Investigation Of Methane Research Articles

Investigation of methane and ethane diffusivity in the glass reinforced epoxy composite: Experimental and simulation

New polymeric pipes have been used to overcome difficulties created by metal pipes in gas transmission lines such as corrosion and leakage. In this work, diffusion and solubility cells are designed to determine the diffusivity and possible leakage of methane and ethane gases in the glass-reinforced epoxy (GRE) composite. A composite sample with a diameter of 5.95 mm and thickness of 1.40 mm to determine the diffusivity and a composite powder to estimate the gas solubility are used. The experiments are done under temperatures varied from 25 to 40 ℃ and a pressure of 20 bar. The results show that the diffusivity of both gases increases with increasing temperature; while gas solubility decreases. The highest diffusion coefficient of methane and ethane are observed at 8.23 × 10−11 and 7.94 × 10−11 m2/s at 40 ℃, respectively. Moreover, novel correlations for estimating gas diffusion coefficient and mass flow rate in terms of temperature are developed based on the experimental data with the correlation coefficients (R2) of 0.98 and 1 and the average relative error percent (AREP) less than 4.5% and 0.5%, respectively. Interestingly, CFD (Computational fluid dynamics) results show a good consistency with experimental data for gas concentration profiles through the composite with AREP ranges of 1.95–15.78%.

Investigation of methane and ethane pyrolysis with highly active and durable iron-alumina catalyst to produce hydrogen and valuable nano carbons: Continuous fluidized bed tests and reaction rate analysis

The goal of this research work was to evaluate a novel iron-alumina catalyst for methane and ethane pyrolysis with high conversion rates to H2 with a long life time to address two major issues reported with previous catalysts. Fluidized bed tests demonstrated continuous hydrogen production while collecting carbon containing fines. During the 230 h fluid bed test the methane conversion rate to hydrogen at 700 °C remained above 80% for 160 h while creating valuable nano carbons. Similarly high catalyst lifetimes with high methane conversions have not been reported before. Ethane was more active than methane for pyrolysis with 100% conversion to H2. Transmission electron microscopy and Raman analysis of the carbon showed single and multiwall nanotubes and conglomerate nano-fibers. Ethane did not impact the allotrope of carbon formed. TGA was used to create a data array that was used for kinetic analysis and reaction model parametric regressions. Ethane had a higher rate of pyrolysis that was 2.3–2.8 times that of methane. Ethane pyrolysis was found to be more sensitive to temperature with a higher activation energy of 62 kJ/mol as compared to methane at 43 kJ/mol. The frequency factor, Ai, was significantly higher for ethane at 0.73 [[kmol/m3-sec]/[N/m2]n] compared to 0.03 for methane on the same basis. Both gases had a functional partial pressure order dependence of ∼0.6 based on the regression analysis.

Formation of complex hydrocarbon systems from methane at the upper mantle thermobaric conditions

The existence of methane in the Earth’s mantle does not cause any doubt, however, its possible chemical transformation under the mantle thermobaric conditions is not enough known. Investigation of methane at the upper mantle thermobaric conditions, using diamond anvil cells, demonstrated the possible formation of ethane, propane and n-butane from methane, however, theoretical calculations of methane behaviour at extreme temperature and pressure predicted also heavier hydrocarbons. We experimentally investigated the chemical transformations of methane at the upper mantle thermobaric conditions, corresponding to the depth of 70–80 km (850–1000 K, 2.5 GPa), using “Toroid”-type Large reactive volume device and gas chromatography. The experimental results demonstrated the formation of the complex hydrocarbon mixture up to C7 with linear, branched and cycled structures and benzene. Unsaturated hydrocarbons were detected on the trace level in the products mixture. The increasing of exposure time leaded to growth of heavier components in the product systems. The data obtained suggest possible existence of complex hydrocarbon mixtures at the upper mantle thermobaric conditions and provide a new insight on the possible pathways of the hydrocarbons synthesis from methane in the upper mantle.

Investigation of Legacy Methane Seepage into Freshwater Food Webs Using Novel Applications in Stoney Creek, New Brunswick

Legacy oil, gas, and coalfields in the Maritime region have emitted methane into the surrounding ecosystem for more than 100 years. Methane escaping from these legacy sites may have effects on the surrounding terrestrial and aquatic environments. I investigated whether methane could be detected entering streams via groundwater inputs in an area with abandoned and active oil and gas wells. Introduction of a foreign compound, such as methane, could act as an environmental stressor and could impact the local food web starting at the lowest trophic level. I predicted that if methane was entering freshwater streams and being incorporated into the food web, it would be evident in the stable isotopes of consumers and prey. Methane would have a distinct isotopic carbon signature and could be traced through the various biotic compartments. This project focuses on the novel application of using a small thermal imaging camera to help detect subsurface groundwater inputs into the stream for site selection. Using this temperature sensing technology, I found and selected 5 suspected groundwater sources flowing into the stream channel. I collected biofilm (e.g. bacteria, algae, diatoms) and benthic macroinvertebrate from both upstream and downstream of each suspected groundwater input site. With small streams and low summer water levels, I was unable to adequately sample the fish community. Stable isotope analysis of biofilm and benthic macroinvertebrates did not show obvious incorporation of methane into the food web, though some values were suspect. Additionally, I completed a diatom community assessment applying the Eastern Canadian Diatom Index (IDEC) as a measure of the biological integrity of streams and were able to show that the study sites in the Stoney Creek region are currently considered “slightly polluted”, with a few select locations bordering on “polluted”. Although these techniques and tools did show the incorporation of methane in the food web at Stoney Creek, the combination of inexpensive tools can be employed in the investigation of methane at other sites. This study serves as an exploration and application of tools and techniques that have not previously been applied in this context.

An investigation of methane and propane vertical flares

Flame lengths, temperature, species and lift-off heights have been experimentally and numerically investigated and compared for buoyant methane and propane jet diffusion flames at Reynolds number of 5700. The flow field has been modeled using the Reynolds-Averaged Navier–Stokes equation incorporating the k–ε realizable turbulence closure model. Combustion was modeled using the unsteady Eulerian-flamelet model based on the mixture fraction approach and the heat loss by radiation was accounted for using the Discrete Ordinates Method. The GRI mech. 3.0 and the CRECK reaction mechanisms were used to model the kinetics of the methane and propane reactions, respectively. Comparison of the predicted flame length and temperature revealed good agreement with experimental data. Post-flame measurements of NOx and CO revealed greater quantities of both pollutants in the methane flame. Furthermore, investigation of the effect of the burner nozzle thickness on the flame lift-off heights showed that the lift-off height decreased as the nozzle thickness was increased, with the methane flame displaying higher lift-off heights.

Modeling CO2 injection at Cranfield, Mississippi: Investigation of methane and temperature effects

AbstractA large‐scale carbon dioxide (CO2) injection pilot is ongoing at Cranfield, Mississippi, in a saline aquifer with high dissolved methane (CH4) content, employing one injection well and two observation wells. The breakthrough of CH4 and CO2 at the observation wells provides insights to phase partitioning and the multipath nature of flow through the formation. Injected CO2 is cooler than the formation temperature, making temperature another useful observation. Simulations of the first year of CO2 injection were conducted with the numerical simulator TOUGH2 and the equation of state module EOS7C, which includes CO2, CH4, and H2O, using an axisymmetric model with layering based on well logs from the injection well. Although the simplification of an axisymmetric model precludes study of formation dip or lateral heterogeneity, its simple structure enables a focus on physical processes involving the phase partitioning of CH4 and CO2, and temperature effects. Field observations that the model reproduces include the arrival of a bank of free‐phase CH4 ahead of the main CO2 plume at each observation well, and non‐monotonic changes in CH4 and CO2 mole fraction as a function of time, suggesting that multiple distinct flow paths exist between the injection well and the observation wells, each with its own bank of free‐phase CH4 leading the CO2. Model results are compared with temperature observations made in the field with a Distributed Temperature Sensor (DTS) system, suggesting that a well‐defined thermal response reached the near observation well within the seven‐month monitoring period, but not the more distant observation well. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd

Forensic Geo-Gas Investigation of Methane: Characterization of Sources within an Urban Setting

A forensic geo-gas investigation within an urban environment has identified distinct compositional and stable-isotope characteristics related to various reference sources of methane gas by using analytical techniques such as geochemical screening, stable-carbon and stable-hydrogen isotope analysis, and radioactive carbon-isotope analysis. The results of the investigation concluded that the combination of a number of geochemical indicators produced a distinctive geo-gas fingerprint for samples from similar reference sites.

Chemical sputtering of carbon in Tore-Supra outboard pump limiter

The use of a large amount of carbon in tokamaks induces two major problems mainly due to the chemical sputtering: erosion and tritium retention. In the Tore-Supra outboard pump limiter, the in situ chemical sputtering yield of the carbon neutralizer plate has been studied. Investigation of methane and heavier hydrocarbon (C 2D x and C 3D y ) emission has been performed in ohmic and lower hybrid heated discharges, by means of mass spectrometry and optical spectroscopy. Simulation performed with a Monte Carlo code (BBQ) allows validation of the sputtering yield calculation method and show good agreement with experimental data.

96/03509 Sorption investigation of methane on coal

96/03509 Sorption investigation of methane on coal