The broader impact/commercial potential of this Small Business Innovation Research (SBIR) project is the potential to deploy a powerful tool for carbon capture. CO2-capture is the foundation of greenhouse gas mitigation. The high cost of current processes for CO2-capture have prevented their widespread deployment. High-pressure, Density-driven Separator (HDS) technology efficiently and continuously captures CO2 from gas streams, including both flue gas and fuel gas. An HDS module produces nearly Pure High-pressure CO2 (PH-CO2). HDS technology has transformational operating expense enabled by innovative strategies for compression, expansion, energy recovery, and subsequent use of the dense and light fractions. An HDS module has no moving parts, membranes, pressure swings or temperature swings. Therefore, HDS technology has the potential for very low capital expense. These low costs allow access to financial markets. Other revenue sources are also facilitated by low capture cost. For instance, PH-CO2 is food grade, valued in excess of $100/ton. PH-CO2 is suitable for enhanced oil recovery. HDS technology separates CO2 from fuel gas, producing a valuable high-pressure vapor, in addition to PH-CO2. HDS technology dramatically reduces the CO2-capture cost and provides a purity that enables a profitable B2B model. This STTR Phase I project proposes to develop HDS technology. Quantitative metrics will be refined and employed to develop detailed capital expense and operating cost models. Two technical hurdles must be overcome to reduce these costs. These hurdles are also opportunities for innovation. The first opportunity is to achieve sufficient volumetric efficiency in the pressure vessel for commercial deployment. The equilibrium state inside the HDS module is perfect separation. Increasing the rate of approach to that equilibrium state reduces the size and cost of the HDS module. This will be accomplished by exploiting the synergy between fluid state, surface state, fluid motion, and gravity. This synergy coalesces CO2, allowing its rapid separation from the remaining components of flue gas and fuel gas. The second opportunity is to achieve sufficient overall process efficiency for commercial deployment. The power required for compression determines operating expense. Our strategy involves operating the near-isothermal cold compression train and near-isothermal hot expansion train as a heat engine (an approximation of the Ericsson cycle). In this manner, innovative gerotor compressors and expanders work together with heat exchangers using waste heat to reduce or eliminate operating costs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
