Calculation methods for carbon footprint vary in literature; here, we utilize two metrics, following the methods of Deutz et al., Qiu et al., and de Jonge et al. The first metric is carbon footprint, which is the amount of CO2 captured subtracted from the amount of CO2 emitted, normalized to the amount of CO2 captured (Eq. 3). If more CO2 is emitted than captured, the carbon footprint is positive, whereas a negative carbon footprint indicates more CO2 is captured than emitted. An ideal CO2 capture process with no associated emissions or environmental impact will have a carbon footprint of -1 t-CO2e/t-CO2 captured.