Final Report Summary - CO2TRAP (Microbially enhanced geologic carbon capture, trapping and storage (CO2TRAP))
SUMMARY REPORT: CO2TRAP.
INTRODUCTION: Geologic storage of carbon dioxide, also known as carbon capture and storage (CCS), is one strategy to reduce the emission of greenhouse gases generated through the combustion of fossil fuels. Geologic sequestration of CO2 involves the injection of supercritical CO2 into underground brine formations such as oil bearing formations, deep un-mineable coal seams, and deep saline aquifers.
Sites where CO2 is stored could be closed and responsibility transferred with lower risk, higher confidence, thus greater insurability, if technologies existed that: i) would hasten the rate of CO2 trapping so long term stability could be reached in decades rather than centuries and ii) if rock formations could be sealed near wells, to prevent leakage through degraded steel and concrete in the closed injection well.
Previous work by the fellow has demonstrated such technology – via carbonate mineral forming bacteria and biofilms in the subsurface. This has been driven by enhancing rates of ureolysis, either by native organisms or by injected ureolytic organisms. Here, we have shown that carbonate mineral forming microorganisms and biofilms can enhance Geologic Carbon Storage (GCS) via solubility-trapping, mineral-trapping, and CO2(g) leakage reduction, by reducing flow though high permeability zones in porous media. This technology addresses EU Directive 2009/31/ to investigate methods to safely abandon GCS sites, with lower risk and higher confidence.
Such work has however, been performed under low pressure conditions for a simple brine composition. The CO2TRAP project has therefore developed this green-technology to address key knowledge gaps, specifically relating to simulating subsurface conditions. We have;
(i) Determined the effect of pressure on the biomineralization process
(ii) Determined the stability of carbonate minerals to SC-CO2 / brine mixtures under reservoir conditions
(iii) Up scaled the process from the lab to the field.
The data produced will enhance the EU’s ability to develop energy efficient, low carbon water and air treatment technologies through the 21st century for a long term environmentally sustainable future.
KEY RESULTS: The project has demonstrated that we can induce biominerlisation under reservoir conditions and that the calcium carbonate deposits produced are resilient to super-critical CO2. The model organisms used are also resilient to super-critical CO2. This indicates that contrary to prior understanding that super-critical CO2 would have a highly deleterious effect on microbes and biominerals, our work has demonstrated this is in fact not the case. Lab scale flow reactor work and field tests have demonstrated upscaling from the lab to the field, and demonstrate that mineral formation is controllable over space and time. Therefore microbially enhanced mineral formation and CO2 trapping may offer an important way to enhance the capacity and rates of CO2 storage, and reduce leakage from, the subsurface.
SOCIO-ECONOMIC IMPACTS: CO2TRAP and associated partner projects have involved a number of industrial partners who have been central to steering aspects of the research. A number of provisional patents have been applied for indicating the potential socio-economic impact. This technology addresses EU Directive 2009/31/ to investigate methods to safely abandon GCS sites, with lower risk and higher confidence.
INTRODUCTION: Geologic storage of carbon dioxide, also known as carbon capture and storage (CCS), is one strategy to reduce the emission of greenhouse gases generated through the combustion of fossil fuels. Geologic sequestration of CO2 involves the injection of supercritical CO2 into underground brine formations such as oil bearing formations, deep un-mineable coal seams, and deep saline aquifers.
Sites where CO2 is stored could be closed and responsibility transferred with lower risk, higher confidence, thus greater insurability, if technologies existed that: i) would hasten the rate of CO2 trapping so long term stability could be reached in decades rather than centuries and ii) if rock formations could be sealed near wells, to prevent leakage through degraded steel and concrete in the closed injection well.
Previous work by the fellow has demonstrated such technology – via carbonate mineral forming bacteria and biofilms in the subsurface. This has been driven by enhancing rates of ureolysis, either by native organisms or by injected ureolytic organisms. Here, we have shown that carbonate mineral forming microorganisms and biofilms can enhance Geologic Carbon Storage (GCS) via solubility-trapping, mineral-trapping, and CO2(g) leakage reduction, by reducing flow though high permeability zones in porous media. This technology addresses EU Directive 2009/31/ to investigate methods to safely abandon GCS sites, with lower risk and higher confidence.
Such work has however, been performed under low pressure conditions for a simple brine composition. The CO2TRAP project has therefore developed this green-technology to address key knowledge gaps, specifically relating to simulating subsurface conditions. We have;
(i) Determined the effect of pressure on the biomineralization process
(ii) Determined the stability of carbonate minerals to SC-CO2 / brine mixtures under reservoir conditions
(iii) Up scaled the process from the lab to the field.
The data produced will enhance the EU’s ability to develop energy efficient, low carbon water and air treatment technologies through the 21st century for a long term environmentally sustainable future.
KEY RESULTS: The project has demonstrated that we can induce biominerlisation under reservoir conditions and that the calcium carbonate deposits produced are resilient to super-critical CO2. The model organisms used are also resilient to super-critical CO2. This indicates that contrary to prior understanding that super-critical CO2 would have a highly deleterious effect on microbes and biominerals, our work has demonstrated this is in fact not the case. Lab scale flow reactor work and field tests have demonstrated upscaling from the lab to the field, and demonstrate that mineral formation is controllable over space and time. Therefore microbially enhanced mineral formation and CO2 trapping may offer an important way to enhance the capacity and rates of CO2 storage, and reduce leakage from, the subsurface.
SOCIO-ECONOMIC IMPACTS: CO2TRAP and associated partner projects have involved a number of industrial partners who have been central to steering aspects of the research. A number of provisional patents have been applied for indicating the potential socio-economic impact. This technology addresses EU Directive 2009/31/ to investigate methods to safely abandon GCS sites, with lower risk and higher confidence.