Phase Equilibria of Clathrate Hydrates in Hydrogen Sulfide + diethylene Glycol or Triethylene Glycol + water System

A modified CPA equation of state has been applied for the description of noninhibited hydrates. In this work, this model is applied to the description of dissociation curves of hydrates inhibited by six thermodynamic inhibitors (methanol, ethanol, MEG, DEG, TEG, and glycerol), while also focusing on promoting a correct simultaneous description of SLE and VLE between the inhibitors and water. The study concern some of the most well-known hydrate formers (methane, ethane, propane, CO 2 , Xe, and H 2 S) and mixtures of these gases. The maximum number of binary interaction parameters applied between water and the hydrate inhibitor is two, one for the physical term and one for association. A comparison between this approach and the hydrates model present on Multiflash is reported, revealing that the present approach, while less accurate than Multiflash is still able to correctly describe hydrate inhibition, VLE and LLE, while using a smaller number of parameters.

show abstract

“…wt % refers to weight percentage of inhibitor in aqueous solution. ○, Mohammadi and Richon; □, Ng and Robinson; ◊, Mohammadi and Richon …”

Section: Results and Discussionmentioning

confidence: 99%

Modeling Hydrate Dissociation Curves in the Presence of Hydrate Inhibitors with a Modified CPA EoS

Palma

Queimada

Coutinho

2019

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Experimental and predicted hydrate dissociation conditions for a binary mixture of the H 2 S + CH 4 + H 2 O system at different H 2 S concentrations: curves represent model and HydraFlash results: solid black curve: the proposed model predictions; dotted red curve: the HydraFlash predictions. Symbols represent experimental data: (□) pure CH 4 ; ( ○ ) 0.005 mole fraction H 2 S; (◇) 0.0311 mole fraction H 2 S; (▲) 0.044 mole fraction H 2 S; (△) 0.0715 mole fraction H 2 S; (●) 0.1151 mole fraction H 2 S; (■) pure H 2 S …”

Section: Resultsmentioning

confidence: 99%

Experimental Measurements and Thermodynamic Modeling of CH₄ + H₂S + MEG Hydrate Phase-Equilibrium Conditions at 6.2–12.3 MPa

Aminolroayaei

Rizi²,

Mohammad-Taheri³

et al. 2022

J. Chem. Eng. Data

View full text Add to dashboard Cite

This work generated experimental gas hydrate equilibrium data with a gas composition containing CH 4 (99 mol fraction) + H 2 S (1 mol fraction) similar to the field. The stepwise heating isochoric pressure search method was used for uninhibited and inhibited systems with mono-ethylene glycol (MEG). Thermodynamic consistency of the experimental data in the presence of MEG was performed for each concentration. Based on the three assessments presented, the experimental data consistency was good for 15 and 20 wt % and moderate for 10 wt %. Finally, an in-house model was developed based on the experimental data. The proposed model with the given assumptions and limitations showed 1−2% more deviation than HydraFlash predicted for the system containing 10−20 wt % MEG. In this work, the prediction of HydraFlash was the one with the lowest average absolute relative deviation in pressure (AARDP) % between different equations of state available in the software for each system. Hence, the deviation range of AARDP % was acceptable for an in-house model to be developed for the gas industry compared to the commercial software.

show abstract

Universal correlation for gas hydrates suppression temperature of inhibited systems: III. salts and organic inhibitors

Lee

et al. 2018

AIChE Journal

View full text Add to dashboard Cite

In Parts I and II, the Hu‐Lee‐Sum (HLS) correlation was developed and demonstrated to have an inherent generality and simplicity to predict structures I and II gas hydrates suppression temperature for both single and mixed salts systems. Utilization of thermodynamic hydrate inhibitors (THIs) is common practice in industry to prevent hydrate formation. Therefore, the HLS correlation is extended to predict hydrate suppression temperature with either single or mixed THIs, including any combination of inorganic salts and organic inhibitors. It is verified that hydrate equilibrium conditions with organic inhibitors also shows nearly independence of the water activity on temperature. In addition, additive contribution of salts and organic inhibitors to the water activity are used to determine the hydrate suppression temperature. A comprehensive comparison between the literature data and predicted results demonstrate the reliability of the HLS correlation for any combination of inorganic salts and organic inhibitors. © 2018 American Institute of Chemical Engineers AIChE J, 64: 4097–4109, 2018

show abstract

Phase Equilibria of Clathrate Hydrates in Hydrogen Sulfide + diethylene Glycol or Triethylene Glycol + water System

Cited by 8 publications

References 15 publications

Modeling Hydrate Dissociation Curves in the Presence of Hydrate Inhibitors with a Modified CPA EoS

Modeling Hydrate Dissociation Curves in the Presence of Hydrate Inhibitors with a Modified CPA EoS

Experimental Measurements and Thermodynamic Modeling of CH₄ + H₂S + MEG Hydrate Phase-Equilibrium Conditions at 6.2–12.3 MPa

Universal correlation for gas hydrates suppression temperature of inhibited systems: III. salts and organic inhibitors

Contact Info

Product

Resources

About

Phase Equilibria of Clathrate Hydrates in Hydrogen Sulfide + diethylene Glycol or Triethylene Glycol + water System

Cited by 8 publications

References 15 publications

Modeling Hydrate Dissociation Curves in the Presence of Hydrate Inhibitors with a Modified CPA EoS

Modeling Hydrate Dissociation Curves in the Presence of Hydrate Inhibitors with a Modified CPA EoS

Experimental Measurements and Thermodynamic Modeling of CH4 + H2S + MEG Hydrate Phase-Equilibrium Conditions at 6.2–12.3 MPa

Universal correlation for gas hydrates suppression temperature of inhibited systems: III. salts and organic inhibitors

Contact Info

Product

Resources

About

Experimental Measurements and Thermodynamic Modeling of CH₄ + H₂S + MEG Hydrate Phase-Equilibrium Conditions at 6.2–12.3 MPa