Biosurfactant as an Enhancer of Geologic Carbon Storage: Microbial Modification of Interfacial Tension and Contact Angle in Carbon dioxide/Water/Quartz Systems

Authors

Taehyung Park, Korea Advanced Institute of Science and Technology
Hyun-Woo Joo, Korea Advanced Institute of Science and Technology
Gyeong-Yeong Kim, Korea Advanced Institute of Science and Technology
Seunghee Kim, University of Nebraska-LincolnFollow
Sukhwan Yoon, Korea Advanced Institute of Science and Technology
Tae-Hyuk Kwon, Korea Advanced Institute of Science and TechnologyFollow

ORCID IDs

Seunghee Kim

Document Type

Article

Date of this Version

2017

Citation

Park T, Joo H-W, Kim G-Y, Kim S, Yoon S and Kwon T-H (2017) Biosurfactant as an Enhancer of Geologic Carbon Storage: Microbial Modification of Interfacial Tension and Contact Angle in Carbon dioxide/Water/Quartz Systems. Front. Microbiol. 8:1285. doi: 10.3389/fmicb.2017.01285

Comments

Copyright © 2017 Park, Joo, Kim, Kim, Yoon and Kwon. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).

Abstract

Injecting and storing of carbon dioxide (CO₂) in deep geologic formations is considered as one of the promising approaches for geologic carbon storage. Microbial wettability alteration of injected CO₂ is expected to occur naturally by microorganisms indigenous to the geologic formation or microorganisms intentionally introduced to increase CO₂ storage capacity in the target reservoirs. The question as to the extent of microbial CO₂ wettability alteration under reservoir conditions still warrants further investigation. This study investigated the effect of a lipopeptide biosurfactant—surfactin, on interfacial tension (IFT) reduction and contact angle alteration in CO₂/water/quartz systems under a laboratory setup simulating in situ reservoir conditions. The temporal shifts in the IFT and the contact angle among CO₂, brine, and quartz were monitored for different CO₂ phases (3 MPa, 30°C for gaseous CO₂; 10 MPa, 28°C for liquid CO₂; 10 MPa, 37°C for supercritical CO₂) upon cultivation of Bacillus subtilis strain ATCC6633 with induced surfactin secretion activity. Due to the secreted surfactin, the IFT between CO₂ and brine decreased: from 49.5 to 30 mN/m, by ~39% for gaseous CO₂; from 28.5 to 13 mN/m, by 54% for liquid CO₂; and from 32.5 to 18.5 mN/m, by ~43% for supercritical CO₂, respectively. The contact angle of a CO₂ droplet on a quartz disk in brine increased: from 20.5° to 23.2°, by 1.16 times for gaseous CO₂; from 18.4° to 61.8°, by 3.36 times for liquid CO₂; and from 35.5° to 47.7°, by 1.34 times for supercritical CO₂, respectively. With the microbially altered CO₂ wettability, improvement in sweep efficiency of injected and displaced CO₂ was evaluated using 2-D pore network model simulations; again the increment in sweep efficiency was the greatest in liquid CO₂ phase due to the largest reduction in capillary factor. This result provides novel insights as to the role of naturally occurring biosurfactants in CO₂ storage and suggests that biostimulation of biosurfactant production may be a feasible technique for enhancement of CO₂ storage capacity.