Evaluation of cooking processes for Trema orientalis pulping

Abstract

Chemical and morphological properties support Trema orientalis as a new source for pulping (yield, 46-52%). Using soda, soda-anthraquinone (AQ), kraft, alkaline-sulfite-anthraquinone-methanol (ASAM), acetic acid (AA) and formic acid (FA) pulping processes, ASAM pulp (yield, 51.7 %; kappa number, 13.4) showed excellent initial brightness (53.2 %), which indicated better bleachability. Prebleaching of pulps by oxygen, peroxyaid and xylanase treatments, indicated O₂-prebleaching reduced kappa number (44-53%). Prebleached pulps were bleached in Chlorine dioxide-Extraction-Chlorine dioxide (DED) and Chelation-Peroxie-Peroxide (QPP) bleaching sequences. ASAM and kraft pulps exhibited better brightness than soda-AQ pulp. Viscosity of bleached pulp from kraft process was lower than that of soda-AQ and ASAM processes. Strength properties of pulps from soda, soda-AQ, kraft and ASAM processes were acceptable. The a-cellulose (> 94 %) in FA pulp suggests further study for dissolving pulp.