Lignin valorization : extraction characterization and applications The topic of this project is the use of lignin as alternative source of aromatic building blocks and oligomers to fossil feedstocks. Lignin is known as the most abundant aromatic polymer in nature and is isolated from the lignocellulosic component of plants by different possible extraction treatments. Both the biomass source and the extraction method affect the structure of the isolated lignin therefore influencing its further application. Lignin was extracted from beech wood by two different hydrothermal alkaline treatments which use NaOH and Ba(OH)2 as base and by an acid catalyzed organosolv process. Moreover lignin was isolated from bamboo beech wood and coconut by soda treatment of the biomasses. A comparison of the structural features of such isolated lignins was performed through the use of a wide range of analytical methods. Alkaline lignins resulted in a better candidate as carbon precursor and macromonomers for the synthesis of polymer than organosolv lignin. In fact alkaline lignins showed higher residual mass after carbonization and higher content of the reactive hydroxy functionalities. In contrast the lignin source turned out to slightly affect the lignin hydroxyl content. One of the most common lignin modifications is its deconstruction to obtain aromatic molecules which can be used as starting materials for the synthesis of fine chemicals. Lignin deconstruction leads to a complex mixture of aromatic molecules. A gas chromatographic analytical method was developed to characterize the mixture of products obtained by lignin deconstruction via heterogeneous catalytic hydrogenolysis. The analytical protocol allowed the quantification of three main groups of molecules by means of calibration curves internal standard and a preliminary silylation step of the sample. The analytical method was used to study the influence of the hydrogenolysis catalyst temperature and system (flow and batch reactor) on the yield and selectivity of the aromatic compounds. ...