The present Thesis includes the following sections: i) an introduction to the constituents of lignocellulosic materials, with a focus on the lignin and lipophilic extractives, and the utilization of these materials in industrial processes; ii) the main objectives of the Thesis; iii) a detailed description of the materials and methods used; iv) the corresponding references cited; v) the main results obtained and their discussion, which are presented as scientific publications; and finally vi) the main conclusions drawn from the results.In the present PhD Thesis, the chemical composition of diverse lignocellulosic materials, including fast growing eucalypt trees (woody) and elephant grass crops (non-woody) as well as agricultural residues (wheat straw) was studied. Special emphasis was put on the composition and structural characteristics of the lignin and lipophilic extractives, which play a decisive role in the industrial processes of these materials. On the other hand, the structural modifications of the lignin from eucalypt wood during different alkaline deconstruction processes were studied. This information constitutes an important starting point in order to optimize biorefinery processes, particularly in the cooking processes used for the production of cellulose pulp or in the production of bioethanol.Este trabajo se ha llevado a cabo en el Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNASCSIC). Ha sido financiado por una beca FPI del Ministerio de Educación y Ciencia, asignada al proyecto de investigación ´Utilización de cultivos agrícolas y forestales para la producción de pasta de papel: Tratamientos enzimáticos para la eliminación de lípidos y lignina´ (AGL2008-00709), y por el proyecto europeo
´Optimised pre-treatment of fast growing woody and nonwoody Brazilian crops by
detailed characterisation of chemical changes produced in the lignin-carbohydrate matrix (LIGNODECO)´ (KBBE-244362).Peer reviewe
