The effects of initial acetate concentration on CO2–brine-anorthite interactions under geologic CO2 sequestration conditions

摘要: Acetate is one of the most abundant organic compounds in many formation waters and likely to be present deep saline aquifers suitable for geologic CO2 sequestration (GCS). This work studied effect initially acetate on dissolution anorthite (CaAl2Si2O8) subsequent secondary mineral precipitation under GCS conditions (35 °C 74.8 atm). Anorthite was chosen as a model because abundance feldspar clayey sandstones possibility metal carbonation. In this study, found decrease cumulative aqueous concentrations Al, Si, Ca upon injection by inhibiting increasing amount precipitates. The extent concentration changes element-specific (Al > Si Ca), more significant systems with lower salinity pH. For dissolution, acetic acid inhibited proton-mediated decomposition Al/Si-containing framework, while anions may have facilitated ion-exchange between interstitial cations. precipitation, stoichiometry analysis suggested Al-containing mineral(s). presence kaolinite confirmed using high resolution transmission electron microscopy's diffraction data. An increase relative due initial mass balancing verified cleaved surfaces atomic force microscopy analysis. These results provide new insights understanding predicting system evolution scCO2 acetate.