Biomass structural components

Carbohydrates account for the greatest proportion of plant biomass, with cellulose and hemi-cellulose acting as major structural components of plant tissues and plant... 

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. 

Generally, polymers from renewable resources have different origins such as natural (e.g., polysaccharides - namely cellulose and starch, which are produced in large amounts protein gums), synthetic (e.g., polylactic acid, PLA) derived from natural monomers, and microbial (e.g., polyhydroxybutyrate, PHB) [1, 5] The main components of biomass are cellulose, lignin, hemicelluloses and extractives and, as a nonwood structural component, starch. 

Carbohydrates account for the greatest proportion of plant biomass, with cellulose and hemicellulose acting as major structural components of plant tissues and cell walls. Pectic polysaccharides from plants have been the subject of studies for long time mainly focused on their physical properties, their chemical and physical modification, and their application. These polysaccharides have the potential for use as prebiotics as they are not easily digested in the human gut and can be considered as a rich source of... 

Biomass is generally made up of polymers, oligomers, monomers, and other nonpolymerizable simple organic compounds, including metallic salts and complexes [17,29,30]. Polymers are, of course, the major components and have been serving human civilizations from time immemorial. The literature on natural polymers is vast and only a few reviews and books are cited here for further reference [3,17,18,24,29-31,37-53]. The outstanding aspect of natural polymers is their wide variety, which provides innumerable opportunities for structural modifications and utilization. 

Simultaneous to the understanding of some basics of hydrothermal carbonization using pure carbohydrate models, the synthesis of hydrothermal carbon materials using raw biomass was continued. It has been analyzed whether complex biomass - hy-drothermally carbonized - can also be directed to complex structural motifs with distinct surface polarities. Ideally, for this purpose one can use the structures and functionalization components already included in the biomass. We specifically selected waste biomass for material synthesis, starting products which are known to be hard to use otherwise, rich in ternary components, and applied different HTC conditions [29]. That way, one can avoid the food-raw materials competition, a prerequisite we regard as crucial for the development of a fully sustainable chemistry. 

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