热水预水解对松木及其水解液主要化学成分的影响

研究了热水预水解对松木原料中主要碳水化合物的影响,探讨了阿拉伯糖、半乳糖、葡萄糖、木糖和甘露糖的溶出规律及热水预水解对水解液中各聚糖浓度变化的影响;并研究了170℃水解温度对松木原料的化学组成如聚戊糖、苯-醇抽出物、综纤维素、木素、灰分含量的影响。结果表明,预水解过程中,各种聚糖的溶出速度从快到慢依次是:阿拉伯糖、半乳糖、甘露糖、木糖和葡萄糖,水解过程只有部分半纤维素被降解,大量半纤维素还将依赖后续蒸煮和漂白过程予以除去;在180℃的水解温度下,水解液中各聚糖的浓度随水解时间快速下降,糠醛和羟甲基糠醛的浓度则迅速增加,不利于水解液发酵制备乙醇;随着水解时间的延长,松木聚戊糖、灰分含量逐渐减少;苯-醇抽出物含量逐渐增加;综纤维素含量先快速下降,90 min后基本保持不变;木素含量先减少后又略有增加。     

近红外法制浆材定量模型的研究

通过国标方法测定了7种制浆常用木材原料共计44个样品的综纤维素、木质素、苯醇抽出物含量,并通过AnatrisⅡ型近红外光谱仪采集了样品的近红外光谱图。利用偏最小二乘法PLS建立综纤维素、木质素、苯醇抽出物的预测模型,并对其进行内部交叉验证,最终综纤维素、木质素、苯醇抽出物近红外模型RCV分别为0.9812、0.9226、0.9709,RMSECV分别为0.1890、0.6019、0.2288,RPD值分别为5.18、2.59、4.18。再用独立验证进一步检验模型质量,预测值与真实值偏差不大。结果表明,近红外光谱法可对制浆材材性进行快速测定。     

植物纤维原料的基本特性与纸浆性能的关系

用不同的植物纤维原料制得的浆和纸的品质均有差异,这些都与所用原料的化学组成及其生物结构有密切关系。因此,对不同产地不同品种的植物纤维原料(或新原料),均应对其化学组分进行化学分析。研究表明,不论何种植物纤维原料,其主要化学组分均为纤维素、半纤维素及木素三种,另外还有单宁、果胶质、有机溶剂抽出物(包括树脂、脂舫、蜡     

造纸法抄造烟草薄片用主要原材料成分分析

采用常规造纸纤维原料分析方法对造纸法抄造烟草薄片用主要原材料——烟梗和碎烟叶进行分析。实验表明:两种原料中的冷、热水抽出物和苯醇抽出物含量相当高,尤其是1%NaOH抽出物含量更高,几乎高达80%;综纤维素含量、木素含量较低,而果胶含量较高接近于韧皮纤维原料;对两种原料纤维进行筛分和Kajaani纤维分析,得出两种原料中细小纤维的含量较高,纤维的平均长度较短,纤维的长宽比较小。     

芦苇APMP性能和化学组分变化的研究

探讨了NaOH和H2O2对芦苇机械浆的物理性质的影响,对苇片(浆)化学组分在制浆过程的变化进行了考察.实验结果表明,各化学组分在制浆过程中发生了较大的变化,其中1%NaOH抽出物由原料的29.50%下降到成浆的17.45%,苯醇抽出物由3.11%下降到1.06%,木素由24.36%下降到20.16%,戊聚糖由19.76%下降到15.61%.同时,芦苇APMP的白度不断上升,达到55.9%ISO,而得率逐渐下降,最后纸浆得率为79.9%.     

引种四川桤木木材化学组分的分析与评价

首次报道了四川桤木５、８和１１２年生３种树龄木材的化学组分测定结果。与其它制浆阔叶木的比较表明,虽然四川桤木的木素含量略高,但木材密度适中,灰分含量中等,各种抽出物含量较低,纤维素含量较高,是优良的纸浆纤维用材。研究发现,木材密度、灰分和热水、苯醇同物含量在个体间差异很大,而其它组分在个体间较为均一。树龄与木材密度和灰分含量的关系不大,而对其它组分影响显著,年幼树木的木材抽出物和戊聚糖含量高,而木     

棕榈丝制浆造纸性能分析

对棕榈丝的纤维形态、化学成分和制浆造纸的可行性进行研究试验。研究结果表明：棕榈丝的纤维均长度为0．74mm,平均宽度为14．96μm纤维素和木素的含量分别为40.05％和14．69％,均低于阔叶木和针叶木且高于草类原料;热水抽出物、1％NaOH抽出物、苯-醇抽出物含量均高于阅叶材和针叶材,棕榈丝原料中含有较高的皂化物和细小纤维。棕榈丝采用硫酸盐法制浆物理性能要优于烧碱蒽醌法所制得的浆料。     

3种丛生竹化学成分与纤维形态研究

研究了大型丛生竹车筒竹、箣竹和越南巨竹的化学成分和纤维特征,并与青皮竹作比较;结果表明,车筒竹、箣竹和越南巨竹的综纤维素含量分别达73.43％、71.71％和67.37％,酸不溶木素分别为23.13％、21.39％和23.72％,均与青皮竹的相应值基本相当;抽出物中,3种竹材的苯-醇抽出物均较低,而热水抽出物和氢氧化钠抽出物较高;纤维特征方面,3种竹材纤维长度分别为2.37mm、2.27mm和2.49m,属于长纤维原料,且高于青皮竹;纤维长宽比分别达144、124和128,与青皮竹相当或略小,而壁腔比均小于青皮竹。从对造纸原料的要求看,3种竹材综纤维素含量较高,木素与抽出物含量较低或中等,纤维形态较好,适宜作为造纸原料。     

芒秆的化学成分特征以及制浆方法的研究

主要研究了芒秆的化学成分对浆得率和漂白的影响。实验用芒秆材料采自于浙江农林大学实验地。实验对芒秆的水分、灰分、苯-醇抽出物、克拉森木素及综纤维素的含量进行了定量分析,明确了各成分对浆得率和ECF、TCF漂白的影响。本实验用硫酸盐法对芒秆进行蒸煮,通过改变其蒸煮温度、时间和活性碱添加率等,测得了浆得率及卡伯值。毛竹、洋麻韧皮和桉木进行了同样的实验进行比较。分析了影响浆得率、TCF漂白和ECF漂白的各种因素,并且验证芒秆原料的制浆可行性。     

圆果黄麻的制浆性能试验

对圆果黄麻的纤维形态、化学成分及制浆性能进行了研究。结果表明,圆果黄麻韧皮部纤维平均长度为2.17mm,木质芯部平均长度为0.64mm;圆果黄麻全秆的纤维素和木素含量均低于针叶材和阔叶材;热水抽出物、1%NaOH抽出物、苯-醇抽出物含量均高于针叶材和阔叶材;圆果黄麻全秆适于采用机械法、烧碱-蒽醌法、硫酸盐法、碱性亚硫酸钠法制浆。     

嗜碱性木素降解菌降解能力的初步研究

通过比较不同嗜碱细菌对麦草中木素、纤维素和半纤维素的降解率, 并比较不同菌株的产酶及酶活情况, 筛选出了木素降解能力较强, 而纤维素和半纤维素降解能力相对较弱的嗜碱性木素降解菌。在ｐＨ≈１０－４的条件下培养８ｄ 后, 菌株６ 降解了３２－３７％ 的麦草木素, 而纤维素和半纤维素分别降解了２１－４８％ 和２２－６９％ 。这与其产酶情况基本一致, 该菌株的酶活最高, 分别为ＭｎＰ２７１－３０Ｕ／Ｌ和ＬｉＰ４１－９４Ｕ／Ｌ。     

Effect of seed culture on solid-state bioconversion of wheat straw by Phanerochaete chrysosporium for animal feed production

The solid-state bioconversion of wheat straw by Phanerochaete chrysosporium for the production of animal feed was studied. This study was performed based on a central composite experimental design. The conditions of the seed culture most suitable for rapid induction of the ligninolytic activity of the fungus, when the seed culture is subsequently used for solid-state bioconversion of wheat straw, were determined. When the seed culture with an initial pH of 5.8 was grown under agitated conditions at 130 rpm in baffled flasks at 38 degrees C, it was predicted to give lignin degradation of 19.5% and cellulose degradation of 17.8%. A time profile study of the solid-state bioconversion of wheat straw indicated that the highest lignin and lowest cellulose degradation levels occurred on the sixth day of cultivation. The desirability coefficient for this process also passed through a maximum of 0.705 on the sixth day.     

Biochemical characterization of wheat straw cell wall with special reference to bioactive profile

The core objective of the current study was to extract and characterize the wheat straw cell wall for its nutritional and bioactive profile. For the purpose, four different wheat straw varieties namely Ujala-16, Johar-16, Gold-16, and Galaxy-13 were procured from Ayub Agriculture Research Institute, Faisalabad, Pakistan. The whole research was conducted in three different phases. In first phase, nutritional composition and mineral profile of straw of different wheat varieties were determined. In second phase, wheat straw cell wall of different varieties was isolated and characterized for its important bioactive constituents, such as lignin, cellulose, hemicelluloses, phytosterol, and policosanol (PC) content. Results showed that straw of different wheat varieties contained 7.75–9.24, 3.98–5.06, 3.43–3.98, and 1.60–2.24 g/100 g moisture, ash, protein, and fat contents, respectively, whereas potassium, calcium, phosphorus, and magnesium were 1.19–2.03, 0.10–0.79, 0.10–0.98, 0.03–0.98 ppm, respectively. Moreover, lignocellulosic mass: cellulose 37.75–38.18 g/100 g raw material, lignin 15.67–16.07 g/100 g raw material, hemicelluloses 28.25–28.98 g/100 g raw material, was present in wheat straw and varied significantly among different varieties. In addition, phytosterol ranged from 854 to 1176 mg/kg in straw of different wheat cultivars, whilst PC from 196.09 to 236.48 mg/kg. Conclusively, wheat straw was an excellent source of many important bioactive moieties especially lignocelluloses and could have functional use.     

光叶楮杆芯APMP制浆过程中化学成分的变化

对光叶楮杆芯APMP制浆过程中化学成分变化的研究表明:用光叶楮杆芯制APMP浆料,在热水预处理后得率下降高达5个百分点,这与光叶楮杆芯水溶液抽出物含量高有关.热水预处理阶段得率的降低是由于部分苯-醇抽出物、1%NaOH抽出物和水抽出物及少量低分子戊聚糖的溶出造成的;在化学处理阶段和磨浆过程中得率的降低主要是碱性条件下,1%NaOH抽出物、戊聚糖和木素部分溶出的结果.含量高的水抽出物、1%NaOH抽出物、戊聚糖以及洗涤过程中薄壁细胞和细小纤维的流失,是导致光叶楮杆芯APMP浆料得率偏低的原因.     

不同Cu离子浓度和pH值对云芝降解秸秆中木质素和纤维素的影响

云芝(Coriolus versicolor)对秸秆中木质素与纤维素的降解情况受不同Cu2+浓度和pH值条件的影响,设定不同条件可以提高木质素的降解率,降低纤维素的降解率,以更好地保存纤维素的完整性,实现秸秆中主要成分的分离。通过均匀设计法,设定不同的Cu2+浓度环境X1(0、1.0、2.0、4.0、6.0mmol/L)和不同pH值条件X2(2.2、2.8、3.4、4.0、4.6),测定相应条件下云芝的菌丝生长情况、木质素酶活力、纤维素酶活力以及秸秆中木质素和纤维素的降解率。结果表明：木质素的降解率与Cu2+浓度呈正相关,与pH值呈负相关;纤维素的降解率与pH值呈正相关,与Cu2+ 浓度呈负相关。通过试验所得方程预测得知,Cu2+浓度6mmol/L、pH2.2是优化的云芝降解、分离秸秆中主要成分的条件,在该条件下,由所得方程可知秸秆中木质素的降解率为16.1%,纤维素的降解率为27.7%。     

麦草秸秆微晶纤维素的制备工艺

研究以麦草秸秆为原料制取微晶纤维素的制备工艺。运用添加乙酸的乙醇法低污染制浆技术,溶出麦草秸秆中的木素、半纤维素等杂质,采用全无氯的臭氧及过氧化氢漂白工艺对粗纤维素进行漂白,然后通过盐酸水解和稀碱处理制备得到微晶纤维素。结果表明,试验制取的微晶纤维素符合合成革用微晶纤维素的标准。在提取粗纤维素过程中催化剂乙酸的最佳用量是2%。水解时间对微晶纤维素产品聚合度的影响较大。麦草秸秆制取微晶纤维素的最佳工艺条件为:液比1:15,水解温度70℃,水解时间90min。碱处理的工艺条件为:碱浓5%,温度80℃,处理时间30min。     

兴安落叶松化学组成的研究

对兴安落叶松化学组成进行较深入分析研究，表明其特性如下：提取物含量较高，尤以热水提取物最甚，主要含阿拉伯糖基－半乳聚糖。苯醇提取物中除主要含树脂外，还有相当量的黄酮类化合物。总木质素含量与一般针叶材类似，但酸溶木质素很低；综纤维素含量比一般木材都低，其糖基组成分析表明在测定过程中阿拉伯糖基－半乳聚糖基本上流失，因此综纤维素含量的测定不宜采用现行的标准方法；灰分含量较低，但有２３种元素组成，其主要元素为Ｃａ、Ｋ、Ｍｎ和Ｍｇ。     

麦草生物化学制浆

报导了用降解木素菌预处理麦草对化学制浆的影响。用Ceriporiopsissubvermispora菌处理麦草可分别降低原料中木素和抽提物含量16.5%和44.3%。对于菌处理后麦草的化学制浆,在用碱量相同情况下,可降低纸浆卡伯值22%-27%;在相同卡伯值下可降低碱用量30kg/t原料;或在相同卡伯值下可缩短蒸煮时间30%。生物化学麦草浆与未经菌预处理化学麦草浆参照对比,纸浆白度较高,废水污染化学需氧量(COD)负荷较低。     

Effects of sodium hydroxide on cereal straws in relation to the enhanced degradation of structural polysaccharides by rumen microorganisms

The action of sodium hydroxide on the rate and extent of loss of wall polysaccharides from wheat and barley straws incubated in the rumen of the sheep was studied using a nylon bag technique. Cellulose loss reached a maximum in straws treated with 10 g NaOH 100 g^?1 straw. Further increase in amounts of alkali applied resulted in additional solubilisation of straw constituents, particularly xylan, but did not further enhance cellulose degradation. Rates of degradation of isolated straw, cotton and wood celluloses correlated with three of four measures of cellulose crystallinity obtained by X-ray diffraction and infrared analysis. Treatment of cellulose samples with 20 g NaOH 100 g^?1 cellulose did not affect rates of loss or produce detectable changes to cellulose morphology. Loss of acetic acid esters, which accompanied alkali treatment, did not relate to improvements to digestibility. The rate of loss of cellulose from delignified neutral detergent fibre (NDF) was that shown by the isolated straw cellulose, despite the presence of acetylated hemicellulose. Deacetylation of delignified NDF with NaOH or sodium methoxide did not enhance rates of xylose or cellulose loss. In lignified wall material (NDF) the molar ratio acetyl:xylose (approximately 1:3.5) and proportion of the major phenolic acids (p-coumaric and ferulic acids) remained essentially constant throughout the course of degradation in the rumen. It is suggested that loss of phenolic acids, while not directly contributing to digestibility enhancement, may model the susceptibility of ester linkages formed between polysaccharide and polyphenolic material to alkali. The extent of solubilisation of p-coumaric acid produced by NaOH showed a linear relationship with cellulose digestibility. An upper limit of 40% acid detergent lignin and 55% of total phenolics were released by NaOH, the extent of release closely paralleling cellulose digestibility. Phenolic material resistant to alkali remained associated with wall polysaccharides and was not released from nylon bags until over 50% of cellulose (and hemicellulose) had been degraded.     

白腐菌对稻草秸秆中木质纤维素降解规律的研究

通过对傅里叶变换红外光谱(FTIR)谱图的分析和木质纤维素组分含量变化的测定,研究了3株白腐菌在50天培养期内降解稻草中木质纤维素的规律。结果表明,3株白腐菌对稻草秸秆中木质纤维素的降解具有一定的顺序和选择性,先降解半纤维素和木质素,再同时降解半纤维素、纤维素和木质素。从降解比例来看,白腐菌对半纤维素和木质素具有很好的降解优势,对半纤维素有较好的降解选择性。