Reduced Recalcitrance and Improved Pulp Properties in Eucalypt Woods Pretreated with White-Rot Fungi and Mild Alkali
Reduced Recalcitrance and Improved Pulp Properties in Eucalypt Woods Pretreated with White-Rot Fungi and Mild Alkali
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DOI：
10.1021/acs.iecr.3c03325
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发表时间：
2023-11-29
影响因子：
4.2
通讯作者：
Carvalho，Maria da Graca V. S.
中科院分区：
文献类型：
--
作者：
da Costa，Ricardo M. F.;Almeida，Bruno;Carvalho，Maria da Graca V. S.
蓝桉（EGB）是非常适合硫酸盐法制浆，由于其物理化学性质，而更多的柠檬酸木材需要苛刻的热化学条件，以达到相同的脱木素水平。纸浆和造纸工业越来越多地寻求解决方案，以有效地开发柠檬酸原料，同时减少制浆和漂白过程中的化学品使用。本研究旨在评价生物预处理和弱碱预处理是否能降低桉木的漂白度，提高硫酸盐法制浆和漂白效率。用白腐菌（WRF）和0.1M NaOH对EGB、Eucalyptus nitens（ENT）和Eucalyptus urograndis（EUG）木片进行预处理。结果表明，这些预处理主要是通过打破酯键参与细胞壁聚合物交联，促进脱乙酰化，木质素分离，增加纤维素的可及性，和木片浸渍在制浆过程中。WRF和弱碱预处理相结合，大大降低了木材的抗弯强度，改善了纸浆的性能。残余木质素含量（K#）减少了9%，在EGB中，15%的ENT，和16%的EUG，而漂白过程中二氧化氯消耗减少了16%，在EGB中，19%的ENT，和13%的EUG。这些预处理可以大大降低化学要求，并导致更高的相对产量，最终降低成本和硫酸盐法制浆和漂白的环境影响。
Eucalyptus globulus(EGB) is well suited for kraft pulping due to its physicochemical properties, whereas more recalcitrant woods require harsher thermochemical conditions to attain identical delignification levels. The pulp and paper industry is increasingly seeking solutions to efficiently explore recalcitrant feedstocks while reducing chemical usage during pulping and bleaching. The present work aimed at assessing whether biological and mild alkali pretreatments are able to reduce eucalypt wood recalcitrance and increase kraft pulping and bleaching efficiency. EGB,Eucalyptus nitens(ENT), andEucalyptus urograndis(EUG) woodchips were pretreated with white-rot fungi (WRF) and/or 0.1 M NaOH. Results suggested that these pretreatments mainly act by breaking ester bonds involved in cell wall polymer cross-linking, promoting deacetylation, lignin detachment, increased cellulose accessibility, and woodchip impregnation during pulping. Combined WRF and mild alkali pretreatments substantially reduced wood recalcitrance and improved pulp properties. Residual lignin content (K#) was reduced by up to 9% in EGB, 15% in ENT, and 16% in EUG, whereas ClO2consumption during bleaching was reduced by up to 16% in EGB, 19% in ENT, and 13% in EUG. These pretreatments can substantially reduce chemical requirements and lead to higher relative yields, ultimately reducing costs and environmental impacts of kraft pulping and bleaching.