title: Feasibility of a perfluorocarbon tracer based network to support monitoring, verification, and accounting of sequestered CO₂.
abstract: Carbon capture and sequestration (CCS) will act as a bridging technology necessary to facilitate a transition from fossil fuels to a sustainable energy based economy. The Department of Energy (DOE) target leak rate for sequestration reservoirs is 1% of total sequestered CO(2) over the lifetime of the reservoir. This is 0.001% per year for a 1000 year lifetime of a storage reservoir. Effective detection of CO(2) leaks at the surface may require incorporation of a tracer tag into the sequestered CO(2). We applied a simple Gaussian Plume model to predict dispersion of a direct leak into the atmosphere and used the results to examine the requirements for designing a perfluorocarbon (PFT) monitoring network and tracer tagging strategy. Careful consideration must be given to the climate implications of using these compounds. The quantity of PFTs needed for tagging sequestered CO(2) is too large to be practical for routine monitoring. Tagging at a level that will result in 1.5 times background at a sampler 1 km from a leak of 0.01% per year will require 625 kg per year of PFT. This is a leak rate 10 times greater than the 1000 year DOE requirement and will require 19 tons of injected PFT over the 30 year lifetime of a 1000 mega watt coal fired plant. The utility of PFTs or any other tracer will be lost if the background levels are allowed to rise indiscriminately. A better use of PFTs is as a tool in sequestration research. Instead, geological surveys of sequestration sites will be necessary to locate potential direct pathways and develop targeted monitoring strategies. A global agreement on the use of tracers for monitoring CCS projects should be developed.
authors.affiliation: Brookhaven National Laboratory, Upton, New York 11073-5000, USA. twatson@bnl.gov
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Watson
authors.forename: Terrence
authors.initials: T
authors.lastname: Sullivan
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis*; D057965:Carbon Sequestration; D004784:Environmental Monitoring / Q000379:methods*; D005466:Fluorocarbons / Q000032:analysis* / Q000737:chemistry; D007202:Indicators and Reagents / Q000032:analysis; D008956:Models, Chemical; D013997:Time Factors
chemical_list: D005466:Fluorocarbons; D007202:Indicators and Reagents; D002245:Carbon Dioxide