Non-starch polysaccharides from sunflower (Helianthus annuus) meal and palm kernel (Elaeis guineenis) meal—preparation of cell wall material and extraction of polysaccharide fractions

Two different chemical methods, sequential extraction with alkali and sodium chlorite and treatment with 4-methylmorpholine N-oxide (MMNO), were applied to the extraction of non-starch polysaccharides (NSP) from the enzymically deproteinated, water-insoluble cell wall materials of sunflower (Helianthus annuus L) meal and palm kernel (Elaeis guineensis Jacq) meal. The NSP content accounted for 550 g kg^?1 (sunflower meal) and 750 g kg^?1 (palm kernel meal) of the cell wall materials. Neither of the treatments alone was capable of solubilising more than about half of the original NSP. Combined treatment using alkali/chlorite followed by MMNO completely dissolved cell wall material from palm kernel meal, whereas a small residue (40 g kg^?1 of original NSP) was left in sunflower meal. Loss of NSP occurred with both methods (total NSP recovery ranging from 88% for alkali/chlorite extraction of sunflower to 64% for MMNO extraction of palm kernel). Due to differences in solubility revealed upon acidification and/or dialysis, extracts became subdivided into precipitates and soulble fractions. The sugar composition of the resulting fractions enabled a tentative identification of teh major non-starch polysaccharides; sunflower meal was found to contain cellulose, (acidic) xylans, polyuronide-containing fractions and xyloglucan; palm kernel meal was found to contain mannans, cellulose and xylans, with the major part of the mannans originating from the endosperm and the xylans being almost exclusively located in the endocarp.     

Delignification of intact biomass and cellulosic coproduct of acid‐catalyzed hydrolysis

The kinetics of acid‐catalyzed hemicellulose removal and also alkaline delignification of oat hull biomass were investigated. All three operational parameters namely, catalyst concentration (0.10–0.55 N H₂SO₄), temperature (110–130°C), and residence time (up to 150 min) affected the efficiency of hemicellulose removal, with 100% of hemicellulose removed by appropriate selection of process parameters. Analysis of delignification kinetics (in the temperature range of 30–100°C) indicated that it can be expressed very well by a two‐phase model for the crude biomass and also for the hemicellulose‐prehydrolyzed material. The application of acid‐catalyzed prehydrolysis improved the capacity of lignin dissolution especially at lower temperatures (30 and 65°C) and accelerated the dissolution of lignin. This acceleration of delignification by prehydrolysis was possible at all levels of temperature in the bulk phase; however, results were more significant at the lower temperatures in the terminal phase. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1783–1791, 2015     

乙醇麦草浆洗涤前后臭氧脱木素的对比研究

本试验主要对未洗乙醇浆直接臭氧脱木素,然后再经过乙醇水洗涤后纸浆卡伯值的变化进行了初步研究,并和洗涤后纸浆臭氧处理进行比较.结果表明：未洗乙醇浆直接臭氧脱木素对降低卡伯值非常有效,用0.5%的臭氧即可将卡伯值从128降低到34,这对于制取低卡伯值乙醇浆提出了新的思路和工艺.并与臭氧处理OP浆进行了对比,初步证明前者卡伯值降低率大于后者的原因除与乙醇浆中的还原性物质有关外,也与吸附木素形态及木素在纤维中的存在位置有关.     

New catalytic processes for a sustainable chemistry of cellulose production from wood biomass

The present paper describes the results of studies directed to novel catalytic processes design for the environmentally friendly production of cellulose. The new delignification catalyst which is produced by chemical interaction of elemental sulfur with hydrazine in superbase medium was used for the improvement of efficiency and ecological purity of the conventional pulping process. This catalyst reduces the concentration of polysulfides in pulping liquor and the yield of side sulfur-containing compounds (by 1.5 times). The processes of wood delignification with sulfur-free reagents based on catalytic pulping with acetic acid and hydrogen peroxide and on the delignification of steam-activated wood with NaOH or Na₂CO₃ solutions have prospects for the environmentally benign production of cellulose. The new catalytic process of vanillin production by oxidation of lignosulfonates with molecular oxygen was described.     

Chemical-biotechnological processing of pine bark

Samples of Pinus pinaster were treated with NaOH solutions to obtain both a phenolic extract and a solid residue suitable for processing into different marketable end-products. The experiments performed in the study of the alkaline extraction followed an incomplete factorial design. The independent variables considered and their variation ranges were: liquor/bark ratio (5.25–12.73), temperature (100–130°C) and NaOH concentration (1–3% w/v). The effect of these variables on the residue yield, the lignin content, the polysaccharide content and the glucan/polysaccharide ratio were assessed. The solid residues from the alkaline treatments were delignified using acetic acid and hydrogen peroxide and submitted to enzymatic saccharification. The composition and the susceptibility to hydrolysis of processed samples is discussed.     

硫酸盐苇浆的TCF漂白工艺

研究硫酸盐苇浆的几种TCF漂白方法。结果表明,在两段氧脱木素的第一段加入过氧化氢,可使纸浆硬度降低62.3%以上,并有利于纸浆后续的漂白探讨了O_P/OMP_OP、O_P/OMPP_O、O_P/OMPMP_O、O_P/OMP_OMP等漂序,其中O_P/OMPMP_O漂序的漂白效果最好,可将纸浆漂到87.6%ISO的白度,且当P_O段H_2O用量为0.3%时,纸浆白度也可以达到85%ISO以上     

O-H-M-P漂白工艺及设备

O-H-M-P漂白工艺是ECF漂白的一种发展方向,其漂白关键点是氧脱木素和H2O2漂白的工艺控制及合理的设备选型。近几年在国内得到了迅速推广,是一种清洁制浆工艺,具有良好的环境效益和经济效益。     

甲酸/过氧甲酸脱木素及制浆工艺研究进展

甲酸法制浆作为一种具有巨大发展潜力的有机溶剂制浆方法,引起了研究人员的广泛关注。本文主要阐述了甲酸法制浆的特点、反应机理及几种典型甲酸法制浆工艺的研究进展,并对甲酸法制浆在生物质精炼平台的构建方面作了展望。     

三倍体毛白杨硫酸盐浆氧脱木素试验

通过正交试验,分析了三倍体毛白杨硫酸盐浆氧脱木素中主要因素对纸浆卡伯值、白度和粘度的影响大小的顺序,均为:用碱量 >温度 >氧压.并选定较适宜的氧脱木素工艺条件为:浆浓 10%,用碱量 3%,MgSO4 0.5%,氧压 0.6MPa,温度 100℃,时间 60min.     

马尾松硫酸盐浆氧脱木素的研究

对马尾松硫酸盐浆（卡伯值26．7，粘度928cm3／g）氧脱木素工艺参数、H2O2对氧脱木素的强化以及氧脱木素前活化预处理进行了较为详尽的探索．该研究将为后续无氯多段漂白的研究提供依据。