Biopower with molten carbonate fuel cell carbon dioxide capture: Performance, cost, and grid-integration evaluations

Bioenergy with carbon capture and storage for power generation (BECCS-power) is a negative emissions technology that could potentially play significant roles in helping achieve climate-change mitigation goals. We evaluate a novel BECCS-power technology utilizing molten carbonate fuel cell-based post-combustion carbon dioxide (CO2) capture (MCFC-CC). We present detailed, internally self-consistent plant-level performance simulation results, techno-economic analyses, and lifecycle greenhouse gas emissions assessment for this technology, with comparisons against conventional monoethanolamine-based post-combustion CO2 capture (MEACC) and biopower without CO2 capture. We additionally carry out grid capacity expansion modeling to 2050 to assess how BECCS-power options might compete with other generators in a case study region (southern region of the Midcontinent Independent System Operator, MISO). This comprehensive work is not only the first rigorous engineering assessments of MCFC for BECCS but also the first techno-economic analyses of MCFC-CC of any type that includes its evaluation in the context of power grid operation. For a biomass input rate of 500 MW thHHV , a MCFC-CC plant generates triple the power and has nearly double the efficiency of a MEA-CC plant (261.5 MWe at 33.5% efficiency vs. 87.2 MWe at 17.4% efficiency). The plants generate comparable levels of negative emissions per tonne of biomass input: 1.3 and 1.5 tCO2, respectively. For a fully-depreciated coal-fired steam-cycle plant repowered for biomass and CO2 capture, the (Nth plant) levelized cost of electricity (LCOE) for MCFC-CC ($113/ MWh) is about half that for MEA-CC owing to a lower estimated unit capital cost ($2,479/kWnet vs. $4,665/ kWnet) and higher efficiency. When 45Q tax credits available under the 2022 Inflation Reduction Act (IRA) are applied, the LCOE of the MCFC-CC is comparable to that of a plant without CO2 capture ($85/MWh). From the capacity expansion modeling, if the southern MISO grid would have a target grid-average carbon emission intensity of 50 kgCO2/MWh or less in 2050, several gigawatts of Bio-MCFC-CC would be economically deployed, and the marginal cost of emissions abatement ($92/tCO2) would be dramatically lower than if it were not a deployment option.