【摘要】：用韌皮纖維作原料進(jìn)行生物法制漿，已成為近年來(lái)造紙工業(yè)清潔生產(chǎn)研究的一大熱點(diǎn)。本文對(duì)雜交構(gòu)樹皮生物法制漿的反應(yīng)歷程進(jìn)行研究，首先通過(guò)條件實(shí)驗(yàn)利用其成漿過(guò)程中聚戊糖、果膠、木素含量等組成成分的變化進(jìn)行了分析，以找到不同酶用量、溫度、pH值下酶處理的作用效果，對(duì)其不同影響因素進(jìn)行分析；其次探討了不同時(shí)間下各個(gè)組分的含量變化，以及對(duì)酶處理前后木素、果膠以及纖維形態(tài)的變化進(jìn)行對(duì)比與分析。 實(shí)驗(yàn)選定果膠酶為構(gòu)樹皮生物制漿的活性酶，采用單因素實(shí)驗(yàn)與正交實(shí)驗(yàn)結(jié)合的方法確定其生物制漿的最佳工藝條件。結(jié)果表明，當(dāng)酶用量1‰，溫度50℃，體系pH為4時(shí)，可取得理想的成漿效果。在此工藝條件下，戊聚糖含量從10.05%下降到7.83%，下降了2.22%；果膠含量從8.86%下降到3.13%，果膠去除率達(dá)到64.67%；卡伯值從初始的29.51下降到19.23，下降了11.28。在實(shí)驗(yàn)室選定條件范圍內(nèi)的外界因子下，溫度的三個(gè)水平所導(dǎo)致的果膠脫除率的差異最大，即溫度的影響是最大的，其次是pH值，，影響最小的是酶用量。 通過(guò)對(duì)構(gòu)樹皮酶法脫除果膠的反應(yīng)歷程研究，對(duì)其不同作用時(shí)間下的聚戊糖、果膠含量，以及卡伯值的測(cè)定，可以得出：在反應(yīng)的前30min，果膠脫除率較少，從8.86%下降到7.75%，只下降了1.11%，而在30min～120min是大量除果膠階段，在此過(guò)程中果膠含量從7.75%下降到3.66%，脫除了總脫除量的69.91%，而在120min～300min時(shí)，果膠含量只下降了0.65%。同樣，在30min～120min時(shí)，卡伯值下降程度也比較大，而只有聚戊糖含量下降比較少，僅僅下降了2.22%。 從對(duì)酶處理前后漿料的纖維形態(tài)觀察圖可以看出，酶處理脫除大部分果膠，但是仍有少部分殘余，這可能是由于果膠酶的單一選擇性；從果膠紅外譜圖可以看出，酶處理使果膠中甲氧基有一定程度的脫除；從對(duì)木素的結(jié)構(gòu)分析可知，原料中的木素和殘余木素結(jié)構(gòu)發(fā)生變化，說(shuō)明酶處理的過(guò)程中木素中可能有羥基縮合成醚鍵的反應(yīng)，且可能木素發(fā)生氧化反應(yīng)，生成新的共軛羰基。
[Abstract]:Biological pulping with phloem fiber as raw material has become a hot spot in clean production of papermaking industry in recent years. In this paper, the reaction mechanism of biological pulping of hybrid tree bark was studied. Firstly, the changes of pentose, pectin, lignin content and other components in the pulp were analyzed through conditional experiments, in order to find out the different enzyme dosage and temperature. The effect of enzyme treatment under pH value was analyzed. Secondly, the content changes of each component at different time were discussed, and the changes of lignin, pectin and fiber morphology before and after enzymatic treatment were compared and analyzed. Pectinase was selected as the active enzyme in the biological pulping of the bark and the optimum conditions of the biological pulping were determined by the combination of single factor experiment and orthogonal experiment. The results showed that when the amount of enzyme was 1 鈥

本文編號(hào)：2332184