Belinda Isabel Soares

• Chemical Engineering Master
• PhD Student at University of Aveiro

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 E...

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 process...

The mechanisms responsible for the good solubility of lignin in aqueous solutions of deep eutectic solvent are here investigated using both monomer model compounds and technical lignins (kraft and organosolv). The results show the ability of deep eutectic solvents to act either as hydrotropes or co-solvents enhancing the solubility of poorly solubl...

The aim of this study is to evaluate the possibility of using unrefined crude glycerol (CG), a byproduct of the biodiesel industry, in the production of polyurethane foams. In order to assess the suitability of this raw material for the production of polyurethane foams, two samples of crude glycerol with different compositions in glycerol, fatty ac...

The solids choline chloride and urea, mixed in a 1:2 molar proportion, form the iconic deep eutectic solvent “Reline”. A combination of computational and vibrational spectroscopy tools, including inelastic neutron scattering (INS), have been used to probe intermolecular interactions in the eutectic mixture. Reline’s experimental spectra were estima...

Helicobacter pylori is the etiologic agent of several gastric disorders. The growing rates of unsuccessfulness of available antibiotics-based therapy led to the need for non-antibiotic compounds for H. pylori treatment. The antibacterial activity of Eucalyptus nitens and Eucalyptus globulus outer bark lipophilic extracts were evaluated against a pa...

The solubilities of lignin monomeric model compounds and technical lignins (organosolv and kraft) in aqueous solutions of several deep eutectic solvents (DES) were here investigated. The effects of DES components, temperature and concentration, were evaluated. The results show aqueous solutions of DES to be a new class of powerful solvents where bo...

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 interes...

In 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 e...

The 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 propose, different liquefaction conditions were carry out at atmospheric pressure and moderate temperature where PEG and glycerol were used as solvents and sulfuric acid used as...

BACKGROUND: Based on the biorefinery concept, themain 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 st...

Ecopolyol 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 fi...

Ecopolyols production from acid liquefaction of cork powder and coffee grounds was investigated using PEG#400 and glycerol in the presence of sulfuric acid. The liquefaction conditions were optimized by statistical analysis using a 23 full-factorial design with temperature, sulfuric acid concentration and time as process parameters. The minimum res...

Lignocellulosic biomass residues represent a renewable, biodegradable, abundant and cheap source of raw materials for the chemical industry without affecting food and feed supplies [1]. The polyurethane industries are aware of this trend and have been exploring the development of low-cost polyols from different biomass resources by liquefaction met...

Ecopolyols production from acid liquefaction of cork powder and coffee grounds was investigated using PEG#400 and glycerol in the presence of sulfuric acid. The liquefaction conditions were optimized by statistical analysis using a 23 full-factorial design with temperature, sulfuric acid concentration and time as process parameters. The minimum res...

Oxypropylated lignin, oxypropylated cork, starch, soybean, sugar beet pulp and data seeds have been used as replacements of petroleum feedstocks in the synthesis of polyurethane foams (PUFs) and the results demonstrated that replacing a typical petroleum-based polyol with this type of materials, foams had comparable foaming kinetics, density, cellu...

The urgency to find alternative raw materials to fossil ones in order to reach sustainable development is leading a number of research groups to devise synthetic paths and processes based on agro-forest residues [1]. In the present study we investigated the valorization of coffee grounds via the liquefaction for subsequent use as polyols in the pro...

Polyols productions from coffee grounds via acid liquefaction were investigated using Polyethylene glycol and Glycerol in the presence of sulphuric acid. We evaluated the influence upon the liquefaction yield of three operating variables, the maximal temperature (160–200ºC), the amount of added sulphuric acid (1–3% w/w) and the reaction time at max...

Biomass residues are a potential renewable source for the sustainable production of chemicals, materials, fuels and energy (without affecting food and feed supplies) embodying the so-called biorefinery concept [1]. In this context, agro-forestry and agro-food industry by-products have attracted considerable interest of researchers and industrials a...

Two treatments, an induced autohydrolysis and an acid hydrolysis, were applied to Eucalyptus globulus wood chips prior to the cooking stage to extract the hemicellulosic fraction that otherwise would be dissolved in the black liquor and burnt in the recovery boiler. The obtained hydrolysates, rich in xylose, were detoxified by overliming and used f...

The aim of this thesis was to evaluate the valorisation possibility of lignocellulosic by-products arising from industrial activities such as agro-food and agro-forestry industries into liquid polyols precursors in the synthesis of polyurethane and polyesters. The process is based on the oxypropylation of the biomass which occurs in a two step reac...

The current study evaluates the extension of the biorefinery concept in a Portuguese pulp and paper mill using two different strategies to optimize the lignocellulosic biomass conversion: i) the extraction of nearly 50% of Eucalyptus globulus hemicelluloses prior to cooking stage by introducing a pre-treatment to wood chips, instead of being dissol...

O objectivo deste trabalho é avaliar o efeito independente das características principais das tecnologias Lo Solids e Compact Cooking, relacionadas com o perfil de sólidos dissolvidos e o perfil de sulfureto propiciado pela impregnação de licor negro, respectivamente, sobre o cozimento da madeira de E. globulus e propriedades da pasta crua e pasta...

Two treatments, an induced autohydrolysis and an acid hydrolysis, were applied to Eucalyptus globulus wood chips prior to the cooking stage to extract the hemicellulosic fraction that otherwise would be dissolved in the black liquor and burnt in the recovery boiler. The obtained hydrolysates, rich in xylose, were detoxified by overliming and used f...

A primary hydrolysis treatment (auto or acid-catalysed) of Eucalyptus globulus wood was performed before the cooking stage to extract part of the hemicelluloses that otherwise would be dissolved in the kraft liquor and burned. As xylose was the main monosaccharide Pichia stipitis was selected to produce bioethanol. Two methods were tested, with dif...