Evaluation of Unbleached Pulps from Miscanthus x giganteus and Miscanthus Cultivars for Tissue Paper Production

Abstract

This study assessed the suitability of four Miscanthus cultivars as alternative raw materials for pulp and paper production. A field evaluation revealed that cultivars 1 and 6 achieved the highest biomass yield ratios, at 2.4 and 2.0, compared to Miscanthus x giganteus. Chemical characterization identified cultivar 6 as favorable for pulping, exhibiting low extractives (1.35%), Klason lignin (14.5%) and moderate ash contents (1.37%). Pulp yields of up to 61.5% were achieved by soda pulping at 160 °C for 90 min and the addition of 15% NaOH by weight of the raw material. Cultivar 23 had the lowest residual lignin content at 1.1%. After refining to 500 PFI revolutions, sheets (30 gsm basis weight) produced from cultivar 6 achieved a tensile index of 43.9 N·m/g. The same tensile index as eucalyptus (44.0 N·m/g) was exhibited after 3000 rotations in the PFI mill. Overall, the results demonstrated that the selected Miscanthus cultivars, especially cultivar 6, is a promising source of fiber, particularly for products that require high absorbency and strength.