CCS and Power Systems

Carbon Storage - Geologic Storage Technologies and Simulation and Risk Assessment


The Coal-Seq III Consortium: Advancing the Science of CO2 Sequestration in Coal Seam and Gas Shale Reservoirs


Performer: Advanced Resources International, Inc.

Project No: FE0001560


Accomplishments


  • The project team completed a trial experiment using a coal sample available from a prior Coal-Seq study. The coal was obtained from a mining operation in the San Juan basin.

  • The project team has successfully compiled a database comprised of experimental vapor-liquid equilibrium (VLE) and pressure-volume-temperature (PVT) data from the literature for mixtures of CO2 and water.

  • The CO2 gas density measurements performed earlier were used to calibrate the density meter. In particular, a weighted regression technique was used, where the weights were the expected uncertainties in gas densities. The regressions provided a weighted average absolute deviation (WAAD) of 0.5 in CO2 densities. Further, an average absolute deviation (AAD) of 0.0001 g/cc was obtained, which correspond to an average absolute percentage deviation (percent AAD) of 0.03 percent.

  • Gas density measurements were conducted for pure methane and nitrogen to validate the density meter calibrations performed earlier with CO2. The density meter predicted the densities of pure methane and nitrogen with WAADs of 0.8 and 0.7, respectively. This corresponds to AADs of 0.0001 g/cc (percent AADs of 0.05 percent) for both methane and nitrogen. Thus, the density meter calibration appears capable of predicting densities of methane, nitrogen and CO2 within their expected uncertainties, on average.

  • The recently developed volume translation method for the Peng-Robinson equation of state was extended to mixtures. For this purpose, detailed thermodynamic expressions were derived and these were implemented in the computational algorithm used to perform volumetric and phase equilibrium calculations.


Project Details