Unlocking the potential of pulp and paper industry to achieve carbon-negative emissions via calcium looping retrofit

Pulp and paper is considered to be the fourth most energy-intensive industry (EII) worldwide. However, as most of the CO₂ emissions are of biomass origin, this sector has the potential to become a carbon-negative industry. This study proposes a new concept for conversion of the pulp and paper industry to carbon negative that relies on the inherent CO₂ capture capability of the Kraft process. The techno-economic performance of the proposed carbon-negative system, based on calcium looping (CaL) retrofitted to a pulp and paper plant, was evaluated. The effect of CaL design specifications and cost assumptions on the thermodynamic and economic performance were evaluated. Under the initial design assumptions, the reference pulp and paper plant was shown to turn from electricity importer to electricity exporter with the cost of CO₂ avoided equal to 39.0 €/tCO₂. The parametric study showed that an increase in the fresh limestone make-up rate resulted in a linear increase of the specific primary energy consumption for CO₂ avoided (SPECCA) and a reduction in the amount of electricity exported to the electric grid. This translates into an increase in the price of pulp and newsprint, and the cost of CO₂ avoided. This study has also demonstrated that the pulp and paper industry has high potential to become carbon negative. It has been shown that carbon capture and storage would become economically viable in this industry if the negative CO₂ emissions are recognised and a negative CO₂ emissions credit of at least 41.8 €/tCO₂ is implemented.