Chemical Pulping of Steam‐Exploded Mixed Hardwood Chips

Abstract

We determined the pulping yields for steam‐exploded and untreated mixed hardwood chips for kraft pulping processes with and without anthraquinone and/or polysulphide. The pulp yield from steam‐exploded chips was 1–3% lower than from untreated chips under similar conditions. The benefit of kraft pulping with anthraquinone and/or polysulphide was found to be more pronounced for the exploded chips than for the untreated chips.

Keywords:

• Chemical pulping
• exploded pulps
• steaming
• hardwoods
• chips
• yield
• analysis
• polysulfides
• anthraquinone
• H factor
• kappa number

Special thanks to André Audet for the bleaching of the pulp samples. Thanks are also due to William Reed and Yves Desjardins for their technical support during the chemical impregnation of the mixed hardwood chips in preparation for steam explosion in the continuous digester. We also thank Zhi‐Hua Jiang and Richard Berry for their critical review of the manuscript.