Andrew, JEJohakimu, Jonas KSithole, Bishop B2014-10-272014-10-272014Andrew, J.E, Johakimu, J and Sithole, B.B. 2014. Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips. Nordic Pulp & Paper Research Journal, vol.29(3), pp 383-3910283-2631http://hdl.handle.net/10204/7741http://www.npprj.se/html/np-viewarticleabstract.asp?m=8942&mp=750Copyright: 2014 Arbor Publishing Ab. Nordic Pulp & Paper Research Journal, vol.29(3), pp 383-391. Abstract onlyThe effect of hemicellulose pre-extraction of South African Eucalyptus grandis wood chips using green liquor, on subsequent kraft pulping and bleaching processes was studied. This was done in the context of a biorefinery mill producing both ethanol and bleached Eucalyptus kraft pulp. The pre-extraction (hydrolysis) of hemicelluloses prior to kraft pulping reduced the demand of pulping chemicals by as much as 20% and still resulted in pulps with similar kappa numbers and yields as pulps produced from unhydrolyzed wood chips (control pulps). In addition, the hexenuronic acid (HexA) content of the brownstock prehydrolyzed kraft (PHK) pulps were about 30% lower compared to the control pulps. This led to improvements in the subsequent pulp bleach-ability. Savings in chlorine dioxide for PHK pulps ranged between 2-18% for sequences that used chlorine dioxide as the primary oxidative bleaching chemical. When ozone was used in combination with chlorine dioxide, mixed results were obtained – PHK pulps showed better bleach-abilities when ozone followed immediately after oxygen delignification, i.e. OZDED or OZD(EP)D, but not when ozonation followed the acid hydrolysis (A) stage.enSouth African Eucalyptus grandisKraft pulpingEucalyptus kraft pulpGreen liquorPre-hydrolyzed kraft pulp BleachinChlorine dioxideOzoneHexenuronic acidsArticleAndrew, J., Johakimu, J. K., & Sithole, B. B. (2014). Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips. http://hdl.handle.net/10204/7741Andrew, JE, Jonas K Johakimu, and Bishop B Sithole "Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips." (2014) http://hdl.handle.net/10204/7741Andrew J, Johakimu JK, Sithole BB. Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips. 2014; http://hdl.handle.net/10204/7741.TY - Article AU - Andrew, JE AU - Johakimu, Jonas K AU - Sithole, Bishop B AB - The effect of hemicellulose pre-extraction of South African Eucalyptus grandis wood chips using green liquor, on subsequent kraft pulping and bleaching processes was studied. This was done in the context of a biorefinery mill producing both ethanol and bleached Eucalyptus kraft pulp. The pre-extraction (hydrolysis) of hemicelluloses prior to kraft pulping reduced the demand of pulping chemicals by as much as 20% and still resulted in pulps with similar kappa numbers and yields as pulps produced from unhydrolyzed wood chips (control pulps). In addition, the hexenuronic acid (HexA) content of the brownstock prehydrolyzed kraft (PHK) pulps were about 30% lower compared to the control pulps. This led to improvements in the subsequent pulp bleach-ability. Savings in chlorine dioxide for PHK pulps ranged between 2-18% for sequences that used chlorine dioxide as the primary oxidative bleaching chemical. When ozone was used in combination with chlorine dioxide, mixed results were obtained – PHK pulps showed better bleach-abilities when ozone followed immediately after oxygen delignification, i.e. OZDED or OZD(EP)D, but not when ozonation followed the acid hydrolysis (A) stage. DA - 2014 DB - ResearchSpace DP - CSIR KW - South African Eucalyptus grandis KW - Kraft pulping KW - Eucalyptus kraft pulp KW - Green liquor KW - Pre-hydrolyzed kraft pulp Bleachin KW - Chlorine dioxide KW - Ozone KW - Hexenuronic acids LK - https://researchspace.csir.co.za PY - 2014 SM - 0283-2631 T1 - Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips TI - Bleaching of kraft pulps produced from green liquor pre-hydrolyzed South African Eucalyptus grandis wood chips UR - http://hdl.handle.net/10204/7741 ER -