Calculation of water content in water–methane system

Two methods to calculate the water content of water (1)–methane (2) system in the liquid–gas and ice–gas regions at temperatures from 253 to 373 K are proposed and tested in this work. Both are based on the assumption that the influence of methane solubility in liquid water on the calculated water content can be neglected (i.e., only pure water is considered in the liquid phase). A survey of experimental data is also given.

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Development of Predictive Techniques for Estimating Liquid Water-Hydrate Equilibrium of Water-Hydrocarbon System

Journal of Thermodynamics ◽

10.1155/2009/120481 ◽

2009 ◽

Vol 2009 ◽

pp. 1-12 ◽

Cited By ~ 15

Author(s):

Amir H. Mohammadi ◽

Dominique Richon

Keyword(s):

Experimental Data ◽

Gas Hydrates ◽

Liquid Water ◽

Pure Water ◽

Neural Network Algorithm ◽

Water Fugacity ◽

Independent Experimental Data ◽

Pure Hydrocarbon ◽

Coefficient Method ◽

Artificial Neural Network Algorithm

In this communication, we review recent studies by these authors for modeling the -H equilibrium. With the aim of estimating the solubility of pure hydrocarbon hydrate former in pure water in equilibrium with gas hydrates, a thermodynamic model is introduced based on equality of water fugacity in the liquid water and hydrate phases. The solid solution theory of Van der Waals-Platteeuw is employed for calculating the fugacity of water in the hydrate phase. The Henry's law approach and the activity coefficient method are used to calculate the fugacities of the hydrocarbon hydrate former and water in the liquid water phase, respectively. The results of this model are successfully compared with some selected experimental data from the literature. A mathematical model based on feed-forward artificial neural network algorithm is then introduced to estimate the solubility of pure hydrocarbon hydrate former in pure water being in equilibrium with gas hydrates. Independent experimental data (not employed in training and testing steps) are used to examine the reliability of this algorithm successfully.

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Relationship between optical extinction and liquid water content in fogs

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-9623-2013 ◽

2013 ◽

Vol 6 (6) ◽

pp. 9623-9653

Author(s):

C. Klein ◽

A. Dabas

Keyword(s):

Refractive Index ◽

Linear Relationship ◽

Water Content ◽

Liquid Water ◽

Pure Water ◽

Liquid Water Content ◽

Usual Practice ◽

Optical Extinction ◽

The Real ◽

The Impact

Abstract. Studies carried out in the late 1970s suggest a simple linear relationship exists in practice between the optical extinction in the thermal IR and the liquid water content (LWC) in fogs. Such a relationship opens the possibility to monitor the vertical profile of the LWC in fogs with a rather simple backscatter lidar. Little is known on how the LWC varies as a function of height and during the fog life cycle, so the new measurement technique would help understand fog physics and provide valuable data for improving the quality of fog forecasts. In the present article, the validity of the linear relationship is revisited at the light of recent observations of fog droplet size distributions measured with a combination of sensors covering a large range of droplet radii. In particular, large droplets (radius above 15 μm) are detected, which was not the case in the late 1970s. The results confirm the linear relationship still holds, at least for the mostly radiative fogs observed during the campaign. The impact of the precise value of the real and imaginary parts of the refractive index on the coefficient of the linear relationship is also studied. The usual practice considers droplets are made of pure water. This assumption is probably valid for big droplets, it may be questioned for small ones since droplets are formed from condensation nuclei of highly variable chemical composition. The study suggests the relationship is mostly sensitive to the real part of the refractive index and the sensitivity grows with the size of fog droplets. However, large fog droplets are more likely to have an index close to that of water since they are mainly composed of water.

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Relationship between optical extinction and liquid water content in fogs

Atmospheric Measurement Techniques ◽

10.5194/amt-7-1277-2014 ◽

2014 ◽

Vol 7 (5) ◽

pp. 1277-1287 ◽

Cited By ~ 3

Author(s):

C. Klein ◽

A. Dabas

Keyword(s):

Linear Relationship ◽

Water Content ◽

Liquid Water ◽

Pure Water ◽

Liquid Water Content ◽

Condensation Nuclei ◽

Usual Practice ◽

Optical Extinction ◽

Variable Chemical ◽

The Impact

Abstract. Studies carried out in the late 1970s suggest that a simple linear relationship exists in practice between the optical extinction in the thermal IR and the liquid water content (LWC) in fogs. Such a relationship opens the possibility to monitor the vertical profile of the LWC in fogs with a rather simple backscatter lidar. Little is known on how the LWC varies as a function of height and during the fog life cycle, so the new measurement technique would help understand fog physics and provide valuable data for improving the quality of fog forecasts. In this paper, the validity of the linear relationship is revisited in the light of recent observations of fog droplet size distributions measured with a combination of sensors covering a large range of droplet radii. In particular, large droplets (radius above 15 μm) are now detected, which was not the case in the late 1970s. The results confirm that the linear relationship still holds, at least for the mostly radiative fogs observed during the campaign. The impact of the precise value of the real and imaginary parts of the refractive index on the coefficient of the linear relationship is also studied. The usual practice considers that droplets are made of pure water. This assumption is probably valid for big drops, but it may be questioned for small ones since droplets are formed from condensation nuclei of highly variable chemical composition. The study suggests that the precise nature of condensation nuclei will primarily affect rather light fogs with small droplets and light liquid water contents.

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An Accurate Model to Calculate CO2 Solubility in Pure Water and in Seawater at Hydrate–Liquid Water Two-Phase Equilibrium

Minerals ◽

10.3390/min11040393 ◽

2021 ◽

Vol 11 (4) ◽

pp. 393

Author(s):

Mengyao Di ◽

Rui Sun ◽

Lantao Geng ◽

Wanjun Lu

Keyword(s):

Experimental Data ◽

Phase Equilibrium ◽

Liquid Water ◽

Model Comparison ◽

Pure Water ◽

Co2 Storage ◽

Co2 Solubility ◽

Two Phase ◽

Hydrate Phase ◽

Water Equilibrium

Understanding of CO2 hydrate–liquid water two-phase equilibrium is very important for CO2 storage in deep sea and in submarine sediments. This study proposed an accurate thermodynamic model to calculate CO2 solubility in pure water and in seawater at hydrate–liquid water equilibrium (HLWE). The van der Waals–Platteeuw model coupling with angle-dependent ab initio intermolecular potentials was used to calculate the chemical potential of hydrate phase. Two methods were used to describe the aqueous phase. One is using the Pitzer model to calculate the activity of water and using the Poynting correction to calculate the fugacity of CO2 dissolved in water. Another is using the Lennard–Jones-referenced Statistical Associating Fluid Theory (SAFT-LJ) equation of state (EOS) to calculate the activity of water and the fugacity of dissolved CO2. There are no parameters evaluated from experimental data of HLWE in this model. Comparison with experimental data indicates that this model can calculate CO2 solubility in pure water and in seawater at HLWE with high accuracy. This model predicts that CO2 solubility at HLWE increases with the increasing temperature, which agrees well with available experimental data. In regards to the pressure and salinity dependences of CO2 solubility at HLWE, there are some discrepancies among experimental data. This model predicts that CO2 solubility at HLWE decreases with the increasing pressure and salinity, which is consistent with most of experimental data sets. Compared to previous models, this model covers a wider range of pressure (up to 1000 bar) and is generally more accurate in CO2 solubility in aqueous solutions and in composition of hydrate phase. A computer program for the calculation of CO2 solubility in pure water and in seawater at hydrate–liquid water equilibrium can be obtained from the corresponding author via email.

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Theoretical analysis of counter-current absorption of a poorly soluble gas based on the PDE-AD model

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19861222 ◽

1986 ◽

Vol 51 (6) ◽

pp. 1222-1239 ◽

Cited By ~ 1

Author(s):

Pavel Moravec ◽

Vladimír Staněk

Keyword(s):

Experimental Data ◽

Liquid Phase ◽

Gas Phase ◽

Transfer Functions ◽

Packed Bed ◽

Packed Bed Column ◽

Interfacial Transport ◽

Gaseous Component ◽

Poorly Soluble ◽

Counter Current

Expression have been derived in the paper for all four possible transfer functions between the inlet and the outlet gas and liquid steams under the counter-current absorption of a poorly soluble gas in a packed bed column. The transfer functions have been derived for the axially dispersed model with stagnant zone in the liquid phase and the axially dispersed model for the gas phase with interfacial transport of a gaseous component (PDE - AD). calculations with practical values of parameters suggest that only two of these transfer functions are applicable for experimental data evaluation.

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Effect of ionizing radiation on the kinetics of hydrogenation on the Ni-MgO mixed catalyst

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19821780 ◽

1982 ◽

Vol 47 (7) ◽

pp. 1780-1786 ◽

Cited By ~ 2

Author(s):

Rostislav Kudláček ◽

Jan Lokoč

Keyword(s):

Experimental Data ◽

Activation Energy ◽

Liquid Phase ◽

Ionizing Radiation ◽

Oxide Catalyst ◽

Absorbed Dose ◽

Hydrogenation Rate ◽

Solution Composition ◽

Mixed Catalyst ◽

Kinetics Of

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.

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Proof of Concept: Development of Snow Liquid Water Content Profiler Using CS650 Reflectometers at Caribou, ME, USA

Sensors ◽

10.3390/s17030647 ◽

2017 ◽

Vol 17 (3) ◽

pp. 647 ◽

Cited By ~ 2

Author(s):

Carlos Pérez Díaz ◽

Jonathan Muñoz ◽

Tarendra Lakhankar ◽

Reza Khanbilvardi ◽

Peter Romanov

Keyword(s):

Water Content ◽

Liquid Water ◽

Liquid Water Content ◽

Concept Development ◽

Proof Of Concept

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Electrically Induced Liquid–Liquid Phase Transition in a Floating Water Bridge Identified by Refractive Index Variations

Water ◽

10.3390/w13050602 ◽

2021 ◽

Vol 13 (5) ◽

pp. 602

Author(s):

Elmar C. Fuchs ◽

Jakob Woisetschläger ◽

Adam D. Wexler ◽

Rene Pecnik ◽

Giuseppe Vitiello

Keyword(s):

Phase Transition ◽

Refractive Index ◽

Liquid Phase ◽

Pure Water ◽

Resonance Effect ◽

Water Bridge ◽

Liquid Phase Transition ◽

Light Passing ◽

Floating Water Bridge ◽

Set Up

A horizontal electrohydrodynamic (EHD) liquid bridge (also known as a “floating water bridge”) is a phenomenon that forms when high voltage DC (kV·cm−1) is applied to pure water in two separate beakers. The bridge, a free-floating connection between the beakers, acts as a cylindrical lens and refracts light. Using an interferometric set-up with a line pattern placed in the background of the bridge, the light passing through is split into a horizontally and a vertically polarized component which are both projected into the image space in front of the bridge with a small vertical offset (shear). Apart from a 100 Hz waviness due to a resonance effect between the power supply and vortical structures at the onset of the bridge, spikes with an increased refractive index moving through the bridge were observed. These spikes can be explained by an electrically induced liquid–liquid phase transition in which the vibrational modes of the water molecules couple coherently.

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