Gaseous Water Research Articles

Insight into blast furnace dust for selective catalytic reduction of NOx: An experimental and DFT study

Blast furnace dust (BFD), a solid waste generated from the ironmaking process, causes the environmental problems of soil and water pollution. In this work, we develop the selective catalytic reduction (SCR) catalyst for the nitric oxides (NO) reduction using BFD as the raw material by the co-precipitation method. To guarantee the strongest catalytic capability, different calcined temperatures are tested to activate the catalysts, where the prepared catalysts are labeled as BFD-T with the capital letter T to represent the calcination temperature. α-Fe2O3 is the main crystal phase in BFD-T catalyst and the mesoporous structure is mainly concentrated in 2–15 nm. The BFD-400 catalyst presents the best SCR performances and further increasing of the calcination temperature for the catalyst preparation reduces the reducibility, specific surface area and surface adsorbed oxygen of the catalyst. In the temperature range of 225 ℃ to 350 ℃, the BFD-400 catalyst presents the nitrogen oxides (NOx) conversion of more than 90%, which is attributed to the increase of ferric ion on the catalyst surface. Meanwhile, density functional theory (DFT) is applied to study the adsorption states of the reactant molecules on the catalyst surface and reaction mechanism. During the SCR process, this catalyst shows the excellent resistance to sulfur and water in the coal-fired flue gas due to the weak adsorption energy calculation.

Advances in electron beam technology for environmental and biotechnological applications at Fraunhofer FEP

An expanding part of electron beam technology developed at Fraunhofer FEP tackles ecological and biotechnological challenges of highest relevance. Antimicrobial and fungicidal effects of electron beam are exploited in the chemical-free phytosanitary treatment of seeds. Chemical pollutants but also pathogens in gaseous effluents and waste water can be efficiently neutralized. Medical products such as tools, packaging and implants can be sterilized, disinfected, or even biologically advantageously functionalized. Viruses can be inactivated via electron beam to produce vaccines with an excellent antigen conservation leading to a high degree of immunization with good reproducibility, but without the usage of additional chemicals. Plasma synthesis in electron beam-sustained discharges allows for an exceptionally efficient energy transfer to non-reactive greenhouse gases like CO2 and CH4 and is a promising approach to the economical, scalable production of media for sustainable chemical energy storage (Power to X - PtX), driving the energy transition and reducing greenhouse gases. The publication gives an overview of the recent advances of electron beam technology at Fraunhofer FEP in these emerging fields of application.

Hydrocracking of n-hexadecane via liquid or gaseous water assisted pulsed spark discharge in liquid

In view of the problem that it is difficult to ignite discharge in the insulating liquid medium, the method of water assisted where the spark will occur was proposed. The introduction of water in any form lead to easier breakdown in the insulating liquid medium, and can also avoid carbon deposition caused by spark discharge, so as to achieve the purpose of reducing the discharge voltage. This paper also analyzes the liquid products after discharge, and it is found that the higher heating value of the liquid products was influenced by water state and peak voltage, which increased by 2.25% under the action of spark discharge. In addition, extending processing time may not be a good way to increase higher heating value of liquid products. This method not only solves the difficult problem of plasma generation in liquid medium, but also provides evidence for plasma-chemical reactions in heavy oil cracking and hydrogenation.

CAGE15-5 Cruise Report: Marine Geological Cruise to Storfjordrenna, Bjørnøyrenna and Thor Iversenbanken

The cruise was a part of the Centre of Excellence for Gas Hydrate, Environment and Climate (CAGE) at UiT – The Arctic University of Norway. The cruise aimed at investigating areas with gas venting from the seabed in central Bjørnøyrenna and outer Storfjordrenna, as well as subglacial meltwater systems in Thor Iversenbanken, central Barents Sea. More specific objectives included: Acquisiton of a P-cable 3D seismic survey over part of a large crater and pingo field in central BjørnøyrennaSampling gas in water, sediments and air in areas of gas venting within the crater and pingo fieldAcquisiton of gravity cores for identification of palaeo-subglacial lakes in Thor IversenbankenAcquisiton of 2D seismic across subglacial meltwater systems in Thor IversenbankenAcqusition of 2D seismic across pingos identified in StorfjordrennaSampling of gas in air in the area where pingos have been identified in Storfjordrenna The cruise may be known as: CAGE15_5

Moisture migration in the cathode GDL of PEMFC under variable physical parameters based on a modified two-fluid model

To predict the morphology and migration of water in the porous electrode of proton exchange membrane fuel cell (PEMFC) more accurately, a modified mathematical model of with extensions of the original two-fluid model is presented based on the heat and mass transfer model of unsaturated porous media. The model integrated the mechanisms of the capillary effect, pressure, diffusion, and phase-to-phase interaction, and was applied to the numerical study of the single-fluid channel cell herein. The results show that the interaction between the gas and liquid is dominated by the drag force caused by relative motion, which highly depends on the position and local water saturation. What's more, a higher porosity facilitates the discharge of liquid and gaseous water in the GDL, while for the permeability, there exists a local optimum value which leads to a lowest liquid saturation in the GDL and helps to avoid the flooding phenomenon.

CAGE19-2 Cruise Report: Hunting gas flares and launching seafloor observatory

The cruise was part of the Centre of Excellence(SFF) Centre for Arctic Gas Hydrate, Environment and Climate Climate (CAGE) at UiT – The Arctic University of Norway. It was partly supported by The Norwegian Petroleum Directory (NPD). The cruise had the following scientific objectives: Identification of gas seepage associated with assumed hydrocarbon reservoirs subcropping the sea floor due to erosion of overlying cap rocks.Identification of gas seepage related to leakage along faults breaching the seafloor.Acqusition of multibeam, subbottom profiler-, seismic data and samples of gas in water and sediments for cross disciplinary investigations by CAGEDeployment of seafloor observatory and oceanographic studies west of Prins Kars Forland The cruise may be known as: CAGE19_2

Experimental and Numerical Simulation Study on the Influence of Gaseous Water on the Mechanical Properties of Red-Layer Mudstone in Central Sichuan

Experimental and Numerical Simulation Study on the Influence of Gaseous Water on the Mechanical Properties of Red-Layer Mudstone in Central Sichuan

Influence of transition metal catalysts on the decomposition product distribution of PCBs and PCDD/Fs

In this study, reliable and stable polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) generation systems were used to investigate catalyst performance. The distribution characteristics of PCBs and PCDD/Fs after reaction were evaluated under different simulated flue gas conditions using NiO- and MnO2-loaded γ-Al2O3 and ZSM-5 catalysts. The results showed that the active metal of the catalyst affected mainly the decomposition efficiency, the substrate type affected the distribution characteristics of PCBs, and both the active metal and substrate type jointly determined the fingerprint distribution characteristics of PCBs. Moreover, there was an apparent marginal effect of the active metal loading on the same catalyst and the decomposition efficiency of the pollutants. In the temperature range of 100–350 °C, temperature variation had little effect on the removal efficiency of PCBs, but the gas–solid phase distribution characteristics of the pollutants changed significantly, and large amounts of di- and tri-CBs were generated in the products at 200 °C. A small amount of water generated hydrogen via the water–gas shift reaction at medium temperature, which promoted the hydro-dechlorination reaction of the chlorinated organics. However, excess water in the substrate gas competes with the pollutants for adsorption sites and reduces the reaction activity of the catalyst.

Quantum Phase Transition Predicted for Gaseous Water

Water molecules that are close enough to “see” each other but far enough apart to be gas-like can undergo a quantum phase transition, a finding of relevance for making future water-based quantum devices.

Early Release Science of the exoplanet WASP-39b with JWST NIRCam

Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in equilibrium, revealing planet formation histories. Transmission spectroscopy (for example, refs. 1,2) provides the necessary means by constraining the abundances of oxygen- and carbon-bearing species; however, this requires broad wavelength coverage, moderate spectral resolution and high precision, which, together, are not achievable with previous observatories. Now that JWST has commenced science operations, we are able to observe exoplanets at previously uncharted wavelengths and spectral resolutions. Here we report time-series observations of the transiting exoplanet WASP-39b using JWST’s Near InfraRed Camera (NIRCam). The long-wavelength spectroscopic and short-wavelength photometric light curves span 2.0–4.0 micrometres, exhibit minimal systematics and reveal well defined molecular absorption features in the planet’s spectrum. Specifically, we detect gaseous water in the atmosphere and place an upper limit on the abundance of methane. The otherwise prominent carbon dioxide feature at 2.8 micrometres is largely masked by water. The best-fit chemical equilibrium models favour an atmospheric metallicity of 1–100-times solar (that is, an enrichment of elements heavier than helium relative to the Sun) and a substellar C/O ratio. The inferred high metallicity and low C/O ratio may indicate significant accretion of solid materials during planet formation (for example, refs. 3,4,) or disequilibrium processes in the upper atmosphere (for example, refs. 5,6).

RELIABILITY OF WATER CONTENT DATA FOR NATURAL GAS-HYDRATE SYSTEMS USING SEMI-EMPIRICAL CORRELATIONS

Water in natural gas can result in various operational problems, which may lead to equipment failure and plant shutdown. Knowing the amount of water capable of condensing from natural gas is essential. Many methods have been developed for ascertaining the amount of this condensable water (water content) from many gas mixtures. However, when hydrates are present, available methods for estimating the amount of condensable water are scarce and very limited in the open literature. The reliability of the data has always been a cause for concern due to the tendency for the inaccuracy of the results. In this study, two semi-empirical methods for ascertaining the amount of condensable water in natural gas with and without hydrates were used to test the reliability of the water content data of four different published natural gas-hydrate systems, including methane and propane gas mixture, raw/unprocessed, binary (methane + water), and synthetic natural gas. The results showed that only the data set for the methane and propane gas mixture was a reliable gas-hydrate equilibrium system, while the synthetic gas mixture needed further validation. Therefore, the methodology in this study can be used as a quick and simple means for ascertaining the reliability of water content data of natural gas-hydrate systems.

Quantitative monitoring of dissolved gases in a flooded borehole: calibration of the analytical tools

Gas monitoring is a prerequisite to understanding the exchange, diffusion, and migration processes of natural gases within underground environments, which are involved in several applications such as geological sequestration of CO2. In this study, three different techniques (micro-GC, infrared, and Raman spectroscopies) were deployed on an experimental flooded borehole for monitoring purposes after CO2 injection. The aim was to develop a real-time chemical monitoring device to follow dissolved gas concentrations by measurements in water inside the borehole but also at the surface through a gas collection system in equilibrium with the borehole water. However, all three techniques must be calibrated to provide the most accurate quantitative data. For this, a first step of calibration in the laboratory was carried out. A new calibrations were required to determine partial pressure and/or concentrations of gases in water or in the gas collection system. For gas phase analysis, micro-GC, FTIR spectroscopy, and Raman spectroscopy were compared. New calibration of the micro-GC was done for CO2, CH4, and N2 with uncertainty from ±100 ppm to 1.5 mol% depending on the bulk concentration and the type of gas. The FTIR and Raman spectrometers were previously calibrated for CO2, and CO2, N2, O2, CH4, and H2O, respectively with an accuracy of 1–6% depending on concentration scale, gas and spectrometer. Dissolved CO2 in water was measured using a Raman spectrometer equipped with an immersion probe. The uncertainty on the predicted dissolved CO2 concentration and partial pressure was ±0.003 mol·kg−1 and ±0.05 bar, respectively.

Health effect of radon gas in water on children at Al-Najaf schools

Health effect of radon gas in water on children at Al-Najaf schools

Measuring the efficiency of greenhouse gases to absorb heat

Greenhouse gases are a very important part of the Earth’s atmosphere that cause the Earth to warm enough to support life, but when they are too abundant can also cause global warming. To find out which greenhouse gas has the greatest effect on temperature, we measured the percent temperature change over time in three of the four major greenhouse gases (water vapor, carbon dioxide, and nitrous oxide) compared to regular air when exposed to the sun. We measured this by putting a thermometer in bottles containing each of the gases. We hypothesized that carbon dioxide would have the greatest percent temperature change. Indeed, we found the temperature of the bottle containing carbon dioxide went up by 41.64%, which was higher than the other gases. We also observed that nitrous oxide had the lowest percentage change, which was 32.19%. Our results suggested that carbon dioxide has the greatest effect on temperature, which could have many ramifications. Carbon dioxide is present everywhere in the atmosphere. This means that the warming effect of carbon dioxide applies globally. Given that there is a large amount of carbon dioxide in the atmosphere and that carbon dioxide emissions are increasing, global warming will increase more leading to ice caps melting, resulting in harm to the environment and all life on Earth.

Study on inhibition effect and mechanism of NH4H2PO4 on explosion of titanium powder

In order to effectively inhibit the explosion of titanium powder, this study used the Hartmann tube experimental system and the 20 L explosion tank experimental system to carry out flame propagation and explosion overpressure experiments, respectively, and the effect of NH4H2PO4 on the explosion suppression of titanium powder was studied. The results show that when the addition of NH4H2PO4 powder is 50%, the flame propagation velocity and explosion pressure can be reduced to the minimum, and the explosion pressure can be basically suppressed. Finally, the inhibition mechanism of NH4H2PO4 on the explosion of titanium powder was analyzed. The endothermic decomposition of NH4H2PO4 absorbed the energy needed by the explosion of titanium powder. Oxides produced by the decomposition of NH4H2PO4 powder cover the surface of titanium powder, increase the thickness of the oxide film, and play a role of heat insulation; the gaseous water produced by the decomposition of NH4H2PO4 powder reduces the concentration of oxygen in the air and increases the difficulty of the explosion reaction. NH4H2PO4 powder traps the free radicals needed for the explosion to block the chain reaction.

Research on the dissipation framework and dissipation coefficient prediction model of the supersaturated dissolved gas in solid media containing water

Supersaturation of dissolved gas in water will cause fish to suffer from gas bubble diseases and even death. Therefore, it is imperative to illustrate the dissipation process of dissolved gas and then seek measures to remit the negative effects of dissolved gas supersaturation on fish. Generally, adding solid media (SM) to water has proven to be an effective and economical way to remove supersaturated dissolved gas from aquaculture water. While, the supersaturated dissolved gas dissipation framework in solid media containing water was still unclear. In this paper, combined with laboratory experiments and research available in the literature, the dissipation framework of dissolved gas was proposed along with the calculation of the liquidgas interfacial transfer mass, solid wall adsorption mass, porous media adsorption mass, and inner dissipation mass. The solid wall adsorption coefficient was found to follow a power function of the contact angle, and the porous adsorption coefficient logarithmically increased with the specific surface area. It was found that the inner dissipation coefficient exponentially increased with increasing total dissipation coefficient. Utilizing an approximation algorithm method, a model for the prediction of the dissipation coefficient was established. The research reported in this paper could contribute to enriching the research field of supersaturated dissolved dissipation and is significant for ecological and environmental protection.

Effect of Mixing in Test Section on Hydrate Synthesis via Explosive Boiling of Liquefied Hydrate-Forming Gas in Water with Addition of SDS during Decompression

Effect of Mixing in Test Section on Hydrate Synthesis via Explosive Boiling of Liquefied Hydrate-Forming Gas in Water with Addition of SDS during Decompression

The generalized method for estimating reserves of shale gas and coalbed methane reservoirs based on material balance equation

As the main unconventional natural gas reservoirs, shale gas reservoirs and coalbed methane (CBM) reservoirs belong to adsorptive gas reservoirs, i.e., gas reservoirs containing adsorbed gas. Shale gas and CBM reservoirs usually have the characteristics of rich adsorbed gas and obvious dynamic changes of porosity and permeability. A generalized material balance equation and the corresponding reserve evaluation method considering all the mechanisms for both shale gas reservoirs and CBM reservoirs are necessary. In this work, a generalized material balance equation (GMBE) considering the effects of critical desorption pressure, stress sensitivity, matrix shrinkage, water production, water influx, and solubility of natural gas in water is established. Then, by converting the GMBE to a linear relationship between two parameter groups related with known formation/fluid properties and dynamic performance data, the straight-line reserve evaluation method is proposed. By using the slope and the y -intercept of this straight line, the original adsorbed gas in place (OAGIP), original free gas in place (OFGIP), original dissolved gas in place (ODGIP), and the original gas in place (OGIP) can be quickly calculated. Third, two validation cases for shale gas reservoir and CBM reservoir are conducted using commercial reservoir simulator and the coalbed methane dynamic performance analysis software, respectively. Finally, two field studies in the Fuling shale gas field and the Baode CBM field are presented. Results show that the GMBE and the corresponding straight-line reserve evaluation method are rational, accurate, and effective for both shale gas reservoirs and CBM reservoirs. More detailed information about reserves of shale gas and CBM reservoirs can be clarified, and only the straight-line fitting approach is used to determine all kinds of reserves without iteration, proving that the proposed method has great advantages compared with other current methods.

Comprehensive Fluid Compositional Analysis Program to Support the Interpretation of Chichimene Field In-Situ Combustion Pilot

Summary The evaluation of enhanced oil recovery (EOR) methods in Colombia has been very active during the past decade. One of the most recent and promising pilots is the in-situ combustion (ISC) in Chichimene field, starting in September 2019. Based on international ISC field experiences, this pilot represents a unique case study given the depth (≈8,000 ft) of this heavy crude oil (9 °API) reservoir. The pilot project consists of one injector, seven producers, and two temperature observation wells between the injector and first-line wells. Production response shows encouraging results. Its interpretation is supported by a comprehensive fluid compositional analysis, which is the main objective of this paper. This paper describes the compositional analysis of produced fluids (gas, oil, and water) and the influence of the current flow assurance program. Geochemical simulations support the evaluation of scaling tendencies, and possible corrosion trends are based on iron and manganese concentrations following the National Association of Corrosion Engineers (NACE) standards. Crude oil analysis is based on conventional techniques (i.e., acid number, distillation curves, etc.) and biomarkers to infer possible thermal maturation changes in the produced oil. Results confirm predicted cycles of CO2 and H2S during the planning of the monitoring program. The solubility of both gases in water leads to their acidification and the formation of carbonate and sulfate scales characterized in production wells. The precipitation of solids was also influenced by the N2-based H2S scavenger decomposition downhole due to the water pH increment observed with the dosage increases. The scaling tendencies did not impact the productivity due to the high reservoir permeability. The precipitation of iron species made it difficult to interpret NACE standards to infer corrosion except for wells shut in for more than 2 months showing a higher concentration of Fe and Mn. However, a recent casing inspection job at one of the first-line producers shows no corrosion signs. Heavy metals such as nickel and vanadium were analyzed in water to infer the possible corrosion or thermal cracking of porphyrins in crude oil. Changes in the paraffinic fractions and biomarkers (i.e., methyl phenanthrene index, mono- and tri-aromatic steroids) suggest an increased thermal maturity of the produced oil. The robust monitoring program has provided important insights from the ISC process and flow assurance strategy supporting possible expansion plans. This study provides valuable guidelines for monitoring programs based on compositional analysis of produced fluids, including the influence of production chemistry. Lessons learned through the Chichimene ISC monitoring program can be valuable in interpreting thermal and potentially nonthermal EOR projects.

Thermochemical activation of CO2 into syngas over ceria-supported niobium oxide catalyst: An integrated experimental-DFT study

Thermochemical splitting of a mixture of CO2 and water into syngas (and methane) remains a viable approach toward an industrial-scale treatment of CO2 emission. However, most deployed catalysts encompass expensive metallic ingredients such as Pd or Pt. In an integrated experimental-modelling approach, this work reports a high conversion of CO2 over alternative and cost-effective configurations. Ceria-based catalysts are proven to be effective in numerous catalytic processes owing to the facile switch in the Ce redox cycle. Evolution of H2 and CO from thermochemical splitting of water and carbon dioxide is an important process in the production of syngas and in fuel cell applications. In this study, NbOx ceria catalysts are prepared, characterized, and applied for production of syngas via the thermochemical splitting of CO2 and gaseous water. It was observed that presence of Nb in the ceria matrix up to 12 wt%, increases the reaction yield at higher temperature (up to 79% CO2 conversion with 80% selectivity to syngas at 600 ºC). Moreover, the catalytic reaction was found to display a higher selectivity towards syngas over the ceria supported catalysts. The attained conversion is higher than other ceria-supported catalysts such as Rh-CeO2, CeO2-ZrO2, and V2O5-CeO2. Mapped-out reaction pathways by DFT calculations portray accessible routes into syngas. Results provided herein should be useful to optimize a continuous process for the valorization of CO2 into syngas over relatively affordable a catalytic formulation.