Idalina Domingos

Agri-food waste has proved to be a valuable bioresource that can be used to obtain a variety of valuable materials, ingredients and chemicals. The optimum conditions for extracting bioactive compounds from sweet cherry seeds (SCS) with different solvents and temperatures were tested in this work. The choice criteria were based on the most efficient extracting capacity while looking for cleaner techniques with lower health or environmental impacts. Some extracting solvents (methanol, ethanol and water) were tested in different combinations and temperatures. The obtained extracts were evaluated for total phenolic compounds and some families of phenolics as well, using spectrophotometric methods. The results obtained showed that the highest extraction of total phenolic compounds was at 70 °C with 60:40 ratio water:ethanol (2.65 mg GAE/g), while maximum flavonoids were obtained at 80 °C and 50% ethanolic aqueous solution (7.26 mg QE/g). The highest value for ortho-diphenols was 21.47 mg...

Invasive plants spread in such a way that they are threats to native species and to biodiversity. In this context, this work aims to determine possible valorizations of Scotch Broom Cytisus scoparius (L.) Link. This species harvested in the Viseu region was used in the present study. The eco-valorization of these renewable resources was made by conversion into liquid mixtures that can later be used in the manufacture of valuable products. For a better understanding of the results obtained, a chemical characterization of the Cytisus scoparius branches (CsB) was made. The ash content, extractives in dichloromethane, ethanol and water, lignin, cellulose and hemicellulose of the initial material were determined. Liquefaction was made in a reactor with different granulometry, temperatures and time. Results show that Broom is mainly composed of cellulose (36.1%), hemicelluloses (18.6%) and lignin (14.6%) with extractives mainly soluble in ethanol, followed by water and a small amount in d...

Forests in Portugal are highly dependent on a short number of wood species, and new species with higher profitability are needed. The Paulownia species has generated great interest due to its fast-growing and relatively good wood properties. However, environmental factors have shown that Paulownia grows differently in each case. This study intends to determine the properties of young Paulownia trees from Portuguese plantations to determine the best age to cut the trees according to their use. The chemical composition (extractives in dichloromethane, ethanol and water, lignin, α-cellulose, and hemicelluloses), heating value, elemental analysis (CHNO), inorganic elements and thermogravimetric analyses (TGA), and the most important mechanical and physical properties (density, MOE, bending strength, water absorption equilibrium, moisture content, and dimensional changes) were determined for 1-, 3-, and 5-year-old trees. The results show that, chemically, the extractives increased while ...

Chestnut shell (CS) is a by-product of some food sector companies. The aim of this study was to test the suitability of this material to be liquefied with polyalcohols, optimizing the main liquefaction parameters in order to use the liquefied material for the production of high added value products. As the chemical composition of the fruit shell depends on the variation in the soil, climate, and species, the chemical composition of CS was determined. Liquefaction was performed with 50:50 ethyleneglycol:glycerol catalyzed by sulfuric acid. Different tests were carried out and several parameters were tested: particle size, temperature 130–190°C, and time 15–120 min. Chemical composition of CSs was determined. The main component found was lignin with 47.0%, which is higher than α-cellulose with around 20.5%, hemicelluloses 15.2%, and extractives in ethanol 8.8%. For the tested parameters, the best liquefaction yield was obtained at 190°C, 30 min, and a 40–60 particle size.

The cultivation of walnut (Juglans regiaL.) for the exploitation of the fruit has been increasingly recognized worldwide; therefore, it is important to valorize a large amount of biomass from walnut shells (WS), where liquefaction may play an important role. This work intends to contribute to an improved understanding of the best uses for this material. The assays were made with a binary mixture of ethylene glycol and glycerol (1:1 v/v) as solvents, catalyzed by sulfuric acid. The tested parameters were as follows: particle size >0.420–0.177 mm, temperature 140–200°C, and reaction time between 15 and 60 min. The initial dried material, the liquefied material, and the resulting solid residue were analyzed by FTIR-ATR for polyol characterization. The results showed that WS are mostly composed of lignin with 35.0% and polysaccharides, 30.0% cellulose and 24.9% hemicelluloses. High-lignin content indicated that WS might be used as a bio-fuel or adhesives. Extractives represent 10.2% ...

The liquefaction process of cork based tree barks has led to an increase of interest due to its potential innovation in the lumber and wood industries. In this particular study the bark of <em>Quercus cerris</em> (Turkish oak) is used due to its appreciable amount of cork tissue, although of inferior quality when compared to the cork provided by other Quercus trees. This study aims to optimize alkaline catalysis liquefaction conditions, regarding several parameters. To better comprehend the possible chemical characteristics of the bark of <em>Quercus cerris</em>, a complete chemical analysis was performed. The liquefaction process was performed in a double-jacket reactor heated with oil, using glycerol and a mixture of glycerol/ethylene glycol as solvents, potassium hydroxide as a catalyst, and varying the temperature, liquefaction time and granulometry. Due to low liquefaction efficiency resulting from the first experimental procedures a study was made regar...

Currently, the polyurethanes industry is dependent on fossil resources to obtain their basic raw materials (polyols and isocyanate), as these are obtained from petroleum products. The aim of this work was to use biopolyols from liquefied Pseudotsuga (<em>Pseudotsuga menziesii</em>) and Turkey oak (<em>Quercus cerris</em>) barks for the production of polyurethane foams and optimize the process. Liquefaction was done with glycerol catalyzed by KOH. Foams were produced following different formulations and using biopolyols from both barks. Subsequently, the foams were characterized according to their mechanical properties and the reaction of the foam formation was monitored by FTIR-ATR. The results show that it is possible to produce polyurethane foams using bio-based polyols and the liquefaction conditions are very important because they influence the characteristics of biopolyols and, consequently the characteristics of the foams. However, the process has to be...

Between 2005 and 2015, the forest area occupied by maritime pine trees in Continental Portugal decreased by about 10.6%, and the existing volume decreased by about 18.4% mainly due to fires and pests (e.g., nematode) that occurred during this period. The purpose of this study was to study the evolution of the land use environmental impact of 1 m3 of maritime pine, standing in Portuguese forest, during that period using the model by Milà i Canals based on soil organic matter measured by soil organic carbon. Results show that the land use impact category increased from 16,812 kg C deficit in 2005 to 18,423 kg C deficit in 2015. Land transformation to forest roads is the main contribution for land use impact representing 54% of the total value followed by land occupation as forest that represents about 40%.

Coffee is a drink enjoyed by millions of people worldwide and progressively more studies are made to prove its benefits, this drink however has a high production of waste, the coffee grounds. The coffee grounds represent a biodegradable waste and with high richness chemistry that should be valued. The present study aims to contribute to the development of scientific knowledge on the chemical composition of spent coffee ground (SCG) and isolate the holocellulose from this by-product, to assess its potential for the production of cellulosic pulp or type I cellulose. Cellulose was isolated using Kürscher and Hoffer method and characterized by X-ray diffraction (with 66.1% of crystallinity) and C NMR CP/MAS. SCG holocellulose was prepared by two types of oxidative cooking: with alkaline hydrogen peroxide and with peracetic acid.

Hardness is an important wood property for several applications. Typically, it is necessary to use traditional methods, such as a universal test machine, to determine a wood’s hardness value. This work reports the hardness of some wood species before and after heat treatment (ThermoWood method) using the Shore-D hardness method. The Shore-D hardness value of untreated wood ranged between 35.3 for Limba wood and 77.2 for Santos wood. With heat treatment, hardness decreased, and the decrease was greater for samples that underwent harsher treatment (2 h at 212 °C). The decrease of hardness was highest for Sipo wood (14%) and the lowest for Afrormosia wood (2.5%). Analysis of variance tests showed that there was a significant difference between wood species, heat treatment, and the interaction between both variables at the chosen level of significance (P ≤ 0.05). Results showed that Shore-D hardness could be used to measure hardness directly in a production line or in small wood compani...

Portugal has historically been a big wine producer. It produced 7 million hectoliters of wine in 201516 campaign, generating 24.5 million kg of grape stalks that can be used for Bioenergy. The aim of this study was to quantify the potential environmental impacts associated with grape stalks when they are used as fuel in a furnace to produce heat and identify the “hotspots”, using the Life Cycle Assessment methodology. The method chosen for environmental impact assessment was CML-IA baseline V3.04 available in the software SimaPro8.3.0. The results show that heat production from pellets made with grape stalks is more environmentally harmful in terms of “marine aquatic ecotoxicity” and it is due to electricity mainly used in the “pellets production” and “heat production” processes. Electricity use is the “hotspot” presenting a great potential for environmental improvement of the product system.

The aim of this work was to test polyalcohol liquefaction for processing orange peel into value added products such as adhesives, foams, chemicals or even as liquid fuel. Dry orange peel was liquefied using a mixture of ethyleneglycol and glycerol (50/50) as solvents catalysed by sulphuric acid (SA). A ratio of 9:1 solvent/lignocellulosic material (LM) was used and 3% of sulphuric acid (SA) was added based on the solvent mass. The liquefaction temperatures tested were 160oC, 180oC and 200oC. The time ranged between 60-120 min. The Initial peel, the liquefied material and the resulting solid residue were analysed by FTIR-ATR. The liquefaction yield ranged from 79% to 92%. The results showed that it is possible to achieve a high liquefaction yield even at low temperatures. The solid residue and the original material have similar spectra, the main differences are observed between the original orange peel and the liquefied material.

A series of high density fiberboard (HDF) panels, bonded with melamine/urea-formaldehyde (MUF), were exposed to a post manufacture hot pressing at various temperatures and pressing durations using a hot press and just enough pressure to ensure firm contact between the panel and the press platens. The experimental plan was developed for three different temperatures of 95, 180 and 210oC and two different pressing times, of 22 and 35 seconds. The panels were made with pine fibers (pinus pinaster) at a target density of 930 kg/m3 and target thickness of 6.7 mm. The results indicated that the pos-manufacture hot-pressing of the exterior HDF panels resulted in a slightly improvement of the modulus of elasticity (MOE), bending strength and internal bonding (IB) of the panels used as substrates. A reduction in moisture content and thickness as well as an increase in density and thickness swelling was also noticed with an increase in the temperature and pressing time.

The outer bark of Douglas-fir (Pseudotsuga menziesii) has a significant amount of cork tissue that may be an important source of chemicals derived from its natural polymers, suberin, cellulose, hemicelluloses and lignin. The present work focuses on the polyalcohol liquefaction of Douglas-fir bark with glycerol and polyethylene glycol (PEG) in order to obtain a liquid that can be further processed to other chemicals and products. The results show that Pseudotsuga bark can be liquefied in a significant percentage in presence of alkali. The best liquefaction yield was obtained with 6% KOH as agents. Although the use of a cosolvent is favorable, good liquefaction yields can also be obtained by glycerol alone. Lower temperatures are favorable as they lead to acceptable liquefaction yields. FTIR-ATR studies showed that all the structural compounds of the bark were attacked and depolymerized. The process tested has a high potential for generation of value-added products from liquefied Doug...

Abstract The aim of this work is to generate generic life cycle inventory data for Portuguese softwood as material and as fuel. The ecoinvent database was used where the principal assumptions were changed to include the Portuguese situation. New economic allocation and correction factors to include mass, energy, and carbon dioxide uptake from nature were calculated forming the new inventory tables for round, industrial, and residual wood (Portuguese softwood). The Ecoindicator99 method was chosen to assess the environmental impact and to check the influence of the data adaptation on the life cycle impact assessment (LCIA) final results. The study shows that differences exist between ecoinvent and Portuguese data for the softwood production in relation to tree species, yield of forest and time from planting trees to final harvesting, length and width of forest roads or total area and land use. The life cycle impact assessment results are completely different for all sorts of softwood...

Wood modification by furfurylation depends on impregnation, so only some species can be treated and even so generally only sapwood samples can be used. Another question is that if the impregnation is not even the properties may vary along the board. The objective of this work was to determine the differences in the main wood properties along the treated board. Furfurylation was tested in maritime pine samples (Pinus pinaster Aiton,) with both sapwood and heartwood. Density, dimensional stability and water absorption by the water soaking method were determined. The differences between untreated and treated wood and also between treated heartwood and sapwood are high. Despite the higher density (and furfuryl content) near the sides of the board the differences along sapwood boards are very small.

ABSTRACT Resumo. O objetivo deste estudo é determinar e comparar o impacte ambiental da produção de cavacas e de estilha, na floresta de pinheiro bravo em Portugal e traçar os respetivos perfis ambientais. As cavacas, normalmente utilizadas como combustível, são provenientes de madeira residual que é cortada em rolos com 1 metro de comprimento, que são rachados numa máquina acionada por trator. Os rolos de pequeno diâmetro e os ramos não são rachados. A estilha é proveniente de madeira industrial que é estilhada, junto ao caminho florestal, num estilhador móvel, logo após o abate da árvore. A base de dados "ecoinvent" foi utilizada e adaptada à situação Portuguesa e com o auxílio do software "SimaPro 7.3.3" procedeu-se a uma "Análise de Ciclo de Vida", conforme descrito na série de Normas ISO 14040. O método "Ecoindicator99" foi o escolhido para traçar e comparar os perfis ambientais dos dois produtos. Os resultados mostram que na produção de cavacas de pinho o processo "Madeira residual de pinho, seca naturalmente, na floresta portuguesa (x=20%)" é aquele que contribui maioritariamente para todas as categorias de impacte, exceto para a acidificação e que, na produção de estilha de pinho, os impactes ambientais em todas as categorias, são maioritariamente provenientes do processo "Madeira industrial de pinho, na floresta portuguesa (x=102%)". Em termos comparativos, as cavacas são preferíveis à estilha nas categorias de impacte "Carcinogens, Resp. organics, Radiation, Ecotoxicity, Lande use e Minerals" e o inverso é verdadeiro apenas para as categorias "Resp. inorganics, e Acidification/Eutrophication". A escolha de um daqueles produtos é indiferente para a categoria de impacte "Climate Change" e praticamente indiferente para as categorias "Ozon layer e Fossil fuels". Abstract: The aim of this study was to dtermine and compare the environmental impact of firewood (split wood) and chips at Portuguese Pinus pinaster forest and plot their environmental profile. The firewood, usually used as fuel, is provided from residual wood that is cut into one meter long log pieces, split with a mobile, tractor-powered cleaving machine. Small-diameter logs and branches are not splited. Wood chips are provided from industrial wood that is fed into a mobile chopper machine, immediately after harvesting, at the forest road. The database "ecoinvent" was used and adapted to include the Portuguese situation and with the help of the software "SimaPro 7.3.3 a Life Cycle Assessment was performed according to ISO 14040 series of standards.The method "Ecoindicator99" was chosen to plot and compare the environmental profiles of the two products. The results show that, in firewood production, the process "residual wood pine, naturally dried, at Portuguese forest, (x=20%)" is the one which contributes the most to all types of impact categories, except for acidification and, in wood chips production, environmental impacts in all categories, are mostly from the process "industrial wood pine, at Portuguese forest (x=102%)". Comparatively, firewood is preferable to wood chips in the impact categories "Carcinogens, Resp. organics, Radiation, Ecotoxicity, Lande use and Minerals" and the reverse is true only for categories "Resp. inorganics, and Acidification/Eutrophication". The contribution of both products for "Climate Change" is the same and for "Ozone layer and Fossil fuels" is almost the same.