[雙語(yǔ)翻譯]--外文翻譯--用于制漿造紙的不同非木本植物纖維的化學(xué)組成的評(píng)價(jià)（英文）

1、 The Open Agriculture Journal, 2010, 4, 93-101 93 1874-3315/10 2010 Bentham Open Open Access Evaluation of the Chemical Composition of Different Non-Woody Plant Fibers Used for Pulp and Paper Manufacturing Gisela Mar

2、ques*, Jorge Rencoret, Ana Gutiérrez and José C. del Río Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080- Seville, Spain Abstract: The chemical composition of sev

3、eral non-woody plant fibers (bast fibers from flax, hemp, kenaf, jute; leaf fi- bers from sisal, abaca and curaua; and giant reed), which are used as raw materials for pulp and papermaking, has been evaluated. Particula

4、r attention was paid to the composition of the lipophilic compounds and the structure of the lignin polymer since they are important components of the fiber that strongly influence the pulping and bleaching performances

5、. Keywords: Non-woody fibers, flax, hemp, kenaf, jute, sisal, abaca, giant reed, paper pulp, lipophilic extractives, lignin. 1. INTRODUCTION An alternative to woody raw materials for pulp and paper production in develop

6、ing countries is the use of non-woody fibers from field crops and agricultural residues. In devel- oped countries, non-woody fibers are mainly used for the production of specialty papers, i.e., tea bags, filter papers,

7、 bank notes, etc. On the other hand, there is a growing need within Europe to consider alternative agricultural strategies that move an agricultural industry purely focused on food production to one that also supplie

8、s the needs of other indus- trial sectors, such as paper and textiles. Non-wood fibers, therefore, could become important raw materials in this transformation [1-3]. The main sources of non-woody raw materials are agr

9、icultural residues from monocotyledons, including cereal straw and bagasse, or plants grown specifi- cally for the fiber, such as bamboo, reeds, and some other grass plants such as flax, hemp, kenaf, jute, sisal, or ab

10、aca. Non-woody plants offer several advantages including short growth cycles, moderate irrigation requirements and low lignin content, which in principle would result in reduced energy and chemicals consumption durin

11、g pulping [4]. Plant fibers are constituted by three structural polymers (the polysaccharides cellulose, and hemicelluloses and the aromatic polymer lignin) as well as by some minor non- structural components (i.e. pr

12、oteins, extractives, minerals). Pulping and bleaching performances are highly dependent on the relative content, structure and reactivity of the plant components. In particular, the lignin content and its compo- sitio

13、n in terms of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) moieties and the different inter-unit linkages are important factors in pulp production affecting the delignifi- cation rate. It has been shown that high

14、er S/G ratios in woods implied higher delignification rates, less alkali con- sumption and therefore higher pulp yield [5]. On the other *Address correspondence to this author at the Instituto de Recursos Natu- rales y

15、Agrobiología de Sevilla, CSIC, P.O. Box 1052, 41080- Seville, Spain; Tel: +34 95 4624711; Fax: +34 95 4624002; E-mail: gisela@irnase.csic.es hand, among the non-structural components, lipophilic ex- tractives pre

16、sent special relevance due to their high impact in paper pulp manufacturing [6]. Lipophilic extractives include different classes of compounds (i.e. alkanes, fatty alcohols, fatty acids, free and conjugated sterols, t

17、erpenoids, triglyc- erides and waxes), which have different behavior during pulping and bleaching [6-8]. These lipophilic compounds, even when present in low amounts in the raw material, may play an important role dur

18、ing the industrial wood processing for pulp and paper production since they are at the origin of the so-called pitch deposits. Pitch deposition is a serious problem in the pulp and paper industry being responsible for

19、 reduced production levels, higher equipment maintenance costs, higher operating costs, and an increased incidence of defects in the finished products, which reduces quality and benefits [6]. In order to maximize the

20、 exploitation of non-woody plant fibers for paper pulp production, a more complete under- standing of its chemistry is required. Most studies have been devoted to the chemical characterization of woody materials, whil

21、e studies on non-woody fibers have been comparatively scarce. In this context, the main objective of this work is to revise and evaluate the chemical composition of different non-woody plant fibers used for pulp and p

22、apermaking, that will help improving the industrial processes in which they are used as raw materials. 2. ANALYTICAL METHODOLOGIES 2.1. Samples The samples selected for this study were bast fibers from flax (Linum usi

23、tatissimum), hemp (Cannabis sativa), kenaf (Hibiscus cannabinus) and jute (Corchorus capsularis); leaf fibers from sisal (Agave sisalana), abaca (Musa textilis) and curaua (Ananas erectifolius); as well as giant reed

24、(Arundo donax). 2.2. Chemical Analyses For hemicellulose and Klason lignin content estimation, milled samples were extracted with acetone in a Soxhlet ap-Evaluation of the Chemical Composition of Different Non-Woody T

25、he Open Agriculture Journal, 2010, Volume 4 95 heterogeneity of the compounds that may occur and their different behavior during pulping, the knowledge of the chemical nature of these components, especially the lipo

26、- philic compounds, is important in order to predict and con- trol the eventual pitch problems that may occur during pulp-ing and bleaching and to establish appropriate methods and strategies for their control. The com

27、position of the lipids present in the different fi- bers was studied by GC and GC-MS and is shown in Table 4. The main lipid classes found in the non-woody fibers are Table 1. Morphological Characteristics (Length and

28、Width) of the Selected Fibers [19] Fiber Source Length (μm) Width (μm) L/W ratio Bast fibers flax 28000 21 1350:1 hemp 20000 22 1000:1 kenaf 2740 20 135:1 jute 2000 20 100:1 Leaf fibers sisal 3030 17 18

29、0:1 abaca 6000 20 300:1 curaua n.a. n.a. n.a. Reeds giant reed 1180 15 78:1 Woods for comparison softwoods 3000 30 100:1 hardwoods 1250 25 50:1 n.a. not available Table 2. Composition of the Main Constitu

30、ents of the Selected Fibers (% of Dry Matter) [20-22] Ash Acetone Extractives Water-Solubles Klason Lignin Acid-Soluble Lignin Holocellulose Bast fibers flax 1.5 0.7 1.3 2.9 1.6 92.0 hemp 2.0 0.5 1.2 4.6 1.

31、5 90.3 kenaf 1.8 1.0 1.1 11.4 3.0 81.9 jute 2.4 0.5 0.4 13.3 2.8 81.6 Leaf fibers sisal 1.0 0.7 2.3 5.9 3.0 85.0 abaca 0.9 0.5 1.7 7.7 1.4 85.6 curaua 1.3 5.3 5.1 4.9 1.6 92.5 Reeds giant r