As a part of the FP7 funded CarbFix project (no. 283148), the CarbFix team has created improved computer accessible databases describing the thermodynamics and kinetics of fluid-rock interaction during carbon-capture and storage efforts. The databases are open source and can be downloaded below.
A thermodynamic dataset describing 36 mineral reactions of interest for CO2–water–basalt interaction associated with CO2 mineral sequestration was assessed and generated. Mineral selection for the dataset was based on extensive review of natural analogs of water–basalt interaction at low and elevated CO2 conditions. Widely used thermodynamic databases did not contain the mineral assemblage needed for successfully simulating the alteration processes observed in nature as important primary and secondary minerals were found to be missing.
The EQ3/6 V7.2b database was the primary source for aqueous equilibrium constants in the developed dataset but reactions for four missing Al-hydroxy complexes were added. Recently published thermodynamic data were compiled for most of the minerals considered in this study. Mineral solubility constants obtained directly from measurements were compiled to the dataset without modification but SUPCRT92 was used for computing solubility constants when such data was not available. To verify that the presented dataset can capture alterations observed in nature, simulations of CO2–water–basalt interaction were carried out at low and elevated CO2 conditions and compared to observed basalt alteration in Iceland and Greenland. Overall simulated and observed alteration are in close agreement, both at low and elevated CO2 conditions, suggesting the dataset to be well suited for simulations of e.g. CO2–water–basalt interaction associated with CO2 mineral sequestration in basalts.
Click the document below to access the thermodynamic database.
A general database of the current state of knowledge of the rates of mineral dissolution and precipitation reactions has been created by the CarbFix team over the past three years. The database currently contains more than 110 rock forming minerals, and has been put into general form such that it can be readily applied by the scientific community to assess the potential of fluid-rock interactions during carbon capture and storage efforts.
This database was created by first collecting and correlating the existing kinetic rate data available in the scientific literature. In cases where adequate fits of these data were already available in the literature, such fits were adopted in this study. In other cases we have sought to provide a quantitative description of these data consistent with what is known about the dissolution and/or precipitation mechanism of the minerals. The resulting and adopted equations have been incorporated into a PHREEQC enabled computer script to all it to be applied directly in conjunction with this geochemical modelling code. Note that PHREEQC is widely available geochemical computer modelling code, originally created at the US Geological Survey and available free to any potential user via the web,
Click the document below to access the kinetic database.