Equilibrium conditions of clathrate hydrates formed from xenon and aqueous solutions of acetone, 1,4-dioxane and 1,3-dioxolane

2013 ◽  
Vol 339 ◽  
pp. 15-19 ◽  
Author(s):  
Tatsuo Maekawa
Keyword(s):  
Aqueous Solutions ◽  
Clathrate Hydrates ◽  
Equilibrium Conditions

scholarly journals Semi-clathrate hydrate phase stability conditions for methane + TetraButylAmmonium Bromide (TBAB)/TetraButylAmmonium Acetate (TBAA) + water system: Experimental measurements and thermodynamic modeling

2021 ◽  
Vol 76 ◽  
pp. 75
Author(s):  
Hamideh Irannezhad ◽  
Jafar Javanmardi ◽  
Ali Rasoolzadeh ◽  
Khayyam Mehrabi ◽  
Amir H. Mohammadi
Keyword(s):  
Phase Equilibrium ◽  
Aqueous Solutions ◽  
Mass Fraction ◽  
Tetrabutylammonium Bromide ◽  
Clathrate Hydrate ◽  
Clathrate Hydrates ◽  
Stability Conditions ◽  
Equilibrium Conditions ◽  
Hydrate Phase ◽  
Mass Fractions

One of the promising applications of clathrate/gas hydrates is the transport and storage of natural gas. Semi-clathrate hydrates have received more attention due to milder pressure/temperature stability conditions compared to ordinary clathrate hydrates. The most commonly reported semi-clathrate hydrates are formed from a combination of gas + water + quaternary ammonium salts. In this work, a total of 53 equilibrium data for semi-clathrate hydrates of methane + TetraButylAmmonium Bromide (TBAB)/TetraButylAmmonium Acetate (TBAA) aqueous solutions were experimentally measured. For TBAB, three concentrations including 0.0350, 0.0490, and 0.1500 mass fractions were used. For TBAA, a solution with a 0.0990 mass fraction was used. Additionally, the modified Chen–Guo model was applied to calculate the hydrate phase equilibrium conditions of methane + TBAB/TBAA aqueous solutions. The model can accurately calculate the aforementioned semi-clathrate hydrate phase equilibrium conditions with the Average Absolute Deviations ((AAD)T and (AAD)P) of 0.1 K and 0.08 MPa, respectively. The temperature increments for 0.0350, 0.0490, and 0.1500 mass fractions of TBAB are 7.7, 9.4, and 13.5 K, respectively. This value for 0.0990 mass fraction of TBAA is 6.2 K. Therefore, it is concluded that TBAB is a stronger hydrate promoter compared to TBAA.

Hydrate Equilibrium Conditions of (CH4+ C2H6+ C3H8) Gas Mixtures in Sodium Dodecyl Sulfate Aqueous Solutions†

2009 ◽  
Vol 54 (5) ◽  
pp. 1500-1503 ◽  
Author(s):  
Li-Tao Chen ◽  
Chang-Yu Sun ◽  
Yun-Qiang Nie ◽  
Zhan-Song Sun ◽  
Lan-Ying Yang ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Aqueous Solutions ◽  
Sodium Dodecyl ◽  
Gas Mixtures ◽  
Equilibrium Conditions ◽  
Dodecyl Sulfate

scholarly journals Solubility and solubilizing capabilities of aqueous solutions of Extractum Taraxaci e radix cum herba aqu. siccum in light of selected values of general Hildebrand-Scatchard-Fedors theory of solubility

2016 ◽  
Vol 62 (4) ◽  
pp. 49-65 ◽  
Author(s):  
Zbigniew Marczyński ◽  
Sławomira Nowak ◽  
Jerzy Jambor ◽  
Marian Mikołaj Zgoda
Keyword(s):  
Aqueous Solutions ◽  
Gastric Juice ◽  
Surface Activity ◽  
Complex Structure ◽  
Therapeutic Agents ◽  
The Body ◽  
Water Model ◽  
Equilibrium Conditions ◽  
Ubbelohde Viscometer ◽  
Gall Bladder Stones

Summary Introduction: The general Hildebrand-Scatchard theory of solubility supplemented by Fedors’ solubility parameter $- \delta ^{{1 \over 2}} $ was used to estimate the real solubility by −log x2 (log of the mole fraction) of phytochemicals contained in Ext. Taraxaci e radix cum herba aqu. siccum. Surface activity of aqueous solution of extracts was determined and quantified – solubilizing capabilities of solutions of cexp. ≥cmc in relation to cholesterol particle size of Ø=1.00 mm, as well as of ketoprofen were defined. Objective: The calculated value −log x2 collated with the polarity of extraction medium εM allows to estimate the optimal solubility of phytochemicals that determine the viscosity of the aqueous extract of dandelion and above all its surface activity and the ability to solubilize lipophilic therapeutic agents (ketoprofen). Methods: Viscosity of water model solutions of dandelion extracts and exhibition solutions after the effective micellar solubilization of cholesterol and ketoprofen was measured using Ubbelohde viscometer in accordance with the Polish Standard. The surface tension of aqueous solutions of extract and exhibition solutions after solubilization of cholesterol and ketoprofen was measured according to the Polish Standard with stalagmometric method. Results: The calculated factual solubility, and mainly the determined and calculated hydrodynamic size mean, that despite the complex structure of the micelle, it solubilizes cholesterol (granulometric grain of diameter Ø=1.00 mm) and ketoprofen (state of technological fragmentation) in equilibrium conditions. Equilibrium solubilization of ketoprofen also occurs in an environment of model gastric juice (0.1 mol HCl). Conclusions: The obtained results indicate that after the administration (and/or dietary supplementation) with Ext. Taraxaci e radix cum herba aqu. siccum, the physiological parameters of gastric juice would not be measured and its presence (phytosurfactant) in the body of the duodenum (bile A) increases abilities of solubilizing lipophilic therapeutic agents and cholesterol accounting for its use in the treatment of liver diseases and cholesterol gall bladder stones.

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