Numerical Study on the Effect of Thermodynamic Phase Changes on CO2 Leakage

Hariharan Ramachandran, Gary A. Pope, Sanjay Srinivasan

Research output: Contribution to journalConference article

Abstract

Due to the concerns about the effect of greenhouse gases on the climate, Geologic CO2 storage is a very active area of research. One of the biggest risks associated with such projects is the possibility of leakage. Detrimental environmental consequences present a need to study potential leakage scenarios. Stored CO2 may leak if possible leakage pathways are available and favorable. Pressure and temperature decrease from the leakage source to the surface. Below the CO2 saturation pressure, liquid condensation of the CO2 occurs. At even lower temperatures and pressures, in the presence of water, hydrate formation occurs. CO2-hydrate forms when free water is available and the temperature is below 283 K and pressure is below 647 psi. During leakage, decreases in the temperature and pressure results in a CO2 phase change that affects the leakage flux. The purpose of this study is to estimate the leakage flux for different scenarios taking thermodynamic phase changes into account. A numerical model with coupled mass and energy balances was developed and used to estimate the flux as a function of time. Due to wide temperature and pressure changes over the course of the simulation, an accurate fluid properties model is required to reduce fluid properties related errors. Multi-parameter Span-Wagner equation of state for CO2 is used to achieve this. The numerical model allows for CO2 to exist in gas, liquid and hydrate phases. Hydrate formation was modelled using the van der Waals-Platteeuw model. Heat flux from the surroundings play an important role in effecting a phase change. Example calculations indicate a cyclical nature of the leakage flux under certain conditions. These calculations indicate the importance pressure of the leakage source (aquifer), the amount of water in the pathway (fracture/faults), the geothermal gradient and the surface temperature besides the thickness and the permeability of the fracture.

Original languageEnglish (US)
Pages (from-to)3528-3536
Number of pages9
JournalEnergy Procedia
Volume114
DOIs
StatePublished - Jan 1 2017
Event13th International Conference on Greenhouse Gas Control Technologies, GHGT 2016 - Lausanne, Switzerland
Duration: Nov 14 2016Nov 18 2016

Fingerprint

Thermodynamics
Hydrates
Fluxes
Temperature
Numerical models
Water
Fluids
Liquids
Energy balance
Aquifers
Equations of state
Greenhouse gases
Heat flux
Condensation
Gases

All Science Journal Classification (ASJC) codes

  • Energy(all)

Cite this

Ramachandran, Hariharan ; Pope, Gary A. ; Srinivasan, Sanjay. / Numerical Study on the Effect of Thermodynamic Phase Changes on CO2 Leakage. In: Energy Procedia. 2017 ; Vol. 114. pp. 3528-3536.
@article{01a158d7cfa34d838e281958516db3c8,
title = "Numerical Study on the Effect of Thermodynamic Phase Changes on CO2 Leakage",
abstract = "Due to the concerns about the effect of greenhouse gases on the climate, Geologic CO2 storage is a very active area of research. One of the biggest risks associated with such projects is the possibility of leakage. Detrimental environmental consequences present a need to study potential leakage scenarios. Stored CO2 may leak if possible leakage pathways are available and favorable. Pressure and temperature decrease from the leakage source to the surface. Below the CO2 saturation pressure, liquid condensation of the CO2 occurs. At even lower temperatures and pressures, in the presence of water, hydrate formation occurs. CO2-hydrate forms when free water is available and the temperature is below 283 K and pressure is below 647 psi. During leakage, decreases in the temperature and pressure results in a CO2 phase change that affects the leakage flux. The purpose of this study is to estimate the leakage flux for different scenarios taking thermodynamic phase changes into account. A numerical model with coupled mass and energy balances was developed and used to estimate the flux as a function of time. Due to wide temperature and pressure changes over the course of the simulation, an accurate fluid properties model is required to reduce fluid properties related errors. Multi-parameter Span-Wagner equation of state for CO2 is used to achieve this. The numerical model allows for CO2 to exist in gas, liquid and hydrate phases. Hydrate formation was modelled using the van der Waals-Platteeuw model. Heat flux from the surroundings play an important role in effecting a phase change. Example calculations indicate a cyclical nature of the leakage flux under certain conditions. These calculations indicate the importance pressure of the leakage source (aquifer), the amount of water in the pathway (fracture/faults), the geothermal gradient and the surface temperature besides the thickness and the permeability of the fracture.",
author = "Hariharan Ramachandran and Pope, {Gary A.} and Sanjay Srinivasan",
year = "2017",
month = "1",
day = "1",
doi = "10.1016/j.egypro.2017.03.1482",
language = "English (US)",
volume = "114",
pages = "3528--3536",
journal = "Energy Procedia",
issn = "1876-6102",
publisher = "Elsevier BV",

}

Numerical Study on the Effect of Thermodynamic Phase Changes on CO2 Leakage. / Ramachandran, Hariharan; Pope, Gary A.; Srinivasan, Sanjay.

In: Energy Procedia, Vol. 114, 01.01.2017, p. 3528-3536.

Research output: Contribution to journalConference article

TY - JOUR

T1 - Numerical Study on the Effect of Thermodynamic Phase Changes on CO2 Leakage

AU - Ramachandran, Hariharan

AU - Pope, Gary A.

AU - Srinivasan, Sanjay

PY - 2017/1/1

Y1 - 2017/1/1

N2 - Due to the concerns about the effect of greenhouse gases on the climate, Geologic CO2 storage is a very active area of research. One of the biggest risks associated with such projects is the possibility of leakage. Detrimental environmental consequences present a need to study potential leakage scenarios. Stored CO2 may leak if possible leakage pathways are available and favorable. Pressure and temperature decrease from the leakage source to the surface. Below the CO2 saturation pressure, liquid condensation of the CO2 occurs. At even lower temperatures and pressures, in the presence of water, hydrate formation occurs. CO2-hydrate forms when free water is available and the temperature is below 283 K and pressure is below 647 psi. During leakage, decreases in the temperature and pressure results in a CO2 phase change that affects the leakage flux. The purpose of this study is to estimate the leakage flux for different scenarios taking thermodynamic phase changes into account. A numerical model with coupled mass and energy balances was developed and used to estimate the flux as a function of time. Due to wide temperature and pressure changes over the course of the simulation, an accurate fluid properties model is required to reduce fluid properties related errors. Multi-parameter Span-Wagner equation of state for CO2 is used to achieve this. The numerical model allows for CO2 to exist in gas, liquid and hydrate phases. Hydrate formation was modelled using the van der Waals-Platteeuw model. Heat flux from the surroundings play an important role in effecting a phase change. Example calculations indicate a cyclical nature of the leakage flux under certain conditions. These calculations indicate the importance pressure of the leakage source (aquifer), the amount of water in the pathway (fracture/faults), the geothermal gradient and the surface temperature besides the thickness and the permeability of the fracture.

AB - Due to the concerns about the effect of greenhouse gases on the climate, Geologic CO2 storage is a very active area of research. One of the biggest risks associated with such projects is the possibility of leakage. Detrimental environmental consequences present a need to study potential leakage scenarios. Stored CO2 may leak if possible leakage pathways are available and favorable. Pressure and temperature decrease from the leakage source to the surface. Below the CO2 saturation pressure, liquid condensation of the CO2 occurs. At even lower temperatures and pressures, in the presence of water, hydrate formation occurs. CO2-hydrate forms when free water is available and the temperature is below 283 K and pressure is below 647 psi. During leakage, decreases in the temperature and pressure results in a CO2 phase change that affects the leakage flux. The purpose of this study is to estimate the leakage flux for different scenarios taking thermodynamic phase changes into account. A numerical model with coupled mass and energy balances was developed and used to estimate the flux as a function of time. Due to wide temperature and pressure changes over the course of the simulation, an accurate fluid properties model is required to reduce fluid properties related errors. Multi-parameter Span-Wagner equation of state for CO2 is used to achieve this. The numerical model allows for CO2 to exist in gas, liquid and hydrate phases. Hydrate formation was modelled using the van der Waals-Platteeuw model. Heat flux from the surroundings play an important role in effecting a phase change. Example calculations indicate a cyclical nature of the leakage flux under certain conditions. These calculations indicate the importance pressure of the leakage source (aquifer), the amount of water in the pathway (fracture/faults), the geothermal gradient and the surface temperature besides the thickness and the permeability of the fracture.

UR - http://www.scopus.com/inward/record.url?scp=85029643353&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85029643353&partnerID=8YFLogxK

U2 - 10.1016/j.egypro.2017.03.1482

DO - 10.1016/j.egypro.2017.03.1482

M3 - Conference article

AN - SCOPUS:85029643353

VL - 114

SP - 3528

EP - 3536

JO - Energy Procedia

JF - Energy Procedia

SN - 1876-6102

ER -