酚類化合物對聚木糖酶助漂闊葉樹硫酸鹽漿之影響

Effect of phenolic compounds on xylanase assisted bleaching for hardwood kraft pulp

劉家如(Chia-Ju Liu)

指導教授 ： 柯淳涵

國立臺灣大學/生物資源暨農學院/森林環境暨資源學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.03394

摘要

紙廠在製漿造紙過程中產生的黑液，含大量木質素及相關降解物質，其中最常見的物質為酚類化合物，因此紙漿漂白前都要先用大量的水清洗紙漿，以去除附著在紙漿上的黑液，方可進行後續的漂白流程。許多研究指出聚木糖酶對於紙漿漂白有助漂的效果。本研究係模擬紙廠的紙漿進行漂白效能的探討，即酚類化合物存在於紙漿時對於紙漿漂白效能的影響，及上述現象對聚木糖酶協助紙漿漂白效果的影響，目的在於瞭解聚木糖酶的助漂是否可節省漂白前洗漿過程中水資源的使用。
本研究首先探討酚類化合物對一種商用聚木糖酶(Pulpzyme HC)活性的影響。接著取氧漂前及氧漂後的紙漿進行漂白，於酚類化合物存在時進行聚木糖酶助漂，配合二氧化氯漂白及鹼萃，測定經上述處理的紙漿之卡巴值及黏度變化，以瞭解酚類化合物對漂白效果之影響。
研究結果顯示，6種酚類化合物與聚木糖酶反應時，僅有鄰苯二酚及香草醛會影響此商用聚木糖酶的活性，提高酚類化合物濃度，酵素活性降低，另外4種酚類化合物則對此商用聚木糖酶的活性沒有顯著的影響。3種酚類化合物(鄰苯二酚、香草酸、癒創木酚)的存在，會降低漂白的效果，卡巴值及黏度皆隨著酚類化合物濃度的提高而下降愈少。將此商用聚木糖酶應用於含鄰苯二酚的紙漿中進行助漂，卡巴值及黏度均較只加入此商用聚木糖酶助漂的紙漿來得高，顯示鄰苯二酚會降低此商用聚木糖酶的助漂效果。
漂白選擇性(Bleaching selectivity)係漂白效果的表現，研究結果顯示酚類化合物濃度較高時會降低漂白選擇性，而添加此商用聚木糖酶則是提高漂白選擇性；酚類化合物存在時，以此商用聚木糖酶處理紙漿的漂白選擇性則介於上述二者中間，顯示出聚木糖酶對於紙漿漂白的助漂效果，可以抵消酚類化合物對於紙漿漂白效果造成的負面影響。

關鍵字

漂白選擇性 ； 鄰苯二酚 ； 癒創木酚 ； 卡巴值 ； 香草醛 ； 黏度 ； 聚木糖酶

並列摘要

Black liquor produced from kraft pulp contained lot of lignin and lignin-degrading products similar to the structure of phenolic compounds. The most common compounds in black liquor were phenolic compounds. In pulp and paper mill, it would consume lots of water to remove the black liquor then continued to pulp bleaching sequences. Many studies showed that adding xylanase into pulp bleaching sequences could improve the bleaching efficiency. This study simulated the bleaching efficiency in pulp and paper mill to investigate the impact of phenolic compounds on pretreatment of pulp and the impact of phenolic compounds on xylanase pretreatment of pulp. The purpose of this study mainly discussed that the prebleaching ability of xylanase whether reduce the use of water in the process of pulp washing before bleaching.
The study first investigated the impact of phenolic compounds on the activities of Pulpzyme HC. Unbleached and oxygen bleached pulp were used in this study. Adding xylanase into pulp with phenolic compounds subjected to ClO2 bleaching and alkaline extraction. To understand the impact of phenolic compounds on bleaching efficiency measured kappa number and viscosity of the pulp
The six phenolic compounds reacted with xylanase, Pulpzyme HC, only catechol and vanillin acid reduced the xylanase activities. The higher concentration of phenolic compounds, the lower the xylanase activities were. The other phenolic compounds showed no significant effect on xylanase activities. The bleaching efficiency of pulp with phenolic compounds (catechol, vanillin acid and guaiacol) was reduced. Kappa number and viscosity reduced less when adding higher concentrations of phenolic compounds. Adding xylanase into prebleaching sequence of pulp with phenolic compounds, kappa number and viscosity were higher than only adding xylanase. It showed that catechol lowered the prebleaching efficiency of Pulpzyme HC.
Bleaching selectivity could represent the bleaching efficiency. The presence of phenolic compounds was shoed to reduce bleaching selectivity, but Pulpzyme HC prebleaching would increase the bleaching selectivity. The bleaching selectivity of xylanase into pulp prebleaching with phenolic compounds was between solely phenolic compounds and solely Pulpzyme HC. It showed that the bleaching efficiency of adding xylanase into prebleaching sequences could neutralize negative impact of phenolic compounds on prebleaching of pulp.

並列關鍵字

bleaching selectivity ； catechol ； guaiacol ； kappa number ； vanillin ； viscosity ； xylanase

參考文獻

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