Pulp Mill as BioCCU

Corporate image, European emission trading system, and environmental regulations, encourage pulp industry to reduce CO2 emissions. Pulp mills produce CO2 mainly in combustion processes; the largest sources are the recovery boiler, the biomass boiler, and the lime kiln. Due to utilizing mostly biomass-based fuels, the CO2 is largely biogenic. Capture and on-site utilization of CO2 could offer pulp and paper industry the possibility to act as site for negative CO2 emissions, especially when captured biogenic CO2 is used as a raw material for bioproducts. Possibilities for CO2 utilization include tall oil manufacturing, lignin extraction, and production of precipitated calcium carbonate (PCC), depending on local conditions and mill-specific details. In this study, the potential to implement BioCCU in pulp mills was estimated by analyzing the impacts of the processes on the operation of two modern reference mills, a Nordic kraft pulp mill with integrated paper production and a Southern eucalyptus pulp mill. CO2 capture is energy-intensive, and thus the effects on the energy balances of the mills were estimated. When papermaking is integrated in the pulp mill operations, energy adequacy can be a limiting factor for carbon capture implementation. Global CCU potential was estimated based on pulp production data. Pulp mills have notable CO2 capture potential, while the on-site utilization potential using currently available technologies is lower. The future of these processes depends on both technology development, desire to reuse CO2 and prospective changes in legislation.