Pulping of bagasse (Saccrarum officinarum), kash (Saccharum spontaneum) and corn stalks (Zea mays)

Abstract

Bangladesh being a small and populated country faces shortage of fibrous raw materials. The only bagasse-based pulp mill was forced to close down due to inadequate supply of bagasse. In this context, similar alternative raw materials need to be evaluated to support small scale pulp mills in this country. Whole bagasse, kash and corn stalks were assessed in terms of their chemical and morphological characteristics. These fibres showed a moderate level of α-cellulose (43.3, 39.3 and 35.1% respectively) and low level of lignin content (~20%). Alkaline oxidation showed that the lignin of these non-woods was composed of high proportion of p-hydroxyphenyl propane unit. The fiber length of whole bagasse, kash and corn stalks was 1.36 ​mm, 0.86 and 0.90 ​mm, respectively. Soda-anthraquinone (AQ) and formic acid/peroxyformic acid (FA/PFA) pulping processes of these three non-woods were evaluated. FA/PFA process showed higher pulp yield than soda-AQ process. Corn stalk was easier to delignify in soda-AQ process, and showed the lowest pulp yield and kappa number. The papermaking properties of these pulps showed good tensile index (75–85 ​N ​m/g) and moderate tear index (4.5–6 ​mN/m2/g). Brightness of these pulps reached to 84–90% in D(EP)D bleaching and 73–85% in alkaline peroxide bleaching.