Boosting circular economy to combat climate change: from biomass wastes to bio-based added-value products

Identificador:  TDX:4468

Handle: https://hdl.handle.net/20.500.11797/TDX4468

Autors:  Casadó López, Anna

Resum:
In today's society, there is a strong reliance on fossil fuel-derived products, and it is advisable to reduce this dependency for the future of society. Additionally, in the Tarragona area, there is a presence of agri-food industry related to nuts, with the consequent production of lignocellulosic waste, such as almond shells, which could be valorised to obtain chemical compounds with the same functions as petroleum derivatives currently serve. In this thesis, the lignin fraction obtained from crushed almond shells has been used to produce Ordered Mesoporous Carbons (OMCs) through the hard-templating method. These have been used as catalytic supports to prepare Ni catalysts for the reaction of hydrodeoxygenation (HDO) of guaiacol, a lignin model molecule, to produce biofuels, at low temperature and hydrogen pressure. Mesoporous silicas, clays and zeolites have also been used as catalytic supports to prepare the Ni catalysts tested in this reaction. Moreover, carbon dots (CDs) from commercial glucose and xylose, which can be obtained from biomass, have been synthesised at different pH media through microwave-assisted hydrothermal synthesis. As well as CDs from lignin from crushed almond shells, which have been synthesised through hydrothermal and microwave-assisted hydrothermal synthesis. Their structure, morphology and optical properties has been evaluated. And lastly, the optical performance of glucose-derived and xylose-derived CDs has been studied under different temperatures, so as to use them as luminescent thermometric sensors.