Kayser, HenningHenningKayserMüller, ChristophChristophMüllerGarcía-González, Carlos A.Carlos A.García-GonzálezSmirnova, IrinaIrinaSmirnovaLeitner, WalterWalterLeitnerDomínguez de María, PabloPabloDomínguez de María2022-05-092022-05-092012-08-24Applied Catalysis A: General 445/446: 180-186 (2012-11-28)http://hdl.handle.net/11420/12537Aldol condensations between sugar-derived dehydrated aldehydes (e.g. furfural) and acetone have been proposed as a route to provide useful biomass-derived chemicals. In the quest of sustainable catalytic ways for such aldol condensations, this paper assesses the use of dried chitosan-gels as naturally-immobilized, readily available and non-hazardous amino-based organocatalysts. At room temperature chitosan dried gels are not suitable catalysts for the desired reaction. However, at higher temperatures (>90 °C) reaction proceeds efficiently either in solvent-free systems (with addition of catalytic amounts of water) or in water. The set-up of closed reactor set-ups (thermoshakers or microwave reactions) proved highly beneficial for the reaction outcome. Furthermore, chitosan dried gels were successfully re-used for a number of cycles. An efficient catalyst drying method (either lyophilization or scCO2 drying) was crucial to achieve virtually full conversions in 4 h. After pertinent further process optimization, dried chitosan-gels may become very useful catalysts for their use in biomass-based reactions in biorefineries.en0926-860X2012180186Elsevier ScienceAerogelsBiofuelsBiorefineriesChitosanFurfuralGasolineTechnikJournal Article10.1016/j.apcata.2012.08.014Other