The US Department of Energy announced $11.5 million in funding for 12 projects as part of Phase 1 of the Advanced Research Projects Agency-Energy’s (ARPA-E’s) FLExible Carbon Capture and Storage (FLECCS) program.

FLECCS project teams will work to develop carbon capture and storage (CCS) processes that better enable technologies, such as natural gas power generators, to be responsive to grid conditions in a high variable renewable energy (VRE) penetration environment.

FLECCS project teams are developing CCS retrofits to existing power generators as well as greenfield systems that intake fossil carbon-containing fuel like natural gas or bio-gas and output electricity. FLECCS Phase 1 teams will design, model, and optimize CCS processes that enable flexibility on a high-VRE grid. Later in the program, teams that move to Phase 2 will focus on building components, unit operations, and prototype systems to reduce technical risks and costs.

In FLECCS Phase 2, up to $31 million in additional funding will be available for teams. At the conclusion of the Phase 1 period, teams will be down-selected based on an engineering design review and the projected economic impact of their Phase 1 projects on a future electricity grid. Selected teams will move on to receive additional funding, further develop their technologies and address Phase 2 challenges.

Phase 1 FLECCS projects are:

GE Global Research. Flexible Oxy-Fuel Combustion for High-Penetration Variable Renewables - $717,658.
GE Global Research will optimize an oxy-combustion natural gas-fired turbine—the Allam-Fetvedt cycle—for flexible generation on a grid with high-variable renewable energy (VRE) penetration at near-zero carbon emissions. The team will use gas or liquid buffering tanks and tight thermal integration between the air separation unit and the oxy-combustion turbine. The proposed technology easily separates the CO₂ and H₂O in the flue gas of an oxy-combustor. The post-combustion outlet gas is more easily separated into water and CO₂ to the pipeline, thereby lowering the electricity costs of grids with high levels of VRE.

8 Rivers Capital. Enhancing Responsiveness of Gas Turbine Generators through Retrofitting with Exhaust Gas Recycle and a Phase-Change CO₂ Capture Process - $1,178,453.
8 Rivers Capital seeks to enhance the profitability and responsiveness of gas turbine generators in high variable renewable energy environments by retrofitting existing plants with Exhaust Gas Recycle (EGR) and a novel phase-change solvent CO₂ capture system known as UNO MK3, offering a lower cost pathway than new gas turbines with capture. The team’s system uses a low-energy regeneration solvent to maximize EGR potential by reducing absorber and stripper size and cost. The technology uses 10-15% less energy than existing amine absorbents. UNO MK3 allows CO₂ to be withdrawn and stored as solid potassium bicarbonate during high energy demand, eliminating stripper energy and enabling profitable regeneration.

Colorado State University. Synergistic Heat Pumped Thermal Storage and Flexible Carbon Capture System - $1,000,000.
Colorado State University will develop a thermal energy storage system combined with partner ION Clean Energy’s flexible advanced solvent carbon capture technology. The system aims to decrease the levelized cost of electricity for natural gas-fired combined cycle (NGCC) power plants to <75 $/MWh while simultaneously capturing 95% of CO₂ emissions when operating in highly variable renewable energy penetration markets. The team’s approach uses a novel and low-cost heat-pump thermal storage system. This system nables load shifting and NGCC efficiency benefits to reduce capital costs and achieve higher net plant capacities for electrical grid markets that require substantial dynamic changes in power plant output.

RTI International. Advanced CO₂ Capture Solvent Systems for Dynamic Power- $999,470.
RTI International will develop a cost-effective, resilient, load-following advanced CO₂ capture technology for natural gas power plants. The team’s CO₂ capture process maximizes the net present value of the plant by using advanced water-lean solvents (WLSs) and process intensification equipment, such as a rotating packed bed (RPB) centrifugal absorber and dual-stage flash solvent regeneration. Advanced WLSs decrease operating costs by requiring low energy for solvent regeneration. RPBs reduce power plant capital cost by intensifying the absorption process to enable a reduced absorber size compared to conventional packed beds. The dual-stage flash regenerator will improve flexibility and reduce capital cost compared to a conventional reboiler.

University of Pittsburgh. Natural Gas/Direct Air Capture Hybrid Plant - $800,283.
The University of Pittsburgh will develop a natural gas-fired combined cycle (NGCC) power plant hybrid that uses membrane and sorbent carbon capture systems. Under normal operations, the NGCC plant produces power, and the two carbon capture systems capture roughly 99% of the CO₂. During off-peak hours, the NGCC plant powers the two carbon capture systems, one corresponding to the post-combustion gases of the power plant and the other to CO₂ capture from the air. The team will develop models, optimize the system using DOE-developed tools, and perform dynamic simulations. It is expected that the hybrid plant’s negative emissions technology captures more CO₂ than the plant produces, is flexible to changes in the electric grid, and can profit from carbon prices during off-peak hours to minimize capital costs.

Georgia Institute of Technology. Positive Power with Negative Emissions: Flexible NGCC Enabled by Modular Direct Air Capture - $1,009,210.
The Georgia Institute of Technology (Georgia Tech) will develop a modular direct air capture (DAC) process to be integrated with flexible natural gas-fired combined cycle (NGCC) power plants. This approach couples CO₂ emissions capture from the natural gas plant using conventional technology with a novel design based on materials capable of removing CO₂ from the air. The NGCC plant will run continuously, and the conventional technology will perform at its most efficient level. In times of low demand, steam and power from the natural gas plant are directed to remove CO₂ from the atmosphere. The modular nature of the direct air capture system allows for partial operation, making it highly flexible and allowing power generators to respond to variable renewable energy production.

Linde Gas North America. Process Integration and Optimization of an NGCC Power Plant with CO₂ Capture, Hydrogen Production and Storage - $479,966.
Linde Gas aims to develop such a system for natural gas-fired power plants using post-combustion carbon capture and hydrogen technologies. Integrating an electrolyzer for hydrogen production and tanks for hydrogen storage with a natural gas power plant that has carbon capture will enable the plant to operate under more steady-state conditions, improve its efficiency, and increase its capital utilization. Eliminating frequent starts and stops of these large power systems will also reduce fugitive carbon emissions during ramp-ups and ramp- downs. The value of this process design becomes greater as the differential in high and low prices of electricity increases and value for CO₂ emissions improves.

Massachusetts Institute of Technology. Power Plant CO₂ Capture Integrated with Lime-based Direct Air Capture - $810,000.
The Massachusetts Institute of Technology (MIT) will investigate the cost-effective design and operation of a negative carbon emissions power plant concept that combines flue gas CO₂ capture with a lime-based direct air capture (DAC) process while not affecting power plant flexibility. First, the power plant flue gas is fed into a calciner, a reactor that breaks down calcium carbonate (CaCO₃) into lime and carbon dioxide (CO₂). Next, the CO2-rich gas (>30% CO₂) from the calciner is separated to recover high-purity CO₂, which can be stored. Last, the lime goes through a novel DAC process that captures additional CO₂ from the air in the form of solid CaCO₃ that can be sequestered or reused as feed to the calciner. The process can be retrofitted to existing power plants or deployed as part of new low-carbon emissions power plants.

Susteon Inc. A Rapid Temperature Swing Adsorption Carbon Capture Technology for Optimal Operation of a Fossil Power Plant - $789,009.
Susteon will evaluate a CO₂ capture technology using solid sorbents based on thermal swing adsorption that enables power generators to operate the power plant in a “load following” mode in response to grid conditions in a high variable renewable energy penetration environment. The proposed capture technology is currently being demonstrated with flue gas derived from natural gas combustion. Susteon plans to simulate the integration of this technology with an existing natural gas power plant in southern California, a region with a large amount of renewable electricity on the grid.

Southwest Research Institute. Oxygen Storage Incorporated into the Allam Oxy-Fuel Power Cycle - $762,953.
Oxygen-fueled supercritical carbon dioxide (sCO₂) power generation cycles, such as the Allam-Fetvedt cycle, improve efficiency and enable simpler carbon capture strategies. Southwest Research Institute will apply energy storage concepts to this power generation cycle by incorporating oxygen storage adjacent to the air separation unit (ASU). By operating the ASU at higher capacities when power from alternative energies is available (e.g., wind power at night or solar photovoltaic power during the day) and storing liquid oxygen (LOX), greater output from the power plant can be achieved during times of peak electricity demand. Further savings can be achieved by using LOX’s vaporization cooling to reduce the compression power of CO₂ needed for the power cycle.

Luna Innovations, Inc. Flexible FlueCO₂ - $989,660.
Luna Innovations is developing FlueCO₂, a process that enables traditional power generators to respond to increased variable renewable energy while reducing greenhouse gas emissions. FlueCO₂ is a combined membrane and gas processing technology that integrates into existing natural gas combined cycle (NGCC) power plants and actively removes CO₂ from the exhaust gas. The membrane separates CO₂ at unrivaled rates using steam generated within the plant. The CO₂-rich steam leaving the membranes is processed further to remove the water so it can be regenerated into steam at the most energy efficient conditions. Remaining CO₂ is then compressed for pipeline transport.

Envergex, LLC. Flexible Low Temperature CO₂ Capture System, E-CACHYS- $1,953,416.
Envergex aims to integrate a flexible, low-temperature CO₂ capture system (E-CACHYS) into a natural gas combined cycle power plant, capable of operating in a highly variable renewable energy environment, to attain a net-zero carbon electricity system. The technical approach is based on an innovative multi-phase sorbent technology for post combustion capture of CO₂ from flue gas. The hybrid sorbent technology, which consists of a regenerative sorbent and a novel heat exchange system for optimal energy recovery, seamlessly integrates into the natural gas combined cycle architecture. The size of the proposed carbon capture system can align with the average capacity factor of the power plant, enabling constant operating conditions in the capture system and reducing overall plant operating expenses.