Microbially Enhanced Carbon Capture and Storage by Mineral-Trapping and Solubility-Trapping

Environ. Sci. Technol., 2010, 44 (13), pp 5270–5276
Microbially Enhanced Carbon Capture and Storage by Mineral-Trapping and Solubility-Trapping
Andrew C. Mitchell*†§, Knud Dideriksen§, Lee H. Spangler‡, Alfred B. Cunningham† and Robin Gerlach†
Center for Biofilm Engineering, Montana State University, Bozeman, Montana, 59717, Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, 59717, and NanoGeoScience Group, Nano-Science Center, Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
* Corresponding author e-mail: andrew.mitchell@erc.montana.edu., †
Center for Biofilm Engineering, Montana State University.
§University of Copenhagen.
‡Department of Chemistry and Biochemistry, Montana State University.
Abstract
Investigates the potential of microorganisms for enhancing carbon capture and storage (CCS) via mineral-trapping  and solubility trapping. The bacterial hydrolysis of urea (ureolysis) was investigated in microcosms including synthetic brine (SB) mimicking a prospective deep subsurface CCS site with variable headspace pressures [p(CO2)] of 13C-CO2.
Modeling the change in brine chemistry and carbonate precipitation after equilibration with the initial p(CO2) demonstrated that no net precipitation of CO2(g) via mineral-trapping occurred, since urea hydrolysis results in the production of dissolved inorganic carbon. However, the pH increase induced by bacterial ureolysis generated a net flux of CO2(g) into the brine. This reduced the headspace concentration of CO2 by up to 32 mM per 100 mM urea hydrolyzed because the capacity of the brine for carbonate ions was increased, thus enhancing the solubility-trapping capacity of the brine.
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