The Fibre Quality Of Poplar Ethanol Pulping And The Properties Of Paper Made With Poplar Ethanol Pulp

Due to the disadvantages of the KP pulp, even as the dominant pulping process, such assevere air pollution, huge investment for alkali recycling, waste of outgrowth lignin etc., nopollution pulp has been causing great attention. And ethanol pulp has become its mainstreamrecently because of the ethanol recyclable and usability of the lignin from waste liquor as newresource.Our resarch group has been woking on the poplar enthanol pulping since2003. Thstudy includs optimizing pulping conditions, the reaction course of delignification andkinetics, mechanism of pulping,wash condition of pulp, the separation and reuse of pulpingblack liquor, the grading,modification and utilization of ethanol lignin.After that, it isessencial to do further resarch on the pulp quality and its paper performance, it will make upthe foundational theory of ethanol pulp and help the industrialization of the poplar ethanolpulp as well.The pulp quality and paper performanc of auto-catalyzed ethanol pulping andsalt-catalyzed ethanol pulp of poplar were resarched compared with poplar KP pulp andpoplar AS-AQ pulp. Auto-catalyzed ethanol pulping and salt-catalyzed ethanol pulp of poplarwere prepared under the optimized pulping condition.The optimizing cooking conditions ofpoplar KP pulp and AS-AQ pulp were discussed by condition experiment and their screenedyields were made to approximatly the same as salt-catalyzed ethanol pulp’s.The experimentalresults were showen as follows under this circumstance:compared with KP pulp,theunscreened yield of salt-catalyzed pulp was1.18percent higher, Kappa number was13.99higher，lignin content was2percent higher，holocellulose content was1.56percent lower，poly-pentaglucose content was1.68percent higher,viscosity was77ml/g lower，ash contentwas0.025percent lower; compared with AS-AQ pulp,the unscreened yield of salt-catalyzedpulp was0.45percent lower, Kappa number was4.58higher，lignin content was0.13percenthigher，holocellulose content was2.64percent lower，poly-pentaglucose content was1.13percent higher,viscosity was249ml/lower，ash content was0.016percent lower;the yield ofthe auto-catalyed pulp was higher than the salt-catalyzed pulp’s,KP pulp’s,AS-AQ pulp’s as well as Kappa number and its lignin content, holocellulose content, poly-pentaglucose,viscosity were slightly higher than salt-catalyzed pulp’s,ash content was the same. At thesame beating revolution,the turn of beating degree of four kinds of pulp followed byauto-catalyzed pulp, salt-catalyzed pulp, KP pulp, AS-AQ pulp.When the beating degree was30。SR，compared with KP pulp and AS-AQ pulp, the auto-catalyzed pulp and salt-catalyzedpulp had higher small fibre fraction and lower long fibre fraction. The turn of the fiber lengthof four kinds of pulp followed by AS-AQ pulp,KP pulp, salt-catalyzed pulp, auto-catalyzedpulp. The turn of the fiber coarness length of four kinds of pulp followed by, KP pulp,AS-AQ pulp.When the beating degree was approximate，the tensile index of auto-catalyzedpulp and salt-catalyzed pulp were extremely lower than KP pulp’s and AS-AQ pulp’s; thetensile index of auto-catalyzed pulp was lower than salt-catalyzed pulp’s;KP pulp’s was lowerthan AS-AQ pulp’s;the folding index of AS-AQ was extremely higher than the others, KPpulp’s was higher than salt-catalyed pulp’s, salt-catalyed pulp’s was slightly higher thansalt-catalyed’s；the turn of the tearing index of four kinds of pulp followed by AS-AQpulp,KP pulp, salt-catalyzed pulp, auto-catalyzed pulp. The bursting index of AS-AQ wasslightly higher than KP pulp’s and the KP’s was similar with the salt-catalyzed pulp’s,auto-catalyzed pulp’s was slightly lower than salt-catalyzed pulp’s.It was also studied that the bleaching property of the poplar salt-catalyzed pulp and KPpulp and the paper permance of their bleaching pulp.The QP₁P₂bleaching method wasadopted,the brightness of the KP pulp and salt-catalyzed ethonal pulp was33.5%and27.6%,the brightness of the bleaching KP pulp and bleaching salt-catalyzed ethonal pulp was63.4%and72.8%respectively, it indicated that QP₁P₂bleaching was more suitable for salt-catalyzedethonal pulp than KP pulp.When pulps were beated with PFI at the beating revolution, thebeating degeree of salt-catalyzed ethonal pulp increased faster than KP pulp’s,it demonstatedthat the beating power consumption of salt-catalyzed ethanol pulp was less than KP’s；withthe close beating degeree，the tensile index of salt-catalyzed ethanol pulp（34.5。SR）and KPpulp（35.1。SR）was59.5N.m/g,29.9N.m/g，folding was34.5，8，tearing index was33.6mN.m2/g、32mN.m2/g，burting index was4.12Kpa·m2/g、1.99Kpa·m2/g respectively.Thebleaching theory of salt-catalyzed ethonal pulp needs to be researched more deeply in thefuture.It was showen by the comparion experiment when their screen yield were approximate,.the physical strenth of the poplar ethonal pulp wasn’t as good as KP pulp’s andAS^AQ pulp’s and.salt-catalyed ethonal pulp was more fittable for QP₁P₂bleaching than KPpulp.