Gas hydrate formation modeling using two‐phase flow simulation

2009 ◽  
Author(s):  
Youngseuk Keehm ◽  
Jae‐Hyung Lee
Keyword(s):  
Gas Hydrate ◽  
Two Phase Flow ◽  
Hydrate Formation ◽  
Flow Simulation ◽  
Phase Flow ◽  
Two Phase ◽  
Gas Hydrate Formation

Numerical Simulation of Microscopic Formation of Carbon Dioxide Hydrate in Two-Phase Flow

2021 ◽  
Author(s):  
Alan Junji Yamaguchi ◽  
Kaito Kobayashi ◽  
Toru Sato ◽  
Takaomi Tobase
Keyword(s):  
Carbon Dioxide ◽  
Carbon Capture ◽  
Two Phase Flow ◽  
Pore Space ◽  
Carbon Capture And Storage ◽  
Hydrate Formation ◽  
Field Method ◽  
Phase Field Method ◽  
Phase Flow ◽  
Two Phase

Abstract The global warming is an important environmental concern and the carbon capture and storage (CCS) emerges as a very promising technology. Captured carbon dioxide (CO2) can be stored onshore or offshore in the aquifers. There is, however, a risk that stored CO2 will leak due to natural disasters. One possible solution to this is the natural formation of CO2 hydrates. Gas hydrate has an ice-like structure in which small gas molecules are trapped within cages of water molecules. Hydrate formation occurs under high pressure and low temperature conditions. Its stability under these conditions acts like a cap rock to prevent CO2 leaks. The main objective of this study is to understand how hydrate formation affects the permeability of leaked CO2 flows. The phase field method was used to simulate microscopic hydrate growth within the pore space of sand grains, while the lattice Boltzmann method was used to simulate two-phase flow. The results showed that the hydrate morphology within the pore space changes with the flow, and the permeability is significantly reduced as compared with the case without the flow.

Effect of Common Impurities on the Phase Behavior of Carbon-Dioxide-Rich Systems: Minimizing the Risk of Hydrate Formation and Two-Phase Flow

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 921-930 ◽  
Author(s):  
Antonin Chapoy ◽  
Rod Burgass ◽  
Bahman Tohidi ◽  
J. Michael Austell ◽  
Charles Eickhoff
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Phase Behavior ◽  
Water Content ◽  
Thermodynamic Model ◽  
Two Phase Flow ◽  
Hydrate Formation ◽  
Experimental Methodology ◽  
Phase Flow ◽  
Two Phase

Summary Carbon dioxide (CO2) produced by carbon-capture processes is generally not pure and can contain impurities such as N2, H2, CO, H2 S, and water. The presence of these impurities could lead to challenging flow-assurance issues. The presence of water may result in ice or gas-hydrate formation and cause blockage. Reducing the water content is commonly required to reduce the potential for corrosion, but, for an offshore pipeline system, it is also used as a means of preventing gas-hydrate problems; however, there is little information on the dehydration requirements. Furthermore, the gaseous CO2-rich stream is generally compressed to be transported as liquid or dense-phase in order to avoid two-phase flow and increase in the density of the system. The presence of impurities will also change the system's bubblepoint pressure, hence affecting the compression requirement. The aim of this study is to evaluate the risk of hydrate formation in a CO2-rich stream and to study the phase behavior of CO2 in the presence of common impurities. An experimental methodology was developed for measuring water content in a CO2-rich phase in equilibrium with hydrates. The water content in equilibrium with hydrates at simulated pipeline conditions (e.g., 4°C and up to 190 bar) as well as after simulated choke conditions (e.g., at -2°C and approximately 50 bar) was measured for pure CO2 and a mixture of 2 mol% H2 and 98 mol% CO2. Bubblepoint measurements were also taken for this binary mixture for temperatures ranging from -20 to 25°C. A thermodynamic approach was employed to model the phase equilibria. The experimental data available in the literature on gas solubility in water in binary systems were used in tuning the binary interaction parameters (BIPs). The thermodynamic model was used to predict the phase behavior and the hydrate-dissociation conditions of various CO2-rich streams in the presence of free water and various levels of dehydration (250 and 500 ppm). The results are in good agreement with the available experimental data. The developed experimental methodology and thermodynamic model could provide the necessary data in determining the required dehydration level for CO2-rich systems, as well as minimum pipeline pressure required to avoid two-phase flow, hydrates, and water condensation.

Two-phase flow simulation of reactor clarifiers

2008 ◽  
Vol 39 (3) ◽  
pp. 275-280 ◽  
Author(s):  
Wen-Jie Yang ◽  
Chu-Chuao Wang ◽  
Ren-Yi Hsu ◽  
Rome-Ming Wu
Keyword(s):  
Two Phase Flow ◽  
Flow Simulation ◽  
Phase Flow ◽  
Two Phase

Modeling of Sodium Two-Phase Flow With the TRACE Code

2009 ◽  
Author(s):  
Aurelia Chenu ◽  
Konstantin Mikityuk ◽  
Rakesh Chawla
Keyword(s):  
Single Phase ◽  
Two Phase Flow ◽  
Flow Simulation ◽  
Phase Flow ◽  
Fluid Models ◽  
Code System ◽  
Two Phase ◽  
Liquid Flows ◽  
Transfer Mechanisms ◽  
Two Fluid

In the framework of PSI’s FAST code system, the TRACE thermal-hydraulics code is being extended for representation of sodium two-phase flow. As the currently available version (v.5) is limited to the simulation of only single-phase sodium flow, its applicability range is not enough to study the behavior of a Sodium-cooled Fast Reactor (SFR) during a transient in which boiling is anticipated. The work reported here concerns the extension of the two-fluid models, which are available in TRACE for steam-water, to sodium two-phase flow simulation. The conventional correlations for ordinary gas-liquid flows are used as basis, with optional correlations specific to liquid metal when necessary. A number of new models for representation of the constitutive equations specific to sodium, with a particular emphasis on the interfacial transfer mechanisms, have been implemented and compared with the original closure models. As a first application, the extended TRACE code has been used to model experiments that simulate a loss-of-flow (LOF) accident in a SFR. The comparison of the computed results, with both the experimental data and SIMMER-III code predictions, has enabled validation of the capability of the modified TRACE code to predict sodium boiling onset, flow regimes, dryout, flow reversal, etc. The performed study is a first-of-a-kind application of the TRACE code to two-phase sodium flow. Other integral experiments are planned to be simulated to further develop and validate the two-phase sodium flow methodology.

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