Solid Sorbent Direct Air Capture Using Geothermal Energy Resources (S-DAC-GT) - Model for Region Specific Economic Analysis

Abstract

Abstract Low temperature geothermal resources, ranging from 80° to 120°C, may substantially lower both the cost and the CO2 emissions footprint of CO2 direct air capture (DAC) systems. This paper provides a model for determining a region-specific economic analysis for DAC with solid sorbent (S-DAC) using geothermal resources (S-DAC-GT). This paper provides a model for calculating estimated cost and carbon emissions for potential S-DAC facilities on a region-specific basis. The paper outlines the necessary region-specific characteristics required as parameters for the techno-economic model. The region-specific characteristics are then applied to an S-DAC energy and cost model based on existing literature to calculate the levelized cost per tonne of CO2 captured and stored. Further, the model provides a reasonable approximation of the carbon intensity of the S-DAC-GT system. These calculations allow selecting and prioritizing regions appropriate for potential S-DAC-GT facilities operating at a scale of ~1 Mt CO2 captured and stored per year. Existing DAC techno-economic analyses are region agnostic and do not account for geothermal energy as the primary thermal energy source. The novelty of this paper is its deeper technical and economic analysis using geothermal energy as the thermal resource for the S-DAC process. This paper provides a model for customization of the techno-economic model specific to the target region. Further, the paper provides a consistent methodology for differentiating S-DAC-GT costs and carbon intensity by region.