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Experimental and numerical modeling of CO 2 leakage in the vadose zone
Author(s) -
Gasparini Andrea,
Credoz Anthony,
Grandia Fidel,
Garcia David Angel,
Bruno Jordi
Publication year - 2015
Publication title -
greenhouse gases: science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.45
H-Index - 32
ISSN - 2152-3878
DOI - 10.1002/ghg.1523
Subject(s) - vadose zone , saturation (graph theory) , leakage (economics) , soil water , environmental science , soil science , dns root zone , tracer , geology , physics , mathematics , macroeconomics , combinatorics , economics , nuclear physics
Abstract This study presents the experimental and modeling results of CO 2 injection and transport in the vadose zone performed in PISCO2 facilities at the ES.CO2 center in Ponferrada (North Spain). During 46 days of experiments, 62.10 kg of CO 2 were injected through 16 micro‐injectors in a 35 m 3 experimental unit filled with sandy material. Monitoring and mapping of surface CO 2 flux were performed periodically to assess the evolution of CO 2 migration through the soil and to the atmosphere. Numerical simulations were run using TOUGH2 code with EOS7CA research module considering two phases (gas and liquid) and three components (H 2 O, CO 2 , air). Two layers (sand, gravel) and atmosphere boundary were implemented taking into account heterogeneous soils, homogeneous soil, rainfall, temperature, and liquid saturation to allow a better understanding of CO 2 behavior in the vadose zone. This combined experimental and modeling approach shows that CO 2 leakage in the vadose zone quickly comes out through preferential migration pathways and spots with the ranges of fluxes in the ground/surface interface from 2.5 to 600 g·m −2 ·day −1 . This gas channeling is mainly related to soil compaction and climatic perturbation. This has significant implications for design‐adapted detection and monitoring strategies of early leakage in commercial CO 2 storage. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd