Massachusetts Institute of Technology (MIT)

The Massachusetts Institute of Technology (MIT) will investigate the cost-effective design and operation of a negative carbon emissions power plant concept, invented by 8 Rivers Capital, 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 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. The DAC process will continue working even when the power plant is not operating. Preliminary calculations indicate that the system can achieve negative emissions as great as -0.16 tCO2/MWh under baseload operating conditions.