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微生物酶对机械法制浆磨浆能耗的影响

The Influence on Refining Energy of Mechanical Pulping with Microbe and Enzyme

【作者】 隋晓飞

【导师】 陈嘉川;

【作者基本信息】 山东轻工业学院 , 制浆造纸工程, 2008, 硕士

【摘要】 随着环保意识的增强和环境法规的实施,生物制浆技术和生物处理技术逐渐在制浆造纸行业得到了迅速研究和发展。经过生物处理的纸浆比未处理的浆料,制浆能耗降低,纸张物理性能好,对环境污染少,后续可漂性好。因此生物制浆技术日益受到国内外专家学者的重视,逐渐成为解决能源消耗,提高纸张质量,减少环境污染的有效途径之一。为此国内外科研人员对造纸工业充分利用生物技术降低制浆能源消耗等进行了广泛、深入地研究,并取得了一定的成果。微生物酶在生物制浆工艺技术中,发挥着重要的作用,对能耗的减少、纸浆性能的改善,产生了很好的效果。本论文对白腐菌和其他生物酶生物处理杨机械浆料进行了研究和探索。主要进行了利用白腐菌在适宜的温度和时间条件下进行培养、优化和接种:温度为28~30℃,时间为4~5天,进行白腐菌的固体扩大培养或者转接;在温度28~30℃,时间10天左右,在水浴振荡器里进行白腐菌的粗酶液的液体培养。粗酶液中含有白腐菌产生的漆酶、木素过氧化物酶和锰过氧化物酶等生物酶。利用白腐菌或白腐菌产粗酶液,及工业生产的商品酶-纤维素酶(绿色木霉产纤维素酶)、半纤维素酶(AU-PE89木聚糖酶)分别制定处理条件来生物处理杨木机械浆降低磨浆能耗、改善纤维性能以及提高浆料后续可漂性进行了研究。采用扫描电镜、纤维分析仪等仪器对于生物处理的杨木机械浆纤维改性或变化的作用机理和理论进行研究和讨论;生物机械法制浆已有较多的研究,但生物处理大都放在磨浆前对纤维原料(木片、稻麦草等)进行预处理。本论文中,杨木机械浆生物处理过程是在第一段磨浆和第二段磨浆之间,便于微生物酶能进入纸浆的纤维细胞壁中,直接同纤维原料进行接触降解或反应,微生物酶在此能够起很好的作用。结果表明,采用适宜的生物处理条件进行处理纸浆,能够明显降低磨浆和打浆能耗,纸浆打浆度比对照浆料明显提高5 oSR~15 oSR;还能显著改善纸浆的耐破指数、撕裂指数和裂断长等强度性能,特别是耐破指数最好效果能提高100%左右;纸浆的光学性能也得到优化,白度指标随生物处理条件的不同而不同,白腐菌及其粗酶液处理白度明显下降1%ISO~3%ISO左右,商品酶处理条件,白度都明显提高1%ISO~7%ISO左右。此外,采用适宜的生物处理条件对纸浆进行处理能够明显提高纸浆的后续过氧化氢可漂性,浆料最终白度性能提高1%ISO~6%ISO左右,撕裂指数、耐破指数和裂断长等强度性能也继续增加。酶处理对于纸浆耐破指数的提高贡献较大,能够使纸浆耐破指数提高50%以上。生物白腐菌处理中以BYBF白腐菌和Pc-5白腐菌为较佳的白腐菌。各种粗酶液中以Sdu-4粗酶液和洁丽香菇粗酶液处理效果较佳。纤维素酶和木聚糖酶分别是以温度60℃、酶用量20 IU/g为最优处理条件,而混合酶液(纤维素酶和木聚糖酶)是以温度45℃、酶用量20 IU/g为最优处理条件。

【Abstract】 With the intensified consciousness of environment protection and the implement of the environment protection law, bio-pulping and bio-treatment technology have been gradually studied and developed in the pulp and paper industry. And the bio-treated pulp had lower pulping energy consumption, better paper physical properties, less environmental pollution and better subsequent pulp bleachability than the untreated pulp. Therefore, bio-pulping technology has been increasingly paid more attention by more and more experts and professors in China and overseas, and is gradually becoming a way to reduce pulping energy consumption, improve the pulp qualities and reduce environmental impacts. Many researchers have made an extensive and deep studies on utilizing bio-technology to reduce pulping energy consumption and they have got certain achievements. It has been found that Microbe and enzyme, for bio-pulping technologies, had significant effectiveness in reducing energy consumption and improving pulp properties.In this thesis, white-rot fungi and other enzymes treated aspen mechanical pulps were studied. It utilized white-rot fungi to isolate, optimize and inoculate in the feasible temperature and time condition: temperature 28~30℃, time 4~5 days, solid enlarged isolating or grafting white-rot fungi; temperature 28~30℃, time 10 days, isolating crude enzyme solution from white-rot fungi in a constant temperature shaker water bath. The crude enzyme solution from white-rot fungi contained manganese peroxidase-MnP, lignin peroxidase-LiP, laccase and so on. White-rot fungi, white-rot fungi isolating crude enzyme solutions and commercial enzymes including cellulose enzyme (Trichoderma viride cellulase) and hemicellulase (AU-PE89 xylanase) were used to treat triploid aspen mechanical pulp for reducing energy consumption and improving pulp properties and subsequent pulp bleachability. With scanning electron microscopy (SEM) and Fiber quality analysis (FQA), the mechanism and theory of aspen mechanical pulp fibers modification or changes during bio-treatment were researched and discussed. There were many researches on bio-mechanical pulping, but most of the bio-treatments were used to pretreated the fibers or pulps (wood chips and rice wheatstraw) before the refining stage. In this paper, bio-treatments of aspen mechanical pulp were carried out between the first and the second refining stage, which can make microbe and enzyme come into cell wall of fibers easily and react with fibers directly and indirectly to give the resultant pulp better properties. The results indicated that the appropriate bio-treatments can remarkly reduce refining energy consumption. The beating degree of treated pulp can be improved 5 oSR~15 oSR higher than that of the untreated pulp. Additionally, the bio-treatment can improve pulp strength properties such as breaking length, burst index and tear index, especially the burst index was improved by about 100%. Pulp optical properties had been improved, and the brightness depended on the specific treatment conditions, the brightness was remarkly reduced 1%ISO~3%ISO or so with white-rot fungi treatment or white-rot fungi isolating crude enzyme solution treatment. However, the other commercial enzymes obviously improved the brightness 1%ISO~7%ISO or so. Furthermore, the appropriate bio-treatments also can remarkly improve pulp subsequent peroxide bleachability. The resultant brightness can be increased 1%ISO~6%ISO or so as well as improved pulp strength properties. The enzyme treatment had much contributions to burst index improvement, and the burst index can be improved by 50%. It was found that BYBF and Lentinus lepideus white-rot fungi had better treatment effectivness than other white-rot fungi. It also was found that Sdu-4 and Lentinus lepideus isolated crude enzyme solutions had better treatment effectivness than other ones. The best results of cellulase and xylanase treatment were gotten at temperature 60℃and enzyme dosage 20 IU/g, while the best results of mix enzyme treatment came out at temperature 45℃and enzyme dosage 20 IU/g.

【关键词】 杨木漂白制浆白腐菌
【Key words】 white-rot fungienzymerefiningaspenbeatingbleaching
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