Sodium carbonate pulping of oil palm empty fruit bunches for paperboard production

Abstract

Abstract This study investigated the use of sodium carbonate pulping in oil palm empty fruit bunch (OPEFB) pulp production for paperboard manufacturing. The pulping varying the active alkali (AA) (4.5 %, 6.5 %, 8.5 %), NaOH fraction (F) (10 %, 20 %, 30 %), and cooking time (T) (30′, 60′, 90′). The performance was evaluated based on screened pulp yield, kappa number, and delignification selectivity. Furthermore, the functional groups, S/G ratio, and morphological structure of the optimum pulp were observed. The tensile and tear indices of the OPEFB pulp paperboard were also measured. The results suggest sodium carbonate pulping at a low chemical dose successfully produced OPEFB pulp. Based on the highest delignification selectivity value of 12.74, the most effective pulping conditions were achieved with AA-6.5 %, F-30 %, and T-90′. The optimum OPEFB pulp analysis revealed a decrease in lignin proportion with the dominant degradation of the syringyl unit. Thus, the fibers are easily separable during mechanical treatment. These characteristics influenced the paperboard, resulting high tensile and tear indices of 7.90–8.15 Nm g−1 and 15.09–16.25 mN m2 g−1, respectively. Overall, this study demonstrated the potential of sodium carbonate pulping to produce high-quality pulp and paperboard from OPEFBs, highlighting the thoroughness of the research process in the pulp and paper manufacturing field.