Towards large, fossil free mills with integrated biorefineries : trends in modern pulp mills

Abstract

Global economics require ever larger pulp mills with increased energy efficiency. Paris agreement means pulp and paper mills need to significantly reduce fossil fuel based carbon dioxide emissions. World markets are turning towards biobased products. This creates possibilities to manufacture new sellable products. At modern pulp mills, renewable heat and electricity are produced in excess of the own process requirement. Biogas and solid biofuels can be produced at the mill by processing woody biomass residue. These biofuels can then be combusted e.g. in the lime kiln to replace fossil fuels. In Northern regions, crude tall oil and crude turpentine have been produced and refined for sale. Newest mill integrate biorefineries to further increase returns from smaller revenue streams. In this study, benefits and constraints regarding selectable future mill designs are discussed.