Lignocellulose chemical structure

FIGURE 8 Lignocellulose compounds of higher plant structural tissues from terrestrial and land-water interface regions form a major source of RDOM within aquatic ecosystems, and a major metabolic coupling between the drainage basin and aquatic ecosystems. Chemical structure indicates a humic macromolecule (P. Hatcher, personal communication). 

Figure 2.1.1 Schematic illustration of the chemical structure of the major compounds of lignocellulose, namely, cellulose, hemicellulose, and lignin.

Meshitsuka, G, and Isogai, A. 1996. Chemical structure of cellulose, hemicellulose, and lignin. In Hon, D. N.-S. (Ed.), Chemical modification of lignocellulosic materials (pp. 11-34). New York Marcel Dekker. 

Meshitsuka G., Isogai A. Chemical structure, hemicellulose and lignin. In Hon D.N.S. (ed.) Chemical Modification of Lignocellulosic Materials, pp. 11-34. Marcel Dekker Inc., New York (1996)... 

In addition to the chemical structure, the arrangement of the main components in the cell wall and their interaction is of primary importance to the understanding of the ultrastmcture of the cell wall and of the physico-mechanical and other properties of wood materials [2]. However, we have left the ultrastmcture of the cell wall out of the scope of the present review to avoid unnecessary complication and have decided to focus on the types and quantity of chemical linkages between lignin and carbohydrates in lignocellulosics. 

Lignocellulosic materials have a common basic structure, but vary greatly in chemical composition and physical structure.4 Typically, these materials contain 30 percent to 60 percent cellulose, 10 percent to 30 percent hemicellulose (polyoses), and 10 percent to 20 percent ligmn. Cellulose provides strength and flexibility, while lignin supports and protects the cellulose from biological and chemical attack. Hemicellulose bonds lignin to cellulose. 

Carbohydrates would be the predominant raw materials for future biorefineries. The major polysaccharides found in nature are cellulose, hemicellulose and starch (see Chapter 1). These molecules would be mainly utilised after they are broken down to their respective monomers via enzymatic hydrolysis, thermochemical degradation or a combination of these two. Cellulose and hemicellulose, together with lignin, constitute the main structural components of biomass. Starch is the major constituent of cereal crops. This section would focus on the potential utilisation of carbohydrates and lignocellulosic biomass for chemical production. 

Plant cell walls are the source of lignocellulosic materials, also known as biomass, whose structure is chiefly represented by the physico-chemical interaction of cellulose (a linear glucose polymer), with hemicellulose (a highly... 

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