7 documents found, page 1 of 1
Wood delignification with aqueous solutions of deep eutectic solvents
Soares, Belinda; da Costa Lopes, André M.; Silvestre, Armando J.D.; Rodrigues Pinto, Paula C.; Freire, Carmen S.R.; Coutinho, João A.P.The development of a sustainable wood fractionation has been a goal for the pulp and paper industries to develop a bioeconomy. The use of green solvents, in particular deep eutectic solvents (DES) has been explored to accomplish such goal. This work unveils the potential of DES aqueous solutions (at 50 wt% water content) as green solvents for the Eucalyptus globulus Labill. wood delignification. Aqueous solutio...
Thermodynamic characterization of deep eutectic solvents at high pressures
Crespo, Emanuel A.; Costa, João M.L.; Palma, André M.; Soares, Belinda; Martín, M. Carmen; Segovia, José J.; Carvalho, Pedro J.; Coutinho, João A.P.Despite the large spectrum of applications being reported for DESs over the last decade, their thermodynamic characterization is often neglected, hindering a better understanding of their nature, and the development of accurate and robust thermodynamic models to describe them, essential for the conceptual and design stages of new industrial processes. This work aims at decreasing such a gap in literature by rep...
Ionic liquids in chromatographic and electrophoretic techniques: toward additio...
Soares, Belinda; Passos, Helena; Freire, Carmen S. R.; Coutinho, Joao A. P.; Silvestre, Armando J. D.; Freire, Mara G.Due to their unique properties, in recent years, ionic liquids (ILs) have been largely investigated in the field of analytical chemistry. Particularly during the last sixteen years, they have been successfully applied in the chromatographic and electrophoretic analysis of value-added compounds extracted from biomass. Considering the growing interest in the use of ILs in this field, this critical review provides...
Rigid polyurethane foams derived from cork liquefied at atmospheric pressure
Gama, Nuno V.; Soares, Belinda; Freire, Carmen S. R.; Silva, Rui; Brandao, Ines; Pascoal Neto, C.; Barros-Timmons, Ana; Ferreira, ArturThe aim of this study was to evaluate the possibility of using polyols derived from liquefied cork in the production of novel bio-based polyurethane foams (PUFs). For that purpose, different liquefaction conditions were used at atmospheric pressure and moderate temperature where poly(ethylene glycol) and glycerol were used as solvents and sulfuric acid as catalyst. The ensuing polyols were used to produce foams...
Bio-based polyurethane foams toward applications beyond thermal insulation
Gama, Nuno V.; Soares, Belinda; Freire, Carmen S. R.; Silva, Rui; Neto, Carlos P.; Barros-Timmons, Ana; Ferreira, ArturIn this work the preparation of viscoelastic bio-based polyurethane foams (PUFs) using polyols obtained via acid liquefaction of coffee grounds wastes has been optimized. In a first stage, the effect of different ratios of isocyanate content to hydroxyl number (0.6, 0.7 and 0.8) and of three distinct percentages of catalyst (3%, 5% and 7%) on the extent of the polymerization reaction was studied by infrared spe...
Spent coffee grounds as a renewable source for ecopolyols production
Soares, Belinda; Gama, Nuno; Freire, Carmen S. R.; Barros-Timmons, Ana; Brandao, Ines; Silva, Rui; Pascoal Neto, Carlos; Ferreira, ArturBACKGROUNDBased on the biorefinery concept, the main focus of this work was the increase in value of spent coffee grounds via an acid liquefaction process using polyhydric solvents in the presence of sulfuric acid, at moderate temperature. For that purpose the effect of temperature, sulfuric acid concentration and time on biomass conversion was studied using design of experiments combined with statistical analy...
Ecopolyol Production from Industrial Cork Powder via Acid Liquefaction Using Po...
Soares, Belinda; Gama, Nuno; Freire, Carmen; Barros-Timmons, Ana; Brandao, Ines; Silva, Rui; Pascoal Neto, Carlos; Ferreira, ArturEcopolyol production from acid liquefaction of cork powder was studied for the first time using PEG 400 and glycerol as liquefaction solvents in the presence of sulfuric acid at moderate temperature and atmospheric pressure. The effect of the temperature, concentration of catalyst, and time on the liquefaction yield has been investigated using a fixed set of reaction conditions namely, a liquefaction solvent mi...