Novel catalytic systems for sustainable chemical processes ; Novi katalitički sustavi za održive kemijske procese

Utilisation of renewable biomass for sustainable production has been recognised as a possible substitute for non-renewable fossil fuels. A bio based economy will substantially reduce the dependence on petroleum feedstock, mitigate the global warming by reducing CO2 emissions, reduce waste disposal and finally increase the economic benefits. Current efforts have been performed to develop new routes in the synthesis of alkyl levulinates from levulinic acid, as a starting material. Over the past five years, the alkyl levulinates have attracted the attention of researches due to their specific physical-chemical properties and possible applications. Beside the use of renewable feedstock, heterogeneous catalysis has gain also a lot of attention in the area of green chemistry. This thesis work is part of broad research project carried out at the Laboratory of Green Synthetic Chemistry (Green S.O.C., University of Perugia, Italy) aiming at the development of fully green synthetic methodologies for the preparation of value-added bio-chemicals. The preparation of alkyl levulinates starting from levulinic acid implies the use of an alcohol as a reagent, in the present of an acid catalyst (so-called esterification reactions). The approach used is based on the preparation of novel heterogeneous catalysts, specifically cross-linked polystyrene-based acid catalysts, featuring different properties in term of density in active sites and physical morphologies. To verify their catalytic efficiency, esterification reactions of levulinic acid with different alcohols were conducted. ; Korištenje obnovljivih izvora biomase za održivu proizvodnju prepoznato je kao moguća zamjena za neobnovljiva fosilna goriva. Bio-utemeljeno gospodarstvo će značajno smanjiti ovisnost o naftnim sirovinama, ublažiti globalno zatopljenje, smanjenjem CO2 emisija, smanjiti odlaganja otpada i konačno povećati ekonomsku korist. Trenutni pokušaji provode se s ciljem razvoja novih smjerova u sintezi alkil-levulinoata iz levulinske kiseline, kao polaznog ...