Influence of Temperature on Kraft Pulping of Whole Bagasse and Depithed Bagasse

Abstract

Bagasse is a heterogeneous material consisting of 60–70% fiber, and rest is pith. In this paper, the impact of temperatures (165 °C and 140 °C) and time (0.5 h and 1 h) on kraft pulping of whole bagasse and depithed bagasse was analyzed. The resulting pulps were refined, and handsheets were made before subjecting them to mechanical testing. The cellulose content (%), water absorption capacity (%), water retention values were found to be higher, and the Klason’s lignin and ash contents were found to be lower for depithed bagasse pulp compared to whole bagasse pulp. However, the handsheets made from whole bagasse pulp (165 °C) were stiffer and also exhibited higher tensile strength index values compared to sheets from depithed bagasse pulp, indicating its suitability for packaging. Thermogravimetric analysis revealed better thermal stability for both pulps up to 250 °C. The pulp and black liquor characteristic values of depithed bagasse processed for 1 h at 165 °C are promising and encouraging for paper making.