A novel high pressure column flow reactor for experimental studies of CO2 mineral storage.

The objective of this study was to design, build, and test a large scale laboratory high pressure column

flow reactor (HPCFR) enabling experimental work on water–rock interactions in the presence of dissolved

gases, demonstrated here by CO2. The HPCFR allows sampling of a pressurized gas charged liquid along

the flow path within a 2.3 m long Ti column filled with either rock, mineral, and/or glass particles. In this

study, a carbonated aqueous solution (1.2 M CO2(aq)) and basaltic glass grains was used. Given the pressure

and temperature rating (up to 10 MPa at 90 C) of the HPCFR, it can also be used with different gas

and/or gas mixtures, as well as for supercritical fluid applications. The scale of the HPCFR, the possibility

of sampling a reactive fluid at discrete spatial intervals under pressure, and the possibility of monitoring

the evolution of the dissolved inorganic carbon and pH in situ all render the HPCFR unique in comparison

with other columns constructed for studies of water–rock interactions. We hope that this novel experimental

device will aid in closing the gap between bench scale reactor experiments used to generate

kinetic data inserted into reactive transport models and field observations related to geological carbon

sequestration. A detailed description and testing of the HPCFR is presented together with first geochemical

results from a mixed H2O–CO2 injection into a basalt slurry whose solute concentration distribution

in the HPCFR was successfully modelled with the PHREEQC geochemical computer code.