Dissolving pulp from Melocanna baccifera (Muli bamboo) by formic acid process

Abstract

Abstract Bamboo is an increasingly important non-wood fiber source for pulp production, particularly in the Asia-Pacific region. This study produced dissolving pulp from Melocanna baccifera (Muli bamboo), a species native to Bangladesh, using a formic acid (FA)-based organosolv process followed by peroxyformic acid (PFA) treatment and two-stage alkaline peroxide bleaching. The Muli bamboo had 48.89 % α-cellulose, 21.08 % hemicellulose, 23.32 % lignin, and 3.57 % ash. FA delignification was carried out under boiling temperature with varying FA concentrations (70–90 %) and reaction times (4–6 h). Under optimal conditions (90 % FA, 5 h), pulp yield was 46.98 %, kappa number 40.5, and brightness 15.80 %. Subsequently, PFA treatment was carried out with 4 % H 2 O 2 in 80–90 % FA for 2 h at 80 °C, and reduced kappa number to as low as 20.7 and improved the brightness to 39.3 %, though viscosity decreased from 10.4 to 7.4 mPas with increasing FA concentration. Two-stage alkaline peroxide bleaching (4 % and 2 % H 2 O 2 in 1st and 2nd stage, respectively) produced pulps with excellent brightness (>91 %), high α-cellulose content (93.3–95.9 %), and notably low viscosity (2.3 cP). The 90 % FA/PFA-treated pulp achieved 93.58 % brightness and 95.89 % α-cellulose. These properties meet key requirements for dissolving pulp intended for rayon production.