APPITA 2014年第3期中英文摘要

An experimental study of the effect of enzyme-assisted refining on energy consumption and paper properties for mixed hardwood pulp

RASHMI SINGH　NISHI K.BHARDWAJ　BIJAN CHOUDHURY

SUMMARY： Effects of enzyme pretreatment on energy consumption during refining and also on the pulp/paper quality were evaluated. A commercial enzyme liquid formulation was used to study the refining process of bleached mixed hardwood pulp at different doses and reaction times. Enzymes can improve as well as degrade fibre properties, depending on the treatment conditions. At an enzyme dose of 0.06 IU/g o.d. (international unit per gram oven-dry) pulp and 2 h reaction time, 18% reduction in refining energy to reach CSF 300±10 was achieved. The enzyme pretreatment affected web consolidation and also improved the paper strength properties tensile index and burst index by 15% and 13%, respectively. This improvement is mainly due to enhancement of interfibre bondings as revealed by scanning electron microscope (SEM) image analysis.

生物酶预处理对混合阔叶木浆磨浆能耗和纸张性能的影响

RASHMI SINGH　NISHI K.BHARDWAJ　BIJAN CHOUDHURY



APPITA 2014年第3期中英文摘要

An experimental study of the effect of enzyme-assisted refining on energy consumption and paper properties for mixed hardwood pulp

RASHMI SINGHNISHI K.BHARDWAJBIJAN CHOUDHURY

SUMMARY： Effects of enzyme pretreatment on energy consumption during refining and also on the pulp/paper quality were evaluated. A commercial enzyme liquid formulation was used to study the refining process of bleached mixed hardwood pulp at different doses and reaction times. Enzymes can improve as well as degrade fibre properties, depending on the treatment conditions. At an enzyme dose of 0.06 IU/g o.d. (international unit per gram oven-dry) pulp and 2 h reaction time, 18% reduction in refining energy to reach CSF 300±10 was achieved. The enzyme pretreatment affected web consolidation and also improved the paper strength properties tensile index and burst index by 15% and 13%, respectively. This improvement is mainly due to enhancement of interfibre bondings as revealed by scanning electron microscope (SEM) image analysis.

生物酶预处理对混合阔叶木浆磨浆能耗和纸张性能的影响

RASHMI SINGHNISHI K.BHARDWAJBIJAN CHOUDHURY

摘要:本实验研究了生物酶预处理对磨浆能耗和纸浆/纸张性能的影响。实验采用一种商业液体生物酶,在不同用量和反应时间下对漂白混合阔叶木浆进行预处理。实验结果表明,在不同的处理条件下,生物酶可以提高或降低纤维性能。当生物酶用量达到0.06 IU/g绝干浆、反应时间为2 h时,可以使打浆到游离度(CSF )(300±10)mL的磨浆能耗下降18%。酶预处理影响了纤维网络的整合,同时纸张抗张指数和耐破指数分别提高了15%和13%。扫描电子显微镜(SEM)图像分析表明,这种改善主要是由于纤维之间的结合力得到了增强所致。 目前,除非情况特殊,生物质燃料的低价值使得只有大型生物质精炼厂才有可能实现盈利。大型生物质精炼厂的建设需要投入大量的资金,因此有很大的商业风险。然而,一些公司由于有战略上的原因,愿意进入生物质燃料市场。虽然从生物质精炼中提取的燃料价值比较低,但其中混合在这些燃料中的一些化学组分有很高的商业价值。本文表明,通过从快速热解的产品中提取某些化学物质并把剩余组分当作燃料出售,即使很小的生物质精炼厂也能实现较好的经济回报。 通过采用高温二氧化氯(D)和酸性条件下添加钼酸盐催化剂的过氧化氢(Pmo)(DPmo)漂白段比先前更温和的漂白参数,并通过平衡化学品用量、温度、pH值和反应时间,可以达到与参照纸浆几乎完全相同的光学和强度性能。通过这种方式,总二氧化氯用量有可能下降27%。实现该成果的关键因素是较高的最终pH值以及在DPmo段中使用的螯合剂。影响Pmo漂白工段是否能够被大规模推广的关键因素仍然是是否能够实现工厂规模的钼酸盐催化剂的回收和循环使用。 建立了一个实验模式,用电凝聚和沉淀将胶印油墨分散液和胶印新闻洗涤过滤水去污净化。结果发现,未经处理时,模型胶印油墨在pH值4～11时是稳定的,然而,与之不同的是,未经处理的洗涤过滤水因pH值的变化而引起凝聚。使用不锈钢阴极,发现铜阳极比铝阳极更能有效地扰乱胶印油墨的稳定性,而且施加电流与油墨的稳定性被扰乱有正交关系。更进一步发现,胶印油墨在碱性环境下是稳定的,因而阻碍电凝聚和沉淀方式去脱除油墨。油墨的脱稳定性取决于它在金属两极的相互作用下,以及其在酸性下的质变。在酸性环境下,碳黑油墨粒子显示出更为疏水,从而让水电解所产生的气泡更加容易收集这些油墨。 为了提高由阳离子化然后酸水解而产生的第一代淀粉类固化剂(SBFs) 的使用方便性,分别采用酸水解、酶化水解和次氯酸盐氧化来降低原生淀粉的分子质量然后醚化的方式,产生出3种新的SBFs ,而这3种SBFs的置换程度和分子质量均控制为相近。研究了这3种实验性的SBFs对溶解物质和胶体物质的控制能力以及纸张强度的影响,并与传统的聚胺类固化物相比。结果显示,聚胺类固化物对中和溶解物质较好,而 SBFs 在固化胶体物质方面更为出色,而且更好地提升纸张强度。在这些 SBFs 中,其对溶解物质和胶体物质的控制能力,从最好到最差的排列为：酶化水解,酸水解,以氯酸盐氧化降解。

Biorefineries as sources of fuels and chemicals

GEOFF COVEYBRUCE ALLENDERBRONWYN LAYCOCK MIKE O’SHEA

SUMMARY： At present, the value of biofuels is such that only large biorefineries are likely to be economic except in special circumstances. Large biorefineries require a large capital investment and thus represent a large commercial risk. However, there are strategic reasons that make it desirable for some companies to enter the biofuels market now. Although the revenue from fuels from biorefineries is relatively low, some of the chemicals that form components of these fuels are of high inherent value. This paper shows that by extracting some chemicals from the products of fast pyrolysis and selling the remainder as fuel, even quite small biorefineries can become economically attractive.

通过生物质精炼提取燃料和化学品

GEOFF COVEYBRUCE ALLENDERBRONWYN LAYCOCK MIKE O’SHEA

Optimizing the (DPmo) stage for delignification of softwood kraft pulp

THOMAS DIETZTHOMAS CLARKADRIAN LYSAGHT

SUMMARY： By applying bleaching parameters in the (DPmo) stage, which are more moderate compared to those in a previous study, and by balancing chemical charges, temperature, pH and retention time, optical and mechanical pulp properties can be achieved that are almost identical with those of reference pulps. In this way, total chlorine dioxide savings of up to 27% are possible. Key factors for the positive outcome of this study were a higher final pH and the use of a chelating agent in the (DPmo) stage. Key success factor for the broad introduction of Pmo-containing bleaching sequences still remains the mill-scale feasibility of a recovery and recycle process for the molybdate catalyst.

使用DPmo漂白段优化针叶木硫酸盐法浆脱木素工艺

THOMAS DIETZTHOMAS CLARKADRIAN LYSAGHT

Clarification of flexographic wastewater by electrocoagulation and electroflotation

AKPOJOTOR SHEMIJEFFERY HSIEH DANIEL LEE

SUMMARY： A model, flexographic ink dispersion and a flexographic newsprint wash filtrate were decontaminated with electrocoagulation and sedimentation. It was found that without treatment, the model flexographic ink was stable in the pH range of 4 to 11, however, unlike the model flexographic ink dispersion, pH changes induced coagulation in the untreated wash filtrate. Using a stainless steel cathode, it was found that a copper anode was more effective at destabilising flexographic ink than an aluminium anode and that applied current has a positive correlation with ink destabilisation. Additionally, it was found that at an alkaline pH the flexographic ink is stabilised, which prevents removal of the ink by electrocoagulation and sedimentation. The destabilisation of ink dispersions was attributed to their interactions with metal ions and protonation at acidic pH. Under acidic environment, it was suggested that the carbon black ink particles are more hydrophobic, and bubbles generated by the electrolysis of water easily collect these inks.

使用电凝聚法和电浮选法净化胶印废纸脱墨废水

AKPOJOTOR SHEMIJEFFERY HSIEH DANIEL LEE

New starch-based fixing agents made by starch degradation followed by cationic etherification

LIJUN WANGTONGZHOU DILINGZHI LUOZHIJUN HU

SUMMARY： In improving the application convenience of the first generation of starch based fixing agents (SBFs) which are made by cationization followed by acid hydrolysis, three new SBFs were made respectively by degrading the molecular weight of raw starch with acid hydrolysis, enzymatic hydrolysis and hypochlorite oxidation, followed by etherification. The degree of substitution and molecular weight of the three SBFs were controlled to be similar. The performance of these experimental SBFs in controlling the dissolved and colloidal substances and paper strengthening was measured and compared to that of a traditional polyamine fixative. The results show that the polyamine fixative is better in neutralizing the dissolved substances, while the SBFs are better in fixing the colloidal substances and better in enhancing paper strengths. Among the SBFs, the effectiveness of controlling dissolved and colloidal substances and paper strengthening, from best to worst, is in the order of enzymatic, acid and finally hypochlorite degradation.

由淀粉降解然后阳离子醚化而产生的新的淀粉类固化剂

LIJUN WANGTONGZHOU DILINGZHI LUOZHIJUN HU

APPITA Vol 67 No3-2014