芦苇化学成分及其化学机械浆性能研究

对芦苇碱性过氧化氢机械浆(APMP)和磺化化学机械浆(SCMP)的制浆性能进行了研究。测定了芦苇的化学成分,发现其综纤维素含量高,1%NaOH抽出物和戊聚糖含量低。通过正交试验优选出芦苇APMP和SCMP的适宜预处理工艺条件。结果表明,经过两段碱性过氧化氢预处理,然后磨浆,可制得白度达57.8%(ISO,以下同)、裂断长2.82 km、撕裂指数3.7 mN.m2/g的芦苇APMP。经过磺化处理,然后磨浆,可制得白度40.6%、裂断长3.48 km、撕裂指数达4.2 mN.m2/g的芦苇SCMP。芦苇SCMP经H2O2单段漂白,H2O2用量为2.0%(质量分数,以下同)时,成浆白度达51.3%,裂断长为3.81 km,撕裂指数4.6 mN.m2/g。     

漆酶-介体系统处理麦草化学浆全无氯漂白性能的研究

采用漆酶－介体系统对麦草化学浆进行预处理，研究了几种全无氯漂白（TCF漂白）[氧碱脱木质素配合两段过氧化氢漂白（OEPP），两段过氧化氢漂白（QPP）和过乙酸配合一段过氧化氢漂白(PaP)]对漆酶处理后纸浆漂白性能的作用，结果表明，麦草浆经过漆酶预处理后，白度上升了12．9个白度单位（%,ISO)，漆酶处理浆氧碱脱木质素配合过氧化氢漂白后比原浆在相同条件下漂白后白度高14个白度单位以上，经两段过氧化氢漂白后白度比原浆在相同条件下（过氧化氢用量4％）漂白后白度高18．3个白度单位，经过乙酸过氧化氢漂白后比原浆在相同条件下漂白后白度高8．1个白度单位。漆酶处理浆漂白后强度比原浆漂白后的低，但是其白度高，如漂至相同的白度可以节约大量漂剂，有利于改善浆的质量，降低漂白废水的污染负荷。     

木聚糖酶预处理对麦草化学机械浆可漂性及白度的改善

探讨了以玉米芯片为碳源制备木聚糖酶及麦草化学机械浆经该木聚糖酶预处理后可漂性和白度的改善效果。结果表明，直接以玉米芯为底物、里氏木霉为菌种产酶效果较好，当底物浓度为18g/L时，木聚糖酶活力可达38．34IU／mL。木聚糖酶预处理有利于改善麦草化机浆的可漂性，促进其过氧化氢漂白，有提高漂白浆白度，降低漂剂消耗。研究表明，当经单段H2O2漂至相同白度时，木聚糖酶预处理后可节约50％的H2O2用量。若麦草CMP酶处理后采用高浓度两段过氧化氢漂白，即XP3P3漂序（H2O2总量为6％0时，白度可达60％（ISO）以上。     

马尾松TMP漂白性能的研究

对马尾松热磨机械浆(TMP)进行了过氧化氢(H2O2)、甲脒亚磺酸盐(FAS)单段漂白以及H2O2-FAS两段漂白实验的研究。结果表明,H2O2漂白马尾松TMP较适宜的工艺条件为H2O2用量2.5%,NaOH用量1.3%,Na2SiO3用量2.5%,浆浓20%,温度80℃,时间60min;FAS漂白马尾松TMP较适宜的工艺条件为FAS用量2.5%,NaOH用量0.625%,浆浓15%,温度80℃,时间75min。H2O2、FAS单段漂白后纸浆白度分别为72.6%ISO和58.2%ISO,H2O2-FAS两段漂白后纸浆白度可达76.3%ISO。     

蔗渣浆全无氯清洁漂白生产实践

总结了蔗渣浆清洁漂白生产线运行全无氯(Op QPo)流程时的小试实验、流程设计及生产实践经验。结果表明:未漂蔗渣浆经强化氧脱木质素处理之后,卡伯值从14.0~15.0降至7.0~7.3,脱木质素率达到50%~51%,白度则从42%~45%(ISO,下同)提高至58%~60%,生产运行效果优于小试实验;经后续预处理和压力过氧化氢漂白之后,纸浆产品白度达到80%以上,黏度在800 m L/g以上,产品质量明显优于传统氯气漂白-碱处理-次氯酸盐漂白(CEH)漂白;漂白过程不产生有毒有害的可吸附有机卤化物(AOX),且仅螯合预处理(Q)段有废水排放,废水色度低、污染负荷轻,易处理,可达标排放;相对传统漂白,新技术的实施并不会增加运行费用,主体设备投资约为1 355万元人民币。     

三种速生阔叶木的PRC-APMP制浆性能比较

对比了杨木、桉木和相思木3种速生阔叶木的材性和PRC-APMP制浆性能,研究结果表明:杨木比桉木和相思木具有更高的聚戊糖和1%NaOH抽出物含量;桉木综纤维素含量略低于杨木和相思木,同时木质素含量最高;桉木材密度最大,相思木次之,杨木较低。采用PRC-APMP制浆方法,在NaOH总用量5.5%,H_2O_2用量5.0%浸渍漂白条件下,相思木制浆得率最高(83.8%),桉木次之(82.4%),杨木最低(81.3%)。桉木成浆白度最高78.2%(ISO,下同),杨木次之75.3%,相思木浆白度最低70.7%。在同等浆料打浆度条件下,相思木成浆抗张强度大于杨木和桉木,同时消耗磨浆电耗也最高;杨木成浆的纤维长度较大,浆料撕裂强度大于相思木和桉木;桉木成浆的抗张和撕裂强度均最低,但浆料具有高松厚度特性。     

碱性木聚糖酶在中小径竹KP浆漂白中的应用

探讨碱性木聚糖酶用于中小径竹KP浆漂白预处理的最佳工艺条件及碱性木聚糖酶预处理对中小径竹KP浆ECF漂白的影响.结果表明,碱性木聚糖酶Unikfect 100处理浆的最佳工艺为:浆浓度4%,pH值9.0,温度65℃,时间20 min,酶用量15.0×10-7 mol·s-1g-1浆;对ECF漂白的影响为:O-X-D1-EOP-D2漂序的漂白效果优于O-D/C-EOP-D2,在白度相近的情况下,纸浆的粘度及物理强度较高.     

麦草化学机械浆过氧化氢漂白工艺优化的研究

探讨了过氧化氢(H2O2)漂白麦草化学机械浆的各种影响因素。优化后的工艺条件为:H2O26%(质量分数,下同),浆浓20%,MgSO40.05%,二乙烯三胺五乙酸(DTPA)0.3%,Na2SiO35.0%,NaOH3.5%,漂白温度80℃,漂白时间2.5h,白度可以达到53%(ISO),能够满足配抄普通文化用纸的要求。     

尾巨桉与马占相思P-RC APMP工艺制浆性能比较

以尾巨桉和马占相思为原料,采用经化学预处理的碱性过氧化氢机械浆(P-RCAPMP)制浆工艺对比研究两者的制浆性能.研究结果表明,相同的H2O2用量(4.0%)和NaOH用量(3.5%)条件下,2种原料制得纸浆的白度相近,均可达75%左右;马占相思原料制浆得率比尾巨桉约高3%左右,物理强度性能远优于尾巨桉浆,相同的250mL加拿大标准游离度(CSF)下,尾巨桉纸页的抗张强度仅为20.1N·m/g,而马占相思纸页的抗张强度可达到26.0N·m/g以上.制得相近CSF的纸浆,马占相思制浆所需的磨浆电耗比尾巨桉略高;2种原料制浆废水的化学耗氧量(COD)和生物耗氧量(BOD)发生量相近,而尾巨桉的制浆废水中固体悬浮物(SS)及总固形物(TS)含量远高于马占相思废水.     

离子液体预处理对纸浆酶漂效果的研究

以杨木碱性过氧化氢机械浆(APMP)、化学热磨机械浆(CTMP)、硫酸盐浆(KP)和麦草CTMP 4种浆为原料,对纸浆在应用生物酶漂白前利用离子液体进行温和预处理,控制离子液体BmimC l用量为1.0%(以绝干纸浆质量计,下同)、EmimD MP用量为1.2%,研究发现离子液体预处理可明显改善纸浆的酶漂效果,且EmimD MP的效果更优。表现为应用离子液体预处理后成纸的光学性能及物理强度明显改善,EmimD MP预处理后杨木KP浆白度可提高4.27%(ISO),不透明度增加了2.46%,麦草CTMP成纸的抗张指数、耐破指数、环压指数、撕裂指数及耐折度分别增加12.21%、29.80%、22.45%、44.82%和52.50%。纤维质量分析仪(FQA)、X射线衍射(XRD)和扫描电镜(SEM)分析结果显示,离子液体处理后4种纸浆纤维质量提高,平均长度增加,细小纤维含量降低,纤维结晶度提高,其中EmimD MP处理后杨木KP浆结晶度提高了11.21%,纸浆表面发生明显分丝帚化,增加了药液的渗透能力。     

酶处理改善稻草浆滤水性能的研究

分别用木聚糖酶和纤维素酶对漂白稻草浆进行处理，发现经酶处理后的浆料，它们的滤水性均得到明显改善，且白度亦有不同程度提高，其中纤维素酶的效果更好，但纤维素酶用量过多，则会对纤维造成损伤，影响浆料强度。     

Industrial utilization of tobacco stalks II: preparation and characterization of tobacco pulp by steam explosion pulping

Our previous paper showed tobacco stalks to posses the characteristics of a raw material for pulp and paper application. It contains the major biomass constituents and cell components common to wood species. In this study, preparation and characterization of tobacco stalk pulp by steam explosion (SE) pulping at two chemical pretreatments were attempted. Chemical pretreatment prior to SE pulping improved the brightness, yield, and strength properties of the resulting tobacco SE pulps in the order: 6% Na₂SO₃ + 1% NaOH > 6% Na₂SO₃ > control (untreated). The 6% Na₂SO₃ + 1% NaOH-impregnated tobacco stalks produced SE pulps of good fiber length distribution and considerable properties that compare well with pulps from other raw materials obtained from previous studies, and the nonimpregnated ones showed strength properties superior to those of their poplar counterpart. Prior to bleaching, pretreating the tobacco stalk SE pulps with two stages, 2% NaOH at 90°C, improved the initial pulp brightness by about 5 points. Two-stage 6% H₂O₂ bleaching gave a comparable effect with hypochlorite bleaching for both tobacco and poplar, giving a 29–34 brightness point increase for tobacco SE pulp and 61 for the poplar samples. The differences in the bleaching responses for untreated tobacco and poplar SE pulps were attributed to the differences in their lignin structure, as shown in the total yield of their respective nitrobenzene oxidation products and FT-IR spectra. Tobacco SE pulps contain more of the guaiacyl-type lignin and poplar the syringyl-type lignin.This paper was presented in part during the 1998 CORESTA (Cooperation Centre for Scientific Research Relative to Tobacco) Congress, Brighton, UK, October 1998     

木质素化学改性抑制杨木碱性过氧化氢机械浆返色的研究

中试系统制备了杨木碱性过氧化氢机械浆。分别在水相 /有机溶剂相 /气相等条件下 ,使用乙酐处理杨木化机浆 (原浆及硼氢化钠还原后纸浆 ) ,分别抄造成 60g/m2 纸片 ,测定了不同时间紫外线照射后试样白度。运用返色值 (PCno .)和白度稳定效果 (BSE)等指标评价处理后浆料的光学稳定性。研究结果表明 ,有机溶剂相和气相乙酰化后的纸浆 ,光学稳定性的提高程度取决于乙酐用量和反应时间即乙酰化程度。通过乙酰化 ,可以获取光学完全稳定的杨木化机浆。紫外漫射反射光谱表明 ,杨木APMP机械浆光诱导返色的主要原因是纸浆木质素中羰基和酚羟基团吸收紫外光后变化形成发色结构所致。还原配合纸浆乙酰化处理 ,可能成为防止高得率纸浆返色的工业应用方法     

紫外吸收剂和游离基捕获剂对杨木APMP纸浆白度稳定效果的研究

高得率纸浆残余木质素中对紫外光和近紫外光高度敏感的特定化学的。结合大气中的氧分子,通过形成游离基中间体而产生发色物质,导致高得率纸浆的光返色（返黄）。紫外吸收类化合物、离基捕获呈抗氧剂等处理纸浆罅纸张返色的研究已有报道。本文研究了杨森ＡＰＭＰ纸浆手抄片添加紫外吸收类化合物、游离基捕获剂和抗氧剂等的工艺条件效果。结果Ｔｉｎｕｖｉｎ１１３０与脂肪醇混合物处理还原,纸浆抗光诱导返色效果尤为显著,该技术方     

Polyelectrolyte swelling behavior of chlorite delignified spruce wood fibers

Summary A coarse thermomechanical Asplund pulp was prepared from Norway spruce (Picea abies). The pulp was delignified to different degrees using acidified sodium chlorite. The swelling behavior (measured as water retention value=WRV) of the resulting pulps was studied under various chemical conditions (pH and conc. of NaCl). It is shown that chlorite-delignified pulps have an appreciable polyelectrolytic character. Whereas the WRV of an Asplund pulp does not respond to changes in the chemical environment, the delignified pulp has a WRV of 155 at pH 3 and 250 at pH 9. Compared under the same chemical conditions, the WRV increases with increasing degree of delignification (<70%) and is approximately constant at high degrees of delignification (>70%).The authors are indebted to Mr. Claes Beer at Sund-Defibrator, who assisted with the preparation of the Asplund pulp     

On the selectivity of ozone delignification of softwood kraft pulps

Summary Ozonation of kraft pulp and oxygen-delignified kraft pulp in acetic acid/water mixtures has been studied at different pulp consistencies with and without an inhibitor to obtain information about the limitations of the selectivity of the ozone treatment. The experiments have been performed according to a full factorial design and data have been analysed by stepwise regression analysis. The results show that a better delignification selectivity can be achieved when ozone is applied in acetic acid media instead of conventional aqueous media. By combining conventional oxygen delignification and ozonation in acetic acid, pulps with equal strength properties and better optical properties compared to those of conventional O(DC)E prebleached pulps can be obtained. This study has also revealed that the reagent is utilized far more efficiently in ozonation at high pulp consistency (35%) than in ozonation at low consistency (1%), and that a similar selectivity can be achieved in both types of ozonation by choosing appropriate conditions. The greater selectivity of ozonation in acetic acid than in water is interpreted in terms of different stabilities of the oxidant in these reaction media. The relation between the formation of hydroxyl radicals and the extent and selectivity of delignification during ozonation has been investigated. The final bleaching of pulps prebleached with ozone in acetic acid medium has been studied. Two final bleaching sequences are presented, by which pulps with ISO brightness levels of 79% and 90% can be produced.The authors are indebted to the Swedish National Board for Technical Development (Styrelsen för Teknisk Utveckling) for financial support for this work and to STORA Technology for pulp tests and analyses     

Steam explosion pretreatment used to remove hemicellulose to enhance the production of a eucalyptus organosolv dissolving pulp

The steam explosion (SE) pretreatment associated with the organosolv process was investigated to produce dissolving pulp from eucalyptus. Prehydrolysis Kraft (PHK) pulping was also done to produce viscose and acetate grade pulps as reference. The organosolv pulps were delignified in two steps with sodium chlorite. Viscose and acetate grade PHK pulps were bleached by OD₀(EH)D₁P and OD₀(EP)D₁PCCE sequences, respectively. Dilute acid-catalyzed (with acid addition) SE pretreatment dissolved more xylan than auto-catalyzed (no acid addition) SE pretreatment. Steam-exploded unbleached organosolv pulps showed lower residual lignin content and screened yield than unbleached organosolv pulps without SE pretreatment. Steam explosion pretreatment helped to decrease lignin content and damaged fiber length of unbleached organosolv pulps. The 1.0% H₂SO₄ organosolv pulp (organosolv dissolving pulp at bioconversion conditions) showed the highest reactivity. Even showing low viscosity for some applications, in general, the organosolv dissolving pulps produced in this study can be used for making lyocell fibers.     

Response of <Emphasis Type="Italic">Eucalyptus camaldulensis</Emphasis> and <Emphasis Type="Italic">Acacia mangium</Emphasis> kraft pulp in different ECF bleaching options

In this study, the response of Eucalyptus camaldulensis and Acacia mangium kraft pulp to different options of ECF bleaching was investigated. Oxygen-delignified pulps of both species having similar kappa number (c.a. 12) were used. Both the pulps were prebleached using conventional ClO₂ stage (D₀), combined use of ClO₂ and O₃ (DZ), hot acid treatment before D₀ (A_hotD₀) and hot acid treatment before (DZ) i.e., A_hot(DZ), hot ClO₂ treatment (D_HT) and A_hot followed by D_HT (A_hotD_HT). All prebleached pulps were finally bleached to 90%+ ISO brightness using D₁ option. The overall benefits of other options were not considerable compared to D₀ and (DZ). From the ClO₂ consumption point of view, for a certain species, the option A_hot(DZ) was the best. Instead of D₁ in final bleaching, pressurized hydrogen peroxide (PO) was also investigated in the case of D₀ and (DZ) prebleached pulps. (PO)-bleached pulp produced higher brightness stability but lower viscosity compared to D₁.     

TCF Bleaching of Populus tomentosa Kraft Pulps with H2O2 Pretreatment under Acid Condition

The process of peroxide bleaching of Populus tomentosa kraft pulp with H2O2 pretreatment under acid condition was studied. The variations of pulp characteristics such as brightness, Kappa number and viscosity during the peroxide bleaching process were discussed and the concept of the A/B value was presented for the first time. The results show that acid pretreatment with H2O2 is essential to improve pulp brightness and avoid viscosity loss. The conclusion is reached that the A/B value has great influence on pulp properties when the total amount of peroxide used in the bleaching process is 2%–5%. Pulp with a high viscosity and brightness can be obtained when A/B is about 0.15.