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1.
采用分子改良后的木聚糖酶对芦苇浆进行生物预处理,考察了改良木聚糖酶辅助漂白的效果。结果表明,酶预处理可以降低CEH三段漂白中氯化C段的氯气用量60%。改良木聚糖酶预处理辅助漂白芦苇纸浆最佳条件为:pH为7.0,温度60℃,浆浓(质量分数)5%,酶用量12μmol/(min.g),预处理时间60 min。在此条件下C段氯用量降至对照的40%时,酶处理漂后样品白度可达到84.0%(ISO),高出对照样的白度3.7%(ISO)。改良木聚糖酶预处理还能够改善纸浆漂后样的物理性能。  相似文献   

2.
KRAFT WOOD PULP TCF AND ECF BLEACHING WITH ENZYME PRETREATMENT *   总被引:1,自引:0,他引:1  
针叶木硫酸盐浆用木聚糖酶Irgazyme40_X4进行预处理,然后进行各种无元素氯(ECF)和全无氯(TCF)漂白.实验结果表明,酶预处理能提高后续漂白效果,提高白度,降低卡伯值,并改善纸浆的粘度,在不用元素氯的情况下,能将纸浆漂白到88%ISO以上的白度  相似文献   

3.
INTRODUCTIONXylanase pretreatment can produce many small holes on pulp surfaces and cross section by removing part xylose that may be sucked back or exists in style of LCC. Thus penetrability of following chemicals. Olsen [1] observed coordinated pretreatment of xylanase and lignin enzyme (compound of lignin peroxide enzyme and manganese peroxide enzyme) had better delignification than sole xylanase and sole laccase lignin enzyme. So we can forecast that coordinated pretreatment of xylan…  相似文献   

4.
探讨了嗜热真菌耐热木聚糖酶助漂针叶木硫酸盐浆的应用前景.着重研究了应用耐热木聚糖酶进行生物助漂的酶用量、酶处理的pH值以及漂白用氯量等影响因素.结果表明,在不影响纸浆的各项性能的情况下,经酶处理的纸浆白度相比对照增加1.06%~5.11%ISO.同时,酶处理纸浆漂白时可减少漂白用氯量.另外,在偏碱性条件下进行酶处理对纸浆漂白效果的影响较为显著.纸浆纤维的扫描电镜结果显示,酶未对纤维造成损伤,而是改善了纸浆纤维的可漂性.该耐热木聚糖酶非常适宜应用于酶助漂.  相似文献   

5.
低纤维素酶活木聚糖酶对麦草浆的辅助漂白作用   总被引:4,自引:2,他引:4  
利用低纤维素酶活木聚糖酶对麦草浆进行预处理,研究木聚糖酶在氯、碱、次氯酸盐(CEH)三段漂白中对氯气用量的减少以及对漂白过程中纸浆木质纤维组分变化的影响。结果表明:经过木聚糖酶预处理,在保证纸浆漂后白度的同时,氯气用量可以减少50%;木聚糖酶预处理对纸浆中的木素有脱除作用,且能促进木素在碱抽提过程中的溶出,但木聚糖酶对戊聚糖和纤维素也有不同程度的降解作用;酶处理浆漂后的木素和半纤维素的含量略低于未经处理的对照浆,纤维素含量则略高于对照浆。  相似文献   

6.
Thc zeta potential and cationic demands of various kraft pulps - unbleached, bleached and beaten to different freeness levels were determined in the laboratory. The zeta potential of pulp where the final stage was a lignin degrading and dissolving treatment such as alkaline extraction or hypochlorite was lower than the unbleached pulp. The cationic demand of unbleached pulp was higher compared to that of bleached pulp. Beaten pulps showed larger cationic demands than the unbeaten pulps, which can be attributed to the larger specific surface area of pulp components. Fibres become increasingly electronegative when beaten and therefore cationic demand of pulps increases with beating. When the zeta potential method is used with furnishes of different freeness,the linear relationship is observed. However, the slope is decreasing with the decrease in freeness of the pulp.  相似文献   

7.
木聚糖酶漂白机理的形态研究   总被引:8,自引:0,他引:8  
用扫描电镜观察经木聚糖酶处理过的纸浆纤维样品,发现木聚糖酶可使纤维的表面和内部超微结构发生变化。结果表明,产自于黑曲霉的1#木聚糖酶和产自于里氏木霉的2#木聚糖酶由于含纤维素酶活较高,故经处理后的纤维结构遭受严重损伤,因此也降低了纤维强度;而产自于荧光假单孢菌的3#木聚糖酶由于含纤维素酶活较低,故经预处理后可使纤维表面和横断面上产生比较均匀的孔洞和裂隙,既可增加后续漂剂的渗透性,又不影响纤维的强度,是马尾松KP浆进行生物预处理的较为理想的木聚糖酶。  相似文献   

8.
研究了菠萝叶的纤维形态及化学成分,比较了菠萝叶的硫酸盐法和烧碱法制浆工艺,同时探讨了浆料的漂白性能.试验结果表明,菠萝叶是一种良好的长纤维造纸原料,其碱法浆性能好,利用次氯酸盐二段漂白可使浆的白度达到70%.  相似文献   

9.
SUMMARYWith the development of paper machine and the enlarger of cooking capability, higher requirement of bleaching system in paper mill is brought forward. At present, many straw-pulp mills completed single-stage hypochlorite bleaching through horizontal bleaching machine, which had the disadvantages of large area and low product ability. So there always was no enough space for paper mills to increase the product ability. Bleaching process became the key handicap to increase the product a…  相似文献   

10.
江蓠藻酸化漂白及其琼胶分子结构保护的研究   总被引:8,自引:0,他引:8  
对江蓠藻的NaClO漂白法和H2O2漂白法的漂白工艺和机理进行了深入的研究,NaClO漂白法和H2O2漂白法均应在弱碱性条件下漂白,然后再酸化,既可达到好的漂白效果(白度>48)和容易出胶的目的,又能避免琼胶分子在漂白过程中分子结构的破坏,得到高强度的琼胶,这样可以协调解决琼胶白度与凝胶强度之间的矛盾。  相似文献   

11.
摘要:采用四种不同的碱抽提方式对麦草浆二氧化氯漂白(D0)进行强化,考查了不同碱抽提方式的强化效果,并对不同ECF漂白流程进行了对比研究。结果表明:在D0ED1漂白流程中,不同碱抽提方式对D0木素的修饰效果不同,就后续D1漂段而言,四种不同碱抽提模式下纸浆的可漂性顺序为:D0EOP>D0EP>D0EO>D0E。在D0ED1漂白流程中,D1段ClO2对白度的提升是有限的,达到白度极限后再增加ClO2用量对白度提高不明显。本实验条件下D1段ClO2用量以1.0%~1.2%为佳。从D0ED1与D0EP各漂白流程的对比来看,在终段漂白中以P取代D1效果要好,表明H2O2用于终段漂白其效果要好于ClO2。从其它ECF漂白流程的对比来看,D0EPP和D0EOPP流程漂白效果优于其它流程。本实验条件下采用D0EPP和D0EOPP漂白流程,麦草浆漂后白度可分别达到83.8%和85.7%。  相似文献   

12.
The potential use of Samaar Morr (JUNCUS A CUTUS) plant as fibrous material in papermaking was evaluated in this study. The chemical analysis and fibre charactersitcs of this plant were determined for better understanding its behaviour in papermaking. Samaar morr stalks were subjected to sulfur-free three-stage (peroxyformic acid, formic acid, peroxyformic acid) Milox process. Some conventional pulping experiments such as soda,soda-anthraquinon (S-AQ), kraft and kraft-AQ pulping in addition to two- and one-stage peroxyformic acid pulping were also carried out for comparison with the three-stage peroxyformic acid pulping method. It was found that the pulping with Milox process produces pulp with good properties compared to the pulp produced from the other methods. The physical and optical properties of different pulps were also examined. The behaviour of Milox samaar morr pulp towards bleaching with alkaline hydrogen peroxide has been investigated in presence and absence of formic acid. The results showed that the final brightness about 81.5% ISO could be achieved after 3% peroxide in two bleaching steps with formic acid treatment between the two steps.  相似文献   

13.
采用常规碱抽提(E)、氧加强的碱抽提(EO)、H2O2强化的碱抽提(EP)、氧和H2O2强化的碱抽提(EOP)对ClO2脱木素(D0)麦草浆进行改性,考查不同碱抽提方式的改性效果在后续漂段(D1)的体现,并就不同无元素氯(ECF)漂白流程(D0ED1、D0P、D0A/QP、D0EP、D0EPD1、D0EPP)进行对比.结果表明:不同碱抽提方式对D0浆木素的改性效果不同,就对后续漂段D1的影响而言,4种不同碱抽提方式下纸浆的可漂性顺序为D0EOPD0EPD0EOD0E;在4种碱抽提方式所对应的D0ED1漂白流程中,D1段ClO2用量的增加对白度的提升是有限的,以0.8%~1.0%为佳;D0EPD1和D0EPP流程漂白效果优于其它流程,采用D0EPD1和D0EPP流程漂后白度可分别达到82.3%ISO和83.8%ISO,均适用于麦草浆短序ECF漂白.  相似文献   

14.
INTRODUCTIONThe increasing consumption of paper and paper board all over the world and the more and more serious legislative constraints on forest resources intensify the shortage of pulping materials. Agricultural residues such as wheat straw are of increasing interests in countries and areas which have abundant plantation of agricultures and are lack of wood supply. One of the problems associated with the wheat straw pulp was the low pulp yield and low bleachability relative to wood pulp…  相似文献   

15.
1INTRODUCTIONChina is a country using the most variety of non-wood fiber raw material and is the largest country producing non-wood fiber pulp and paper in the world[1]. Bamboo is one kind of the main non-wood species for papermaking in China. Although the structure of raw materials for papermaking has being adjusted through increasing the proportion of wood pulp and by effectively utilizing waste paper source, non-wood species will still remain an important fiber resource[1,2].At present…  相似文献   

16.
改进的硫酸盐蒸煮浆比常规硫酸盐浆有较好的漂白性,在相同的漂白工艺条件下,改进的硫酸盐蒸煮浆比常规硫酸盐浆所用的化学药品少而成浆白度高。用改良硫酸盐法制得的浆比常规硫酸盐法制得的浆易漂;用氧碱次氯酸钠漂白,蓝桉比例大的成浆白度高,比例少的白度较差,且氧碱次氯酸钠漂白比常规次氯酸钠漂白成浆白度可提高2~3倍;过氧化物H2O2的漂白过程聚合度下降较少,很适合强煮弱漂的制浆工艺,成浆白度与次氯酸钠相差不大,但可减少污染。用蓝桉60%的混合材制的浆粕,进行纺丝验证试验,纺丝的各种性能好,能纺出质量较好的粘胶纤维。  相似文献   

17.
中浓纸浆是一种非常特殊的介质,中浓纸浆在升流式反应器中的运动特性关系到反应器的反应效率和反应质量.为探求中浓纸浆在升流式反应器内的流动规律,作者利用自行研制的中浓纸浆漂白试验系统采用示踪法进行了研究.结果证明:中浓纸浆在升流塔内流动时的运动和塔器的截面形状,流动速度相关.对其中气体的运移也进行了一定深度的研究.  相似文献   

18.
研究了过渡金属离子对废纸浆H2O2漂白的影响.研究结果表明,经较强的螯合处理之后重新加Cu2 ,Fe2 和Mn2 ,漂后纸浆的白度降低,残余H2O2减少,漂白效率降低.  相似文献   

19.
A comparative evaluation of DQP, OQP and CEH bleaching of non-wood fibres has revealed that wheat straw, reed, bagasse and bamboo pulps can be bleached to brightness levels of just above 80% ISO,when applying an OQP bleaching sequence and to brightness levels of about 85% ISO when applying the DQP sequence using 10 - 15 kg/tp of ClO2 (aC1.),15 - 20 kg/tp of H2O2 together with 1 - 2 kg/tp of EDTA. The P.C. numbers of the DQP and OQP bleached pulps are much lower and the viscosity much higher than those of the CEH bleached pulps.Compared with CEH pulps, both the DQP and OQP pulps had better strength properties, particularly Tear Index. In spite of their higher final brightness levels,the DQP pulps show similar or better strength properties than the OQP pulps. A comparison of the CEH and DQP effluents showed that the DQP bleaching could reduce the pollution load (CODCDBOD5, SS) by 35 to 60% without the need for recirculation of any effluent streams. The AOX levels could be reduced by 87 to 93%.  相似文献   

20.
Laccase has been proven that it has a good selectivity and efficiency in pulp bleaching. In this paper, the effects of LMS (Laccase Mediator System) treatment on delignification and bleaching of wheat straw pulp at various conditions, such as laccase dosage,temperature, oxygen pressure and pH, were investigated. The TCF sequence including LMS can bleach the wheat straw pulp to 81% ISO brightness with good strength. The synergetic biobleaching of LMS and xylanase of wheat straw pulp was also investigated. It was found that the final brightness and strength of synergetic biobleaching pulps increased to a certain extent and the bleaching selectivity was improved. The combination of the enzymes is feasible for the delignification and bleaching.  相似文献   

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