Hydraulic and carbonizing actions of sulfuric acid to straw pulp and paper black liquor

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Preparation of adhesive for bamboo plywood using concentrated papermaking black liquor directly

Adhesive for bamboo plywood prepared directly using lignin existing in the black liquor as a kind of material replacing phenol was proposed on the basis of the same structural properties of lignin and phenol. The results indicate that the reaction time of black liquor methylating is 30min, when the ratio of alkali to formaldehyde is controlled at approximately 0.20, decomposition rate of formaldehyde is the lowest and the effect of black liquor methylating is the best, the optimal molar ratio of phenol： formaldehyde to NaOH to H2O of preparing phenolic resin is 1.00 ： 1.50 ： 0.50 ： 9.00, and the suitable viscosity is 27 - 30 Pa· s. At different mass ratios of methylated black liquor to phenolic resin, all terms of performance of black liquor phenolic resin are excellent and satisfy the requirement. All terms of performance of bamboo plywood prepared using this technique are hetter than that of excellent bamboo plywood of national criteria. Using this technique, the cost is depressed by 28.69% without altering the traditional adhesive producing technique flow, and without using additional equipment.

Study on Synthesis of Nanometer SiC Precursors with Sol-Gel of SiO_2-Lignin in the Pulp Black Liquor

In the process of synthesis of nanometer SiC precursors with sol-gel of SiO2 and lignin , the products of all sizes required can be controlled by the concentration of reac-t ants , pH, temperature, reaction and ageing time , and so on . The best conditions in this research are : the concentration of Na2SiO3 and organic matters are 4. 50% and 26.4% respectively, pH = 3.3 , T = 65℃ , ageing time is 30min , dried at 150 ℃ , the size of SiC precursors is about 2.0μm .

Lignin Extraction from Black Liquor and its Application Prospects in Pulp Mills

This paper summarizes the possible application of lignin extraction from black liquor and the development of lignin extraction technology.Lignin extraction from black liquor is an important,economical method to resolve the bottleneck associated with the recovery boiler and achieve the targeted capacity expansion in pulp mills.A few of key issues must be taken into cosideration when lignin extraction technology is adopted on the industrial scale.

Combustion and Sulfur-fixing Performance of Pulping Black Liquor Coal-water Slurry

The effects of adding pulping black liquor and other additives to coal-water slurry(CWS) on the sulfur-fixing performance of the resultant mixture(pulping black liquor coal-water slurry) were evaluated. The experimental results demonstrated that the ash content of the black liquor coalwater slurry decreased as the addition of pulping black liquor in the mixture increased. Nevertheless, the addition amount should be appropriately selected to ensure that the black liquor coal-water slurry had a moderate calorific value. Addition of black liquor improved the combustion performance of CWS by lowering the ignition point and stabilizing the combustion process; moreover, the sulfur-fixation ratio after combustion increased by 12 to 16 percentage points than that of CWS, and the content of high-melting-point salt in the ash from CWS after adding black liquor was low. The sulfur-fixing ratio of CWS after adding a sulfur-fixing agent was effectively increased by 25 to 30 percenatge points, but with compromise of the fluidity and stability of the CWS; thus, the addition amount of a sulfur-fixing agent should be optimized.

Preparation of Adsorbent with Magnesium Sulfate and Straw Pulp Black Liquor and Its Phenol Adsorption Properties

A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.

New Advanced Technology on Waste Resourcelization of the Black Pulping Liquor

Combining the characteristics of the black pulping liquor that contains a lot of lignin and other biomass resources, the technology of comprehensive waste utilization is employed. The reconstructive preparation of modified urea-formaldehyde glue by adding black pulping liquor and the application in extruding the medium density fibre board using this modified urea-formaldehyde glue is researched. Results show that when applying the preparation technology that alkaline reaction and then weak acid reaction, the appropriate preparation process is as follows： the adding urea process is divided into three stages （proportion 2 ： 1 ： 1） ; the pH value is 8.0, and the reaction time is 40 min in the addition reaction stage; the pH value will be naturally reduced to 3.5 -5.0, and the reaction time is 45 min in the aggregation reaction stage; the pH value is 8.0 in the urea complement stage. And the optimal condition of the reconstructive preparation the modified ureaformaldehyde glue is adding the condensed black pulping liquor after hydroxymethylation in the beginning of polycondensation reaction by 5% proportion. The application in extruding medium density fibre board with this modified urea-fosmaldehyde glue is proved feasible.

MICROBIAL STRENGTHEN OF COTTON PULP BLACK LIQUOR ANAEROBIC TREATMENT AND BMP MEASUREMENT

This paper illustrates the general experiment principle of anaerobic biological cotton pulp black liquor microbial degradation, including the process and result of experiment. The result shows that the decrement of COD may arrive at 80% by the strengthen effect of Photosynthetic Bacteria. The biochemical methane Potential (BMP) and Chemical Oxygen Demand (COD) of cotton pulp black liquor are also measured during the experiment using improved measure method. The equivalent of COD and BMP is verified as a result. Finally analysis is done based on the experiment result.

ON THE BLACK LIQUOR AND RECYCLE COOKING OF AS-AQ STRAW PULP

Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.

A win-win technique of stabilizing sand dune and purifying paper mill black-liquor

The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment was carded out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant- friendly material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert species （i.e., Agriophyllum squarrosum （L.） Moq. and Artemisia desertorum Spreng. etc.） could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate condition. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents in the soil was negligible.

Combined effect of US/PFS on the black liquor of making paper

The reed pulping black liquor is used as a sample. Researches of (1) combined effect of ultrasound(US)/polyferric sulphate(PFS)/hydrogen peroxide(H 2O 2); (2) effects of the horn tip areas; (3) effect of dose of PFS were carried. Extrapolation of these experiments indicated treatment results are possibly related to complex chemical compositions in the reed pulping black liquor.

THE LIGNIN CONTENT IN BLACK LIQUID OF STRAW AS-AQ BY ULTRAVIOLET SPECTROPHOTOMETER

The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured results of the lignin content by UV. The calculation method for the absorption coefficient and the scanning spectrum property of liquor acidified by SO2 are introduced in this paper.

Strength Performance and Microstructure Characteristic of Naturally-Bonded Fiberboard Composite from Malaysian Bamboo(Bambusa vulgaris)

This study investigated the mechanical properties and microstructural characteristics of fiberboard composite produced by naturally-bonded Malaysian bamboo fiber(Bambusa vulgaris).The components that obtained through soda pulping of bamboo culms such as fiber and black liquor,were used for the preparation of high-density fibreboard composite at two target densities of 850 and 950 kg/m^(3).The bamboo fiberboard composite(BFC)were then produced at 200°C and two pressing parameters of 125 and 175 s/mm.The mechanical properties,e.g.,flexural strength and internal bonding(IB)of BFC samples were evaluated according to BS EN 310:1993 and BS EN 319:1993,respectively.It was found that the mechanical performance of the composite with 850 kg/m^(3)density was significantly higher than 950 kg/m^(3)ones,especially for the samples with 125 s/mm pressing parameter.Microstructure characteristic of the BFC samples illustrated that the fiber linkages were cracked in the composites with higher density,e.g.,the composite with the density of 950 kg/m^(3)and also black liquor were slightly degraded at longer pressing time,which led to the reduction in mechanical properties,especially in IB strength.

黑液循环蒸煮木片制浆技术研究

为了提高化学浆得率,提出黑液循环蒸煮木片制浆方法。通过基础实验和工业生产试验研究,得到结果:黑液循环制备化学浆的基础实验用碱量为木片的26%,浆得率为63.6%,比传统碱法制浆工艺得率50.0%提高13.6%;在工业生产试验中,用碱量为木片的18%,结合蒸煮压力波动变化,纸浆平均得率为63.9%,比传统蒸煮制浆工艺得率50%提高13.9%。此外,循环蒸煮获得的纸浆性能良好,从而证明黑液循环蒸煮木片的制浆方法是可行的。

造纸竹浆黑液的接枝磺化工艺及高效减水剂

对竹浆黑液的接枝磺化工艺进行了优化,研究了亚硫酸钠、甲醛用量及温度对磺化产品减水分散性能和特性黏度的影响规律。结果表明,亚硫酸钠及甲醛用量对磺化改性产品的分散性能影响较大。优化的磺化工艺为:m(S)∶m(L)=0.72,m(F)∶m(L)=1.82,磺化温度为55℃,缩合温度为98℃。优化产品GCL1-JB的特性黏度为6.7mL/g,磺化度为2.3mmol/g。掺GCL1-JB的水泥净浆流动度达到FDN的水平,GCL1-JB具备一定的缓凝效果。

SBR生物技术处理竹浆造纸黑液的研究

通过循序间歇式活性污泥法（ＳＢＲ）处理可使经酸析木质素后所得黑液中的ＢＯＤ５和ＣＯＤ显著减少，当进水中ＣＯＤ浓度为１０９０—１１７０ｍｇ／Ｌ时，ＢＯＤ５去除率为７０％—８３％，ＣＯＤ去除率为５４．５％—６３％，出水中ＢＯＤ５和ＣＯＤ的浓度分别为７６—１０１ｍｇ／Ｌ和４１９—５００ｍｇ／Ｌ．内电解与ＳＢＲ联合对黑液的处理更为有效．当进水ＣＯＤ浓度为１０４６—１１００ｍｇ／Ｌ时，ＢＯＤ５和ＣＯＤ去除率分别为６７％—６８％和７１．４—７６．９％，出水ＢＯＤ５和ＣＯＤ浓度分别达３３—４８ｍｇ／Ｌ和２４２—３１５ｍｇ／Ｌ，符合ＧＢ８９７８－８８国家排放标准．内电解显著提高了后续ＳＢＲ处理的效果．研究了ＣＯＤ一级降解反应动力学，得到了动力学常数Ｋ１和不可生化降解的ＣＯＤ浓度．模拟数据与试验数据吻合良好．

利用竹浆黑液制备无烟煤水煤浆的研究

利用竹浆黑液(BL)和无烟煤制备水煤浆(CWS),研究了竹浆黑液水煤浆(BCWS)表观黏度、稳定性及流变特性变化规律。结果表明:当BL干物质添加量为0.5%时,浆体表观黏度最低,煤浆浓度为70%时,黏度<1 000 m Pa·s;BCWS的流变特性属于宾汉塑性流体,随着剪切速率的增大,呈剪切变稀的现象,其析水率较低,稳定性较好。

竹浆黑液接枝磺化产物的超滤分级及减水分散性能

采用超滤将竹浆黑液接枝磺化产物(GCL1-JB)分成4个不同分子量范围的级分,采用凝胶渗透色谱进行分子量表征,研究了不同分子量的级分对水泥净浆和砂浆性能的影响.结果表明:高分子量级分对水泥净浆和砂浆的减水分散性能优于低分子量级分;高分子量级分(大于50000)掺量为0.5%时,水灰比为0.29的水泥净浆流动度达287mm,120min经时流动度损失为7%,砂浆的3天、7天和28天抗压强度比分别为159.4%、193.4%和143.8%;中等分子量级分具有很强的引气性和缓凝作用,可改善新拌砂浆的工作性,但是硬化砂浆后期的抗压强度较低;中分子量级分(10000～50000)掺量为0.5%时,水泥净浆的初凝时间延长140 min,终凝时间延长297 min,28天砂浆抗压强度比达99.8%.

蔗渣碱法造纸黑液回收木质素的结构及其燃烧特性

以酸析法从蔗渣碱法造纸黑液中回收蔗渣木质素(BL),通过红外光谱(FTIR),核磁共振氢谱(~1H NMR)和凝胶渗透色谱(GPC)对其进行了表征。结果表明,BL主要由愈创木基丙烷单元(G)和紫丁香基丙烷单元(S)通过C—O、C—C键合方式连接而成,其分子量分布较宽,分子之间存在较大差异。通过热重分析法(TG)研究了BL的燃烧特性,结果表明BL的燃烧主要发生在300~500℃的阶段,在此过程中BL分子中的C—C键发生断裂形成挥发分和焦炭,并迅速燃烧,失重率超过80%。通过扫描电子显微镜(SEM)和X射线荧光光谱(XRF)研究了BL在300、600、900和1100℃燃烧灰渣(BLR)的微观形貌和元素组成,结果表明BL呈结实、饱满的颗粒状,而BLR则表现为多孔的疏松堆积体或规则的片状结晶颗粒。随着燃烧温度的升高,BLR中的Na和K质量分数逐渐减少,而其他元素质量分数变化不大。

煤灰矿物质在炉内的迁徙分布规律及其对沾污结渣的影响

在0.25MW试验炉上进行热态试验,对新汶矿务局黑液水煤浆和常规水煤浆进行对比燃烧试验,从炉膛不同部位的灰渣成分分析炉内的结渣机理。研究了煤中钠、钾、钙、铝、硅、铁等矿物质元素沿烟气行程的分布,着重研究了不同成分对结渣的形成及分布的影响。结果表明,沿火焰行程,煤中各矿物质的分布是不一样的,其中碱金属质量分数炉壁渣比空间颗粒明显减小,呈先减小后增大趋势,炉壁渣的铝质量分数明显超过空间颗粒物,呈先增大后减小趋势,硅则和铝恰恰相反,使得硅铝比先增大后减小,其它各元素的附着机理也有各自的规律,其矿物质元素分布与煤灰熔融性基本一致。