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.

生物酶預處理對混合闊葉木漿磨漿能耗和紙張性能的影響

RASHMI SINGH　NISHI K.BHARDWAJ　BIJAN CHOUDHURY

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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.

生物酶預處理對混合闊葉木漿磨漿能耗和紙張性能的影響

RASHMI SINGHNISHI K.BHARDWAJBIJAN CHOUDHURY

摘要:本實驗研究了生物酶預處理對磨漿能耗和紙漿/紙張性能的影響。實驗采用一種商業液體生物酶,在不同用量和反應時間下對漂白混合闊葉木漿進行預處理。實驗結果表明,在不同的處理條件下,生物酶可以提高或降低纖維性能。當生物酶用量達到0.06 IU/g絕干漿、反應時間為2 h時,可以使打漿到游離度(CSF )(300±10)mL的磨漿能耗下降18%。酶預處理影響了纖維網絡的整合,同時紙張抗張指數和耐破指數分別提高了15%和13%。掃描電子顯微鏡(SEM)圖像分析表明,這種改善主要是由于纖維之間的結合力得到了增強所致。 目前,除非情況特殊,生物質燃料的低價值使得只有大型生物質精煉廠才有可能實現盈利。大型生物質精煉廠的建設需要投入大量的資金,因此有很大的商業風險。然而,一些公司由于有戰略上的原因,愿意進入生物質燃料市場。雖然從生物質精煉中提取的燃料價值比較低,但其中混合在這些燃料中的一些化學組分有很高的商業價值。本文表明,通過從快速熱解的產品中提取某些化學物質并把剩余組分當作燃料出售,即使很小的生物質精煉廠也能實現較好的經濟回報。 通過采用高溫二氧化氯(D)和酸性條件下添加鉬酸鹽催化劑的過氧化氫(Pmo)(DPmo)漂白段比先前更溫和的漂白參數,并通過平衡化學品用量、溫度、pH值和反應時間,可以達到與參照紙漿幾乎完全相同的光學和強度性能。通過這種方式,總二氧化氯用量有可能下降27%。實現該成果的關鍵因素是較高的最終pH值以及在DPmo段中使用的螯合劑。影響Pmo漂白工段是否能夠被大規模推廣的關鍵因素仍然是是否能夠實現工廠規模的鉬酸鹽催化劑的回收和循環使用。 建立了一個實驗模式,用電凝聚和沉淀將膠印油墨分散液和膠印新聞洗滌過濾水去污凈化。結果發現,未經處理時,模型膠印油墨在pH值4～11時是穩定的,然而,與之不同的是,未經處理的洗滌過濾水因pH值的變化而引起凝聚。使用不銹鋼陰極,發現銅陽極比鋁陽極更能有效地擾亂膠印油墨的穩定性,而且施加電流與油墨的穩定性被擾亂有正交關系。更進一步發現,膠印油墨在堿性環境下是穩定的,因而阻礙電凝聚和沉淀方式去脫除油墨。油墨的脫穩定性取決于它在金屬兩極的相互作用下,以及其在酸性下的質變。在酸性環境下,碳黑油墨粒子顯示出更為疏水,從而讓水電解所產生的氣泡更加容易收集這些油墨。 為了提高由陽離子化然后酸水解而產生的第一代淀粉類固化劑(SBFs) 的使用方便性,分別采用酸水解、酶化水解和次氯酸鹽氧化來降低原生淀粉的分子質量然后醚化的方式,產生出3種新的SBFs ,而這3種SBFs的置換程度和分子質量均控制為相近。研究了這3種實驗性的SBFs對溶解物質和膠體物質的控制能力以及紙張強度的影響,并與傳統的聚胺類固化物相比。結果顯示,聚胺類固化物對中和溶解物質較好,而 SBFs 在固化膠體物質方面更為出色,而且更好地提升紙張強度。在這些 SBFs 中,其對溶解物質和膠體物質的控制能力,從最好到最差的排列為：酶化水解,酸水解,以氯酸鹽氧化降解。

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.

通過生物質精煉提取燃料和化學品

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漂白段優化針葉木硫酸鹽法漿脫木素工藝

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.

使用電凝聚法和電浮選法凈化膠印廢紙脫墨廢水

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.

由淀粉降解然后陽離子醚化而產生的新的淀粉類固化劑

LIJUN WANGTONGZHOU DILINGZHI LUOZHIJUN HU

APPITA Vol 67 No3-2014