteracted by increased processing emissions. The transportation of all global bauxite to Norway and other nations with low-emissions electricity for production of aluminum could result in an overall reduction of industry emissions of up to 44%.

Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

Science.gov (United States)

Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

2012-05-15

A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

Numerical Investigation of the Low-Caloric Gas Burning Process in a Bottom Burner

Directory of Open Access Journals (Sweden)

Redko A.

2017-08-01

Full Text Available The use of low-grade gases in the fuel and energy balance of enterprises makes it possible to increase the energy efficiency of technological processes. The volumes of low-grade gases (blast furnace and coke oven gases, synthesis gas of coal gasification processes, biogas, coal gas, etc. that are utilized more significant in technological processes but their calorific value are low. At the same time artificial gases contain ballast gaseous (СО2, H2O and mechanical impurities that are harmful gas impurities. Their use requires technological preparation. Thus coal methane is characterized of high humidity, coal dust and drip moisture, variable composition. Thus was effective burning of coal methane it is required the development of constructive and regime measures that ensure a stable and complete burning of gaseous fuels. In this article it is presented the results of computer simulation of a stationary turbulent diffusion flame in a restricted space in the process of burning natural gas and coal methane in a bottom burner. The calculation results contain the fields of gear, temperature, concentration of CH4‚ CO‚ H2O‚ CO2 and nitrogen oxides. The structural elements of the flame (recirculation zone, hot "dome", mixing layer and far trace are determined. It has been established that complete combustion of coal methane in a modified bottom burner is ensured and the numerical values of nitrogen oxide concentrations in the flame are consistent with the literature data.

System and process for polarity swing assisted regeneration of gas selective capture liquids

Science.gov (United States)

Heldebrant, David J.; Tegrotenhuis, Ward E.; Freeman, Charles J.; Elliott, Michael L.; Koech, Phillip K.; Humble, Paul H.; Zheng, Feng; Zhang, Jian

2017-07-18

A polarity swing-assisted regeneration (PSAR) process is disclosed for improving the efficiency of releasing gases chemically bound to switchable ionic liquids. Regeneration of the SWIL involves addition of a quantity of non-polar organic compound as an anti-solvent to destabilize the SWIL, which aids in release of the chemically bound gas. The PSAR decreases gas loading of a SWIL at a given temperature and increases the rate of gas release compared to heating in the absence of anti-solvent.

Bio-films and processes of bio-corrosion and bio-deterioration in oil-and gas-processing industry

Energy Technology Data Exchange (ETDEWEB)

Kholodenko, V.P.; Irkhina, I.A.; Chugunov, V.A.; Rodin, V.B.; Zhigletsova, S.K.; Yermolenko, Z.M.; Rudavin, V.V. [State Research Center for Applied Microbiology, Obolensk, Moscow region (Russian Federation)

2004-07-01

As a rule, oil- and gas-processing equipment and pipelines are attacked by different microorganisms. Their vital ability determines processes of bio-deterioration and bio-corrosion that lead often to technological accidents and severe environmental contamination. Bio-films presenting a complex association of different microorganisms and their metabolites are responsible for most of damages. In this context, to study the role bio-films may play in processes of bio-damages and in efficacy of protective measures is important. We have developed method of culturing bio-films on the surface of metal coupons by using a natural microbial association isolated from oil-processing sites. Simple and informative methods of determining microbiological parameters of bio-films required to study bio-corrosion processes are also developed. In addition, a method of electron microscopic analysis of bio-films and pitting corrosion is offered. Using these methods, we conducted model experiments to determine the dynamics of corrosion processes depending on qualitative and quantitative composition of bio-films, aeration conditions and duration of the experiment. A harmful effect of soil bacteria and micro-mycetes on different pipeline coatings was also investigated. Experiments were conducted within 3-6 months and revealed degrading action of microorganisms. This was confirmed by axial tension testing of coatings. All these approaches will be used for further development of measures to protect gas- and oil-processing equipment and pipelines against bio-corrosion and bio-damages (first of all biocides). (authors)

Gas, gas, gas... discoveries and developments booming worldwide

International Nuclear Information System (INIS)

Maxwell, F.

2000-01-01

Deep water exploration is yielding more than billion barrel oil fields. Unocal's 3 May discovery of 2-3 Tcf of gas in its Kutei block of Indonesia marks the first major discovery of natural gas in the deep water frontier: Wildcats Gula and Gada were drilled in over 1800 m of water as part of an aggressive search for gas instigated by Unocal last year. The author makes a survey of gas exploration and development throughout the world. (author)

Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

International Nuclear Information System (INIS)

Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

2014-01-01

Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

Intelligent Integration between Human Simulated Intelligence and Expert Control Technology for the Combustion Process of Gas Heating Furnace

Directory of Open Access Journals (Sweden)

Yucheng Liu

2014-01-01

Full Text Available Due to being poor in control quality of the combustion process of gas heating furnace, this paper explored a sort of strong robust control algorithm in order to improve the control quality of the combustion process of gas heating furnace. The paper analyzed the control puzzle in the complex combustion process of gas heating furnace, summarized the cybernetics characteristic of the complex combustion process, researched into control strategy of the uncertainty complex control process, discussed the control model of the complex process, presented a sort of intelligent integration between human-simulated intelligence and expert control technology, and constructed the control algorithm for the combustion process controlling of gas heating furnace. The simulation results showed that the control algorithm proposed in the paper is not only better in dynamic and steady quality of the combustion process, but also obvious in energy saving effect, feasible, and effective in control strategy.

LYAPUNOV-Based Sensor Failure Detection and Recovery for the Reverse Water Gas Shift Process

Science.gov (United States)

Haralambous, Michael G.

2002-01-01

Livingstone, a model-based AI software system, is planned for use in the autonomous fault diagnosis, reconfiguration, and control of the oxygen-producing reverse water gas shift (RWGS) process test-bed located in the Applied Chemistry Laboratory at KSC. In this report the RWGS process is first briefly described and an overview of Livingstone is given. Next, a Lyapunov-based approach for detecting and recovering from sensor failures, differing significantly from that used by Livingstone, is presented. In this new method, models used are in t e m of the defining differential equations of system components, thus differing from the qualitative, static models used by Livingstone. An easily computed scalar inequality constraint, expressed in terms of sensed system variables, is used to determine the existence of sensor failures. In the event of sensor failure, an observer/estimator is used for determining which sensors have failed. The theory underlying the new approach is developed. Finally, a recommendation is made to use the Lyapunov-based approach to complement the capability of Livingstone and to use this combination in the RWGS process.

Sensing the gas metal arc welding process

Science.gov (United States)

Carlson, N. M.; Johnson, J. A.; Smartt, H. B.; Watkins, A. D.; Larsen, E. D.; Taylor, P. L.; Waddoups, M. A.

1994-01-01

Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-by-pass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

Dominant rate process of silicon surface etching by hydrogen chloride gas

International Nuclear Information System (INIS)

Habuka, Hitoshi; Suzuki, Takahiro; Yamamoto, Sunao; Nakamura, Akio; Takeuchi, Takashi; Aihara, Masahiko

2005-01-01

Silicon surface etching and its dominant rate process are studied using hydrogen chloride gas in a wide concentration range of 1-100% in ambient hydrogen at atmospheric pressure in a temperature range of 1023-1423 K, linked with the numerical calculation accounting for the transport phenomena and the surface chemical reaction in the entire reactor. The etch rate, the gaseous products and the surface morphology are experimentally evaluated. The dominant rate equation accounting for the first-order successive reactions at silicon surface by hydrogen chloride gas is shown to be valid. The activation energy of the dominant surface process is evaluated to be 1.5 x 10 5 J mol - 1 . The silicon deposition by the gaseous by-product, trichlorosilane, is shown to have a negligible influence on the silicon etch rate

Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

Directory of Open Access Journals (Sweden)

Orlov Alexey

2016-01-01

Full Text Available This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge cascades for separation of multicomponent isotope mixtures.

New challenges in gas

Energy Technology Data Exchange (ETDEWEB)

Mandil, C. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Chabrelie, M.F. [Cedigaz, 92 - Rueil Malmaison (France); Streicher, C. [Prosernat, 92 - Paris la Defense (France)] [and others

2003-07-01

New developments in the area of gas treatment will be to a large extent driven by the need to find appropriate solutions to the fundamental need of sustainable development. New gas treatment processes are developed with the aim to minimise contaminant emissions and meet most stringent environmental specifications. A new major challenge for the industry will be to implement new cost effective technologies for reducing CO{sub 2} emissions. Industry has also to minimise its costs, and therefore, in order to ensure at the same time a better protection of the environment and a better safety, it is necessary to innovate. The purpose of this seminar is precisely to identify better the innovations which are required in the area of gas treatment. These proceedings comprise 8 papers and a summary of the contributions to a round-table discussion dealing with the options for CO{sub 2} capture and sequestration. The presentations treat of: the future prospects for the gas industry (M.F. Chabrelie, Cedigaz); the solutions for offshore gas treatment (C. Streicher, Prosernat); gas treatment with membranes (H. Meyer, GTI); the Axens Multibed{sub TM} technology for natural gas treatment (G. Jochem, Axens); the potentials and applications for the Propure co-current contactors (F.P. Nilsen, ProPure); the production of very-sour and super-sour large gas reserves: the new challenges (F. Lallemand, TotalFinaElf); Hybrisol, a new gas treatment process for sour natural gases (F. Lecomte, IFP); and the conception and building of large acid-gas removal units (J. Castel, Technip-Coflexip). (J.S.)

Origin and Processes Highlighted By Noble Gases Geochemistry of Submarine Gas Emissions from Seeps at the Aquitaine Shelf (Bay of Biscay):

Science.gov (United States)

Battani, A.; Ruffine, L.; Donval, J. P.; Bignon, L.; Pujol, M.; Levaché, D.

2014-12-01

Noble gases are widely used as tracers to both determine fluid origin and identify transfer processes governing fluid flow in natural systems. This work presents the preliminary results and interpretations from submarine gas samples collected during the GAZCOGNE2 cruise (2013). The seepage activity and the spatial distribution of the widespread emission sites encountered at this area are described by (Dupré et al. 2014). Gas composition shows that methane is the dominant species compared to the C2+. The associated δ13C and δD signatures point to a biogenic origin- through CO2 reduction- of the gas. Helium concentrations are very low, ranging from 0.1 and 2.3 ppm, indicating a low residence time of the fluids in the subsurface. However, the resulting helium isotopic ratios are mostly crustal fingerprinted (around 0.02). The R/Ra values sometimes exhibit higher value of 0.2, indicative either an ASW (air saturated water) value, or the fingerprint of ancient mantle helium, the later in agreement with the geological structural context of the Parentis Basin. Most of the samples exhibit a mixing between ASW and air, probably by excess air addition to the initial ASW concentration. The elemental Ne/Ar ratio is remarkably constant for the totality of the samples, with a value typical of ASW (0.2). This result implies that the migrating gas phase is "stripping" the original water matrix from its noble gas content, as described by Gillfillian et al., 2008. This further indicates that an intermediate reservoir of biogenic gas should be present at depth. The GAZCOGNE study is co-funded by TOTAL and IFREMER as part of the PAMELA (Passive Margin Exploration Laboratories) scientific project. References: Dupré, S., L. Berger, N. Le Bouffant, C. Scalabrin, and J. F. Bourillet (2014), Fluid emissions at the Aquitaine Shelf (Bay of Biscay, France): a biogenic origin or the expression of hydrocarbon leakage?, Continental Shelf Research, doi:10.1016/j.csr.2014.07.004. Gilfillan S

ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE REACTOR SYSTEM - APPLICATIONS ANALYSIS REPORT

Science.gov (United States)

The ELI Eco Logic International Inc. (Eco Logic) process thermally separates organics, then chemically reduces them in a hydrogen atmosphere, converting them to a reformed gas that consists of light hydrocarbons and water. A scrubber treats the reformed gas to remove hydrogen chl...

Suggestions on the development strategy of shale gas in China

Directory of Open Access Journals (Sweden)

Dazhong Dong

2016-12-01

Full Text Available From the aspects of shale gas resource condition, main exploration and development progress, important breakthrough in key technologies and equipment, this paper systematically summarized and analyzed current situation of shale gas development in China and pointed out five big challenges such as misunderstandings, lower implementation degree and higher economic uncertainty of shale gas resource, and still no breakthrough in exploration and development core technologies and equipment for shale gas buried depth more than 3500 m, higher cost and other non-technical factors that restrict the development pace. Aiming at the above challenges, we put forward five suggestions to promote the shale gas development in China: (1 Make strategies and set goals according to our national conditions and exploration and development stages. That is, make sure to realize shale gas annual production of 20 × 109 m3, and strives to reach 30 × 109 m3. (2 Attach importance to the research of accumulation and enrichment geological theory and exploration & development key engineering technologies for lower production and lower pressure marine shale gas reservoir, and at the same time orderly promote the construction of non-marine shale gas exploration & development demonstration areas. (3 The government should introduce further policies and set special innovation funds to support the companies to carry out research and development of related technologies and equipment, especially to strengthen the research and development of technology, equipment and process for shale gas bellow 3500 m in order to achieve breakthrough in deep shale gas. (4 Continue to promote the geological theory, innovation in technology and management, and strengthen cost control on drilling, fracturing and the whole process in order to realize efficient, economic and scale development of China's shale gas. (5 Reform the mining rights management system, establish information platform of shale

xCOLD GASS: The Complete IRAM 30 m Legacy Survey of Molecular Gas for Galaxy Evolution Studies

Science.gov (United States)

Saintonge, Amélie; Catinella, Barbara; Tacconi, Linda J.; Kauffmann, Guinevere; Genzel, Reinhard; Cortese, Luca; Davé, Romeel; Fletcher, Thomas J.; Graciá-Carpio, Javier; Kramer, Carsten; Heckman, Timothy M.; Janowiecki, Steven; Lutz, Katharina; Rosario, David; Schiminovich, David; Schuster, Karl; Wang, Jing; Wuyts, Stijn; Borthakur, Sanchayeeta; Lamperti, Isabella; Roberts-Borsani, Guido W.

2017-12-01

We introduce xCOLD GASS, a legacy survey providing a census of molecular gas in the local universe. Building on the original COLD GASS survey, we present here the full sample of 532 galaxies with CO (1–0) measurements from the IRAM 30 m telescope. The sample is mass-selected in the redshift interval 0.01 {10}9 {M}ȯ . The CO (1–0) flux measurements are complemented by observations of the CO (2–1) line with both the IRAM 30 m and APEX telescopes, H I observations from Arecibo, and photometry from SDSS, WISE, and GALEX. Combining the IRAM and APEX data, we find that the ratio of CO (2–1) to CO (1–0) luminosity for integrated measurements is {r}21=0.79+/- 0.03, with no systematic variations across the sample. The CO (1–0) luminosity function is constructed and best fit with a Schechter function with parameters {L}{CO}* =(7.77+/- 2.11)× {10}9 {{K}} {km} {{{s}}}-1 {{pc}}2, {φ }* =(9.84+/- 5.41)× {10}-4 {{Mpc}}-3, and α =-1.19+/- 0.05. With the sample now complete down to stellar masses of 109 {M}ȯ , we are able to extend our study of gas scaling relations and confirm that both molecular gas fractions ({f}{{{H}}2}) and depletion timescale ({t}{dep}({{{H}}}2)) vary with specific star formation rate (or offset from the star formation main sequence) much more strongly than they depend on stellar mass. Comparing the xCOLD GASS results with outputs from hydrodynamic and semianalytic models, we highlight the constraining power of cold gas scaling relations on models of galaxy formation.

Evidence for non-axisymmetry in M 31 from wide-field kinematics of stars and gas

Science.gov (United States)

Opitsch, M.; Fabricius, M. H.; Saglia, R. P.; Bender, R.; Blaña, M.; Gerhard, O.

2018-03-01

Aim. As the nearest large spiral galaxy, M 31 provides a unique opportunity to study the structure and evolutionary history of this galaxy type in great detail. Among the many observing programs aimed at M 31 are microlensing studies, which require good three-dimensional models of the stellar mass distribution. Possible non-axisymmetric structures like a bar need to be taken into account. Due to M 31's high inclination, the bar is difficult to detect in photometry alone. Therefore, detailed kinematic measurements are needed to constrain the possible existence and position of a bar in M 31. Methods: We obtained ≈220 separate fields with the optical integral-field unit spectrograph VIRUS-W, covering the whole bulge region of M 31 and parts of the disk. We derived stellar line-of-sight velocity distributions from the stellar absorption lines, as well as velocity distributions and line fluxes of the emission lines Hβ, [O III] and [N I]. Our data supersede any previous study in terms of spatial coverage and spectral resolution. Results: We find several features that are indicative of a bar in the kinematics of the stars, we see intermediate plateaus in the velocity and the velocity dispersion, and correlation between the higher moment h3 and the velocity. The gas kinematics is highly irregular, but is consistent with non-triaxial streaming motions caused by a bar. The morphology of the gas shows a spiral pattern, with seemingly lower inclination than the stellar disk. We also look at the ionization mechanisms of the gas, which happens mostly through shocks and not through starbursts. This paper includes data taken at The McDonald Observatory of The University of Texas at Austin.This research was supported by the DFG cluster of excellence "Origin and Structure of the Universe".Full Tables B.4-B.7 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A38

Integrated underground gas storage of CO2 and CH4 to decarbonize the "power-to-gas-to-gas-to-power" technology

Science.gov (United States)

Kühn, Michael; Streibel, Martin; Nakaten, Natalie; Kempka, Thomas

2014-05-01

underground reservoir. If existing locations in Europe, where natural gas storage in porous formations is performed, were to be extended by CO2 storage sites, a significant quantity of wind and solar energy produced could be stored as methane. The overall process chain is in this case carbon neutral. Kühn M., Nakaten N., Streibel M., Kempka T. (2013) Klimaneutrale Flexibilisierung regenerativer Überschussenergie mit Untergrundspeichern. ERDÖL ERDGAS KOHLE 129(10), 348-352. Nakaten, N., Schlüter, R., Azzam, R., Kempka, T. (2014) Development of a techno-economic model for dynamic calculation of COE, energy demand and CO2 emissions of an integrated UCG-CCS process, Energy (in press). doi: 10.1016/j.energy.2014.01.014 Streibel M., Nakaten N., Kempka T., Kühn M. (2013) Analysis of an integrated carbon cycle for storage of renewables. Energy Procedia 40, 202-211. doi: 10.1016/j.egypro.2013.08.024.

Techno-economic process design of a commercial-scale amine-based CO_2 capture system for natural gas combined cycle power plant with exhaust gas recirculation

International Nuclear Information System (INIS)

Ali, Usman; Agbonghae, Elvis O.; Hughes, Kevin J.; Ingham, Derek B.; Ma, Lin; Pourkashanian, Mohamed

2016-01-01

Highlights: • EGR is a way to enhance the CO_2 content with reduction in design variables and cost. • Both process and economic analyses are essential to reach the optimum design variables. • Commercial-scale NGCC with and without EGR is presented. • Process design of the amine-based CO_2 capture plant is evaluated for with and without EGR. - Abstract: Post-combustion CO_2 capture systems are gaining more importance as a means of reducing escalating greenhouse gas emissions. Moreover, for natural gas-fired power generation systems, exhaust gas recirculation is a method of enhancing the CO_2 concentration in the lean flue gas. The present study reports the design and scale-up of four different cases of an amine-based CO_2 capture system at 90% capture rate with 30 wt.% aqueous solution of MEA. The design results are reported for a natural gas-fired combined cycle system with a gross power output of 650 MW_e without EGR and with EGR at 20%, 35% and 50% EGR percentage. A combined process and economic analysis is implemented to identify the optimum designs for the different amine-based CO_2 capture plants. For an amine-based CO_2 capture plant with a natural gas-fired combined cycle without EGR, an optimum liquid to gas ratio of 0.96 is estimated. Incorporating EGR at 20%, 35% and 50%, results in optimum liquid to gas ratios of 1.22, 1.46 and 1.90, respectively. These results suggest that a natural gas-fired power plant with exhaust gas recirculation will result in lower penalties in terms of the energy consumption and costs incurred on the amine-based CO_2 capture plant.

Adequate Measuring Technology and System of Fission Gas release Behavior from Voloxidation Process

International Nuclear Information System (INIS)

Park, Geun Il; Park, J. J.; Jung, I. H.; Shin, J. M.; Yang, M. S.; Song, K. C.

2006-09-01

Based on the published literature and an understanding of available hot cell technologies, more accurate measuring methods for each volatile fission product released from voloxidation process were reviewed and selected. The conceptual design of an apparatus for measuring volatile and/or semi-volatile fission products released from spent fuel was prepared. It was identified that on-line measurement techniques can be applied for gamma-emitting fission products, and off-line measurement such as chemical/or neutron activation analysis can applied for analyzing beta-emitting fission gases. Collection methods using appropriate material or solutions were selected to measure the release fraction of beta-emitting gaseous fission products at IMEF M6 hot cell. Especially, the on-line gamma-ray counting system for monitoring of 85Kr and the off-line measuring system of 14C was established. On-line measuring system for obtaining removal ratios of the semi-volatile fission products, mainly gamma-emitting fission products such as Cs, Ru etc., was also developed at IMEF M6 hot cell which was based on by measuring fuel inventory before and after the voloxidation test through gamma measuring technique. The development of this measurement system may enable basic information to be obtained to support design of the off-gas treatment system for the voloxidation process at INL, USA

Chemical hot gas purification for biomass gasification processes; Chemische Heissgasreinigung bei Biomassevergasungsprozessen

Energy Technology Data Exchange (ETDEWEB)

Stemmler, Michael

2010-07-01

The German government decided to increase the percentage of renewable energy up to 20 % of all energy consumed in 2020. The development of biomass gasification technology is advanced compared to most of the other technologies for producing renewable energy. So the overall efficiency of biomass gasification processes (IGCC) already increased to values above 50 %. Therefore, the production of renewable energy attaches great importance to the thermochemical biomass conversion. The feedstock for biomass gasification covers biomasses such as wood, straw and further energy plants. The detrimental trace elements released during gasification of these biomasses, e.g. KCl, H{sub 2}S and HCl, cause corrosion and harm downstream devices. Therefore, gas cleaning poses an especial challenge. In order to improve the overall efficiency this thesis aims at the development of gas cleaning concepts for the allothermic, water blown gasification at 800 C and 1 bar (Guessing-Process) as well as for the autothermic, water and oxygen blown gasification at 950 C and 18 bar (Vaernamo-Process). Although several mechanisms for KCl- and H{sub 2}S-sorption are already well known, the achievable reduction of the contamination concentration is still unknown. Therefore, calculations on the produced syngas and the chemical hot gas cleaning were done with a thermodynamic process model using SimuSage. The syngas production was included in the calculations because the knowledge of the biomass syngas composition is very limited. The results of these calculations prove the dependence of syngas composition on H{sub 2}/C-ratio and ROC (Relative Oxygen Content). Following the achievable sorption limits were detected via experiments. The KCl containing syngases were analysed by molecular beam mass spectrometry (MBMS). Furthermore, an optimised H{sub 2}S-sorbent was developed because the examined sorbents exceeded the sorption limit of 1 ppmv. The calculated sorption limits were compared to the limits

CO₂ Capture Membrane Process for Power Plant Flue Gas

Energy Technology Data Exchange (ETDEWEB)

Toy, Lora [Research Triangle Inst. International, Research Triangle Park, NC (United States); Kataria, Atish [Research Triangle Inst. International, Research Triangle Park, NC (United States); Gupta, Raghubir [Research Triangle Inst. International, Research Triangle Park, NC (United States)

2012-04-01

Because the fleet of coal-fired power plants is of such importance to the nation's energy production while also being the single largest emitter of CO₂, the development of retrofit, post-combustion CO₂ capture technologies for existing and new, upcoming coal power plants will allow coal to remain a major component of the U.S. energy mix while mitigating global warming. Post-combustion carbon capture technologies are an attractive option for coal-fired power plants as they do not require modification of major power-plant infrastructures, such as fuel processing, boiler, and steam-turbine subsystems. In this project, the overall objective was to develop an advanced, hollow-fiber, polymeric membrane process that could be cost-effectively retrofitted into current pulverized coal-fired power plants to capture at least 90% of the CO₂ from plant flue gas with 95% captured CO₂ purity. The approach for this project tackled the technology development on three different fronts in parallel: membrane materials R&D, hollow-fiber membrane module development, and process development and engineering. The project team consisted of RTI (prime) and two industrial partners, Arkema, Inc. and Generon IGS, Inc. Two CO₂-selective membrane polymer platforms were targeted for development in this project. For the near term, a next-generation, high-flux polycarbonate membrane platform was spun into hollow-fiber membranes that were fabricated into both lab-scale and larger prototype (~2,200 ft²) membrane modules. For the long term, a new fluoropolymer membrane platform based on poly(vinylidene fluoride) [PVDF] chemistry was developed using a copolymer approach as improved capture membrane materials with superior chemical resistance to flue-gas contaminants (moisture, SO₂, NO_x, etc.). Specific objectives were: - Development of new, highly chemically resistant, fluorinated polymers as membrane materials with minimum selectivity of 30 for CO₂ over N₂ and CO�

Qualification of the ALKASORB sorbent for the sorption-enhanced water-gas shift process

Energy Technology Data Exchange (ETDEWEB)

Van Selow, E.R.; Cobden, P.D.; Dijk, Van H.A.J.; Walspurger, S.; Verbraeken, P.A.; Jansen, D.

2013-07-01

For the sorption-enhanced water-gas shift (SEWGS) process, a new sorbent material has been qualified in a reactor of 2 m length under conditions close to industrial designs. The sorbent ALKASORB is a potassium-carbonate promoted hydrotalcite-based compound. ALKASORB is shown to have many favourable properties in comparison to the reference sorbent, in particular with respect to mechanical stability. The cyclic capacity of the new compound is substantially higher than the cyclic capacity of the reference sorbent, and it allows a reduction of the steam requirement of 50%. The sorbent has demonstrated catalytic activity for the water-gas shift reaction that is sufficient to omit a separate catalyst. It is demonstrated that the sorbent remains chemically and mechanically stable during operation of at least 2000 adsorption-desorption cycles, even in the presence of H2S in the feed. H2S is shown not to influence CO2 adsorption capacity and is co-captured with the CO2. In contrast to the reference material that showed mechanical degradation during extended adsorption-desorption cycles, the new material is stable and allows to obtain carbon capture levels exceeding 95% more efficiently and more economically since the required size of the vessels will be smaller.

FIELD DEMONSTRATION OF A MEMBRANE PROCESS TO RECOVER HEAVY HYDROCARBONS AND TO REMOVE WATER FROM NATURAL GAS

Energy Technology Data Exchange (ETDEWEB)

R. Baker; R. Hofmann; K.A. Lokhandwala

2003-02-14

The objective of this project is to design, construct and field demonstrate a membrane system to recover natural gas liquids (NGL) and remove water from raw natural gas. An extended field test to demonstrate system performance under real-world conditions would convince industry users of the efficiency and reliability of the process. The system has been designed and fabricated by Membrane Technology and Research, Inc. (MTR) and will be installed and operated at British Petroleum (BP)-Amoco's Pascagoula, MS plant. The Gas Research Institute will partially support the field demonstration and BP-Amoco will help install the unit and provide onsite operators and utilities. The gas processed by the membrane system will meet pipeline specifications for dewpoint and Btu value and can be delivered without further treatment to the pipeline. Based on data from prior membrane module tests, the process is likely to be significantly less expensive than glycol dehydration followed by propane refrigeration, the principal competitive technology. At the end of this demonstration project the process will be ready for commercialization. The route to commercialization will be developed during this project and may involve collaboration with other companies already servicing the natural gas processing industry.

Microbial methane oxidation processes and technologies for mitigation of landfill gas emissions

DEFF Research Database (Denmark)

Scheutz, Charlotte; Kjeldsen, Peter; Bogner, J.E.

2009-01-01

Landfill gas containing methane is produced by anaerobic degradation of organic waste. Methane is a strong greenhouse gas and landfills are one of the major anthropogenic sources of atmospheric methane. Landfill methane may be oxidized by methanotrophic microorganisms in soils or waste materials...... to predict methane emissions from landfills. Additional research and technology development is needed before methane mitigation technologies utilizing microbial methane oxidation processes can become commercially viable and widely deployed....

Computer simulation of the off gas treatment process for the KEPCO pilot vitrification plant

International Nuclear Information System (INIS)

Kim, Hey Suk; Maeng, Sung Jun; Lee, Myung Chan

1999-01-01

Vitrification technology for treatment of low and intermediate radioactive wastes can remarkably reduce waste volume to about one twentieth of the initial volume as they are collected and converted into a very stable form. Therefore, it can minimize environmental impact when the vitrified waste is disposed of. But an off gas treatment system is necessary to apply this technology because air pollutants and radioisotopes are generated like those of other conventional incinerators during thermal oxidation process at high temperature. KEPCO designed and installed a pilot scale vitrification plant to demonstrate the feasibility of the vitrification process and then to make a conceptual design for a commercial vitrification facility. The purpose of this study was to simulate the off gas treatment system(OGTS) in order optimize the operating conditions. Mass balance and temperature profile in the off gas treatment system were simulated for different combinations of combustible wastes by computer simulation code named OGTS code and removal efficiency of each process was also calculated with change of design parameters. The OGTS code saved efforts,time and capital because scale and configuration of the system could be easily changed. The simulation result of the pilot scale off gas process as well as pilot tests will be of great use in the future for a design of the commercial vitrification facility. (author)

Microstructural Characterization of a Polycrystalline Nickel-Based Superalloy Processed via Tungsten-Intert-Gas-Shaped Metal Deposition

Science.gov (United States)

Clark, Daniel; Bache, Martin R.; Whittaker, Mark T.

2010-12-01

Recent trials have produced tungsten-inert-gas (TIG)-welded structures of a suitable scale to allow an evaluation of the technique as an economic and commercial process for the manufacture of complex aeroengine components. The employment of TIG welding is shown to have specific advantages over alternative techniques based on metal inert gas (MIG) systems. Investigations using the nickel-based superalloy 718 have shown that TIG induces a smaller weld pool with less compositional segregation. In addition, because the TIG process involves a pulsed power source, a faster cooling rate is achieved, although this rate, in turn, compromises the deposition rate. The microstructures produced by the two techniques differ significantly, with TIG showing an absence of the detrimental delta and Laves phases typically produced by extended periods at a high temperature using MIG. Instead, an anisotropic dendritic microstructure was evident with a preferred orientation relative to the axis of epitaxy. Niobium was segregated to the interdendritic regions. A fine-scale porosity was evident within the microstructure with a maximum diameter of approximately 5 μm. This porosity often was found in clusters and usually was associated with the interdendritic regions. Subsequent postdeposition heat treatment was shown to have no effect on preexisting porosity and to have a minimal effect on the microstructure.

Development of the krypton absorption in liquid carbon dioxide (KALC) process for HTGR off-gas reprocessing

International Nuclear Information System (INIS)

Glass, R.W.; Beaujean, H.W.R.; Cochran, H.D. Jr.; Haas, P.A.; Levins, D.M.; Woods, W.M.

1975-01-01

Reprocessing of High-Temperature Gas-Cooled Reactor (HTGR) fuel involves burning of the graphite-matrix elements to release the fuel for recovery purposes. The resulting off-gas is primarily CO 2 with residual amounts of N 2 , O 2 , and CO, together with fission products. Trace quantities of krypton-85 must be recovered in a concentrated form from the gas stream, but processes commonly employed for rare gas removal and concentration are not suitable for use with off-gas from graphite burning. The KALC (Krypton Absorption in Liquid CO 2 ) process employs liquid CO 2 as a volatile solvent for the krypton and is, therefore, uniquely suited to the task. Engineering development of the KALC process is currently under way at the Oak Ridge National Laboratory (ORNL) and the Oak Ridge Gaseous Diffusion Plant (ORGDP). The ORNL system is designed for close study of the individual separation operations involved in the KALC process, while the ORGDP system provides a complete pilot facility for demonstrating combined operations on a somewhat larger scale. Packed column performance and process control procedures have been of prime importance in the initial studies. Computer programs have been prepared to analyze and model operational performance of the KALC studies, and special sampling and in-line monitoring systems have been developed for use in the experimental facilities. (U.S.)

Gas pixel detectors

International Nuclear Information System (INIS)

Bellazzini, R.; Baldini, L.; Brez, A.; Cavalca, F.; Latronico, L.; Massai, M.M.; Minuti, M.; Omodei, N.; Pesce-Rollins, M.; Sgro, C.; Spandre, G.; Costa, E.; Soffitta, P.

2007-01-01

With the Gas Pixel Detector (GPD), the class of micro-pattern gas detectors has reached a complete integration between the gas amplification structure and the read-out electronics. To obtain this goal, three generations of application-specific integrated circuit of increased complexity and improved functionality has been designed and fabricated in deep sub-micron CMOS technology. This implementation has allowed manufacturing a monolithic device, which realizes, at the same time, the pixelized charge-collecting electrode and the amplifying, shaping and charge measuring front-end electronics of a GPD. A big step forward in terms of size and performances has been obtained in the last version of the 0.18 μm CMOS analog chip, where over a large active area of 15x15 mm 2 a very high channel density (470 pixels/mm 2 ) has been reached. On the top metal layer of the chip, 105,600 hexagonal pixels at 50 μm pitch have been patterned. The chip has customable self-trigger capability and includes a signal pre-processing function for the automatic localization of the event coordinates. In this way, by limiting the output signal to only those pixels belonging to the region of interest, it is possible to reduce significantly the read-out time and data volume. In-depth tests performed on a GPD built up by coupling this device to a fine pitch (50 μm) gas electron multiplier are reported. Matching of the gas amplification and read-out pitch has let to obtain optimal results. A possible application of this detector for X-ray polarimetry of astronomical sources is discussed

Acetone-butanol-ethanol from sweet sorghum juice by an immobilized fermentation-gas stripping integration process.

Science.gov (United States)

Cai, Di; Wang, Yong; Chen, Changjing; Qin, Peiyong; Miao, Qi; Zhang, Changwei; Li, Ping; Tan, Tianwei

2016-07-01

In this study, sweet sorghum juice (SSJ) was used as the substrate in a simplified ABE fermentation-gas stripping integration process without nutrients supplementation. The sweet sorghum bagasse (SSB) after squeezing the fermentable juice was used as the immobilized carrier. The results indicated that the productivity of ABE fermentation process was improved by gas stripping integration. A total 24g/L of ABE solvents was obtained from 59.6g/L of initial sugar after 80h of fermentation with gas stripping. Then, long-term of fed-batch fermentation with continuous gas stripping was further performed. 112.9g/L of butanol, 44.1g/L of acetone, 9.5g/L of ethanol (total 166.5g/L of ABE) was produced in overall 312h of fermentation. At the same time, concentrated ABE product was obtained in the condensate of gas stripping. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal physics of gas-thermal coatings formation processes. State of investigations

International Nuclear Information System (INIS)

Fialko, N.M.; Prokopov, V.G.; Meranova, N.O.; Borisov, Yu.S.; Korzhik, V.N.; Sherenkovskaya, G.P.; AN Ukrainskoj SSR, Kiev

1993-01-01

The analysis of state of investigations of gas-thermal coatings formation processes in presented. Classification of approaches to mathematical simulation of thermal phenomena studies is offered. The general characteristics of three main approaches to the analysis of heat transport processes is given. Some problems of mathematical simulation of single particle thermal interaction with solid surface are considered in details. The main physical assumptions are analysed

Time resolved Thomson scattering diagnostic of pulsed gas metal arc welding (GMAW) process

International Nuclear Information System (INIS)

Kühn-Kauffeldt, M; Schein, J; Marquès, J L

2014-01-01

In this work a Thomson scattering diagnostic technique was applied to obtain time resolved electron temperature and density values during a gas metal arc welding (GMAW) process. The investigated GMAW process was run with aluminum wire (AlMg 4,5 Mn) with 1.2 mm diameter as a wire electrode, argon as a shielding gas and peak currents in the range of 400 A. Time resolved measurements could be achieved by triggering the laser pulse at shifted time positions with respect to the current pulse driving the process. Time evaluation of resulting electron temperatures and densities is used to investigate the state of the plasma in different phases of the current pulse and to determine the influence of the metal vapor and droplets on the plasma properties

Biological Effect of Gas Plasma Treatment on CO2 Gas Foaming/Salt Leaching Fabricated Porous Polycaprolactone Scaffolds in Bone Tissue Engineering

Directory of Open Access Journals (Sweden)

Tae-Yeong Bak

2014-01-01

Full Text Available Porous polycaprolactone (PCL scaffolds were fabricated by using the CO2 gas foaming/salt leaching process and then PCL scaffolds surface was treated by oxygen or nitrogen gas plasma in order to enhance the cell adhesion, spreading, and proliferation. The PCL and NaCl were mixed in the ratios of 3 : 1. The supercritical CO2 gas foaming process was carried out by solubilizing CO2 within samples at 50°C and 8 MPa for 6 hr and depressurization rate was 0.4 MPa/s. The oxygen or nitrogen plasma treated porous PCL scaffolds were prepared at discharge power 100 W and 10 mTorr for 60 s. The mean pore size of porous PCL scaffolds showed 427.89 μm. The gas plasma treated porous PCL scaffolds surface showed hydrophilic property and the enhanced adhesion and proliferation of MC3T3-E1 cells comparing to untreated porous PCL scaffolds. The PCL scaffolds produced from the gas foaming/salt leaching and plasma surface treatment are suitable for potential applications in bone tissue engineering.

Linking Effective Project Management to Business Strategy in Oil and Gas Industry through Decision-making Processes

Science.gov (United States)

Adeleke, Adeyinka

The construction project in the oil and gas industry covers the entire spectrum of hydrocarbon production from the wellhead (upstream) to downstream facilities. In each of these establishments, the activities in a construction project include: consulting, studies, front-end engineering, detail engineering, procurement, program management, construction, installation, commissioning and start-up. Efficient management of each of the activities involved in construction projects is one of the driving forces for the successful completion of the project. Optimizing the crucial factors in project management during each phase of a project in an oil and gas industry can assist managers to maximize the use of available resources and drive the project to successful conclusions. One of these factors is the decision-making process in the construction project. Current research effort investigated the relationship between decision-making processes and business strategy in oil and gas industry using employee surveys. I recruited employees of different races, age group, genders, and years of experience in order understand their influence on the implementation of the decision-making process in oil and gas industry through a quantitative survey. Decision-making was assessed using five decision measures: (a) rational, (b) intuitive, (c) dependent, (d) avoidant, and (e) spontaneous. The findings indicated gender, age, years of work experience and job titles as primary variables with a negative relationship with decision-making approach for employees working in a major oil and gas industry. The study results revealed that the two most likely decision-making methods in oil and gas industry include: making a decision in a logical and systematic way and seek assistance from others when making a decision. Additionally, the two leading management approaches to decision-making in the oil and gas industry include: decision analysis is part of organization culture and management is committed to

New design of process for cold forging to improve multi-stage gas fitting

Directory of Open Access Journals (Sweden)

Han-Sung Huang

2016-04-01

Full Text Available This work develops a process that solves the problem of the formation of cracks inside forged gas fittings in the cold forging process that arises from poor forging process design. DEFORM-3D forming software was utilized, and macroscopic experiments with optical microscopy and scanning electron microscopy were conducted to investigate the processed structures and the distribution therein of metal flow lines, and to find the internal micro-cracks to determine whether the cold forging process is reasonable. Analytical results herein demonstrate that the stress and strain inside the gas fitting can be elucidated using metal forming software. Together with experimental results, they demonstrate that a concentration of stress damages the workpiece in the forming process. Moreover, as metal flow lines become narrower, the workpiece becomes more easily damaged. Consequently, the improved cold forging process that is described in this work should be utilized to reduce the occurrence of fine cracks and defects. Planning for proper die design and production, increasing the quality of products, and reducing the number of defective products promote industrial competitiveness.

Design and analysis of a small-scale natural gas liquefaction process adopting single nitrogen expansion with carbon dioxide pre-cooling

International Nuclear Information System (INIS)

Yuan, Zongming; Cui, Mengmeng; Xie, Ying; Li, Chunlin

2014-01-01

With the growth of energy consumption and environmental protection concerns, it is of enormous economic and environmental values for the development of stranded gas. As a means for exploitation and transportation of stranded gas to market, a novel small-scale liquefaction process adopting single nitrogen expansion with carbon dioxide pre-cooling is put up with in this paper. Taking unit energy consumption as the target function, Aspen HYSYS is employed to simulate and optimize the process to achieve the liquefaction rate of 0.77 with unit energy consumption of 9.90 kW/kmol/h. Furthermore, the adaptability of this process under different pressure, temperature and compositions of feed gas is studied. Based on the optimization results, the exergy losses of main equipment in the process are evaluated and analyzed in details. With compact device, safety operation, simple capability, this liquefaction process proves to be suitable for the development of small gas reserves, satellite distribution fields of gas or coalbed methane fields. - Highlights: •A novel small-scale liquefaction process used in stranded gas is designed. •The adaptability of this process under different pressure, temperature and compositions of feed gas is studied. •The exergy analysis of main equipment in the process is analyzed

Design and analysis of a small-scale natural gas liquefaction process adopting single nitrogen expansion with carbon dioxide pre-cooling

Energy Technology Data Exchange (ETDEWEB)

Yuan, Zongming; Cui, Mengmeng; Xie, Ying; Li, Chunlin

2014-03-01

With the growth of energy consumption and environmental protection concerns, it is of enormous economic and environmental values for the development of stranded gas. As a means for exploitation and transportation of stranded gas to market, a novel small-scale liquefaction process adopting single nitrogen expansion with carbon dioxide pre-cooling is put up with in this paper. Taking unit energy consumption as the target function, Aspen HYSYS is employed to simulate and optimize the process to achieve the liquefaction rate of 0.77 with unit energy consumption of 9.90 kW/kmol/h. Furthermore, the adaptability of this process under different pressure, temperature and compositions of feed gas is studied. Based on the optimization results, the exergy losses of main equipment in the process are evaluated and analyzed in details. With compact device, safety operation, simple capability, this liquefaction process proves to be suitable for the development of small gas reserves, satellite distribution fields of gas or coalbed methane fields. - Highlights: •A novel small-scale liquefaction process used in stranded gas is designed. •The adaptability of this process under different pressure, temperature and compositions of feed gas is studied. •The exergy analysis of main equipment in the process is analyzed.

Industrial natural gas supply options in British Columbia

International Nuclear Information System (INIS)

1994-01-01

Information is provided on the availability and cost of natural gas in British Columbia for use by firms interested in establishing gas-intensive industrial facilities in the province. British Columbia has an abundant supply of natural gas, originating mainly from deposits in the westernmost part of the Western Canadian Sedimentary Basin in the northeast part of the province. Recoverable resources in British Columbia are estimated at 1,000-1,400 billion m 3 . Over 200 producers compete to sell natural gas for both domestic and export markets. Gathering, processing, and transmission of the gas is undertaken mainly by the Westcoast Energy pipeline system, and distribution is undertaken by several distribution utilities. At present, all large industrial gas users buy their firm gas requirements directly from gas producers, often using gas marketers or brokers to assist in purchasing. Regulation of the gas industry is performed by the British Columbia Utilities Commission, which sets rules for energy supply contracts, and by the National Energy Board, which sets tolls for gathering, processing, and transporting gas. Factors affecting gas pricing are discussed, with reference to both the wellhead price and the cost of gathering, processing, and transportation. Firm gas costs for two hypothetical industrial loads in British Columbia are illustrated. Potential intensive uses of natural gas in the province are outlined, including power generation, liquefaction for export, manufacturing, production of direct reduced iron, and as petrochemical feedstocks. 5 figs., 2 tabs

The deregulation of the Italian natural gas industry and diversification processes in the down-stream sector

International Nuclear Information System (INIS)

Fazioli, R.; Quaglino, S.; Di Domenico, M.

2000-01-01

The opening of the italian gas market , due to the privatisation and liberalisation process, has been implemented by the important normative evolution of this sector both at european and national level. The debate following this process in the gas market has focussed, basically, on the up-stream sector leaving aside the important down-stream sector also concerning gas local distribution and sales. In this article it is paid more attention to the down-stream sector considering the firms' evolution from a basic mono utility to multi utility and multi services organisational structure. This potential firms' evolution in the italian gas market will be considered also referring to specific international experience in this market [it

An evaluation of Substitute natural gas production from different coal gasification processes based on modeling

International Nuclear Information System (INIS)

Karellas, S.; Panopoulos, K.D.; Panousis, G.; Rigas, A.; Karl, J.; Kakaras, E.

2012-01-01

Coal and lignite will play a significant role in the future energy production. However, the technical options for the reduction of CO 2 emissions will define the extent of their share in the future energy mix. The production of synthetic or substitute natural gas (SNG) from solid fossil fuels seems to be a very attractive process: coal and lignite can be upgraded into a methane rich gas which can be transported and further used in high efficient power systems coupled with CO 2 sequestration technologies. The aim of this paper is to present a modeling analysis comparison between substitute natural gas production from coal by means of allothermal steam gasification and autothermal oxygen gasification. In order to produce SNG from syngas several unit operations are required such as syngas cooling, cleaning, potential compression and, of course, methanation reactors. Finally the gas which is produced has to be conditioned i.e. removal of unwanted species, such as CO 2 etc. The heat recovered from the overall process is utilized by a steam cycle, producing power. These processes were modeled with the computer software IPSEpro™. An energetic and exergetic analysis of the coal to SNG processes have been realized and compared. -- Highlights: ► The production of SNG from coal is examined. ► The components of the process were simulated for integrated autothermal or allothermal coal gasification to SNG. ► The energetic and exergetic evaluation of the two processes is presented.

REGIONAL VARIATIONS IN THE DENSE GAS HEATING AND COOLING IN M51 FROM HERSCHEL FAR-INFRARED SPECTROSCOPY

Energy Technology Data Exchange (ETDEWEB)

Parkin, T. J.; Wilson, C. D.; Schirm, M. R. P.; Foyle, K. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Baes, M.; De Looze, I. [Sterrenkundig Observatorium, Universiteit Gent, Krijgslaan 281 S9, B-9000 Gent (Belgium); Boquien, M.; Boselli, A. [Laboratoire d' Astrophysique de Marseille-LAM, Université d' Aix-Marseille and CNRS, UMR7326, 38 rue F. Joliot-Curie, F-13388 Marseille Cedex 13 (France); Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Cormier, D. [Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Karczewski, O. Ł. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Lebouteiller, V.; Madden, S. C.; Sauvage, M. [CEA, Laboratoire AIM, Irfu/SAp, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Roussel, H. [Institut d' Astrophysique de Paris, UMR7095 CNRS, Université Pierre and Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France); Spinoglio, L., E-mail: parkintj@mcmaster.ca [Istituto di Astrofisica e Planetologia Spaziali, INAF-IAPS, Via Fosso del Cavaliere 100, I-00133 Roma (Italy)

2013-10-20

We present Herschel PACS and SPIRE spectroscopy of the most important far-infrared cooling lines in M51, [C II](158 μm), [N II](122 and 205 μm), [O I](63 and 145 μm), and [O III](88 μm). We compare the observed flux of these lines with the predicted flux from a photon-dominated region model to determine characteristics of the cold gas such as density, temperature, and the far-ultraviolet (FUV) radiation field, G{sub 0}, resolving details on physical scales of roughly 600 pc. We find an average [C II]/F{sub TIR} of 4 × 10{sup –3}, in agreement with previous studies of other galaxies. A pixel-by-pixel analysis of four distinct regions of M51 shows a radially decreasing trend in both the FUV radiation field, G{sub 0}, and the hydrogen density, n, peaking in the nucleus of the galaxy, and then falling off out to the arm and interarm regions. We see for the first time that the FUV flux and gas density are similar in the differing environments of the arm and interarm regions, suggesting that the inherent physical properties of the molecular clouds in both regions are essentially the same.

Pilot test of pressure maintenance by water injection and gas injection in the M'Bega field

Energy Technology Data Exchange (ETDEWEB)

Hodee, B

1965-02-01

The M'Bega reservoir, Gabon, is one that is both fractured and fissured, and its reservoir rock, improperly referred to as silicified clay, is made up of opal-cement silt. At the time it began production, the major unknown factor in this field was the amount of oil it contained. The factor was finally determined after 18 mo. of production, once data was obtained concerning the advance of aquifiers. Up until that time, applied comparisons of successive data could not differentiate between the activity of aquifers and that of dissolved gas expansion with partial segregation. Consequently, a pilot test was made in which pressure was maintained by water injection. Then, with a double drainage phenomena (the tops by the gas, and the flanks by the aquifer water), production of the field consisted of bringing about a coincidence between the water and gas fronts at the level of the existing wells by means of gas injection.

Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

Science.gov (United States)

Schiro, Fabio; Stoppato, Anna; Benato, Alberto

2017-11-01

The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen). Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

Directory of Open Access Journals (Sweden)

Schiro Fabio

2017-01-01

Full Text Available The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen. Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

THE GREEN BANK TELESCOPE MAPS THE DENSE, STAR-FORMING GAS IN THE NEARBY STARBURST GALAXY M82

International Nuclear Information System (INIS)

Kepley, Amanda A.; Frayer, David; Leroy, Adam K.; Usero, Antonio; Marvil, Josh; Walter, Fabian

2014-01-01

Observations of the Milky Way and nearby galaxies show that dense molecular gas correlates with recent star formation, suggesting that the formation of this gas phase may help regulate star formation. A key test of this idea requires wide-area, high-resolution maps of dense molecular gas in galaxies to explore how local physical conditions drive dense gas formation, but these observations have been limited because of the faintness of dense gas tracers like HCN and HCO + . Here we demonstrate the power of the Robert C. Byrd Green Bank Telescope (GBT)—the largest single-dish millimeter radio telescope—for mapping dense gas in galaxies by presenting the most sensitive maps yet of HCN and HCO + in the starburst galaxy M82. The HCN and HCO + in the disk of this galaxy correlates with both recent star formation and more diffuse molecular gas and shows kinematics consistent with a rotating torus. The HCO + emission extending to the north and south of the disk is coincident with the outflow previously identified in CO and traces the eastern edge of the hot outflowing gas. The central starburst region has a higher ratio of star formation to dense gas than the outer regions, pointing to the starburst as a key driver of this relationship. These results establish that the GBT can efficiently map the dense molecular gas at 90 GHz in nearby galaxies, a capability that will increase further with the 16 element feed array under construction

Process for measuring the helium residual gas pressure and circuit for carrying out the process

International Nuclear Information System (INIS)

Schmidt, C.; Cesnak, L.

1983-01-01

In cryotechnic devices, the quality of the thermal insulation can be monitored by checking the pressure of the residual gas. A process is proposed in which a thin super-conducting wire or a superconducting layer acting as vacuum sensor has a heating pulse reaching the critical current applied to it, which produces a local normal conduction zone. The vacuum sensor has a measuring current of constant amount applied to it, which causes a voltage drop on its resistance during the time in which the normal conduction zone exists, the cooling time. The pressure of the residual gas is a function of the integral of the voltage drop and is measured by integrating the voltage during the cooling time. (orig./HP) [de

A Zirconium Dioxide Ammonia Microsensor Integrated with a Readout Circuit Manufactured Using the 0.18 μm CMOS Process

Directory of Open Access Journals (Sweden)

Ming-Zhi Yang

2013-03-01

Full Text Available The study presents an ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS process. The integrated sensor chip consists of a heater, an ammonia sensor and a readout circuit. The ammonia sensor is constructed by a sensitive film and the interdigitated electrodes. The sensitive film is zirconium dioxide that is coated on the interdigitated electrodes. The heater is used to provide a working temperature to the sensitive film. A post-process is employed to remove the sacrificial layer and to coat zirconium dioxide on the sensor. When the sensitive film adsorbs or desorbs ammonia gas, the sensor produces a change in resistance. The readout circuit converts the resistance variation of the sensor into the output voltage. The experiments show that the integrated ammonia sensor has a sensitivity of 4.1 mV/ppm.

Numerical Simulation of the Depressurization Process of a Natural Gas Hydrate Reservoir: An Attempt at Optimization of Field Operational Factors with Multiple Wells in a Real 3D Geological Model

Directory of Open Access Journals (Sweden)

Zhixue Sun

2016-09-01

Full Text Available Natural gas hydrates, crystalline solids whose gas molecules are so compressed that they are denser than a typical fluid hydrocarbon, have extensive applications in the areas of climate change and the energy crisis. The hydrate deposit located in the Shenhu Area on the continental slope of the South China Sea is regarded as the most promising target for gas hydrate exploration in China. Samples taken at drilling site SH2 have indicated a high abundance of methane hydrate reserves in clay sediments. In the last few decades, with its relatively low energy cost, the depressurization gas recovery method has been generally regarded as technically feasible and the most promising one. For the purpose of a better acquaintance with the feasible field operational factors and processes which control the production behavior of a real 3D geological CH4-hydrate deposit, it is urgent to figure out the effects of the parameters such as well type, well spacing, bottom hole pressure, and perforation intervals on methane recovery. One years’ numerical simulation results show that under the condition of 3000 kPa constant bottom hole pressure, 1000 m well spacing, perforation in higher intervals and with one horizontal well, the daily peak gas rate can reach 4325.02 m3 and the cumulative gas volume is 1.291 × 106 m3. What’s more, some new knowledge and its explanation of the curve tendency and evolution for the production process are provided. Technically, one factor at a time design (OFAT and an orthogonal design were used in the simulation to investigate which factors dominate the productivity ability and which is the most sensitive one. The results indicated that the order of effects of the factors on gas yield was perforation interval > bottom hole pressure > well spacing.

FIELD DEMONSTRATION OF A MEMBRANE PROCESS TO RECOVER HEAVY HYDROCARBONS AND TO REMOVE WATER FROM NATURAL GAS

Energy Technology Data Exchange (ETDEWEB)

R. Baker; T. Hofmann; J. Kaschemekat; K.A. Lokhandwala; Membrane Group; Module Group; Systems Group

2001-01-11

The objective of this project is to design, construct and field demonstrate a 3-MMscfd membrane system to recover natural gas liquids (NGL) and remove water from raw natural gas. An extended field test to demonstrate system performance under real-world conditions is required to convince industry users of the efficiency and reliability of the process. The system will be designed and fabricated by Membrane Technology and Research, Inc. (MTR) and then installed and operated at British Petroleum (BP)-Amoco's Pascagoula, MS plant. The Gas Research Institute will partially support the field demonstration and BP-Amoco will help install the unit and provide onsite operators and utilities. The gas processed by the membrane system will meet pipeline specifications for dewpoint and Btu value and can be delivered without further treatment to the pipeline. Based on data from prior membrane module tests, the process is likely to be significantly less expensive than glycol dehydration followed by propane refrigeration, the principal competitive technology. At the end of this demonstration project the process will be ready for commercialization. The route to commercialization will be developed during this project and may involve collaboration with other companies already servicing the natural gas processing industry.

Some interesting developments relating to gas dynamics in the application of the UCOR process for isotope separation

International Nuclear Information System (INIS)

Alant, T.G.; Schumann, W.A.

1980-01-01

The separating element employed in the UCOR process for uranium enrichment has a very small cut, i.e. is highly asymmetrical with respect to the UF 6 flow in the enriched and depleted streams. For the commercial exploitation of the process, the so-called helikon technique of cascading was developed. The process is dependent on the transmission of parallel streams of diffferent isotopic composition through an axial compressor without significant mixing between them. A light gas (H 2 ), which is present in large molar excess, increases the flow velocity of the process gas (UF 6 ) and hence adds to improved separation performance. The separating element not only separates isotopes but also causes appreciable separation between the process gas and the light carrier gas. The paper consists of a brief description of the helikon cascading technique followed by a comprehensive assessment of the various aspects of gas mixing in an axial compressor. Phenomena of mole mass and pressure transients which occur in the module during run-up of the compressors are also discussed. The operating characteristics of axial compressors and of the separating element produce a driving force which tends to cause mole mass and associated pressure gradients to occur circumferentially in a helikon module under static conditions. The paper includes 5 references and 10 figures

Reducing capital and operating costs in gas processing, liquefaction, and storage

Energy Technology Data Exchange (ETDEWEB)

Krusen, III, L C [Phillips Petroleum Co., Bartlesville, OK (United States). Research Div.

1997-06-01

The LNG industry is unanimous that capital costs must be reduced throughout the chain, and especially at the liquefaction facility including associated gas processing and LNG storage. The Ken ai LNG plant provides an example of how both reduced capital and operating costs were attained. This paper will cover cost production strategies that can be applied to liquefaction processes in general, and will than focus on their realization in the Phillips Optimized Cascade LNG process. The paper concludes that reduced LNG plant costs are attainable. (Author).

Reducing capital and operating costs in gas processing, liquefaction, and storage

International Nuclear Information System (INIS)

Krusen, L.C. III

1997-01-01

The LNG industry is unanimous that capital costs must be reduced throughout the chain, and especially at the liquefaction facility including associated gas processing and LNG storage. The Ken ai LNG plant provides an example of how both reduced capital and operating costs were attained. This paper will cover cost production strategies that can be applied to liquefaction processes in general, and will than focus on their realization in the Phillips Optimized Cascade LNG process. The paper concludes that reduced LNG plant costs are attainable. (Author)

Development of biological coal gasification (MicGAS Process)

Energy Technology Data Exchange (ETDEWEB)

Walia, D.S.; Srivastava, K.C.

1994-10-01

The overall goal of the project is to develop an advanced, clean coal biogasification (MicGAS) Process. The objectives of the research during FY 1993--94 were to: (1) enhance kinetics of methane production (biogasification, biomethanation) from Texas lignite (TxL) by the Mic-1 consortium isolated and developed at ARCTECH, (2) increase coal solids loading, (3) optimize medium composition, and (4) reduce retention time. A closer analysis of the results described here indicate that biomethanation of TxL at >5% solids loading is feasible through appropriate development of nutrient medium and further adaptation of the microorganisms involved in this process. Further understanding of the inhibitory factors and some biochemical manipulations to overcome those inhibitions will hasten the process considerably. Results are discussed on the following: products of biomethanation and enhance of methane production including: bacterial adaptation; effect of nutrient amendment substitutes; effects of solids loading; effect of initial pH of the culture medium; effect of hydrogen donors and carbon balance.

FIELD DEMONSTRATION OF A MEMBRANE PROCESS TO RECOVER HEAVY HYDROCARBONS AND TO REMOVE WATER FROM NATURAL GAS; F

International Nuclear Information System (INIS)

Unknown

2002-01-01

The objective of this project is to design, construct and field demonstrate a 3-MMscfd membrane system to recover natural gas liquids (NGL) and remove water from raw natural gas. The gas processed by the membrane system will meet pipeline specifications for dew point and Btu value, and the process is likely to be significantly less expensive than glycol dehydration followed by propane refrigeration, the principal competitive technology. The BP-Amoco gas processing plant in Pascagoula, MS was finalized as the location for the field demonstration. Detailed drawings of the MTR membrane skid (already constructed) were submitted to the plant in February, 2000. However, problems in reaching an agreement on the specifications of the system compressor delayed the project significantly, so MTR requested (and was subsequently granted) a no-cost extension to the project. Following resolution of the compressor issues, the goal is to order the compressor during the first quarter of 2002, and to start field tests in mid-2002. Information from potential users of the membrane separation process in the natural gas processing industry suggests that applications such as fuel gas conditioning and wellhead gas processing are the most promising initial targets. Therefore, most of our commercialization effort is focused on promoting these applications. Requests for stream evaluations and for design and price quotations have been received through MTR's web site, from direct contact with potential users, and through announcements in industry publications. To date, about 90 commercial quotes have been supplied, and orders totaling about$1.13 million for equipment or rental of membrane units have been received

Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery

Energy Technology Data Exchange (ETDEWEB)

Dandina N. Rao; Subhash C. Ayirala; Madhav M. Kulkarni; Wagirin Ruiz Paidin; Thaer N. N. Mahmoud; Daryl S. Sequeira; Amit P. Sharma

2006-09-30

This is the final report describing the evolution of the project ''Development and Optimization of Gas-Assisted Gravity Drainage (GAGD) Process for Improved Light Oil Recovery'' from its conceptual stage in 2002 to the field implementation of the developed technology in 2006. This comprehensive report includes all the experimental research, models developments, analyses of results, salient conclusions and the technology transfer efforts. As planned in the original proposal, the project has been conducted in three separate and concurrent tasks: Task 1 involved a physical model study of the new GAGD process, Task 2 was aimed at further developing the vanishing interfacial tension (VIT) technique for gas-oil miscibility determination, and Task 3 was directed at determining multiphase gas-oil drainage and displacement characteristics in reservoir rocks at realistic pressures and temperatures. The project started with the task of recruiting well-qualified graduate research assistants. After collecting and reviewing the literature on different aspects of the project such gas injection EOR, gravity drainage, miscibility characterization, and gas-oil displacement characteristics in porous media, research plans were developed for the experimental work to be conducted under each of the three tasks. Based on the literature review and dimensional analysis, preliminary criteria were developed for the design of the partially-scaled physical model. Additionally, the need for a separate transparent model for visual observation and verification of the displacement and drainage behavior under gas-assisted gravity drainage was identified. Various materials and methods (ceramic porous material, Stucco, Portland cement, sintered glass beads) were attempted in order to fabricate a satisfactory visual model. In addition to proving the effectiveness of the GAGD process (through measured oil recoveries in the range of 65 to 87% IOIP), the visual models demonstrated

Preparation of basil seed mucilage aerogels loaded with paclitaxel nanoparticles by the combination of phase inversion technique and gas antisolvent process

Directory of Open Access Journals (Sweden)

Seyyed Ghoreishi

2017-09-01

Full Text Available Objective(S: In this work, paclitaxel (PX, a promising anticancer drug, was loaded in the basil seed mucilage (BSM aerogels by implementation of supercritical carbon dioxide (SC-CO2 technology. Then, the effects of operating conditions were studied on the PX mean particle size (MPS, particle size distribution (PSD and drug loading efficiency (DLE. Methods: The employed SC-CO2 process in this research is the combination of phase inversion technique and gas antisolvent (GAS process. The effect of DMSO/water ratio (4 and 6 (v/v, pressure (10-20 MPa, CO2 addition rate (1–3 mL/min and ethanol concentration (5-10% were studied on MPS, PSD and DLE. Scanning electron microscopy (SEM and Zetasizer were used for particle analysis. DLE was investigated by utilizing the high-performance liquid chromatography (HPLC. Results: Nanoparticles of paclitaxel (MPS of 82–131 nm depending on process variables with narrow PSD were successfully loaded in BSM aerogel with DLE of 28–52%. Experimental results indicated that higher DMSO/water ratio, ethanol concentration, pressure and CO2 addition rate reduced MPS and DLE. Conclusions: A modified semi batch SC-CO2 process based on the combination of gas antisolvent process and phase inversion methods using DMSO as co-solvent and ethanol as a secondary solvent was developed for the loading of an anticancer drug, PX, in ocimum basilicum mucilage aerogel. The experimental results determined that the mean particle size, particle size distribution, and drug loading efficiency be controlled with operating conditions.

Geological evaluation on productibility of coal seam gas; Coal seam gas no chishitsugakuteki shigen hyoka ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Fujii, K [University of Shizuoka, Shizuoka (Japan). Faculty of Education

1996-09-01

Coal seam gas is also called coal bed methane gas, indicating the gas existing in coal beds. The gas is distinguished from the oil field based gas, and also called non-conventional type gas. Its confirmed reserve is estimated to be 24 trillion m {sup 3}, with the trend of its development seen worldwide as utilization of unused resource. For the necessity of cultivating relevant technologies in Japan, this paper considers processes of production, movement, stockpiling, and accumulation of the gas. Its productibility is controlled by thickness of a coal bed, degree of coalification, gas content, permeability, groundwater flow, and deposition structure. Gas generation potential is evaluated by existing conditions of coal and degree of coalification, and methane production by biological origin and thermal origin. Economically viable methane gas is mainly of the latter origin. Evaluating gas reserve potential requires identification of the whole mechanism of adsorption, accumulation and movement of methane gas. The gas is expected of effect on environmental aspects in addition to availability as utilization of unused energy. 5 figs.

Biological (flue) gas desulfurization

Energy Technology Data Exchange (ETDEWEB)

Buisman, C.J.N.; Dijkman, H. [PAQUES, Balk (Netherlands); Prins, W.L.; Verbraak, P. [Biostar CV, Balk (Netherlands); Den Hartog, A.J. [Hoogovens Groep BV, IJmuiden (Netherlands)

1995-12-31

Biotechnological research has been carried out to find new micro-organisms and processes to make useful products, and to reveal new ways and biotechnological mechanisms to produce elemental sulfur in waste water treatment. Biotechnological development work has been carried out and the first commercial installation (on 300 m{sup 3}/hr scale) to produce sulfur from polluted waste water was started up in 1992. The importance of this recent research and development in the area of waste water treatment was recognized. In an intensive cooperation between Hoogovens Technical Services and PACQUES the concept for a totally new Biological Flue Gas Desulfurization process (BIO-FGD), producing sulfur as by-product, was invented. It consists of the combination of a sodium scrubber with two biological reactors resulting in a very attractive new concept for a gas cleaning process. A description of the process is given and the pilot plant results are outlined. 4 figs., 5 refs.

40 CFR 63.1015 - Closed vent systems and control devices; or emissions routed to a fuel gas system or process.

Science.gov (United States)

2010-07-01

... devices; or emissions routed to a fuel gas system or process. 63.1015 Section 63.1015 Protection of... fuel gas system or process. (a) Compliance schedule. The owner or operator shall comply with this... emissions from equipment leaks to a fuel gas system or process shall comply with the provisions of subpart...

HM{sup +}–RG complexes (M = group 2 metal; RG = rare gas): Physical vs. chemical interactions

Energy Technology Data Exchange (ETDEWEB)

Harris, Joe P.; Dodson, Hannah; Wright, Timothy G., E-mail: Tim.Wright@nottingham.ac.uk [School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom); Breckenridge, W. H. [Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 (United States)

2015-04-21

Previous work on the HM{sup +}–He complexes (M = Be–Ra) has been extended to the cases of the heavier rare gas atoms, HM{sup +}–RG (RG = Ne–Rn). Optimized geometries and harmonic vibrational frequencies have been calculated using MP2 theory and quadruple-ζ quality basis sets. Dissociation energies for the loss of the rare gas atom have been calculated at these optimized geometries using coupled cluster with single and double excitations and perturbative triples, CCSD(T)theory, extrapolating interaction energies to the basis set limit. Comparisons are made between the present data and the previously obtained helium results, as well as to those of the bare HM{sup +} molecules; furthermore, comparisons are made to the related M{sup +}–RG and M{sup 2+}–RG complexes. Partial atomic charge analyses have also been undertaken, and these used to test a simple charge-induced dipole model. Molecular orbital diagrams are presented together with contour plots of the natural orbitals from the quadratic configuration with single and double excitations (QCISD) density. The conclusion is that the majority of these complexes are physically bound, with very little sharing of electron density; however, for M = Be, and to a lesser extent M = Mg, some evidence for chemical effects is seen in HM{sup +}–RG complexes involving RG atoms with the higher atomic numbers.

Modeling of gas flow and deposition profile in HWCVD processes

Energy Technology Data Exchange (ETDEWEB)

Pflug, Andreas; Höfer, Markus; Harig, Tino; Armgardt, Markus; Britze, Chris; Siemers, Michael; Melzig, Thomas; Schäfer, Lothar

2015-11-30

Hot wire chemical vapor deposition (HWCVD) is a powerful technology for deposition of high quality films on large area, where drawbacks of plasma based technology such as defect generation by ion bombardment and high equipment costs are omitted. While processes for diamond coatings using H{sub 2} and CH{sub 4} as precursor have been investigated in detail since 1990 and have been transferred to industry, research also focuses on silicon based coatings with H{sub 2}, SiH{sub 4} and NH{sub 3} as process gases. HWCVD of silicon based coatings is a promising alternative for state-of-the-art radiofrequency-plasma enhanced chemical vapor deposition reactors. The film formation in HWCVD results from an interaction of several concurrent chemical reactions such as gas phase chemistry, film deposition, abstraction of surplus hydrogen bonds and etching by atomic hydrogen. Since there is no easy relation between process parameters and resulting deposition profiles, substantial experimental effort is required to optimize the process for a given film specification and the desired film uniformity. In order to obtain a deeper understanding of the underlying mechanisms and to enable an efficient way of process optimization, simulation methods come into play. While diamond deposition occurs at pressures in the range of several kPa HWCVD deposition of Si based coatings operates at pressures in the 0.1–30 Pa range. In this pressure regime, particle based simulation methods focused on solving the Boltzmann equation are computationally feasible. In comparison to computational fluid dynamics this yields improved accuracy even near small gaps or orifices, where characteristic geometric dimensions approach the order of the mean free path of gas molecules. At Fraunhofer IST, a parallel implementation of the Direct Simulation Monte Carlo (DSMC) method extended by a reactive wall chemistry model is developed. To demonstrate the feasibility of three-dimensional simulation of HWCVD processes

An experimental approach aiming the production of a gas mixture composed of hydrogen and methane from biomass as natural gas substitute in industrial applications.

Science.gov (United States)

Kraussler, Michael; Schindler, Philipp; Hofbauer, Hermann

2017-08-01

This work presents an experimental approach aiming the production of a gas mixture composed of H 2 and CH 4 , which should serve as natural gas substitute in industrial applications. Therefore, a lab-scale process chain employing a water gas shift unit, scrubbing units, and a pressure swing adsorption unit was operated with tar-rich product gas extracted from a commercial dual fluidized bed biomass steam gasification plant. A gas mixture with a volumetric fraction of about 80% H 2 and 19% CH 4 and with minor fractions of CO and CO 2 was produced by employing carbon molecular sieve as adsorbent. Moreover, the produced gas mixture had a lower heating value of about 15.5MJ·m -3 and a lower Wobbe index of about 43.4MJ·m -3 , which is similar to the typical Wobbe index of natural gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Noble gas absorption process

International Nuclear Information System (INIS)

Thomas, J.W.

1975-01-01

A method of removing a noble gas from air comprising the use of activated carbon filters in stages in which absorption and desorption steps in succession are conducted in order to increase the capacity of the filters is described. (U.S.)

Gas generation in deep radioactive waste repositories: a review of processes, controls and models

International Nuclear Information System (INIS)

Jones, M.A.

1990-10-01

Gas generation within radioactive waste repositories may produce two general problems: 1) breaching of engineered and natural barriers due to high gas pressures; 2) enhanced radiological risk due to reduced groundwater travel times and/or greater aqueous or gaseous activities reaching the biosphere. As a result of these concerns, HMIP must be aware of the current status of relevant research, together with any associated deficiencies. This report addresses the current status of published research on near-field gas generation from worldwide sources and documents the important gas generating processes, the factors controlling them and models available to simulate them. In the absence of suitable models, outline technical specifications for corrosion and microbial degradation gas generation models are defined and the deficiencies in the current understanding of gas generation are highlighted; a conceptual research programme to correct these deficiencies is presented. (author)

Gas discharge processes in the standard and metal channel PMTs

International Nuclear Information System (INIS)

Morozov, V.A.; Morozova, N.V.

2015-01-01

The effect of the potential difference at the focusing chamber electrodes of the XP2020, FEU-85, FEU-87, and FEU-93 photomultipliers on the intensity of afterpulses resulting from gas discharge processes is investigated. The time distribution of the afterpulses in the metal channel PMTs - H6780 and R7600U-200 - is studied as well

High-resolution (noble) gas time series for aquatic research

Science.gov (United States)

Popp, A. L.; Brennwald, M. S.; Weber, U.; Kipfer, R.

2017-12-01

We developed a portable mass spectrometer (miniRUEDI) for on-site quantification of gas concentrations (He, Ar, Kr, N2, O2, CO2, CH4, etc.) in terrestrial gases [1,2]. Using the gas-equilibrium membrane-inlet technique (GE-MIMS), the miniRUEDI for the first time also allows accurate on-site and long-term dissolved-gas analysis in water bodies. The miniRUEDI is designed for operation in the field and at remote locations, using battery power and ambient air as a calibration gas. In contrast to conventional sampling and subsequent lab analysis, the miniRUEDI provides real-time and continuous time series of gas concentrations with a time resolution of a few seconds.Such high-resolution time series and immediate data availability open up new opportunities for research in highly dynamic and heterogeneous environmental systems. In addition the combined analysis of inert and reactive gas species provides direct information on the linkages of physical and biogoechemical processes, such as the air/water gas exchange, excess air formation, O2 turnover, or N2 production by denitrification [1,3,4].We present the miniRUEDI instrument and discuss its use for environmental research based on recent applications of tracking gas dynamics related to rapid and short-term processes in aquatic systems. [1] Brennwald, M.S., Schmidt, M., Oser, J., and Kipfer, R. (2016). Environmental Science and Technology, 50(24):13455-13463, doi: 10.1021/acs.est.6b03669[2] Gasometrix GmbH, gasometrix.com[3] Mächler, L., Peter, S., Brennwald, M.S., and Kipfer, R. (2013). Excess air formation as a mechanism for delivering oxygen to groundwater. Water Resources Research, doi:10.1002/wrcr.20547[4] Mächler, L., Brennwald, M.S., and Kipfer, R. (2013). Argon Concentration Time-Series As a Tool to Study Gas Dynamics in the Hyporheic Zone. Environmental Science and Technology, doi: 10.1021/es305309b

Natural gas participation on brazilian demand supply of liquefied petroleum gas

International Nuclear Information System (INIS)

Freitas Rachid, L.B. de

1991-01-01

Natural Gas Liquids Production, Liquefied Petroleum Gas (LPG) among them, has undergone a continuous growth and technological development until the first half of the eighties. This paper presents the natural gas processing activity development in Brazil, in the last 20 years, and the increasing share of LPG produced from natural gas in the supply of LPG domestic market. Possibilities of achieving greater shares are discussed, based on economics of natural gas processing projects. Worldwide gas processing installed capacity and LPG pricing tendencies, and their influence in the construction of new Natural Gas Processing Units in Brazil, are also discussed. (author)

GAS SURFACE DENSITY, STAR FORMATION RATE SURFACE DENSITY, AND THE MAXIMUM MASS OF YOUNG STAR CLUSTERS IN A DISK GALAXY. II. THE GRAND-DESIGN GALAXY M51

International Nuclear Information System (INIS)

González-Lópezlira, Rosa A.; Pflamm-Altenburg, Jan; Kroupa, Pavel

2013-01-01

We analyze the relationship between maximum cluster mass and surface densities of total gas (Σ gas ), molecular gas (Σ H 2 ), neutral gas (Σ H I ), and star formation rate (Σ SFR ) in the grand-design galaxy M51, using published gas data and a catalog of masses, ages, and reddenings of more than 1800 star clusters in its disk, of which 223 are above the cluster mass distribution function completeness limit. By comparing the two-dimensional distribution of cluster masses and gas surface densities, we find for clusters older than 25 Myr that M 3rd ∝Σ H I 0.4±0.2 , whereM 3rd is the median of the five most massive clusters. There is no correlation withΣ gas ,Σ H2 , orΣ SFR . For clusters younger than 10 Myr, M 3rd ∝Σ H I 0.6±0.1 and M 3rd ∝Σ gas 0.5±0.2 ; there is no correlation with either Σ H 2 orΣ SFR . The results could hardly be more different from those found for clusters younger than 25 Myr in M33. For the flocculent galaxy M33, there is no correlation between maximum cluster mass and neutral gas, but we have determined M 3rd ∝Σ gas 3.8±0.3 , M 3rd ∝Σ H 2 1.2±0.1 , and M 3rd ∝Σ SFR 0.9±0.1 . For the older sample in M51, the lack of tight correlations is probably due to the combination of strong azimuthal variations in the surface densities of gas and star formation rate, and the cluster ages. These two facts mean that neither the azimuthal average of the surface densities at a given radius nor the surface densities at the present-day location of a stellar cluster represent the true surface densities at the place and time of cluster formation. In the case of the younger sample, even if the clusters have not yet traveled too far from their birth sites, the poor resolution of the radio data compared to the physical sizes of the clusters results in measuredΣ that are likely quite diluted compared to the actual densities relevant for the formation of the clusters.

Coke oven gas to methanol process integrated with CO_2 recycle for high energy efficiency, economic benefits and low emissions

International Nuclear Information System (INIS)

Gong, Min-hui; Yi, Qun; Huang, Yi; Wu, Guo-sheng; Hao, Yan-hong; Feng, Jie; Li, Wen-ying

2017-01-01

Highlights: • CO_2 recycle assistance with COG to CH_3OH with dry reforming is proposed. • New process with dry reforming improves H_2 utilization and energy saving. • Process with H_2 separation (CWHS) is more preferable to CH_3OH output. • CWHS shows an excellent performance in energy, economy and CO_2 emission reduction. - Abstract: A process of CO_2 recycle to supply carbon for assisting with coke oven gas to methanol process is proposed to realize clean and efficient coke oven gas utilization. Two CO_2 recycle schemes with respect to coke oven gas, namely with and without H_2 separation before reforming, are developed. It is revealed that the process with H_2 separation is more beneficial to element and energy efficiency improvement, and it also presents a better techno-economic performance in comparison with the conventional coke oven gas to methanol process. The exergy efficiency, direct CO_2 emission, and internal rate of return of the process with H_2 separation are 73.9%, 0.69 t/t-methanol, and 35.1%, respectively. This excellent performance implies that reforming technology selection, H_2 utilization efficiency, and CO_2 recycle ways have important influences on the performance of the coke oven gas to methanol process. The findings of this study represent significant progress for future improvements of the coke oven gas to methanol process, especially CO_2 conversion integrated with coke oven gas utilization in the coking industry.

Gas Hydrate Storage of Natural Gas

Energy Technology Data Exchange (ETDEWEB)

Rudy Rogers; John Etheridge

2006-03-31

Environmental and economic benefits could accrue from a safe, above-ground, natural-gas storage process allowing electric power plants to utilize natural gas for peak load demands; numerous other applications of a gas storage process exist. A laboratory study conducted in 1999 to determine the feasibility of a gas-hydrates storage process looked promising. The subsequent scale-up of the process was designed to preserve important features of the laboratory apparatus: (1) symmetry of hydrate accumulation, (2) favorable surface area to volume ratio, (3) heat exchanger surfaces serving as hydrate adsorption surfaces, (4) refrigeration system to remove heat liberated from bulk hydrate formation, (5) rapid hydrate formation in a non-stirred system, (6) hydrate self-packing, and (7) heat-exchanger/adsorption plates serving dual purposes to add or extract energy for hydrate formation or decomposition. The hydrate formation/storage/decomposition Proof-of-Concept (POC) pressure vessel and supporting equipment were designed, constructed, and tested. This final report details the design of the scaled POC gas-hydrate storage process, some comments on its fabrication and installation, checkout of the equipment, procedures for conducting the experimental tests, and the test results. The design, construction, and installation of the equipment were on budget target, as was the tests that were subsequently conducted. The budget proposed was met. The primary goal of storing 5000-scf of natural gas in the gas hydrates was exceeded in the final test, as 5289-scf of gas storage was achieved in 54.33 hours. After this 54.33-hour period, as pressure in the formation vessel declined, additional gas went into the hydrates until equilibrium pressure/temperature was reached, so that ultimately more than the 5289-scf storage was achieved. The time required to store the 5000-scf (48.1 hours of operating time) was longer than designed. The lower gas hydrate formation rate is attributed to a

Evaluation of energy efficiency efforts of oil and gas offshore processing

DEFF Research Database (Denmark)

Nguyen, Tuong-Van; Voldsund, Mari; Breuhaus, Peter

2015-01-01

the energy performance of these facilities, by decreasing the power and heating requirements and designing more efficient processes. Several technologies that have been proposed are to (i) promote energy integration within the oil and gas processing plant, (ii) add an additional pressure extraction level......, (iii) implement multiphase expanders, and (iv) install a waste heat recovery system. The present work builds on two case studies located in the North and Norwegian Seas, which differ by the type of oil processed, operating conditions and strategies. The findings suggest that no generic improvement can...

Evaluation of off-gas characteristics in vitrification process of ion-exchange resin

International Nuclear Information System (INIS)

Park, S. C.; Kim, H. S.; Yang, K. H.; Yun, C. H.; Hwang, T. W.; Shin, S. W.

2001-01-01

The properties of off-gas generated from vitrification process of ion-exchange resin were characterized. Theoretical composition and flow rate of the off-gas were calculated based on chemical composition of resin and it's burning condition inside CCM. The calculated off-gas flow rate was 67.9 Nm 3 /h at the burning rate of 40 kg/h. And the composition of off-gas was evaluated as CO 2 (41.4%), Steam (40.0%), O 2 (13.3%), NO (3.6%), and SO 2 (1.6%) in order. Then, actual flow rate and composition of off-gas were measured during pilot-scale demonstration tests and the results were compared with theoretical values. The actual flow rate of off-gas was about 1.6 times higher than theoretical one. The difference between theoretical and actual flow rates was caused by the in-leakage of air to the system, and the in-leakage rate was evaluated as 36.3 Nm 3 /h. Because of continuous change in the combustion parameters inside CCM, during demonstration tests, the concentration of toxic gases showed wide fluctuation. However, the concentration of CO, a barometer of incompleteness of combustion inside CCM, was stabilized soon. The result showed quasi-equilibrium state was achieved two hours after feeding of resin. (author)

Process for the removal of sulfur oxides and nitrogen oxides from flue gas

International Nuclear Information System (INIS)

Elshout, R.V.

1992-01-01

This patent describes a continuous process for removing sulfur oxide and nitrogen oxide contaminants from the flue gas generated by industrial power plants and boiler systems burning sulfur containing fossil fuels and for converting these contaminants, respectively, into recovered elemental liquid sulfur and nitrogen ammonia and mixtures thereof. It comprises removing at least a portion of the flue gas generated by a power plant or boiler system upstream of the stack thereof; passing the cooled and scrubbed flue gas through an adsorption system; combining a first portion of the reducing gas stream leaving the adsorbers of the adsorption system during regeneration thereof and containing sulfur oxide and nitrogen oxide contaminants with a hydrogen sulfide rich gas stream at a temperature of about 400 degrees F to about 600 degrees F and passing the combined gas streams through a Claus reactor-condenser system over a catalyst in the reactor section thereof which is suitable for promoting the equilibrium reaction between the hydrogen sulfide and the sulfur dioxide of the combined streams to form elemental sulfur

Investigation of gas-phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping

International Nuclear Information System (INIS)

Bundy, R.D.; Munday, E.B.

1991-01-01

Construction of the gaseous diffusion plants (GDPs) was begun during World War 2 to produce enriched uranium for defense purposes. These plants, which utilized UF 6 gas, were used primarily for this purpose through 1964. From 1959 through 1968, production shifted primarily to uranium enrichment to supply the nuclear power industry. Additional UF 6 -handling facilities were built in feed and fuel-processing plants associated with the uranium enrichment process. Two of the five process buildings at Oak ridge were shut down in 1964. Uranium enrichment activities at Oak Ridge were discontinued altogether in 1985. In 1987, the Department of Energy (DOE) decided to proceed with a permanent shutdown of the Oak Ridge Gaseous Diffusion Plant (ORGDP). DOE intends to begin decommissioning and decontamination (D ampersand D) of ORGDP early in the next century. The remaining two GDPs are expected to be shut down during the next 10 to 40 years and will also require D ampersand D, as will the other UF 6 -handling facilities. This paper presents an investigation of gas- phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping using powerful fluorinating reagents that convert nonvolatile uranium compounds to volatile UF 6 . These reagents include ClF 3 , F 2 , and other compounds. The scope of D ampersand D at the GDPs, previous work of gas-phase decontamination, four concepts for using gas-phase decontamination, plans for further study of gas-phase decontamination, and the current status of this work are discussed. 13 refs., 15 figs

A natural adsorbent for natural gas industry; Um adsorvente nacional para a industria do gas natural

Energy Technology Data Exchange (ETDEWEB)

Cachina, G.H.A.B.; Silveira, V.R.; Melo, D.M.A. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Balthar, A.R.; Oliveira, V.M.; Bayer, M.M. [CTGAS - Centro de Tecnologias do Gas, Natal, RN (Brazil); Barbosa, C.M.M. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

2004-07-01

One the natural pollutants in the natural gas considered critical in reference to the corrosion is the H{sub 2}S. Its presence depends on the origin, as well as the own process used in the gas treatment, it can bring problems to the pipes and the final applications of natural gas (NG). The National Petroleum Agency (ANP) in its entrance number 104/02, establishes that the quantity of H{sub 2}S in NG, of national or imported origin, commercialized at the country can only be at the most 10 - 15 mg/m{sup 3}. In the Natural Gas Processing Unit (UPGN) different methods are used for the removal of H{sub 2}S, the absorption process (e.g. with aminas, Sulfinol{sup R} process) or for adsorption in tower filled with activated coal, zeolites and Sulfatreat{sup R}. In this work, the adsorbent material used is the mineral clay Paligorsquita. That class of clay minerals characterized by pores and a crystalline structure containing Tetrahedral layers linked by chains of longitudinal secondary lines. The typical unitary cell is formed basically by moisturized oxides of aluminum, Sicilian and magnesium of (Mg, Al)5SiO2O(OH)2(H20)4.4H20, with Mg specially located in octahedral sites. (author)

Alloy Effects on the Gas Nitriding Process

Science.gov (United States)

Yang, M.; Sisson, R. D.

2014-12-01

Alloy elements, such as Al, Cr, V, and Mo, have been used to improve the nitriding performance of steels. In the present work, plain carbon steel AISI 1045 and alloy steel AISI 4140 were selected to compare the nitriding effects of the alloying elements in AISI 4140. Fundamental analysis is carried out by using the "Lehrer-like" diagrams (alloy specific Lehrer diagram and nitriding potential versus nitrogen concentration diagram) and the compound layer growth model to simulate the gas nitriding process. With this method, the fundamental understanding for the alloy effect based on the thermodynamics and kinetics becomes possible. This new method paves the way for the development of new alloy for nitriding.

THE GREEN BANK TELESCOPE MAPS THE DENSE, STAR-FORMING GAS IN THE NEARBY STARBURST GALAXY M82

Energy Technology Data Exchange (ETDEWEB)

Kepley, Amanda A.; Frayer, David [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944-0002 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Usero, Antonio [Observatorio Astronómico Nacional, C/Alfonso XII, 3, E-28014 Madrid (Spain); Marvil, Josh [Department of Physics, New Mexico Tech., 801 Leroy Place, Socorro, NM 87801 (United States); Walter, Fabian, E-mail: akepley@nrao.edu [Max Planck Institute fur Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

2014-01-01

Observations of the Milky Way and nearby galaxies show that dense molecular gas correlates with recent star formation, suggesting that the formation of this gas phase may help regulate star formation. A key test of this idea requires wide-area, high-resolution maps of dense molecular gas in galaxies to explore how local physical conditions drive dense gas formation, but these observations have been limited because of the faintness of dense gas tracers like HCN and HCO{sup +}. Here we demonstrate the power of the Robert C. Byrd Green Bank Telescope (GBT)—the largest single-dish millimeter radio telescope—for mapping dense gas in galaxies by presenting the most sensitive maps yet of HCN and HCO{sup +} in the starburst galaxy M82. The HCN and HCO{sup +} in the disk of this galaxy correlates with both recent star formation and more diffuse molecular gas and shows kinematics consistent with a rotating torus. The HCO{sup +} emission extending to the north and south of the disk is coincident with the outflow previously identified in CO and traces the eastern edge of the hot outflowing gas. The central starburst region has a higher ratio of star formation to dense gas than the outer regions, pointing to the starburst as a key driver of this relationship. These results establish that the GBT can efficiently map the dense molecular gas at 90 GHz in nearby galaxies, a capability that will increase further with the 16 element feed array under construction.

Plasma excitation processes in flue gas simulated with Monte Carlo electron dynamics

Energy Technology Data Exchange (ETDEWEB)

Tas, M.A.; Veldhuizen, E.M. van; Rutgers, W.R. [Eindhoven University of Technology (Netherlands). Div. of Electrical Energy Systems

1997-06-07

The excitation of gas molecules in flue gas by electron impact is calculated with a Monte Carlo (MC) algorithm for electron dynamics in partially ionized gases. The MC algorithm is straightforward for any mixture of molecules for which cross sections are available. Electron drift is simulated in the first case for homogeneous electric fields and in the second case for secondary electrons which are produced by electron-beam irradiation. The electron energy distribution function {epsilon}-bar{sub {theta}}, V-bar{sub d}, {lambda}-bar, the energy branching and the rate of excitation are calculated for standard gas mixtures of Ar-N{sub 2}, O{sub 2} and H{sub 2}O. These fundamental process parameters are needed for the study of reactions to remove NO{sub x} from flue gas. The calculated results indicate that the production of highly excited molecules in the high electric field of a streamer corona discharge has an efficiency similar to that of electron-beam irradiation. (author)

Fission gas release and swelling in the fuel pins M1-3 and F9-3: Risoe Fission Gas Project

Energy Technology Data Exchange (ETDEWEB)

Walker, C T; Ray, I L.F.; Coquerelle, M; Blank, H

1982-01-01

This report presents results for the microscopic swelling local swelling and local gas release in the pin sections M1-3-11 and F9-3-44. The local gas release was derived from the concentration of retained xenon which was measured with the electron microprobe. In addition to xenon, the radial distributions of caesium and neodymium were also determined by EMPA. Caesium is assumed to contribute to microscopic swelling because it results mainly from the decay of /sup 133/Xe, /sup 135/Xe and /sup 137/Xe and, therefore, is trapped together with xenon in bubbles and pores. Neodymium, on the other hand, is soluble in UO/sub 2/ and does not migrate under the influence of the temperature gradients that exist during irradiation. Therefore, the radial distribution of this fission product is an indelible imprint of the burn-up from which the average flux depression can be deduced. 1 ref., 15 figs., 3 tabs.

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

of methane, chlorofluorocarbons, and hydrochlorofluorocarbons to the atmosphere. This study was conducted to investigate the effect of oxidation reactions on the overall gas transport regime and to evaluate, the contributions of various gas transport processes on methane attenuation in landfill cover soils....... For this purpose, a reactive transport model that includes advection and the Dusty Gas Model for simulation of multicomponent gas diffusion was used. The simulations are constrained by data from a series of counter-gradient laboratory experiments. Diffusion typically accounts for over 99% of methane emission...... 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...

Universal gas metal arc welding - a cost-effective and low dilution surfacing process

International Nuclear Information System (INIS)

Shahi, AS.; Pandey, Sunil

2006-01-01

This paper describes the use of a new variant of the gas metal arc welding (GMAW) process, termed u niversal gas metal arc welding (UGMAW), for the weld cladding of low carbon steels with stainless steel. The experimental work included single layer cladding of 12 mm thick low carbon steel with austenitic stainless steel 316L solid filler wire of 1.14 mm diameter. Low dilution conditions were employed using both mechanised GMAW and UGMAW processes. Metallurgical aspects of the as welded overlays were studied to evaluate the suitability of these processes for service conditions. It was found that UGMAW claddings contained higher ferrite content; higher concentrations of chromium, nickel and molybdenum; and lower carbon content compared to GMAW claddings. As a result, the UGMAW overlays exhibited superior mechanical and corrosion resistance properties. The findings of this study establish that the new process is technically superior and results in higher productivity, justifying its use for low cost surfacing applications

Environmental Impact Assessment Process for Oil, Gas and Mining Projects in Nigeria: A Critical Analysis

Directory of Open Access Journals (Sweden)

Allan Ingelson and Chilenye Nwapi

2014-06-01

Full Text Available Oil and gas development projects are well known to have damaging environmental effects, and that is especially true in the Niger Delta region. Since the enactment of the Environmental Impact Assessment Act in Nigeria in 1992, there has been a general perception that EIAs are seldom carried out in the region. This article presents a critical analysis of legislation and practice concerning the environmental impact assessment (EIA process for oil and gas projects in Nigeria, the world’s twelfth largest producer of crude oil. It discusses a range of reasons why the impacts of oil and gas projects are not being managed well, despite the legal requirements for EIAs. A review of Nigeria’s environmental governance is presented along with a comprehensive discussion of the EIA process and its significant deficiencies. We argue that the EIA system for oil and gas projects in Nigeria reflects tokenism, resulting in the concentration of benefits of developments in big corporations and government officials. The EIA process in Nigeria faces many challenges that must be addressed in order to improve its effectiveness and alleviate the environmental burdens on this rich oil-producing region.

Hynol: An economic process for methanol production from biomass and natural gas with reduced CO2 emission

Science.gov (United States)

Steinberg, M.; Dong, Yuanji

1993-10-01

The Hynol process is proposed to meet the demand for an economical process for methanol production with reduced CO2 emission. This new process consists of three reaction steps: (1) hydrogasification of biomass, (2) steam reforming of the produced gas with additional natural gas feedstock, and (3) methanol synthesis of the hydrogen and carbon monoxide produced during the previous two steps. The H2-rich gas remaining after methanol synthesis is recycled to gasify the biomass in an energy neutral reactor so that there is no need for an expensive oxygen plant as required by commercial steam gasifiers. Recycling gas allows the methanol synthesis reactor to perform at a relatively lower pressure than conventional while the plant still maintains high methanol yield. Energy recovery designed into the process minimizes heat loss and increases the process thermal efficiency. If the Hynol methanol is used as an alternative and more efficient automotive fuel, an overall 41% reduction in CO2 emission can be achieved compared to the use of conventional gasoline fuel. A preliminary economic estimate shows that the total capital investment for a Hynol plant is 40% lower than that for a conventional biomass gasification plant. The methanol production cost is $0.43/gal for a 1085 million gal/yr Hynol plant which is competitive with current U.S. methanol and equivalent gasoline prices. Process flowsheet and simulation data using biomass and natural gas as cofeedstocks are presented. The Hynol process can convert any condensed carbonaceous material, especially municipal solid waste (MSW), to produce methanol.

Production of gasoline from coal or natural gas by the methanol-to-gasoline process

Energy Technology Data Exchange (ETDEWEB)

Heinritz-Adrian, M.; Brandl, A.; Zhoa, Xinjin; Tabak, S. [Uhde GmbH, Dortmund (Germany)

2007-07-01

After discussing the basis of the methanol-to-gas (MTG) process, the fixed bed and fluid bed versions are described. The Motunui and MTG complex near Montunui, New Zealand that methanol uses natural gas is briefly described. Shanxi Jincheng, Anthracite Coal Mining Co. is currently building its first coal-based MTG plant. 7 refs., 2 tabs.

Exhaust gas clean up process

Science.gov (United States)

Walker, R.J.

1988-06-16

A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

Plasma sprayed thermal barrier coatings for industrial gas turbines: morphology, processing and properties

International Nuclear Information System (INIS)

Gruenling, H.W.; Mannsmann, W.

1993-01-01

Thermal barrier coatings out of fully or partially stabilized zirconia offer a unique chance in gas turbines to increase the gas inlet temperature significantly while keeping the temperature of the structural material of the component within conventional limits. The protection of combustor parts and transition pieces as well as of some stationary gas turbine parts however is state of the art. As a consequence of still insufficient reliability, the application for hot rotating parts is very limited. The introduction as a design element requires safe life within defined time intervals. These depend on the overhaul and repair intervals of the engines. For large land based industrial or utility gas turbines, for example, coating life between 25.000 and 30.000 hrs. is a minimum requirement. Premature failure of a coating by e.g. local spalling causes local overheating of the component with the consequence of its total destruction or even more expensive secondary damages. Life limiting is the corrosion rate at the ceramic-metal interface and the behavior of the coated system under transient operating conditions, where multiaxial strain and stress distributions are generated. Sufficient strain tolerance of the coating both under tensile as well as compressive conditions is required. The properties of thermal barrier coating systems depend strongly on the structure and phase composition of the coating layers and the morphology of and the adhesion at the ceramic-metal interface. They have to be controlled by the process itself, the process parameters and the characteristics of the applied materials (e.g. chemical composition, processing, morphology, particle size and size distribution). It will be reviewed, how properties and structures of coating systems correlate and how structures can be modified by careful control of the process parameters. (orig.)

Tangential inlet supersonic separators: a novel apparatus for gas purification

DEFF Research Database (Denmark)

Wen, Chuang; Walther, Jens Honore; Yang, Yan

2016-01-01

A novel supersonic separator with a tangential inlet is designed to remove the condensable components from gas mixtures. The dynamic parameters of natural gas in the supersonic separation process are numerically calculated using the Reynolds stress turbulence model with the Peng-Robinson real gas...... be generated by the tangential inlet, and it increases to the maximum of 200 m/s at the nozzle throat due to decrease of the nozzle area of the converging part. The tangential velocity can maintain the value of about 160 m/s at the nozzle exit, and correspondingly generates the centrifugal acceleration of 3...

Fracture Dissolution of Carbonate Rock: An Innovative Process for Gas Storage

Energy Technology Data Exchange (ETDEWEB)

James W. Castle; Ronald W. Falta; David Bruce; Larry Murdoch; Scott E. Brame; Donald Brooks

2006-10-31

The goal of the project is to develop and assess the feasibility and economic viability of an innovative concept that may lead to commercialization of new gas-storage capacity near major markets. The investigation involves a new approach to developing underground gas storage in carbonate rock, which is present near major markets in many areas of the United States. Because of the lack of conventional gas storage and the projected growth in demand for storage capacity, many of these areas are likely to experience shortfalls in gas deliverability. Since depleted gas reservoirs and salt formations are nearly non-existent in many areas, alternatives to conventional methods of gas storage are required. The need for improved methods of gas storage, particularly for ways to meet peak demand, is increasing. Gas-market conditions are driving the need for higher deliverability and more flexibility in injection/withdrawal cycling. In order to meet these needs, the project involves an innovative approach to developing underground storage capacity by creating caverns in carbonate rock formations by acid dissolution. The basic concept of the acid-dissolution method is to drill to depth, fracture the carbonate rock layer as needed, and then create a cavern using an aqueous acid to dissolve the carbonate rock. Assessing feasibility of the acid-dissolution method included a regional geologic investigation. Data were compiled and analyzed from carbonate formations in six states: Indiana, Ohio, Kentucky, West Virginia, Pennsylvania, and New York. To analyze the requirements for creating storage volume, the following aspects of the dissolution process were examined: weight and volume of rock to be dissolved; gas storage pressure, temperature, and volume at depth; rock solubility; and acid costs. Hydrochloric acid was determined to be the best acid to use because of low cost, high acid solubility, fast reaction rates with carbonate rock, and highly soluble products (calcium chloride

Optical processes in the performance and recovery of gas-phase switches

International Nuclear Information System (INIS)

Gundersen, M.

1982-01-01

In this paper several optical processes that may be used to affect gas-phase switch performance and operation are discussed, and approaches using a laser to increase recovery rates of switches are presented. In the latter the laser is used during the recovery phase rather than the conductive or closure phase. This papper suggests that it should be possible to use a low-power laser (e.g., one that is technologically feasible to use as part of a switch) to assist in opening the switch by quenching excited atomic and/or molecular species. The application of laser-induced energy extraction to gas-phase switches is also discussed

Acid Gas Removal from Natural Gas with Alkanolamines

DEFF Research Database (Denmark)

Sadegh, Negar

commercially for the removal of acid gas impurities from natural gas. Alkanolamines, simple combinations of alcohols and ammonia, are the most commonly used category of chemical solvents for acid gas capture. This Ph.D. project is aboutthermodynamics of natural gas cleaning process with alkanolamines......Some 40 % of the world’s remaining gas reserves are sour or acid, containing large quantities of CO2 and H2S and other sulfur compounds. Many large oil and gas fields have more than 10 mole % CO2 and H2S content. In the gas processing industry absorption with chemical solvents has been used...... pressure on acid gas solubility was also quantitatively investigated through both experimental and modeling approaches....

Influence of shielding gas pressure on welding characteristics in CO2 laser-MIG hybrid welding process

Science.gov (United States)

Chen, Yanbin; Lei, Zhenglong; Li, Liqun; Wu, Lin

2006-01-01

The droplet transfer behavior and weld characteristics have been investigated under different pressures of shielding gas in CO2 laser and metal inert/active gas (laser-MIG) hybrid welding process. The experimental results indicate that the inherent droplet transfer frequency and stable welding range of conventional MIG arc are changed due to the interaction between CO2 laser beam and MIG arc in laser-MIG hybrid welding process, and the shielding gas pressure has a crucial effect on welding characteristics. When the pressure of shielding gas is low in comparison with MIG welding, the frequency of droplet transfer decreases, and the droplet transfer becomes unstable in laser-MIG hybrid welding. So the penetration depth decreases, which shows the characteristic of unstable hybrid welding. However, when the pressure of shielding gas increases to a critical value, the hybrid welding characteristic is changed from unstable hybrid welding to stable hybrid welding, and the frequency of droplet transfer and the penetration depth increase significantly.

Processing of mixed-waste compressed-gas cylinders on the Oak Ridge Reservation

International Nuclear Information System (INIS)

Morris, M.I.; Conley, T.B.; Osborne-Lee, I.W.

1998-03-01

To comply with restrictions on the storage of old compressed gas cylinders, the environmental management organization of Lockheed Martin Energy Systems must dispose of several thousand kilograms of compressed gases stored on the Oak Ridge Reservation (ORR) because the cylinders cannot be taken off-site for disposal in their current configuration. In the ORR Site Treatment Plan, a milestone is cited that requires repackaging and shipment off-site of 21 cylinders by September 30, 1997. A project was undertaken to first evaluate and then either recontainerize or neutralize these cylinders using a transportable compressed gas recontainerization skid (TCGRS), which was developed by Integrated Environmental Services of Atlanta. The transportable system can: (1) sample, analyze, and identify at the site the chemical and radiological content of each cylinder, even those with inoperable valves; (2) breach cylinders, when necessary, to release their contents into a containment chamber; and (3) either neutralize the gas or liquid contents within the containment chamber or transfer the gas or liquids to a new cylinder. The old cylinders and cylinder fragments were disposed of and the gases neutralized or transferred to new cylinders for transportation off-site for disposal. The entire operation to process the 21 cylinders took place in only 5 days once the system was approved for operation. The system performed as expected and can now be used to process the potentially thousands of more cylinders located across the US Department of Energy (DOE) complex that have not yet been declared surplus

Synthesis and characterization of porous silicon gas sensors

Science.gov (United States)

abbas, Roaa A.; Alwan, Alwan M.; Abdulhamied, Zainab T.

2018-05-01

In this work, photo-electrochemical etching process of n-type Silicon of resistivity(10 Ω.cm) and (100) orientation, using two illumination sources IR and violet wavelength in HF acid have been used to produce PSi gas detection device. The fabrication process was carried out at a fixed etching current density of 25mA/cm2 and at different etching time (5, 10, 15 and 20) min and (8, 16, 24, and 30) min. Two configurations of gas sensor configuration planer and sandwich have been made and investigated. The morphological properties have been studied using SEM,the FTIR measurement show that the (Si-Hx) and (Si-O-Si) absorption peak were increases with increasing etching time,and Photoluminescence properties of PSi layer show decrease in the peak of PL peak toward the violet shift. The gas detection process is made on the CO2 gas at different operating temperature and fixed gas concentration. In the planner structure, the gas sensing was measured through, the change in the resistance readout as a function to the exposure time, while for sandwich structure J-V characteristic have been made to determine the sensitivity.

Gas permeability of ice-templated, unidirectional porous ceramics

Science.gov (United States)

Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J.

2016-01-01

We investigate the gas flow behavior of unidirectional porous ceramics processed by ice-templating. The pore volume ranged between 54% and 72% and pore size between 2.9 ?m and 19.1 ?m. The maximum permeability (?? m?) was measured in samples with the highest total pore volume (72%) and pore size (19.1 ?m). However, we demonstrate that it is possible to achieve a similar permeability (?? m?) at 54% pore volume by modification of the pore shape. These results were compared with those reported and measured for isotropic porous materials processed by conventional techniques. In unidirectional porous materials tortuosity (?) is mainly controlled by pore size, unlike in isotropic porous structures where ? is linked to pore volume. Furthermore, we assessed the applicability of Ergun and capillary model in the prediction of permeability and we found that the capillary model accurately describes the gas flow behavior of unidirectional porous materials. Finally, we combined the permeability data obtained here with strength data for these materials to establish links between strength and permeability of ice-templated materials.

Gas Transfer in Cellularized Collagen-Membrane Gas Exchange Devices.

Science.gov (United States)

Lo, Justin H; Bassett, Erik K; Penson, Elliot J N; Hoganson, David M; Vacanti, Joseph P

2015-08-01

Chronic lower respiratory disease is highly prevalent in the United States, and there remains a need for alternatives to lung transplant for patients who progress to end-stage lung disease. Portable or implantable gas oxygenators based on microfluidic technologies can address this need, provided they operate both efficiently and biocompatibly. Incorporating biomimetic materials into such devices can help replicate native gas exchange function and additionally support cellular components. In this work, we have developed microfluidic devices that enable blood gas exchange across ultra-thin collagen membranes (as thin as 2 μm). Endothelial, stromal, and parenchymal cells readily adhere to these membranes, and long-term culture with cellular components results in remodeling, reflected by reduced membrane thickness. Functionally, acellular collagen-membrane lung devices can mediate effective gas exchange up to ∼288 mL/min/m(2) of oxygen and ∼685 mL/min/m(2) of carbon dioxide, approaching the gas exchange efficiency noted in the native lung. Testing several configurations of lung devices to explore various physical parameters of the device design, we concluded that thinner membranes and longer gas exchange distances result in improved hemoglobin saturation and increases in pO2. However, in the design space tested, these effects are relatively small compared to the improvement in overall oxygen and carbon dioxide transfer by increasing the blood flow rate. Finally, devices cultured with endothelial and parenchymal cells achieved similar gas exchange rates compared with acellular devices. Biomimetic blood oxygenator design opens the possibility of creating portable or implantable microfluidic devices that achieve efficient gas transfer while also maintaining physiologic conditions.

Hot fuel gas dedusting after sorbent-based gas cleaning

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Advanced power generation technologies, such as Air Blown Gasification Cycle (ABGC), require gas cleaning at high temperatures in order to meet environmental standards and to achieve high thermal efficiencies. The primary hot gas filtration process, which removes particulates from the cooled raw fuel gas at up to 600{degree}C is the first stage of gas cleaning prior to desulphurization and ammonia removal processes. The dust concentration in the fuel gas downstream of the sorbent processes would be much lower than for the hot gas filtration stage and would have a lower sulphur content and possibly reduced chlorine concentration. The main aim of this project is to define the requirements for a hot gas filter for dedusting fuel gas under these conditions, and to identify a substantially simpler and more cost effective solution using ceramic or metal barrier filters.

Brazing and diffusion bonding processes as available repair techniques for gas turbine blades and nozzles

International Nuclear Information System (INIS)

Mazur, Z.

1997-01-01

The conventionally welding methods are not useful for repair of heavily damaged gas turbine blades and nozzles. It includes thermal fatigue and craze cracks, corrosion, erosion and foreign object damage, which extend to the large areas. Because of required extensive heat input and couponing, it can cause severe distortion of the parts and cracks in the heat affected zone, and can made the repair costs high. For these cases, the available repair methods of gas turbine blades and nozzles, include brazing and diffusion bonding techniques are presented. Detailed analysis of the brazing and diffusion bonding processes applied for gas turbine blades repair with all elements which presented. Detailed analysis of the brazing and diffusion bonding processes applied for gas turbine blades repair with all elements which have influence to get sound joint is carried out. Depend of kind of blades and nozzle damage or deterioration registered a different methods of brazing and diffusion bonding applicability is presented. (Author) 65 refs

Seasonal atmospheric deposition and air-sea gas exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implications for source-sink processes

Science.gov (United States)

Jiang, Yuqing; Lin, Tian; Wu, Zilan; Li, Yuanyuan; Li, Zhongxia; Guo, Zhigang; Yao, Xiaohong

2018-04-01

In this work, air samples and surface seawater samples covering four seasons from March 2014 to January 2015 were collected from a background receptor site in the YRE to explore the seasonal fluxes of air-sea gas exchange and dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. Gaseous PAH release from seawater to the atmosphere averaged 3114 ± 1999 ng m-2 d-1 in a year round. The air-sea gas exchange of PAHs was the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of total dry and wet deposition. The gas PAH exchange flux was dominated by three-ring PAHs, with the highest value in summer and lowest in winter, indicating a marked seasonal variation owing to differences in Henry's law constants associated with temperature, as well as wind speed and gaseous-dissolved gradient among seasons. Based on the simplified mass balance estimation, a net 11 tons y-1 of PAHs (mainly three-ring PAHs) were volatilized from seawater to the atmosphere in a ∼20,000 km2 area in the YRE. Other than the year-round Yangtze River input and ocean ship emissions, the selective release of low-molecular-weight PAHs from bottom sediments in winter due to resuspension triggered by the East Asian winter monsoon is another potential source of PAHs. This work suggests that the source-sink processes of PAHs at the air-sea interface in the YRE play a crucial role in regional cycling of PAHs.

The Cloud Ice Mountain Experiment (CIME) 1998: experiment overview and modelling of the microphysical processes during the seeding by isentropic gas expansion

Science.gov (United States)

Wobrock, Wolfram; Flossmann, Andrea I.; Monier, Marie; Pichon, Jean-Marc; Cortez, Laurent; Fournol, Jean-François; Schwarzenböck, Alfons; Mertes, Stephan; Heintzenberg, Jost; Laj, Paolo; Orsi, Giordano; Ricci, Loretta; Fuzzi, Sandro; Brink, Harry Ten; Jongejan, Piet; Otjes, René

The second field campaign of the Cloud Ice Mountain Experiment (CIME) project took place in February 1998 on the mountain Puy de Dôme in the centre of France. The content of residual aerosol particles, of H 2O 2 and NH 3 in cloud droplets was evaluated by evaporating the drops larger than 5 μm in a Counterflow Virtual Impactor (CVI) and by measuring the residual particle concentration and the released gas content. The same trace species were studied behind a round jet impactor for the complementary interstitial aerosol particles smaller than 5 μm diameter. In a second step of experiments, the ambient supercooled cloud was converted to a mixed phase cloud by seeding the cloud with ice particles by the gas release from pressurised gas bottles. A comparison between the physical and chemical characteristics of liquid drops and ice particles allows a study of the fate of the trace constituents during the presence of ice crystals in the cloud. In the present paper, an overview is given of the CIME 98 experiment and the instrumentation deployed. The meteorological situation during the experiment was analysed with the help of a cloud scale model. The microphysics processes and the behaviour of the scavenged aerosol particles before and during seeding are analysed with the detailed microphysical model ExMix. The simulation results agreed well with the observations and confirmed the assumption that the Bergeron-Findeisen process was dominating during seeding and was influencing the partitioning of aerosol particles between drops and ice crystals. The results of the CIME 98 experiment give an insight on microphysical changes, redistribution of aerosol particles and cloud chemistry during the Bergeron-Findeisen process when acting also in natural clouds.

5A Zirconium Dioxide Ammonia Microsensor Integrated with a Readout Circuit Manufactured Using the 0.18 μm CMOS Process

Science.gov (United States)

Lin, Guan-Ming; Dai, Ching-Liang; Yang, Ming-Zhi

2013-01-01

The study presents an ammonia microsensor integrated with a readout circuit on-a-chip fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated sensor chip consists of a heater, an ammonia sensor and a readout circuit. The ammonia sensor is constructed by a sensitive film and the interdigitated electrodes. The sensitive film is zirconium dioxide that is coated on the interdigitated electrodes. The heater is used to provide a working temperature to the sensitive film. A post-process is employed to remove the sacrificial layer and to coat zirconium dioxide on the sensor. When the sensitive film adsorbs or desorbs ammonia gas, the sensor produces a change in resistance. The readout circuit converts the resistance variation of the sensor into the output voltage. The experiments show that the integrated ammonia sensor has a sensitivity of 4.1 mV/ppm. PMID:23503294

Application of process tomography in gas-solid fluidised beds in different scales and structures

Science.gov (United States)

Wang, H. G.; Che, H. Q.; Ye, J. M.; Tu, Q. Y.; Wu, Z. P.; Yang, W. Q.; Ocone, R.

2018-04-01

Gas-solid fluidised beds are commonly used in particle-related processes, e.g. for coal combustion and gasification in the power industry, and the coating and granulation process in the pharmaceutical industry. Because the operation efficiency depends on the gas-solid flow characteristics, it is necessary to investigate the flow behaviour. This paper is about the application of process tomography, including electrical capacitance tomography (ECT) and microwave tomography (MWT), in multi-scale gas-solid fluidisation processes in the pharmaceutical and power industries. This is the first time that both ECT and MWT have been applied for this purpose in multi-scale and complex structure. To evaluate the sensor design and image reconstruction and to investigate the effects of sensor structure and dimension on the image quality, a normalised sensitivity coefficient is introduced. In the meantime, computational fluid dynamic (CFD) analysis based on a computational particle fluid dynamic (CPFD) model and a two-phase fluid model (TFM) is used. Part of the CPFD-TFM simulation results are compared and validated by experimental results from ECT and/or MWT. By both simulation and experiment, the complex flow hydrodynamic behaviour in different scales is analysed. Time-series capacitance data are analysed both in time and frequency domains to reveal the flow characteristics.

Characterizing the Heavy Elements in Globular Cluster M22 and an Empirical s-process Abundance Distribution Derived from the Two Stellar Groups

Science.gov (United States)

Roederer, I. U.; Marino, A. F.; Sneden, C.

2011-11-01

We present an empirical s-process abundance distribution derived with explicit knowledge of the r-process component in the low-metallicity globular cluster M22. We have obtained high-resolution, high signal-to-noise spectra for six red giants in M22 using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan-Clay Telescope at Las Campanas Observatory. In each star we derive abundances for 44 species of 40 elements, including 24 elements heavier than zinc (Z = 30) produced by neutron-capture reactions. Previous studies determined that three of these stars (the "r+s group") have an enhancement of s-process material relative to the other three stars (the "r-only group"). We confirm that the r+s group is moderately enriched in Pb relative to the r-only group. Both groups of stars were born with the same amount of r-process material, but s-process material was also present in the gas from which the r+s group formed. The s-process abundances are inconsistent with predictions for asymptotic giant branch (AGB) stars with M <= 3 M ⊙ and suggest an origin in more massive AGB stars capable of activating the 22Ne(α,n)25Mg reaction. We calculate the s-process "residual" by subtracting the r-process pattern in the r-only group from the abundances in the r+s group. In contrast to previous r- and s-process decompositions, this approach makes no assumptions about the r- and s-process distributions in the solar system and provides a unique opportunity to explore s-process yields in a metal-poor environment. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

CO₂ capture from IGCC gas streams using the AC-ABC process

Energy Technology Data Exchange (ETDEWEB)

Nagar, Anoop [SRI International, Menlo Park, CA (United States); McLaughlin, Elisabeth [SRI International, Menlo Park, CA (United States); Hornbostel, Marc [SRI International, Menlo Park, CA (United States); Krishnan, Gopala [SRI International, Menlo Park, CA (United States); Jayaweera, Indira [SRI International, Menlo Park, CA (United States)

2017-02-16

The objective of this project was to develop a novel, low-cost CO₂ capture process from pre-combustion gas streams. The bench-scale work was conducted at the SRI International. A 0.15-MWe integrated pilot plant was constructed and operated for over 700 hours at the National Carbon Capture Center, Wilsonville, AL. The AC-ABC (ammonium carbonate-ammonium bicarbonate) process for capture of CO₂ and H₂S from the pre-combustion gas stream offers many advantages over Selexol-based technology. The process relies on the simple chemistry of the NH₃-CO₂-H₂O-H₂S system and on the ability of the aqueous ammoniated solution to absorb CO₂ at near ambient temperatures and to release it as a high-purity, high-pressure gas at a moderately elevated regeneration temperature. It is estimated the increase in cost of electricity (COE) with the AC-ABC process will be ~ 30%, and the cost of CO₂ captured is projected to be less than $27/metric ton of CO₂ while meeting 90% CO₂ capture goal. The Bechtel Pressure Swing Claus (BPSC) is a complementary technology offered by Bechtel Hydrocarbon Technology Solutions, Inc. BPSC is a high-pressure, sub-dew-point Claus process that allows for nearly complete removal of H₂S from a gas stream. It operates at gasifier pressures and moderate temperatures and does not affect CO₂ content. When coupled with AC-ABC, the combined technologies allow a nearly pure CO₂ stream to be captured at high pressure, something which Selexol and other solvent-based technologies cannot achieve.

Effect of process parameters on power requirements of vacuum swing adsorption technology for CO2 capture from flue gas

International Nuclear Information System (INIS)

Zhang, Jun; Webley, Paul A.; Xiao, Penny

2008-01-01

This study focuses on the effects of process and operating parameters - feed gas temperature, evacuation pressure and feed concentration - on the performance of carbon dioxide vacuum swing adsorption (CO 2 VSA) processes for CO 2 capture from gas, especially as it affects power consumption. To obtain reliable data on the VSA process, experimental work was conducted on a purposely built three bed CO 2 VSA pilot plant using commercial 13X zeolite. Both 6 step and 9 step cycles were used to determine the influences of temperature, evacuation pressure and feed concentration on process performance (recovery, purity, power and corresponding capture cost). A simple economic model for CO 2 capture was developed and employed herein. Through experiments and analysis, it is found that the feed gas temperature, evacuation pressure and feed concentration have significant effects on power consumption and CO 2 capture cost. Our data demonstrate that the CO 2 VSA process has good recovery (>70%), purity (>90%) and low power cost (4-10 kW/TPDc) when operating with 40 C feed gas provided relatively deep vacuum is used. Enhanced performance is obtained when higher feed gas concentration is fed to the plant, as expected. Our data indicates large potential for application of CO 2 VSA to CO 2 capture from flue gas. (author)

A plasma process controlled emissions off-gas demonstration

International Nuclear Information System (INIS)

Battleson, D.; Kujawa, S.T.; Leatherman, G.

1995-01-01

Thermal technologies are currently identified as playing an important role in the treatment of many DOE waste streams, and emissions from these processes will be scrutinized by the public, regulators, and stakeholders. For some time, there has been a hesitancy by the public to accept thermal treatment of radioactive contaminated waste because of the emissions from these processes. While the technology for treatment of emissions from these processes is well established, it is not possible to provide the public complete assurance that the system will be in compliance with air quality regulations 100% of the operating time in relation to allowing noncompliant emissions to exit the system. Because of the possibility of noncompliant emissions and the public's concern over thermal treatment systems, it has been decided that the concept of a completely controlled emissions off-gas system should be developed and implemented on Department of Energy (DOE) thermal treatment systems. While the law of conservation of mass precludes a completely closed cycle system, it is possible to apply the complete control concept to emissions

Inverse magnetostrictive characteristics of Fe-Co composite materials using gas-nitriding process

Science.gov (United States)

Nakajima, Kenya; Yang, Zhenjun; Narita, Fumio

2018-03-01

The inverse magnetostrictive response, known as the Villari effect, of magnetostrictive materials is a change in magnetization due to an applied stress. It is commonly used for sensor applications. This work deals with the inverse magnetostrictive characteristics of Fe-Co bimetal plates that were subjected gas-nitriding process. Gas-nitriding was performed on bimetal plates for 30 min at 853 K as a surface heat treatment process. The specimens were cooled to room temperature after completing the nitriding treatment. Three-point bending tests were performed on the plates under a magnetic field. The changes on the magnetic induction of the plates due to the applied load are discussed. The effect of the nitriding treatment on the inverse magnetostrictive characteristics, magnetostrictive susceptibility, and magnetic hysteresis loop was examined. Our work represents an important step forward in the development of magnetostrictive sensor materials.

Thermal Analysis of the Divertor Primary Heat Transfer System Piping During the Gas Baking Process

International Nuclear Information System (INIS)

Yoder, Graydon L. Jr.; Harvey, Karen; Ferrada, Juan J.

2011-01-01

A preliminary analysis has been performed examining the temperature distribution in the Divertor Primary Heat Transfer System (PHTS) piping and the divertor itself during the gas baking process. During gas baking, it is required that the divertor reach a temperature of 350 C. Thermal losses in the piping and from the divertor itself require that the gas supply temperature be maintained above that temperature in order to ensure that all of the divertor components reach the required temperature. The analysis described in this report was conducted in order to estimate the required supply temperature from the gas heater.

Decision support in the natural gas distribution process of the Ceara state, Brazil; Apoio a decisao no processo de distribucao do gas natural no ambito do estado do Ceara

Energy Technology Data Exchange (ETDEWEB)

Rabelo, Clarice Augusta Carvalho; Arruda, Joao Bosco Furtado; Nobre, Junior, Ernesto Ferreira [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Engenharia de Transportes. Nucleo de Pesquisa em Logistica, Transporte e Desenvolvimento (NUPELTD); br, barruda@det ufc; br, nobre@det ufc

2003-07-01

The participation of natural gas has improved more and more in Brazilian energetic die. In Ceara, the use of natural gas has increased a lot and the expectations are the best. However it's necessary to guarantee a better infrastructure of distribution and interaction among the actors of the sector. This paper is part of a bigger project that intends to contribute with this improvement through an application of multicriteria techniques in the natural gas distribution process in Ceara. The aim of the project is to choose the market segment to be prioritized due to a possible context of restriction of gas offer in order of its potential demands. Nowadays paper, however, only makes a quick analysis of the actual gas situation in Ceara and a small explanation about multicriteria techniques, specifically, the analytic hierarchy process (AHP). Besides, through a simulation of the problem and an application of the analytic hierarchy process, this paper intends to demonstrate the applicability of these methods in this problem. (author)

Decision support in the natural gas distribution process of the Ceara state, Brazil; Apoio a decisao no processo de distribucao do gas natural no ambito do estado do Ceara

Energy Technology Data Exchange (ETDEWEB)

Rabelo, Clarice Augusta Carvalho; Arruda, Joao Bosco Furtado; Nobre Junior, Ernesto Ferreira [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Engenharia de Transportes. Nucleo de Pesquisa em Logistica, Transporte e Desenvolvimento (NUPELTD)]. E-mail: claricerabelo@aol.com; barruda@det.ufc.br; nobre@det.ufc.br

2003-07-01

The participation of natural gas has improved more and more in Brazilian energetic die. In Ceara, the use of natural gas has increased a lot and the expectations are the best. However it's necessary to guarantee a better infrastructure of distribution and interaction among the actors of the sector. This paper is part of a bigger project that intends to contribute with this improvement through an application of multicriteria techniques in the natural gas distribution process in Ceara. The aim of the project is to choose the market segment to be prioritized due to a possible context of restriction of gas offer in order of its potential demands. Nowadays paper, however, only makes a quick analysis of the actual gas situation in Ceara and a small explanation about multicriteria techniques, specifically, the analytic hierarchy process (AHP). Besides, through a simulation of the problem and an application of the analytic hierarchy process, this paper intends to demonstrate the applicability of these methods in this problem. (author)

Control of the geomorphology and gas hydrate extent on widespread gas emissions offshore Romania (Black Sea)

Science.gov (United States)

Riboulot, V.; Cattaneo, A.; Sultan, N.; Ker, S.; Scalabrin, C.; Gaillot, A.; Jouet, G.; Marsset, B.; Thomas, Y.; Ballas, G.; Marsset, T.; Garziglia, S.; Ruffine, L.; Boulart, C.

2016-12-01

The Romanian sector of the Black Sea deserves attention because the Danube deep-sea fan is one of the largest sediment depositional systems worldwide and is considered the world's most isolated sea, the largest anoxic water body on the planet and a unique energy-rich sea. Due to the high sediment accumulation rate, presence of organic matter and anoxic conditions, the Black sea sediment offshore the Danube delta is rich in gas and thus show BSR. The cartography of the BSR over the last 20 years, exhibits its widespread occurrence, indicative of extensive development of hydrate accumulations and a huge gas hydrate potential. By combining old and new datasets acquired in 2015 during the GHASS expedition, we performed a geomorphological analysis of the continental slope north-east of the Danube canyon that reveals the presence of several landslides inside and outside several canyons incising the seafloor. It is a complex study area presenting sedimentary processes such as seafloor erosion and instability, mass wasting, formation of gas hydrates, fluid migration, gas escape, where the imprint of geomorphology seems to dictate the location where gas seep occurs. . Some 1409 gas seeps within the water column acoustic records are observed between 200 m and 800 m water depth. No gas flares were detected in deeper areas where gas hydrates are stable. Overall, 93% of the all gas seeps observed are above geomorphological structures. 78% are right above escarpment induced by sedimentary destabilizations inside or outside canyons. The results suggest a geomorphological control of degassing at the seafloor and gas seeps are thus constrained by the gas hydrates stability zone. The stability of the gas hydrates is dependent on the salinity gradient through the sedimentary column and thus on the Black Sea recent geological history. The extent and the dynamics of gas hydrates have a probable impact on the sedimentary destabilization observed at the seafloor.