【作者】 詹瑶；

【导师】 詹怀宇；

【作者基本信息】 华南理工大学 ， 制浆造纸工程， 2010， 硕士

【摘要】 “林纸一体化”是当今世界先进的造纸工业发展模式,也是我国制浆造纸工业的发展方向。尾叶桉是我国南方的一种速生丰产树种,是一种优良的造纸纤维原料。随着将硫酸盐浆厂转变为综合林业生物质提炼厂概念的提出,以及将木质生物质转变为高附加值化学品的兴起,黑液中木质素成为了重要的可再生资源,亟待对其进行深入的研究开发和利用。本论文以速生材尾叶桉为研究对象,采用硫酸盐法蒸煮,结合氧脱木素和无元素氯漂白,得到高质量的尾叶桉漂白浆,尽量提高原料的利用率。对尾叶桉的硫酸盐法蒸煮、氧脱木素以及后续的无元素氯漂白进行系统的工艺优化和数据分析,对脱木素工艺进行整体优化;比较高卡伯值制浆和中、低卡伯值制浆对后续氧脱木素和ECF漂白的影响。对尾叶桉制浆黑液中具有高附加值的小分子酚醛类物质进行初步的分离与分析,探求一种从黑液中分离这类物质简便而高效的方法。另外,利用近红外光谱分析技术,建立可以预测尾叶桉硫酸盐浆卡伯值和水分的模型,得到比传统方法更快速、准确和环保的测量卡伯值和水分的方法。论文研究了尾叶桉硫酸盐法蒸煮过程中有效碱用量、硫化度、蒸煮温度和保温时间对蒸煮结果的影响。通过对实验数据进行综合分析,得出了高卡伯值尾叶桉KP法蒸煮较为理想的终点卡伯值(卡伯值为40)及其所对应的H因子(297)和活性碱用量(19%～20%,NaOH计)。综合考虑原料利用率、木素溶出效率、浆中HexA含量,尾叶桉KP法蒸煮所得纸浆的卡伯值宜在16～40的范围内。在较大的氧脱木素工艺条件范围内进行实验,探讨氧脱木素过程中用碱量、温度、时间和氧压对氧脱木素效果的影响,比较高、中、低卡伯值三种硫酸盐原浆的氧脱木素特性。优选高、中、低三种卡伯值氧脱木素浆进行后续ECF漂白,讨论(DQ)P漂后浆料的性质。发现高卡伯值浆在氧脱木素时可以较好地保持纸浆得率,减少碳水化合物的降解,其打浆能耗较少。ECF漂白时,在其他条件相同的情况下,只需适当增加有效氯用量,就可以达到和中、低卡伯值浆相当的白度。在本实验条件下,尾叶桉氧脱木素硫酸盐浆卡伯值分别为9,16和20,D段有效氯用量分别为1.5%、2%和4%,P段H2O2用量为2%时,(DQ)P漂白浆的白度都可达到86%ISO以上,且PC值均小于0.5,说明三种卡伯值氧脱木素硫酸盐浆有较好的漂白性能和白度稳定性。另外,三种不同卡伯值的氧脱木素浆经(DQ)P漂白后,其浆张的撕裂指数较低,但抗张强度和耐破强度都很好。利用近红外光谱分析技术建立测定尾叶桉硫酸盐浆卡伯值和水分的数学模型,并对该模型进行了内部检验、外部检验和重现性检验,证明了此模型预测纸浆卡伯值和水分具有良好的精度、重现性和可靠性。另外,采用单一pH值萃取法、有机溶剂-无机溶剂交替萃取法和不同pH值分级萃取法3种较简便的方法对黑液中小分子酚醛类化合物进行初步分离,继而进行鉴定和定量分析,并比较其与木质素产生共沉的程度。发现不同pH值分级萃取法可以有效地防止小分子酚醛类化合物与木质素共沉,获得总量为2397.7mg/L的小分子酚醛类化合物,是一种有效而可行的分离方法。更多还原

【Abstract】 “Forestry-Paper Integration”has been a development model of advanced paper industry, it has also been the developing direction of the China’s paper industry. Eucalyptus urophylla is a main kind of fast-growing wood in south China, and is a good raw material for pulping and papermaking. Nowadays, people already focus on the conception of transferring kraft pulp mill to comprehensive forest biomass refinery, and do lots of researches on changing wooden biomass to high add-value chemicals. Therefore, lignin in the black liquor has become a very significant renewable resource.In this thesis, Eucalyptus urophylla was used as raw material of the research. After kraft pulping, oxygen delignification, and ECF bleaching, high quality and yield bleached pulp was obtained. Kraft pulping, oxygen delignification, and ECF bleaching were regarded as a whole system, and the technologies were optimized systematically. The high Kappa number pulping was compared with medium and low Kappa number pulping, the effects of the Kappa number of origin pulps on the following oxygen delignification and ECF bleaching were analysed. Some high add-value phenolic and aldehyde compounds with low molecular were separated by three ways and the easiest and most efficient method was found. Besides that, a model which could predict Kappa number and moisture content for Eucalyptus urophylla kraft pulp was established by NIR.In the kraft pulping process, the effects of effective alkali dosage、sulfidity、cooking temperature and time on the cooking results were analyzed. And the optimal Kappa number for high Kappa kraft pulping of Eucalyptus urophylla was found to be 40, and the corresponding H-factor was 297, dosage of active alkali was 19%～20%(as NaOH).Comprehensive consideration of utilization ratio of raw material, dissolution efficiency of lignin and the HexA content of pulp, the optimized Kappa number range of Eucalyptus urophylla kraft pulp should be from 16 to 40.In the oxygen delignification process, the experiments were done at a wider range of conditions. The effects of alkali dosage、temperature、time and pressure on the final results and the following ECF bleaching were analyzed. The characters of oxygen delignified pulps of there different Kappa origin pulp were compared. And the characters of the bleached pulp after ECF bleaching of there different Kappa origin pulps were also discussed. Comparing to medium and low Kappa number pulps, the high Kappa origin pulp had better ability to retain the yield during oxygen dilignification process, needed less energy for beating, and could achieve comparative level of brightness as the others with appropriately increasing active chlorine charge during ECF bleaching. When the Kappa numbers of oxygen delignified pulps were 9, 16 and 20, and the corresponding active chlorine dosages in D stage were 1.5%, 2% and 4%, and H2O2 dosage in P stage was 2%, the brightness of (DQ)P bleached pulps could achieve 86%ISO, and PC values were less than 0.5. It showed that the oxygen delignificated kraft pulps of Eucalyptus urophylla with three different Kappa number had preferable bleaching properties and brightness stability. Except for tear index, the tensile strength and burst strength were very good.The Kappa number and moisture content of eucalyptus kraft pulp were measured rapidly by near infrared spectrum. The results of the experiment manifest that the mathematical models of Kappa number and moisture content established by NIR are very reliable after the internal inspection, external inspection and repeatability test, and this method is precise, short-time consuming and environment friendly.Some high add-value phenolic and aldehyde compounds with low molecular were separated by three ways, which were extraction at constant pH value, sequential extraction at different pH values and upersede extraction using organic and inorganic solvents. And the compounds were identified by GC-MS. The method using different pH value for stepwise extraction could prevent the co-precipitation with lignin effectively and obtain a total amount of 2397.7mg/L small molecular phenolic and aldehyde compounds, indicating that it is the easiest and most efficient way.更多还原