Decarbonizing pulp production: a techno-economic study of Carbon Capture from Tomlinson Recovery Boiler flue gas via Molten Carbonate Fuel Cells

The pulp and paper (P&P) industry is a significant contributor to global energy consumption and CO₂ emissions, necessitating effective decarbonization strategies. This work provides the first in-depth evaluation of Molten Carbonate Fuel Cells (MCFCs) as a carbon capture solution in the P&P sector, specifically targeting the Tomlinson recovery boiler. As its CO₂ emissions are predominantly biogenic (carbon neutral), their capture enables the achievement of negative emissions. A case study techno-economic analysis for a reference medium-sized pulp mill in a U.S. context. is conducted to compare MCFC-based capture with conventional amine scrubbing (Cansolv). Two distinct configurations are analyzed for MCFC fuel: natural gas, which is considered the standard operation, and syngas, which is produced on-site through the gasification of waste biomass available in the pulp mill. The results indicate that MCFCs offer a dual advantage by enabling carbon capture while generating electricity. The natural gas-based MCFC system demonstrates a levelized cost of CO₂ capture (56 $/t_CO2) that benefits from revenue generated through electricity sales and an assumed 45 Q tax credit under the Inflation Reduction Act. The Cansolv case using natural gas to provide the energy needed for solvent regeneration has a cost of CO₂ capture of $76/t_CO2. On the other hand, the biomass-based MCFC configuration faces economic challenges due to the high costs of gasification and methanation, leading to a levelized cost of CO₂ capture of 361 $/t_CO2. A Cansolv case using biomass-combustion to provide heat for solvent generation is more economical, with a cost of CO₂ capture of $135/t_CO2.