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Chemical composition and structural features of cellolignin from steam explosio...

Magina, Sandra; Marques, Susana; Gírio, Francisco; Lourenço, Ana; Barros-Timmons, Ana; Evtuguin, Dmitry V.

ABSTRACT: Bark is one of the main wastes of the chemical and mechanical processing of Eucalyptus globulus wood. The proposed biochemical processing of bark via saccharification pathway involves steam explosion (SE) pretreatment (severity factor log R0 of 4.22) followed by enzymatic hydrolysis using an enzymatic cocktail composed of cellulolytic and xylanolytic enzymes. Almost 70% cellulose saccharification was ...

Date: 2024   |   Origin: Repositório do LNEG

Effect of Xylanase-Assisted Treatment of Oxygen-Delignified Eucalypt Kraft Pulp...

Matos, José M.S.; Evtuguin, Dmitry V.; Sousa, António P. M.; Carvalho, Maria Graça V. S.

The effects of treating industrial (laboratory-unwashed) oxygen-delignified eucalypt kraft pulp with a commercial endo-xylanase (X) on ECF bleaching performance were evaluated. Changes in fibre morphology, pulp bleachability and quality, and bleaching effluent parameters were assessed. Although no significant morphological changes were observed, fibres showed some external fibrillation. The X stage reduced both...


Microwaves and Ultrasound as Emerging Techniques for Lignocellulosic Materials

Fernandes, Ana; Cruz-Lopes, Luísa; Esteves, Bruno; Evtuguin, Dmitry V.

Currently, in the context of biorefinery and bioeconomy, lignocellulosic biomass is increasingly used to produce biofuels, biochemicals and other value-added products. Microwaves and ultrasound are emerging techniques that enable efficient and environmentally sustainable routes in the transformation of lignocellulosic biomass. This review presents some of the most important works published in the last few years...


Ellagic acid as stabilizer in the thermo-oxidative degradation of thermoplastic...

Gama, Nuno; Evtyugin, Dmitry D.; Lourenço, Ana; Lopes, Célia; Evtuguin, Dmitry V.

Ellagic acid (EA) is a plant polyphenol with strong antioxidant properties. The stabilizing effect of EA on the thermo-oxidative degradation of the commercial thermoplastic poly(ester-ether urethane) (TPU) was studied for the first time and compared with effect of kraft lignin (KL), butylated hydroxytoluene (BHT) and pentaerythritol tetrakis (Irganox 1010). TPUs doped with antioxidants (ca. 20,000 ppm), were an...


New method for isolating β-sitosterol from bleaching effluent of sulphite pulp ...

Evtyugin, Dmitry D.; Prates, António; Domingues, M. Rosário; Casal, Susana; Evtuguin, Dmitry V.

β-sitosterol (BS) is a phytosterol with wide potential in cosmeceutical, biomedical and food applications. In acid sulphite pulp cooking, BS and its derivatives are considered an underutilized natural source of bioactive compounds, which are adsorbed on the resulting pulp or dispersed in the spent liquor. In this work, a new method for the isolation of BS from alkaline extract (AE) of unbleached sulphite pulp p...


Polyoxometalate functionalized sensors: a review

Veríssimo, Marta I. S.; Evtuguin, Dmitry V.; Gomes, M. Teresa S. R.

Polyoxometalates (POMs) are a class of metal oxide complexes with a large structural diversity. Effective control of the final chemical and physical properties of POMs could be provided by fine-tuning chemicalmodifications, such as the inclusion of othermetals or nonmetal ions. In addition, the nature and type of the counterion can also impact POM properties, like solubility. Besides, POMs may combine with carb...


Changes in sulfite liquor composition while re-profiling mill from paper-grade ...

Magina, Sandra; Mendes, Inês S. F.; Prates, António; Evtuguin, Dmitry V.

The re-profiling from paper-grade to dissolving pulp production is a common trend for acid sulfite cooking of wood. This provides substantial changes in the composition of the spent sulfite liquor (SSL) affecting its potentialities in subsequent processing within the biorefinery concept. In this work, a comparative analysis of the chemical composition of SSL was performed from the magnesium-based acid sulfite c...


Study of the anions profile throughout the sulphite pulp line

Mendes, Inês S. F.; Caldeira, Teresa; Prates, António; Evtuguin, Dmitry V.


New poly(lactic acid) composites produced from coffee beverage wastes

Gama, Nuno; Ferreira, Artur; Evtuguin, Dmitry V.

In this study, aiming to reduce the environmental impact of plastics, new composite materials containing recycled fibers from used paper coffee cups and oil extracted from spent coffee grounds (SCG) were produced. Accordingly, the cellulose fibers were chemically modified using lactic acid to be used as poly(lactic acid) filler reinforcement. The obtained results revealed that its addition improved the mechanic...


Conversion of paper and xylan into laser-induced graphene for environmentally f...

Kulyk, Bohdan; Matos, Marina; Silva, Beatriz F. R.; Carvalho, Alexandre F.; Fernandes, António J. S.; Evtuguin, Dmitry V.; Fortunato, Elvira

Laser-induced graphene (LIG) is a foam-like porous material consisting of few-layer graphene obtained by laser irradiation of a wide range of carbon-containing substrates. Among these, the ability to synthesize LIG from paper and other cellulose-related materials is particularly exciting, as it opens the door to a wide assortment of potential applications in the form of low-cost, flexible, and biodegradable dev...


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