乙酸乙酯法竹材木质素分离技术研究

在一定的温度、压力下,利用乙酸乙酯溶解竹材中的木质素,乙酸乙酯通过蒸馏回收后,可以反复利用;而得到的高纯度木质素是重要的化工原料,整个过程形成一个封闭循环系统,基本上无三废排放。研究结果表明:乙酸乙酯浓度为80%,液固比为10∶1,反应温度155℃下保温3h,木质素的分离效果最佳。     

乙酸乙酯法竹材木质素分离技术研究

在一定的温度、压力下，利用乙酸乙酯溶解竹材中的木质素，乙酸乙酯通过蒸馏回收后，可以反复利用；而得到的高纯度木质素是重要的化工原料，整个过程形成一个封闭循环系统，基本上无三废排放。研究结果表明：乙酸乙酯浓度为80％，液固比为10：1，反应温度155℃下保温3h，木质素的分离效果最佳。     

正交试验法优选云南松松塔中木质素的提取工艺研究

通过丙酮—乙醇法提取云南松松塔中的木质素,以木质素的提取率为指标,考查加热时间、加热温度、料液比、提取剂中丙酮与95%乙醇体积比对木质素提取率的影响,通过正交试验法优选木质素的提取工艺。优选出最佳提取工艺:加热时间70 min,加热温度70℃,料液比1∶11(g/m L),提取剂中丙酮与95%乙醇体积比为2∶3,加入少量浓硫酸作为催化剂,在此条件下,木质素的提取率达到42.33%。优选的提取工艺提取率高、提取剂用量少、有效成分易于溶出、工艺简单。     

木质素环氧树脂的合成条件优化

在氢氧化钠催化下,用从造纸制浆废液中提取的碱木质素与环氧氯丙烷反应合成了木质素环氧树脂,并对其进行了红外光谱表征;用盐酸-丙酮法测定环氧树脂的环氧值,研究了环氧氯丙烷与木质素的质量比、氢氧化钠与木质素的质量比、反应温度和反应时间等因素对环氧值的影响。确定木质素环氧树脂较优的合成条件为:环氧氯丙烷与木质素的质量比10∶1、氢氧化钠与木质素的质量比5∶4、反应温度80℃、反应时间2.5h,在此条件下,木质素环氧树脂的环氧值最大达到0.3619。     

高纯丙酮制备工艺研究

以分析纯丙酮为原料,采用亚沸蒸馏技术,来制备高纯丙酮,纯度可超过99.95%。该技术的关键在于精确控制蒸馏温度和蒸馏次数。     

降解木质素环氧树脂的合成和性能研究

以1-丁基-3-甲基咪唑氯盐([BMIm]Cl)为溶剂,利用盐酸对木质素进行催化降解,得到降解木质素(DLG),然后将降解木质素与环氧氯丙烷(ECH)进行反应合成木质素基环氧树脂(LGEP)。利用SEM、TGA和FT-IR对样品进行表征分析,盐酸-丙酮法测定环氧树脂的环氧值,并通过正交试验得出环氧树脂的最佳合成条件。结果表明:木质素降解后粒径减小,羟基含量明显增加,热稳定性提高,且通过降解木质素有效合成了环氧树脂。环氧树脂的最佳合成条件为:m(ECH)/m(DLG)=3.5∶1,m(Na OH)/m(DLG)=1∶1,反应时间5 h,反应温度90℃;最佳条件下,环氧值最高为3.76 mmol/g。环氧树脂固化后的性能测试表明,固化剂的质量分数为50%时,环氧树脂的黏接剪切强度最高为9.6 MPa。     

利用造纸黑液改性脂肪族减水剂的研究

利用造纸黑液制备木质素磺酸盐减水剂,通过测定水泥浆流动度,确定制各改性脂肪族减水剂的最佳条件：亚硫酸钠和丙酮的摩尔比为2．2：1,甲醛与丙酮的摩尔比为0．7：1,木质素磺酸钠的最佳用量为5g。     

乙醇/丙酮减压分离

为防治环境污染,需对废溶剂中的乙醇/丙酮混合溶液进行分离,本文主要以实验的形式研究乙醇/丙酮的分离,通过实验考察冷凝温度,加热温度及真空度等因素确定了最佳蒸馏条件。     

一种异丙叉丙酮及其制备方法

<正>本发明公开了一种异丙叉丙酮及其制备方法,以重量百分比计,原料包括:双丙酮醇溶液85%~95%和催化剂5%~15%,各原料之和为100%;所述双丙酮醇溶液通过丙酮催化加热回流制备而成,以重量浓度百分比计,将双丙酮醇溶液进行常压蒸馏,加热温度为100℃~120℃,蒸发浓缩后的双丙酮醇重量百分比含量为80%~90%,浓缩后的双丙酮醇溶液     

真空蒸馏法细化NTO及其晶型控制的研究

采用真空蒸馏法,以丙酮为溶剂,通过改变蒸馏温度、溶液初始质量浓度、系统真空度等参数,探讨了各因素对NTO重结晶的粒度分布及晶型的影响.对实验结果进行理论分析,确定了最佳重结晶细化NTO的工艺参数.结果表明,晶型主要受蒸馏温度的影响,其次是系统真空度.在蒸馏温度60 ℃左右、系统真空度0.05 MPa～0.06 MPa、溶液初始质量浓度不低于0.2 g/12 mL时,通过真空蒸馏法可以得到比较规则的立方晶型,颗粒粒度在1 靘左右,且分布范围窄.     

麦草氨法制浆工艺及动力学

1 INTRODUCTION Under the pressure of rising consumption on wood resource, more attention has been paid to using non-wood raw materials in papermaking industry. Pulping on non-wood fiber material is expected to increase from 7%—8% at the present to 10%—15% in 2010 in the world[1]. Non-wood material, particularly wheat straw, are exploited as the main raw material for papermaking in China because of the limited wood resource with a forest coverage of only 13.94%[2]. The main problem that …     

稻草碱性亚硫酸钾清洁制浆工艺研究

研究了稻草碱性K₂SO₃-AQ体系蒸煮优化工艺,结果表明最佳蒸煮条件为:10% 总碱量,0.8的碱比, 0.2% AQ,最高温度 160℃ 和保温时间 120 min。所制得纸浆的卡伯值14.5,粗浆得率 53.8%,细浆得率 42.5%,本体系较传统钠基盐蒸煮的优势是其经济的回收系统,一种新型的生态循环将在农作物和造纸厂之间形成。     

Cleaner Production of Wheat Straw Pulp HUANG

1 INTRODUCTION China is one of the largest non-wood pulping countries because of the shortage of forest resources. Usually pulp mills are located in the countryside in China and caustic soda or lime is used as cooking reagent, which produces high pH wastewater with high content of organic pollutants. Black liquor from straw digestion contains high content of silicate and is highly viscous, so it is difficult to recover alkali from the black liquor. The investment of alkali recovery appa…     

Cleaner Production of Wheat Straw Pulp

A pulping method using NH4OH with less amount of KOH as cooking liquor on wheat straw was developed. KOH could reduce consumption of NH3 and cooking time for its strong alkalinity. The effects of various pulping conditions such as composition of cooking liquor, liquid-to-solid ratio, maximum temperature, cooking time to the maximum temperature and cooking time at the maximum temperature were studied. Experimental results indicated that the rate of delignification was 85.12% and the pulp yield was 49.65% under suitable pulping conditions. It looks promising to use black liquor containing nitrogen, phosphorus, potassium and organic substance as fertilizer resources for agricultural production. A new pattern of ecological cycling may be set up between paper industry and farming.     

One-Step Fractionation of the Main Components of Bamboo by Formic Acid-based Organosolv Process Under Pressure

To promote the efficient utilization of lignocellulosic materials, one-step fractionation by formic acid-based organosolv process under pressure has been studied for converting lignocellulose in its main components. Lignin and hemicelluloses were selectively dissolved, while cellulose was not obviously degraded. Under optimized conditions (85% formic acid, a liquor-to-solid ratio of 7:1, and a temperature of 145°C for 45 min), this process provided a high efficient way to separate the main components of bamboo, obtaining 42.2% cellulose pulp, 31.5% lignin, 8.5% hemicellulose-rich fraction, 3.56% furfural and 3.80% acetic acid. Cellulose pulp with satisfying viscosity could easily be bleached to a high brightness of over 87% ISO with a short bleaching sequence, and had an acceptable paper strength properties. The recovered lignin fraction contained a small amount of carbohydrates and a considerable part of proteins and p-hydroxycinnamates. Additionally, the organic substances in hemicellulose-rich fraction obtained was composed of 95% carbohydrates, most of which was monosaccharides, as well as 5% lignin.     

蒸煮液的物理化学特征及在制浆过程中的行为 Ⅱ.木素对蒸煮液的表面张力的影响

通过加入木素自制黑液及取自一个连续等温蒸煮过程的黑液的数据比较,研究了木素对蒸煮液的表面张力的影响。结果显示,木素起着表面活性剂的作用使蒸煮液的表面张力降低。但木素对实际取得的黑液的表面张力的影响要大于人工自制的,其主要原因是前者还含有木材的其它成分,如半纤维素及脂肪酸。黑液表面张力的主要成分是Lifshitz-van der Waals引力 γLLW,其次是Lewis酸碱反应力γLAB。     

Investigation and Characterization of Lignin Precipitation in the LignoBoost Process

Lignin of high purity can be separated from black liquor using the LignoBoost process, of which the overall efficiency is largely dependent on the precipitation yield of lignin, which depends on the properties of black liquor and process conditions. In this paper, the influences of process conditions on the precipitation yield of lignin from mixed hardwood/softwood black liquor were investigated. The Klason and standard UV method were used to determine lignin concentration. The chemical and structural properties of lignin were also analyzed. The results showed that the precipitation yield of lignin increased along with a decrease in pH and temperature, or with an increase in the ion strength of black liquor, and the yield was lower when mixed softwood/hardwood black liquor was used. It also showed that at a higher precipitation yield the precipitated lignin had a lower average molecular weight but had higher methoxyl and phenolic hydroxyl content.     

相分离条件下楠竹碱木素改性产物的集聚态研究

楠竹经三种条件碱法蒸煮,所得黑液经酸化沉淀干燥,用60％（wt）硫酸、相分离法处理,精制有机相得到三种碱木质素酚,将三种碱木质素酚分别与由竹粉经相分离法直接提取的木质素酚通过红外光谱（FT-IR）、凝胶色谱（GPC）、原子力显微镜（AFM）、动态光散射（DLS）进行结构和分子集聚态的分析与比较.结果表明,在缓和的碱法蒸煮条件下,黑液中的木素还具备一定的酚化改性潜力,所得碱木素酚结构和官能团与竹粉木质素酚未见较大差异,但在分子集聚态上其分散性明显不同于竹粉木质素酚,表现为尺度小,分布密集等特点.     

碱-氧-蒽醌蒸煮麦草脱木素

引　言木素、纤维素和半纤维素是构成麦草的主要成分 ,是自然界中较为丰富的可再生资源 .木素在制浆造纸过程中生成碱木素 ,溶于黑液 ,排入江河后 ,不仅污染了环境 ,而且浪费了大量的木素资源 ,因此寻求对可再生资源的工业化应用途径越来越受到人们的重视 .通常 ,脱木素的方法有亚硫酸盐法和碱法 ,后来许多研究者对其进行了改进 ,不过这些研究的目是为了提高纸浆得率 ,在不破坏纤维素的条件下得到白度好、易漂白、易成浆的纸浆 ,这些方法只考虑了对纤维素进行造纸的利用 ,而没有考虑对纤维素的其他利用途径以及对木素资源的利用[1～ 8] .纤…     

Investigation of liquefied wood residues based on cellulose,hemicellulose, and lignin

Chinese eucalyptus was subjected to a liquefaction process using glycerol/ethylene glycol (EG) as liquefaction solvent. The effects of various liquefaction conditions, including reaction time, liquefaction temperature, acid concentration, and liquor ratio on the chemical composition of liquefied wood residues were studied. The results showed that the whole liquefaction process took place in two stages, the liquefaction yield of wood depended on the reaction temperature, acid concentration and liquor ratio. With increased acid concentration the liquefaction yield, acid‐insoluble lignin, and hemicellulose content of the residues were increased, and the relative content of cellulose was decreased. Fourier transform infrared (FT‐IR) analyses of the residues showed that hemicellulose and lignin were almost decomposed at the initial stages of reaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011