THE INFLUENCE OF COMPOSITION ON THE SWELLING OF KRAFT BLACK LIQUOR DURING PYROLYSIS

During the drying and pyrolysis phases of kraft black liquor combustion, significant swelling of individual liquor particles occurs. Swollen volumes can reach 20 to 30 times the original volume during combustion. The swelling process can affect the combustibility of black liquor and the amount of carryover in a recovery furnace.

The composition of black liquor was found to have a large influence on swelling. A combination of sugar acids and kraft lignin swelled to a larger extent than when either component was pyrolyzed separately. A 1:1 ratio of these two components resulted in maximum swelling for the various ratios tested. The molecular weight of kraft lignin had an effect on swollen volume with higher molecular weight fractions producing lower swelling chars.

Other components were found to reduce the swelling of black liquors. Extractives interfered with the swelling by appearing to change the deformable properties of the pyrolyzing material. Inorganic salts acted as a diluent.

Analysis of the surface characteristics of chars revealed that good swelling chars were composed of small bubbles 50 to 150 microns in diameter. Poor swelling liquors did not exhibit this phenomenon. The formation of bubbles was found to be initiated at 240°C, which closely corresponded to the thermal decomposition temperature of a sugar acid. Kraft lignin appeared to have a major influence on the fluid properties of the pyrolyzing particle. The composition of black liquor determines to a large extent surface forces present in black liquor; these forces are thought to be responsible for the extent to which kraft black liquors deform and swell during pyrolysis.     

抗黑液毒性的纤维素酶产生菌选育的探讨

采用在浓度逐渐提高的黑液梯度平板上连续移接的方法,选育出一株较原菌株Penicillium decumbensJU—Al可抗黑液毒性且快速产生较高活性(滤纸酶活)的纤维素酶的菌株JU—A10。此菌在无黑液的麸皮培养基中连续传40代以后,其以上的特性不变。这表明从JU—1到JU—A10是一个在遗传水平上的改变过程,而非JU—1对黑液环境的生理适应。     

造纸黑液与褐煤制备水煤浆的实验研究

利用造纸黑液和褐煤制备了水煤浆,讨论了最高成浆浓度、流变性、稳定性和加入添加剂种类及用量各因素对黑液煤浆性能的影响.实验结果表明,褐煤和造纸黑液可以制成性能良好的煤浆;制得的煤浆均表现出优越的流变性和稳定性;稀释5倍的黑液制得的煤浆综合性能最好;加入分散剂和稳定剂后,可大幅降低煤浆的黏度,同时也提高了稳定时间.     

造纸黑液中木质素在农业领域的应用

介绍了造纸黑液中木质素在农业领域的最新研究及应用,主要对木质素在肥料、农药、饲料、土壤改良剂、植物生长调节剂、液体地膜等方面的研究进展进行了阐述。     

黑液浓缩新技术研究进展

讨论了黑液浓缩的新技术和新方法,包括热解降低粘度法、膜分离法、除硅法和结冰浓缩法四种。热解降低粘度法和除硅法处理黑液可以得到高浓度黑液,而膜分离法和结冰浓缩法可用来预浓缩黑液并且成本较低。     

黑液和碱木素在石油工业中的应用

本文综述了碱法制浆黑液以及碱木素在石油工业中的应用。黑液可以直接作为低粘度稠油的驱油剂,也可作为高粘度稠油的降粘剂。与蒸汽驱或蒸汽吞吐配合使用,可显著地提高稠油的采收率。从黑液中分离出的碱木素,可用作钻井泥浆添加剂、注水或注蒸汽采油的堵水剂和调剖剂、表面活性剂驱油的牺牲剂、污水处理的絮凝剂等。在石油工业中充分利用碱法制浆黑液和碱木素,对解决黑液污染问题,降低油田化学剂成本,具有重要意义。     

造纸黑液制取木质素磺酸盐研究

以造纸黑液为原料,从中提取木质素,在NaSO3与木质素的质量比为3∶4,反应时间4h,工作压力0.6MPa的最佳条件下,经磺化成木质素磺酸盐。开发的产品可作沥青乳化剂、絮凝剂等。此法不仅提供了一种减少造纸污水对环境污染的方法,而且表明造纸污水的回收利用在工业、建筑业上有一定的利用价值,应用前景广阔。     

造纸黑液混凝处理中助凝剂的替代性研究

造纸黑液的处理常采用聚合氯化铝（PAC）作混凝剂、聚丙烯酰胺（PAM）作助凝剂。但是PAM价格很高,本文目的在于寻求一种PAM替代物。通过混凝实验比较,采用粉煤灰或高岭土作为助凝剂可以与PAM作为助凝剂达到相当的污染物去除效果。采用粉煤灰或高岭土作为助凝剂可以大大降低生产运行成本。     

铁碳微电解对造纸黑液的脱色处理

本文针对用白腐菌-厌氧-好氧生物法处理造纸黑液的出水色度过高,而COD也不能达标的现象,利用铁碳微电解反应柱对出水进行脱色与去除COD的研究.分析了其反应的基本原理,获得了较佳的工艺处理条件：铁炭质量比为2：1,初始pH值4.5～5.5之间,反应时间为30～40min,常温下反应等因素,最终色度与COD的去除率分别达到94.2%与68.9%,出水达到了行业排放标准.     

针叶材造纸蒸煮黑液木质素制备活性炭

以针叶材造纸蒸煮黑液中木质素为原料进行了活炭制备实验。探讨了不同活化时间、活化温度、磷料比对制备活性炭性能的影响。结果表明:针叶材造纸蒸煮黑液中木质素可以作为一种制备活性炭的优良原料,优化条件为:活化温度为550℃,磷料比为4.5∶1,活化时间为40min,制得的活性炭亚甲基蓝吸附值可达到195mL/g,碘吸附值为656mL/g,得率为40.75%。3因素影响顺序依次为:活化温度>磷料比>活化时间。     

浆粕黑液中回收碱的新技术

本课题探讨了阳离于交换膜电渗析法从浆粕黑液中回收碱的新技术,进行了单阳膜、双阳膜、多阳膜的试验,考察了装置设备、工艺条件及电流密度等因素的影响。     

造纸黑液和煤泥制备水煤浆的技术研究

将干燥的块状煤泥研磨至不同粒度的煤粉,与造纸黑液按一定比例配制成水煤浆,考察其综合性能指标.当黑液添加量为7.2%,煤粉粒度小于160目时,制备的水煤浆浓度为67.44%,流动性为A级,稳定性达到20d保持良好.改变黑液的pH值,研究其配制的水煤浆,发现废液pH对水煤浆的成浆性没有太大的影响.由于造纸黑液中含有大量有机质,因此还可提高同等条件下水煤浆的燃烧热值.利用GB 213-87测定所制备水煤浆的恒容高位发热量为21.63MJ/kg,低位发热量为15MJ/kg.     

A THERMODYNAMIC MODEL OF THE HEAT CAPACITY OF COMPOSITIONALLY COMPLEX MULTICOMPONENT POLYMER SOLUTIONS: KRAFT BLACK LIQUOR

A thermodynamic model of the heat capacity of multicomponent polymer solutions is developed and applied to the prediction of the heat capacity of kraft black liquor. The model is developed using a pseudo-binary solution assumption. The form of the excess heat capacity is expressed as Cp^E = γWⁿW₁Wm₂ where γ, m, and n are model parameters. For the particular system studied γ varies linearly with temperature and indicates the magnitude and degree of temperature dependence of the excess heat capacity. Parameters m and n are independent of temperature. The resulting model is capable of predicting the heat capacity of compositionally complex black liquor to within 1-3% of the experimental data. @KEYWORDS: Heat capacity, Thermodynamics, Kraft black liquor, Polymer solutions     

EQUILIBRIUM BEHAVIOR OF KRAFT BLACK LIQUOR IN SUPERHEATED STEAM

The boiling point rise (BPR) of black liquor with solids content of 85 to 98% was measured in superheated steam. The BPR for 85 and 95% solids content liquor is 28 and 52°C, respectively. A surprisingly large amount of liquor swelling occurs in this environment. A swelling mechanism is proposed.     

EQUILIBRIUM BEHAVIOR OF KRAFT BLACK LIQUOR IN SUPERHEATED STEAM

The boiling point rise (BPR) of black liquor with solids content of 85 to 98% was measured in superheated steam. The BPR for 85 and 95% solids content liquor is 28 and 52°C, respectively. A surprisingly large amount of liquor swelling occurs in this environment. A swelling mechanism is proposed.     

A KINETIC STUDY OF THE SULPHURIZATION OF RESIDUAL ASPHALTS

The kinetics of the sulphurization reaction of residual asphalts were investigated at temperatures of 220^°-250^°C and reaction time of 1 hr. The apparent reaction order varied from 1.40-3.50 for the range of temperature studied. The maximum reaction order was obtained at 24O^°C which appeared to be the optimum reaction temperature. The apparent kinetic rate parameters estimated for the sulphurization reactions were activation energy of 99.5 kJ/mol and a frequency factor of 15.48 × 10⁸. The rate parameters show some good agreement with other work reported in the literature.     

煤中吡啶型氮热解机理的量子化学研究

用密度泛函 ( DFT)方法 ,在 UB3LYP/6- 31 G( d)水平上研究了煤中吡啶型氮的热解机理 ,对热解过程中由于官能团周围环境的不同而形成的三类吡啶自由基进行了量子化学计算 ,通过对键的 Mulliken布居数等计算结果的分析 ,分别得到了这三类自由基的热解途径 .并优化得到了反应物、中间体和产物的几何构型 .计算结果表明 ,吡啶型氮主要是以 HCN的形式释放出来的 .NH3 是 HCN二次反应的产物 .     

ROLE OF SUPPORT STRUCTURE ON KINETIC PARAMETER ESTIMATIONS IN A SHELL CATALYST

The kinetic parameters for VOC oxidation by a shell catalyst are generally obtained from the experimental data of conversion-temperature in a laboratory scale isothermal fixed bed reactor. The kinetics of these reactions are often represented by a bi-molecular Langmuir-Hinshelwood expresion. With the help of experimental data for n-hexane, the present study showed that the values of the kinetic parameters estimated depend significantly upon the location and width of the active catalyst layer as well as value of the effective diffusivity of the reactant within the porous structure. The present analysis showed that accurate a priori assessment of these parameters is very important for the reliable estimations of the kinetic parameters.     

间苯二甲酸二缩水甘油酯固化动力学的研究

以DSC为主要测试手段,对间苯二甲酸二缩水甘油酯(DGPA)的不同固化体系进行了研究,得出了固化曲线,并根据经验公式求出了DGPA的固化动力学参数。结果表明,DGPA树脂因固化剂不同,固化动力学参数存在较大差异,其固化活性低于DER331树脂;此外,对于不同固化体系,不同升温速率下,固化剂活性对固化物玻璃化温度影响较大,固化剂活性越高,玻璃化温度越低。