Inorganic Gases Research Articles

Naturally occurring radionuclides and rare earth elements in weathered Japanese soil samples

The activity concentrations of 226Ra and 228Ac in weathered Japanese soils from two selected prefectures have been measured using a γ-ray spectroscopy system with high purity germanium detector. The uranium, thorium, and rare earth elements (REEs) concentrations were determined from the same soil samples using inductively coupled plasma mass spectrometry (ICP-MS). For example, granitic rocks contain higher amounts of U, Th, and light REEs compared to other igneous rocks such as basalt and andesites. Therefore, it is necessary to understand the interaction between REEs and nature of soils since soils are complex heterogeneous mixture of organic and inorganic solids, water, and gases. In this paper, we will discuss about distribution pattern of 238U and 232Th along with REEs in soil samples of weathered acid rock (granite) collected from two prefectures of Japan: Hiroshima and Miyagi.

Generating microbubbles in a co-flowing microfluidic device

This paper introduces an experimental study on the microbubble generation mechanism in a co-flowing microfluidic device. Using propane, butane and air as the dispersed phases and different SDS–PEG solutions as the continuous phases, two kinds of bubble generating phenomena, named “single-bubble generation” flow and “dual-bubble generation” flow, were observed in experiment and uniform bubbles with average diameters ranging from 391μm to 713μm and polydispersity less than 2.9% were successfully prepared. The pressure fluctuation of gas phase is carefully analyzed with the Young–Laplace equation and the bubble generation mechanism is summarized from the dynamic movement of gas–liquid interface. The main factors impacting the bubble size variation are illustrated for both the organic and inorganic gases. A universal correlation is established to predict the average bubble diameters.

Abnormal concentration and origin of heavy hydrocarbon in upper permian coal seams from Enhong syncline, Yunnan, China

Coalbed gas (CBG) in Enhong (恩洪) syncline, eastern Yunnan (云南), China, is characterized by high concentration of heavy hydrocarbon with the highest content of ethane, which is more than 30%. Some previous investigators paid much attention to the abnormal concentration of heavy hydrocarbon in the CBG of Enhong, but few have researched on its origin. This article describes the characteristics of abnormal high concentration of heavy hydrocarbon in Enhong syncline and analyzes its reason from the aspects of origin and evolution of heavy hydrocarbon by carbon isotope, coal petrography, and coal rank. Features of gas carbon isotope composition display that there is no inorganic gas or oil components in the CBG, which is classified to thermogenetic gas produced by humic material, with characteristic of secondary biogenic gas in shallow coal seam. The concentration of heavy hydrocarbon in Enhong syncline increases with the increase of vitrinite, vitrinite/inertinite ratio, and hydrogen/carbon ratio and decreases with the increase of inertinite, so hydrogen-rich vitrinite may be a very important factor resulting in the abnormal concentration of heavy hydrocarbon. It also increases with the increase of degree of coalification of coking to lean coals during which the peak of heavy hydrocarbon generation is reached. Therefore, we think that high concentration of heavy hydrocarbon originated from the coupling effect of higher content of the hydrogen-rich vitrinite in the coal and the coal rank of coking to lean coals.

Simulation of nitrate, sulfate, and ammonium aerosols over the United States

Abstract. Atmospheric concentrations of inorganic gases and aerosols (nitrate, sulfate, and ammonium) are simulated for 2009 over the United States using the chemical transport model GEOS-Chem. Predicted aerosol concentrations are compared with surface-level measurement data from the Interagency Monitoring of Protected Visual Environments (IMPROVE), the Clean Air Status and Trends Network (CASTNET), and the California Air Resources Board (CARB). Sulfate predictions nationwide are in reasonably good agreement with observations, while nitrate and ammonium are over-predicted in the East and Midwest, but under-predicted in California, where observed concentrations are the highest in the country. Over-prediction of nitrate in the East and Midwest is consistent with results of recent studies, which suggest that nighttime nitric acid formation by heterogeneous hydrolysis of N2O5 is over-predicted based on current values of the N2O5 uptake coefficient, γ, onto aerosols. After reducing the value of γ by a factor of 10, predicted nitrate levels in the US Midwest and East still remain higher than those measured, and over-prediction of nitrate in this region remains unexplained. Comparison of model predictions with satellite measurements of ammonia from the Tropospheric Emissions Spectrometer (TES) indicates that ammonia emissions in GEOS-Chem are underestimated in California and that the nationwide seasonality applied to ammonia emissions in GEOS-Chem does not represent California very well, particularly underestimating winter emissions. An ammonia sensitivity study indicates that GEOS-Chem simulation of nitrate is ammonia-limited in southern California and much of the state, suggesting that an underestimate of ammonia emissions is likely the main cause for the under-prediction of nitrate aerosol in many areas of California. An approximate doubling of ammonia emissions is needed to reproduce observed nitrate concentrations in southern California and in other ammonia sensitive areas of California. However, even a tenfold increase in ammonia emissions yields predicted nitrate concentrations that are still biased low in the central valley of California. The under-prediction of nitrate aerosol in the central valley of California may arise in part from an under-prediction of both ammonia and nitric acid in this region. Since nitrate aerosols are particularly sensitive to mixed layer depths, owing to the gas-particle equilibrium, the nitrate under-prediction could also arise in part from a potential regional overestimate of GEOS-5 mixed layer depths in the central valley due to unresolved topography in this region.

Overview of the LADCO winter nitrate study: hourly ammonia, nitric acid and PM<sub>2.5</sub> composition at an urban and rural site pair during PM<sub>2.5</sub> episodes in the US Great Lakes region

Abstract. An overview of the LADCO (Lake Michigan Air Directors Consortium) Winter Nitrate Study (WNS) is presented. Sampling was conducted at ground level at an urban-rural pair of sites during January–March 2009 in eastern Wisconsin, toward the western edge of the US Great Lakes region. Areas surrounding these sites experience multiday episodes of wintertime PM2.5 pollution characterized by high fractions of ammonium nitrate in PM, low wind speeds, and air mass stagnation. Hourly surface monitoring of inorganic gases and aerosols supplemented long-term 24-h aerosol chemistry monitoring at these locations. The urban site (Milwaukee, WI) experienced 13 PM2.5 episodes, defined as periods where the seven-hour moving average PM2.5 concentration exceeded 27 μg m−3 for at least four consecutive hours. The rural site experienced seven episodes by the same metric, and all rural episodes coincided with urban episodes. Episodes were characterized by low pressure systems, shallow/stable boundary layer, light winds, and increased temperature and relative humidity relative to climatological mean conditions. They often occurred in the presence of regional snow cover at temperatures near freezing, when snow melt and sublimation could generate fog and strengthen the boundary layer inversion. Substantial contribution to nitrate production from nighttime chemistry of ozone and NO2 to N2O5 and nitric acid is likely and requires further investigation. Pollutant-specific urban excess during episode and non-episode conditions is presented. The largest remaining uncertainties in the conceptual model of the wintertime episodes are the variability from episode-to-episode in ammonia emissions, the balance of daytime and nighttime nitrate production, the relationship between ammonia controls, NOx controls and ammonium nitrate reductions, and the extent to which snow and fog are causal (either through meteorological or chemical processes) rather than just correlated with episodes because of similar synoptic meteorology.

Field and Laboratory Simulation Study of Hot Spots in Stockpiled Bituminous Coal

Large coal piles (50–150 000 tons) undergo weathering processes during long-term storage in open air. Chemisorption of atmospheric oxygen, formation of surface oxides, and partial oxidative decomposition of the coal macromolecule matrix result in the release of organic and inorganic gases [e.g., methane (CH4), ethylene (C2H4), ethane (C2H6), carbon dioxide (CO2), carbon monoxide (CO), and hydrogen (H2)]. Some of these processes are exothermic, and when the rate of heat dissipation in the pile is lower than that of its formation, a significant increase in the temperature can be measured. These places are termed “hot spots”, which, in extreme cases, can result in fire eruptions. The maximal temperature measured in the hot spots was 330 °C. Monitoring of hot spots at the Israel Electric Company (IEC) bituminous coal storage sites has been conducted. A unique monitoring unit that can penetrate up to 8 m into the coal pile to sample gases and also measure the temperature was used.

Removal of Inorganic Gas Contaminants via the Air Washer of a Make-Up Air Unit in Clean Rooms

Removal of Inorganic Gas Contaminants via the Air Washer of a Make-Up Air Unit in Clean Rooms

Detection of Metabolic Fluxes of O and H Atoms into Intracellular Water in Mammalian Cells

Metabolic processes result in the release and exchange of H and O atoms from organic material as well as some inorganic salts and gases. These fluxes of H and O atoms into intracellular water result in an isotopic gradient that can be measured experimentally. Using isotope ratio mass spectroscopy, we revealed that slightly over 50% of the H and O atoms in the intracellular water of exponentially-growing cultured Rat-1 fibroblasts were isotopically distinct from growth medium water. We then employed infrared spectromicroscopy to detect in real time the flux of H atoms in these same cells. Importantly, both of these techniques indicate that the H and O fluxes are dependent on metabolic processes; cells that are in lag phase or are quiescent exhibit a much smaller flux. In addition, water extracted from the muscle tissue of rats contained a population of H and O atoms that were isotopically distinct from body water, consistent with the results obtained using the cultured Rat-1 fibroblasts. Together these data demonstrate that metabolic processes produce fluxes of H and O atoms into intracellular water, and that these fluxes can be detected and measured in both cultured mammalian cells and in mammalian tissue.

Atmospheric composition and micro-climate in the Alhambra monument, Granada (Spain), in the context of preventive conservation

The world famous Alhambra monument in Granada, Southern Spain, listed as UNESCO world cultural heritage since 1984, represents probably the most beautiful example of Islamic art and architecture from the Middle Ages in Europe. It is visited by ca. 2 million people annually. Granada is situated in a natural basin, surrounded by mountains with altitudes up to 3500 m. Due to this topography and the prevailing low wind speeds, pollution-derived and especially traffic-derived particulate matter often accumulates in the urban air. In order to evaluate the potential conservation risks from the surrounding air, the atmospheric composition in the Alhambra monument was evaluated. Indoor temperature and relative humidity fluctuations were evaluated for their potential degenerative effects. Furthermore, the atmospheric composition in the Alhambra was analyzed in terms of inorganic gases (NO2, SO2, O3, and NH3) and black carbon. It was found that the open architecture protected the indoor environments from developing a potentially harmful microclimate, such as the build-up of humidity resulting from the huge number of daily tourists. On the downside, the strong ventilation made the indoor air hardly different from outdoor air, as characterized by strong diurnal temperature and relative humidity gradients and high traffic-derived pollutant levels.

Direct (without degassing) determination of sulfur-containing compounds in unstable gas condensate by gas chromatography

A procedure has been developed for direct determination of sulfur-containing components in the concentration range 0.0002–0.7 wt % in samples of unstable gas condensate under a pressure of 8 MPa using a gas chromatograph equipped with a flame photometric detector. The determination of the overall composition of samples (including hydrocarbons and inorganic gases) takes no more than 1 h, i.e., is 5 times more rapid than the standard procedure with preliminary sample degassing. In addition, direct (without degassing) determination results is lower errors (the repeatability for the main components is 0.01–0.06; n = 10).

On-line gas chromatographic analysis of higher alcohol synthesis products from syngas

An on-line gas chromatographic (GC) system has been developed for rapid and accurate product analysis in catalytic conversion of syngas (a mixture of H2 and CO) to alcohols, so called “higher alcohol synthesis (HAS)”. Conversion of syngas to higher alcohols is an interesting second step in the route of converting coal, natural gas and possibly biomass to liquid alcohol fuel and chemicals. The presented GC system and method are developed for analysis of the products formed from syngas using alkali promoted MoS2 catalysts, however it is not limited to these types of catalysts. During higher alcohol synthesis not only the wanted short alcohols (∼C2–C5) are produced, but also a great number of other products in smaller or greater amounts, they are mainly short hydrocarbons (olefins, paraffins, branched, non-branched), aldehydes, esters and ketones as well as CO2, H2O. Trace amounts of sulfur-containing compounds can also be found in the product effluent when sulfur-containing catalysts are used and/or sulfur-containing syngas is feed. In the presented GC system, most of them can be separated and analyzed within 60min without the use of cryogenic cooling. Previously, product analysis in “higher alcohol synthesis” has in most cases been carried out partly on-line and partly off-line, where the light gases (gases at room temp) are analyzed on-line and liquid products (liquid at room temp) are collected in a trap for later analysis off-line. This method suffers from many drawbacks compared to a complete on-line GC system. In this paper an on-line system using an Agilent 7890 gas chromatograph equipped with two flame ionization detectors (FID) and a thermal conductivity detector (TCD), together with an Agilent 6890 with sulfur chemiluminescence dual plasma detector (SCD) is presented. A two-dimensional GC system with Deans switch (heart-cut) and two capillary columns (HP-FFAP and HP-Al2O3) was used for analysis of the organic products on the FIDs. Light inorganic gases (H2, CO, CO2, N2) and methane were separated on packed columns and quantified with the TCD. The “sulfur GC” was optimized for on-line trace level sulfur analysis in hydrocarbon matrices and used to understand to which degree sulfur is released from the catalyst and incorporated into the liquid product, and if so in which form. The method provides excellent quantitative measurements with a carbon material balance near 99.5% (carbon in/carbon out) for individual measurement points.

Alternative techniques for extracting alumina from coal fly ash

The extraction of aluminium from coal fly ash (CFA) has been carried out using two extraction techniques, acid leaching with an inorganic acid and gas phase extraction with acetylacetone, a beta-diketone. The acid leaching experiments were carried out at varying factor values of temperature, time, solid to liquid ratio, and acid concentration. Factors investigated for gas phase extraction included acetylacetone flow rate, extraction temperature and time, and aluminium (III) oxide source.Direct leaching of fly ash in 6M sulphuric acid at a solid to liquid ratio of 1:4 gave an extraction of 23.5% at 75°C after 8h 45min of leaching time. With gas phase extraction, 17.9% aluminium extraction was achieved at 250°C, 6mL/min acetylacetone flow rate, after 6h. This represents 85% and 64% extraction from the CFA amorphous phase respectively. It was also found that when a synthetic aluminium (III) oxide mixture with a similar content to CFA (31wt%) was subjected to gas phase extraction, 46.7% extraction could be achieved after 6h at 250°C. The difference in extraction levels could be explained by the fact that the alumina in CFA occurs in both mullite and amorphous phase compared with only the amorphous phase in synthetic fly ash, an indication that mineralogy has a significant effect on the extraction. Therefore the lower extraction from CFA by acetylacetone is possibly due to the non-amenability of the mullite phase to the acetylacetone beta-diketone. The results presented in this paper show that extractions using acetylacetone in the gas phase are comparatively lower than acid leaching but have advantages of reduced extraction times and the possibility of recycling the unreacted acetylacetone.

Ore mineralization in naphtides and problems of its genesis

The paper presents several examples of metalliferous naphtide mineralization hosted in sedimentary and magmatic rocks and discusses different models of their origin. Geological, geochemical, experimental, and thermodynamic data were used to support a hypothesis assuming that metalliferous naphtide deposits were formed during cold and hot (with melt generation) mantle degassing with subsequent condensation of heavy hydrocarbons and organometallic compounds (OMC) in fault zones. Important criteria for discrimination between metalliferous naphtide mineralization of different origin include endo- and biomarkers, Nd and Sr isotopic data, and chondrite-normalized REE distribution patterns. The formation of endogenic metalliferous naphtide deposits does not rule out the possible assimilation of organic components from the host rock. Juvenile water and inorganic gases were found in the hydrothermal solutions contributing to the formation of these deposits.

Impact of the deep convection of isoprene and other reactive trace species on radicals and ozone in the upper troposphere

Abstract. Observations of a comprehensive suite of inorganic and organic trace gases, including non-methane hydrocarbons (NMHCs), halogenated organics and oxygenated volatile organic compounds (OVOCs), obtained from the NASA DC-8 over Canada during the ARCTAS aircraft campaign in July 2008 illustrate that convection is important for redistributing both long- and short-lived species throughout the troposphere. Convective outflow events were identified by the elevated mixing ratios of organic species in the upper troposphere relative to background conditions. Several dramatic events were observed in which isoprene and its oxidation products were detected at hundreds of pptv at altitudes higher than 8 km. Two events are studied in detail using detailed experimental data and the NASA Langley Research Center (LaRC) box model. One event had no lightning NOx (NO + NO2) associated with it and the other had substantial lightning NOx (LNOx > 1 ppbv). When convective storms transport isoprene from the boundary layer to the upper troposphere and no LNOx is present, OH is reduced due to scavenging by isoprene, which serves to slow the chemistry, resulting in longer lifetimes for species that react with OH. Ozone and PAN production is minimal in this case. In the case where isoprene is convected and LNOx is present, there is a large effect on the expected ensuing chemistry: isoprene exerts a dominant impact on HOx and nitrogen-containing species; the relative contribution from other species to HOx, such as peroxides, is insignificant. The isoprene reacts quickly, resulting in primary and secondary products, including formaldehyde and methyl glyoxal. The model predicts enhanced production of alkyl nitrates (ANs) and peroxyacyl nitrate compounds (PANs). PANs persist because of the cold temperatures of the upper troposphere resulting in a large change in the NOx mixing ratios which, in turn, has a large impact on the HOx chemistry. Ozone production is substantial during the first few hours following the convection to the UT, resulting in a net gain of approximately 10 ppbv compared to the modeled scenario in which LNOx is present but no isoprene is present aloft.

Experimental flammability limits and associated theoretical flame temperatures as a tool for predicting the temperature dependence of these limits

The utility and limitations of adiabatic flame temperature calculations and minimum mixture energies in predicting the temperature dependence of flammability limits are explored. The limiting flame temperatures at constant pressure (1 bar) are calculated using a standard widely-used thermodynamic computer program. The computation is based on the calculated limiting flame temperature value at the reference initial temperature and the experimental limit concentration. The values recently determined in large chambers for the lower and upper flammability limits of a variety of simple organic and inorganic gases (methane, ethylene, dimethy lether, and carbon monoxide) are used as the basis for the predictions of the limiting flame temperature concept. Such thermodynamic calculations are compared with more traditional ones based on a limiting mixture energy and a constant average heat capacity of the reactant mixture. The advantages and limitations of the methods are discussed in this paper.

Imaging Devices, Sustainable Design and Indoor Air Quality

Manufacturers today must design products to meet global sustainability requirements that include human healthy and indoor air quality standards. Acceptable indoor environmental quality is a necessary requirement for today's office buildings, schools, public facilities, and personal residences. On a global basis, indoor air quality is one of the top three environmental issues facing all countries and all people. Toxic chemicals, inorganic gases, and particles that are released by products into the indoor environment can contribute to human irritation, discomfort, and long term health consequences to those exposed. These human effects can lead to excessive medical costs, loss of productivity, and undesirable litigation. Imaging devices are known contributors of certain indoor contaminants such as respirable particles, volatile organic compounds (VOCs) including styrene and formaldehyde, and ozone. Sources of these include electronic and heating processes, inks and toners, papers and transparencies, plastics, and cleaning solvents. Manufacturers are proactively designing for the environment, including indoor air quality as an important part of their product stewardship, and eco-criteria are available for acceptable levels of airborne contaminants released by operating equipment. This paper will review current international programs addressing allowable emissions from imaging devices (including Blue Angel, Greenguard, and the State of California), test procedures, and representative emissions data from print devices.Eco-criteria are based on the performance of operating office equipment and acceptable contributions of certain contaminants. Acceptable emission levels of reparable particles, formaldehyde, styrene, benzene, and other VOCs are based on existing health and safety data with some consideration for protecting sensitive people from irritants and odorants. The primary measurement technique, environmental chamber technology, has been validated to test products under realistic use conditions and to determine emission rates of contaminant release. These data can be used in building exposure models to predict and estimate potential human exposures, and to compare product data with prescribed eco-criteria. This measurement technology has been accepted on a global basis.

Development of Inorganic Gas Barrier Material in Solar Cell Devices for Planarization Properties and Sublimate Defect Reduction

This study focuses on inorganic gas barrier material in the advanced process techniques of solar cell devices for planarization properties and sublimate defect reduction. The inorganic gas barrier material have been optimized and studied for excellent surface planarization property. The newest approach by excellent collaborations from both process and material has the planarization property on an irregular substrate such as the patterned steps, via and trenches to increase the depth of focus and pattering resolution. A remarkable reduction in via topography with 0.6 μm as a depth and 0.13 μm as a diameter has been achieved excellent thickness bias less than 50 nm in 220 nm blanket field thickness. In addition, the sublimate amount of the film obtained from the developed inorganic gas barrier material was low as compared with that of the film obtained from the referenced organic non-gas barrier material.

Applying fluid inclusion mass spectrometry to exploration plays

Fluid inclusions have been used to identify oil charge and migration into the Ungumayo anticline, located in the Marañon Basin, Peru. Sandstone samples recovered from an exploration well drilled into the west flank of the trap (Ungumayo-1X) and from a well in the nearest producing oilfield, the Chambira Este Field, were sent for fluid inclusion analyses. The samples containing fluid inclusions were compared using petrography and fluid inclusion geothermometry to identify the local geological controls on the formation of the different fluid inclusion types identified in the wells. The bulk chemical composition of the volatiles inside the fluid inclusions was obtained using mass spectrometry, with ions being identified from inorganic gases, dry organic gases, water-soluble hydrocarbons, C1 to C13 petroleum compounds, and sulphur compounds. The fluid inclusion mass spectrometry results were interpreted by comparing the abundances of specific hydrocarbon-related compounds and mass spectra between samples from the exploration well and the oilfield. The combination of petrography and fluid inclusion techniques confirms the migration of liquid hydrocarbons into the Ungumayo structure. The fluid inclusion mass spectrometry analysis suggests that the Ungumayo structure still contains a non-biodegraded oil accumulation.

Optimal conditions for vacuum desorption

The optimal conditions for the vacuum desorption of components from liquid solutions are found-the maximum pressure and minimum acceptable density of irrigation. The evaporative equipment is modern regular film tubular nozzles. The laminar pressure of liquid and vapor in the downstream parallel flow mode is assumed. The vacuum desorption from water solutions of some inorganic gases that have both low and high solubility is considered as an application to the theory.

Biomass waste gasification – Can be the two stage process suitable for tar reduction and power generation?

A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100–350kWth. The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1–2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15MJ/Nm3), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the second stage presented only few mass% of the inlet biomass stream.