蔗渣浆的全无氯漂白工艺

对蔗渣浆采用过氧化氢强化的氧脱木素(OP)-螯合预处理(Q)-压力过氧化氢漂白(PO)的短序漂白,探讨了将蔗渣浆漂至82%ISO和用非硅过氧化氢漂白稳定剂代替硅酸钠用于过氧化氢漂白的可行性.研究表明,非硅过氧化氢稳定剂PP-1与PP-2耐高温、耐高压,可用于压力过氧化氢漂白.OP段氢氧化钠用量为2.0%(相对于绝干浆质量,下同)、过氧化氢用量为0.5%,PO段过氧化氢用量为3.0%、PP-1用量为0.1%、PP-2用量为0.5%时,蔗渣浆采用OPQPO流程漂白后,浆的白度可达到85%ISO.而且OPQPO从根本上消除了可吸附有机卤化物的产生;经测定,漂白废水属于可生物降解废水.     

MODIFIED OPAL:A NOVEL STABILIZER FOR HYDROGEN PEROXIDE BLEACHING OF PULPS

The possibility of modified opal as the stabilizer of hydrogen peroxide bleaching was investigated. The results showed that the modified opal in place of sodium silicate as the stabilizer of hydrogen peroxide bleaching is feasible. At the same dosage, above 3% ISO can be increased for both wheat straw pulp and deinked pulp. The stabilizing ability of the modified opal to hydrogen peroxide bleaching of pulp is improved markedly. It is favorable for bleaching to increase temperature and time within a permissive extent. The suitable process conditions are 10% of pulp consistency, 3% of hydrogen peroxide, 1.5% of sodium hydroxide, 3% of the modified opal, 70℃ and 60 min when the modified opal is used as the stabilizer of hydrogen peroxide bleaching. At these conditions, the brightness gain can reach about 16% ISO for wheat straw pulp. In addition, it is favorable for bleaching to add a little magnesium sulfate when the modified opal is used as the stabilizer of hydrogen peroxide bleaching, the brightness of pulp can increase I%ISO if0.05% of magnesium sulfate is added. The cost analysis indicated that the modified opal is superior to sodium silicate as the stabilizer of hydrogen peroxide bleaching in economical aspect and has further the potential of market development.     

竹子化机浆漂白工艺及其机理

 竹子作为一种重要的非木材制浆造纸资源,具有生长周期短、储量大及成本低等优点,但是其成浆存在白度低、白度稳定性差、易返黄、废液硅含量高难处理等问题。本研究利用H₂O₂、NaBH₄、Na₂S₂O₄和CH₃COOOH等漂白剂对粉单竹碱性过氧化氢化学机械浆（APMP）进行单段或者两段组合补充漂白,以提高竹子APMP浆的可漂性、白度及其稳定性、强度等。研究结果表明,常规H₂O₂漂白是竹子化机浆最佳单段补充漂白方法。两段补充漂白实验表明,白度提高最大的是H₂O₂→Na₂S₂O₄组合,为73.85% ISO;黏度下降最大的是H₂O₂→NaBH₄组合,漂后浆黏度从960下降到601 mL·g^-1。虽然两段补充漂白漂后浆的黏度有所下降,但其物理强度得到提高。补充漂白的示差红外分析发现：H₂O₂、H₂O₂→Na₂S₂O₄、H₂O₂→NaBH₄ 3种漂白方法的纸浆中共轭羰基含量降低了,而H₂O₂→CH₃COOOH漂白浆中的共轭羰基含量反而增加。甲氧基、紫丁香型木素和缩合的愈创木基环在H₂O₂→Na₂S₂O₄两段补充漂白过程脱除效果最显著。X射线衍射分析表明,补充漂白过程单段H₂O₂和H₂O₂→Na₂S₂O₄两段漂白对碳水化合物的降解作用最小。     

木聚糖酶漂白机理的形态研究

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。     

马尾松化学预热机械浆镁碱过氧化氢漂白

研究了用镁碱代替钠碱的马尾松化学预热机械浆（CTMP）浆过氧化氢漂白工艺及其对纸浆性能的影响,分析了镁碱和钠碱过氧化氢漂白废液对环境的影响.试验结果表明,马尾松CTMP浆镁碱漂白过氧化氢的最佳漂白工艺条件为：H2O2体积浓度为4%,Mg（OH）2质量浓度为1.2%,Na2SiO3质量浓度为1.5%、漂白温度为80℃、漂白时间为120 min,其白度可至63.5%（ISO）,而经钠碱漂白后纸浆的白度值为61.4%（ISO）.镁碱过氧化氢漂白废液化学耗氧量（CODcr）为193.6 g/L,比钠碱过氧化氢漂白废液化学耗氧量（CODcr=312.86 g/L）降低了38.12%.     

谷壳的漂白研究

采用过氧化氢水溶液对谷壳进行了漂白，按3种不同的实验方法进行了一系列漂白试验，详细讨论了最佳的工艺条件以及影响漂白效果的各种可能因素．     

蔗渣浆全无氯漂白的研究

本本文探讨了在Op段低NaOH用量,P段低H2O2用量的条件下采用OpQP流程将蔗渣浆漂至82%ISO的可行性,并讨论了非硅过氧化氢漂白稳定剂代替硅酸钠用于过氧化氢漂白的可行性。研究表明非硅过氧化氢稳定剂PP-2,PP-1耐高温、高压,可用于压力过氧化氢漂白。在Op段2%NaOH,0.5%H2O2;P段3% H2O2,PP-1 0.1%, PP-2 0.5%条件下,蔗渣浆采用OpQPo流程,漂后浆白度达到85%ISO。OpQPo从根本上消除了AOX的产生,经测定漂白废水属于可生物降解废水,只有Q和P段的部分废水进入废水处理系统, 容易通过常规的污水处理方法达到日益严格的国家排放标准。     

HE EFFECT OF TRANSITION METAL IONS-IRON ON HYDROGEN PEROXIDE BLEACHING

Hydrogen peroxide bleaching has been extensively used in high-yield pulp bleaching. Unfortunately,hydrogen peroxide can be decomposed under alkaline condition, especially when transition metal ions exit. Experiments show that the valence of transition metal ion is also responsible for the decomposition of hydrogen peroxide.Iron ions are present in two oxidation states, Fe2+ and Fe3+. They are both catalytically active to hydrogen peroxide decomposition. Because Fe3+ is brown, it can affect the brightness of pulp directly, it can also combine with phenol, forming complexes which not only are stable structures and are difficult to be removed from pulp, but also significantly affect the brightness of pulp because of their color.Sodium silicate and magnesium sulfate, when used together, can greatly decrease hydrogen peroxide decomposition. The optimum dosage of sodium silicate is about 0.1% (on solution) for Fe2+ and 0.25% (on solution) for Fe3+. Adding chelants such as DTPA or EDTA with stabilizers simultaneously can obviously improve pulp brightness. For iron ions, the chelate effect of DTPA is better than that of EDTA.Under acidic conditions, sodium hyposulfite and cellulose can reduce Fe3+ to Fe2+ effectively, and pulp brightness is improved greatly. Adding sodium thiosulfate simultaneously with magnesium sulfate,sodium silicate, and DTPA to alkaline peroxide solution can result in higher brightness of pulp.pH is a key parameter during hydrogen peroxide bleaching, the optimum pH value should be 10.5-12.     

THE EFFECT OF TRANSITION METAL IONS-IRON ON HYDROGEN PEROXIDE BLEACHING

INTRODUCTIONHydrogen peroxide bleaching has been extensively used in high-yield pulp bleaching. IT is well known that hydrogen peroxide can be easily decomposed under alkaline conditions, especially in the presence of transition metal ions due to their catalyzing effect on the decomposition of hydrogen peroxide. Some recent reports show that the valence of transition metal ion can have a drastic effect on the decomposition of hydrogen peroxide.Generally, iron can exist in Fe2+ and Fe3+…     

中浓纸浆清洁漂白技术的理论与实践

纸浆传统低浓含氯漂白方法(如CEH)存在对环境污染、水耗和能耗大、不可能适应大产能的要求等问题,需要用中浓氧脱木素、中浓二氧化氯漂白、中浓过氧化氢漂白及它们的组合等清洁漂白技术来取代.文中结合各类清洁漂白技术的特点,研究适用于各浆种的中浓氧脱木素、中浓过氧化氢等漂白技术,结合工程实践,提出适合我国国情的中浓纸浆少污染漂白技术及全无氯漂白技术,从而满足日益严格的环保要求,实现清洁漂白生产.     

STUDY OF COORDINATED PRETREATMENT OF XYLANASE AND LACCASE ON SODA-AQ WHEAT STRAW PULP BEFORE CEH BLEACHING

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…     

过渡金属离子对废纸浆H2O2漂白的影响

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.     

蔗渣浆的压力过氧化氢漂白

对烧碱-蒽醌(Soda-AQ)法蔗渣浆分别进行了螯合预处理(Q)和常压过氧化氢(P)、压力过氧化氢(PO)漂白的研究,探讨了单段PO漂白蔗渣浆的可行性.正交试验结果表明,PO漂白蔗渣浆优化的漂白条件为漂白温度100℃、时间80min、压力0.6MPa、NaOH用量0.4%.PO漂白浆的白度较高,达84.0%ISO,特性黏度为825.3mL/g,比QP漂白浆的白度高9.9%ISO;PO漂白浆的物理强度性能也较好,浆料的抗张指数为66.67N.m/g,撕裂指数为9.34mN.m2/g,耐破指数为4.31 kPa.m2/g,耐折度为39次.PO漂白废水的化学耗氧量、生化耗氧量及色度较低,漂白废水可全部逆流回用,大大减少了污染排放.     

改良木聚糖酶辅助漂白芦苇浆的工艺研究

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。     

白腐菌改性桉木CTMP浆的漂白研究

利用白腐菌改性处理可以显著提高机械浆的强度性能,有利于拓宽机械浆的应用范围.本文采用白腐菌Trametes hirsute 196对桉木CTMP浆进行改性处理,并探讨了白腐菌处理后纸浆的漂白工艺.研究结果表明:白腐菌处理使桉木CTMP浆白度值从49.6%下降到37.8%,且这种改性后纸浆的可漂性较差,H2O2和Na2S2O4单段漂后纸浆白度均在60%以下,但采用Na2S2O4—H2O2两段组合漂白工艺可以使漂后Bio-CTMP浆白度达到71.3%.     

低纤维素酶活木聚糖酶对麦草浆的辅助漂白作用

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。     

KRAFT WOOD PULP TCF AND ECF BLEACHING WITH ENZYME PRETREATMENT *

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     

硫酸盐木浆漂白前木聚糖酶预处理的研究

研究了木聚糖酶用于硫酸盐木浆 H2 O2 漂白前预处理的工艺条件 ,结果表明 ,预处理最佳工艺条件为 :酶用量为每克浆 2 0 IU ,时间 3h,浆浓为 6 %。在相同的 H2 O2 漂白条件下 ,经酶处理后的浆料白度可提高 2 %～ 3% SBD。     

PEROXIDE BLEACHING OF LOW-FREENESS TMP

Peroxide bleaching is an essential unit operation to produce value-added mechanical pulp-based paper grade. In this paper, we presented the results from peroxide bleaching of low-freeness TMP for the production of SC paper. Two aspects were addressed; the effect of pulp strength and the formation of anionic trashes. The strength properties,such as tensile, burst and zero-span tensile, are improved after the peroxide bleaching process. The amount of anionic trashes formed is almost proportional to the hydrogen peroxide charge.     

XYLANASE PREBLEACHING ON NaOH-AQ WHEAT STRAW PULP

INTRODUCTIONChina is a kingdom of straw pulps and wheat strawhas a dominant proportion in non-wood fiberresource. Wheat straw is inexhaustible annual plant.When it is used to make pulp and paper, there is noproblem of affecting afforestation and energyconsumption. In order to make full use of existedresource and make products of good quality witheffluent of low pollution loading, the study of wheatstraw pulp has realistic meaning. On the other hand,application of biotechnology has penetra…