Sandra Maria da Luz

University of Brasília | UnB · Faculty UnB Gama

The high energy potential of biogas increases its applicability, making it an advantageous option for reducing greenhouse gas emissions. In this study, a life cycle assessment (LCA) was carried out from cradle to gate of two scenarios that exemplify the possibilities of using biogas, produced from dairy cow manure on a Brazilian farm, as an energy...

Although biogas is an alternative to fossil fuels from an environmental, and economic social point of view, there are some challenges to incorporating it into the Brazilian context. Therefore, to increase the employability of the biogas obtained from cattle manure on a Brazilian. As a result, the PSA upgrade, used in scenario 1, has the most impact...

This work investigated the torrefaction process for waste-to-energy (WTE) of Caryocar brasiliense(pequi) seed. Torrefaction (mild pyrolysis) is a pretreatment process (220-300 °C) that improves raw biomass's chemical and physical properties. This investigation aims to understand the thermal degradation kinetics through the torrefaction of pequi see...

The fatigue behavior of epoxy/sisal composites with hygrothermal exposure was investigated. However, their mechanical characterization under cyclic loading associated with aging from hygrothermal exposure is necessary to expand their use in consumer goods and automotive parts. This work used untreated and NaOH-treated sisal fibers (30% in volume) t...

Urban woody residues contribute to overloaded landfills, directly associated with environmental issues. As a technical proposal for energy use and environmental remediation, this work aims to thermally upgrade the residues and characterize its solid biofuel. Firstly, a representative blend (Mangifera indica, Ficus benjamina, Pelthophorum dubium, Pe...

The bottleneck of urban forest waste (UFW) as biofuel relies on surpassing its logistical management, feedstock quantity and supply, heterogeneity, and property drawbacks. This article proposes a hybrid approach based on multicriteria decision methods (MCDM) and response surface methodology (RSM) to optimize the definition of UFW blends and their t...

The bottleneck of hemicellulose as a bio-based material is its processability and property drawbacks (softening and hydrophilicity). Thus, mixing other biopolymers can be an alternative. This article proposes blending hemicellulose (10−50 wt%) with polyhydroxybutyrate (PHB) and poly (lactic acid) (PLA), using acetic acid and chloroform as casting s...

The mechanical performance of a polymeric composite reinforced with fibers, as tensile properties and creep behavior, is strongly influenced by fiber orientation. Although several studies have conducted creep tests on polymeric composites, none have performed creep analyses on sisal/epoxy under actual working stress conditions. In this work, Findle...

This work studied the sheet resistance and conductivity of nanocomposite of regenerated cellulose films (RCFs) and silver nanoparticles (AgNPs). The novelty is associated with obtaining conductive nanocomposite films from jute fibers, which can be promising for application in electronic devices. A combination of chemical treatments was conducted to...

The use of biogas can offer substantial savings in waste management due to its high energy potential. It shows the importance of delineating alternatives that enable the use of biogas in Brazilian territory. Therefore, a Life Cycle Assessment (LCA) of biogas from dairy cow manure was developed ainmed to map the enhancements in biogas utilization. T...

The present work integrates and optimizes energy conversion routes (torrefaction) for urban wastes to energy and resources, providing biofuels for renewable and sustainable energy within an energy-resource-efficient strategy. The proposed methodology combines multicriteria decision methods (MCDM) and response surface methodology (RSM), exploring bi...

The authors report an experimental investigation on square thin-walled energy absorbers with different topologies and materials. The material was steel SAE 1010 and aluminum AL 6160. Some samples non-filled and filled with polymeric material received patterned windows placed in opposite faces with specific dimensions: 20x20, 15x30, and 20x30 mm². Q...

The footwear processes generate a large amount of waste on the soles’ cutting and finishing steps. Styrene–butadiene rubber (SBR) is commonly used as feedstock for soles, mainly presenting good abrasion resistance, deformation and durability. These features make SBR a candidate for the manufacturing of non-slip surfaces, that provide softness, low...

Abstract: For its effective use as a structural component, studies on mechanical behaviour overtime must be carried out in polymer composites reinforced with sisal fibres. The composites developed in this study were reinforced with 50 v% sisal fibre. The manufacturing method used was hand lay-up, and the cure of composites was performed at room tem...

This work studied the influence of the resin/ hardener ratios in the curing process of commercial thermosetting epoxy Araldite LY 5052. For that, a combined Fourier transformer infrared (FTIR) and principal component analysis (PCA) was used to study the chemical changes when the different curing agent ratios (100:22, 100:26, 100:30, 100:34, 100:38,...

Polypropylene is a semi-crystalline thermoplastic widely used in industrial parts, electronic devices, and household appliances. Despite the abundant research on this polymer, its behavior under cyclical loading conditions still requires further analysis. Herein, a preliminary investigation of the uniaxial tensile monotonic and fatigue properties o...

With growing environmental concerns over synthetic polymers, natural polymeric materials, such as hemicellulose, are considered a good sustainable alternative. Curaua fibers could be an excellent source of biopolymer as they have a relatively high hemicellulose content (15 wt%) and only a small amount of lignin (7 wt%). In this work, hemicellulose...

Microfibrillated cellulose (MFC) employed as reinforcement of polymeric matrices can increase elastic modulus, stiffness and strength of a composite. In this work, the assessment of the mechanical, thermal properties and tensile tests assisted by digital image correlation (DIC) was performed for curaua fiber MFC-reinforced polylactic acid (PLA) com...

This work manufactured prepregs by impregnating discontinuous curaua fibers with B-stage epoxy resin. The prepreg layers were then stacked to produce laminates by hot compression. Alkaline treatments were previously applied to the curaua fibers to improve their interface with the polymer matrix. Then, the prepregs and the final composites were stud...

RESUMO A gestão de resíduos agrícolas e industriais é necessária para mitigar a poluição ambiental resultante de manejo de animais. Uma alternativa é utilizar resíduos para geração de energia, tornando um substrato com alto potencial poluidor ao meio ambiente em produto com maior valor agregado, como o biogás. O uso da Avaliação do Ciclo de Vida (A...

A common method used to obtain cellulosic fibers is alkalinization with NaOH. Depending on NaOH content, treatments remove significant quantities of lignin and hemicellulose as small molecules. In biorefineries, where the preservation of components is needed, KOH may prevent hemicellulose chain formation. Here, we studied the efficacy of obtaining...

Abstract Qualitative and quantitative measuring in water bodies, nuclear medicine, agriculture, and world oil production use tracers to monitor, evaluate and continuously improve their processes. The bibliometric information about the past and the future of artificial tracers, to monitor surface and groundwater by using sustainable biodegradable ma...

Starch and celluloses are biodegradable resources of great importance in terms of marketing. These biopolymers can be used to generate films with interesting mechanical, optical, and thermal properties, which can substitute for plastic films in certain applications, e.g., packaging materials. This study describes the preparation of pure plasticized...

Quality control to obtain composite laminates is frequently applied to synthetic fibers/epoxy prepregs. The gel time test, resin, volatiles and fiber content, drape measurement and tack tests together with water absorption capacity are methods currently employed. However, for natural fibers prepregs there is a gap in the literature, which makes the...

Torrefaction is an inert thermal process (up to 300 • C) that promotes changes in the chemical and physical properties of biomass, decreasing the time and energy required for biomass conversion. In this work, an online method-TG coupled with FTIR-and elemental analysis were applied to acquire data in order to perform an experimental and numerical t...

Natural fibres as a reinforcement in polymer composites requires an extensive investigation to better understand their thermal behavior when submitted to different chemical treatments. In this work, the polyester composites with curaua fibre (Ananas erectifolius) treated with common chemical modifiers, as Ba(OH)2, Ca(OH)2, KOH, NaOH and silane were...

In this work, we studied how the short curaua fibres reinforcement behaves on the mechanical properties of different polymeric composites: thermosets as epoxy and polyester and biodegradable thermoplastics, polyhydroxybutyrate (PHB) and polyacid lactic (PLA). The composites with 20 wt% fibre content, in natura or alkali-treated curaua fibres were o...

This study investigated the influence of the surface treatment of curaua fibres (Ananas erectifolius) on the morphological, thermal and mechanical properties of polyester composites when the treated fibres (10 wt-%) were added. The following treatment agents were assessed: 10% Ba(OH)2, 14% Ca(OH)2, 5% NaOH, 10% KOH and 5% silane. The treatments rem...

Previous studies have quantified the efficiency of biomass torrefaction processes by proposing severity indexes to discuss the variability of thermally modified biomass properties. However, comparisons of the accuracy and applicability of those indexes are few in the literature. To fill that gap, this study sought to assess five indexes usually app...

Torrefaction is a promising technology to produce woody sustainable materials and biochar for combustion and gasification. To aid in the process and reactor design concept, numerical models are applied to predict processes parameters giving treatment time estimation, solid and volatile yields, and calorific values of the solid fuels. In this work,...

Keywords: biomass, modelling, thermochemical conversion, torrefaction, upgrading Topic:Biomass Technologies and Conversion to Intermediate Bioenergy Carriers and Products of the Bioeconomy Subtopic:Production of thermally treated solid fuels Event:28th European Biomass Conference and Exhibition Session:3CV.2.5 Pages:694 - 698 ISBN:978-88-89407-20-2...

The use of cellulose nanocrystals as reinforcement in polymers brings challenges mainly related to the dry thermal processing, and their adhesion and dispersion in the matrix. In this work, cellulose nanocrystals from sugarcane bagasse was used as reinforcement in nanocomposites of acrylonitrile-butadiene-styrene. Thus, the main objective of this w...

The interest in natural fibre composites as load-bearing elements has increased strongly in recent years. As natural fibres offer good biodegradability, strong reinforcement and low production costs, some industry sectors have started to substitute conventionally used materials. One excellent example for natural reinforcements is curaua fibres. Reg...

RESUMO O objetivo deste trabalho foi caracterizar os compósitos produzidos com o terpolímero acrilonitrila-butadieno-estireno (ABS) reforçados com fibras de polpa celulose modificadas com nanopartículas de sílica (SiO2). Primeiramente, as fibras foram modificadas utilizando o processo sol-gel, tendo como precursor da sílica o ortosilicato de tetrae...

Two major obstacles to utilizing polyhydroxybutyrate (PHB)—a biodegradable and biocompatible polymer—in commercial applications are its low tensile yield strength (<10 MPa) and elongation at break (~5%). In this work, we investigated the modification of the mechanical properties of PHB through the use of a variety of bio-derived additives. Poly(lac...

Good adhesion at fibre/matrix interface of lignocellulosic fibres is crucial when substituting synthetic fibres in polymer composites. The great variability presented by those fibres requires diverse characterisation studies for better insights on fibre surface treatments and resin systems interactions. In this work, Curaua fibres were treated usin...

Researches on plant fibers for composite applications are increasing due to the demand of materials from renewable sources, which do not consume fossil fuels during manufacture, thus avoiding greenhouse gas emissions. An interdisciplinary approach is required to cover all aspects of plant fiber research, but the actual literature shows many gaps in...

This work evaluated the thermal behavior and cure kinetics of a curauá fibers/epoxy prepreg through TGA and DSC techniques. The prepreg cure kinetics was investigated by a non-isothermal isoconversional method and the variables related to the curing kinetics were obtained by dynamic conditions. The prepreg activation energy was calculated at a give...

RESUMO O poliestireno expandido (EPS) é um polímero reciclável amplamente utilizado na fabricação de embalagens para isolamento acústico, proteção de bens de consumo duráveis e na indústria da construção civil. O PS é facilmente reciclável com o aumento da temperatura, podendo dar origem a novos materiais. Entretanto suas propriedades térmicas pode...

Resumo: O tratamento termomecânico consiste em um processo que combina tratamentotérmico com compressão mecânica sobre a madeira, com a finalidade de se produzir um materialcom menor higroscopicidade. O objetivo neste trabalho é caracterizar e avaliar a resistênciabiológica da madeira perante o ataque de fungos causadores de podridão parda e de pod...

This presentation brings a overview from the different projects that we conduct in the lab.

Resumen Introducción: Los tratamientos alcalinos extraen hemicelulosa de las fibras, las cuales pueden ser reusada en la manufactura de otros materiales, de la cual la fracción celulósica puede ser aplicada como un refuerzo en un compósito. De esta manera, todos los componentes de las fibras son utilizados. Método: En este trabajo, las fibras de cu...

The interaction between natural fibers and polymeric matrices can be the main disadvantage to expansion of natural fibers in industry application. Alkali treatments are usually applied on natural fibers to remove the lignin and extractives improving the adhesion between the reinforcement and matrix, and consequently, the thermal properties. The cur...

Changes in biotic parameters, primarily in those associated with land use, are a fundamental issue for assessing the greenhouse gas (GHG) balance of bioenergy production. From 2002 to 2017, the transition from manual to mechanized sugarcane harvesting in Brazil resulted in 10–20 Mg ha⁻¹ y⁻¹ of biomass, increasing incomes by 150% via bioelectricity....

The use of bio-based materials as a substitute for synthetic materials has garnered increased attention in previous years, especially their use as natural fibre composites. The main drive for their use is the selection and substitution of conventional materials for sustainable ones. In this context, life cycle assessments (LCAs) can provide a robus...

The use of bio-based materials as a substitute for synthetic materials has garnered increased attention in previous years, especially their use as natural fibre composites. The main drive for their use is the selection and substitution of conventional materials for sustainable ones. In this context, life cycle assessments (LCAs) can provide a robus...

Purpose The goal of this study is to characterize a single oil refinery using a mass and energy multi-scale allocation method for 13 different fossil fuel-based products. This method structures a rigorous modeling and data collection approach to fill the gap that exists in traditional methods of life cycle assessment (LCA). Methods The refinery sy...

Purpose Renewable energy sources, particularly biofuels, are being promoted as possible solutions to address global warming and the depletion of petroleum resources. In this context, biodiesel is a solution to the growing demand for renewable fuels. Beef tallow is the second leading raw material after soybean oil used in biodiesel production in Bra...

Resumo: O tratamento termomecânico consiste em um processo que combina tratamento térmico com compressão mecânica sobre a madeira, com a finalidade de se produzir um material com menor higroscopicidade. O objetivo neste trabalho é caracterizar e avaliar a resistência biológica da madeira perante ao ataque de fungos causadores de podridão parda e de...

The environmental and technical feasibility of cellulose nanocrystal production from sugarcane bagasse fibers was evaluated. First, the life cycle assessment (LCA) is presented as a methodology to investigate the most feasible form of obtainment. The environmental impacts regarding climate change and water footprint were evaluated considering a gat...

The aim of this work was to obtain and evaluate the thermal properties of castor oil polyurethane composites reinforced with lignin and cellulose from sugarcane bagasse. Sugarcane bagasse was pretreated and then delignified; then, the cellulose and lignin were milled. To produce the polyurethane, the mass ratio between polyol (castor oil) and diiso...

The present work aimed to study sugarcane bagasse fibers pre-treated with fungi and using NaOH/anthraquinone (AQ) in chemical pulping processes for applications in composite materials. Bagasse was decayed with 250 mg of Ceriporiopsis subvermispora inoculum in a 20 L bioreactor. After that, samples were submitted to similar conditions of decaying wi...

This work describes the surface treatment of coconut fiber and its application in composite materials for reinforcement of polypropylene. Before testing coconut fiber in composite materials, its susceptibility to chemical treatment was characterized by exposure to the following: (1) hot water; (2) aqueous NaOH 2% (w/v); and (3) a sequence of chemic...

Mechanical recycling is utilized to reuse waste and obtain other plastic products via the reprocessing of a material in industrial equipment. Natural fiber composites have become more popular in recent years; however, these composites' mechanical behavior remains less well-understood than single polymers' behavior after recycling. Therefore, the ob...

This chapter describes the different ways of performing sugarcane straw exploitation. This is an important agro-residue in Brazil that has a wide range of feasible applications. For these specific usages, it is essential to have an effective knowledge on the sugarcane straw fiber related to its chemical composition (lignin and carbohydrate contents...

Resumo: O EPS (poliestireno expandido) é um polímero resultante da polimerização do estireno em água e é imensamente utilizado para a confecção de embalagens. Em vista disso, é produzido em grandes proporções. Por outro lado, outro importante resíduo produzido é o bagaço de cana-de-açúcar, por conta da grande produção de açúcar e etanol no Brasil....

Introduction Experimental Results and Discussion Conclusions Acknowledgements

a b s t r a c t Biomass has become important as an alternative to fossil fuels and as a means to decrease greenhouse gas (GHG) emissions, particularly in tropical regions such as Brazil. Therefore, the demand for energy crops has increased strongly, and among such crops, palm oil is distinctive because of its productivity and well-developed product...

Biofuels have been extensively explored and applied in the Brazilian market. In Brazil, ethanol and biodiesel are produced on an industrial scale. Ethanol is commercialized and used in engines in both the hydrated form (96% GL) and the anhydrous form, mixed with gasoline at a proportion of up to 25% by volume. In turn, biodiesel is blended with die...

Accession Number: 66960773; Pereira, Paulo H. Fernandes 1; Email Address: fernandes&lowbar;eng@yahoo.com.br Voorwald, Herman Cornelis Jacobus 1 Cioffi, Maria Odila H. 1 Mulinari, Daniella Regina 2 Luz, Sandra M. Da 3 Silva, Maria Lucia Caetano Pinto Da 4; Affiliation: 1: Department of Materials and Technology, UNESP/FEG, Guaratinguetá/SP, Brazil 2:...

Cellulose fibers were isolated from sugarcane bagasse in three stages. Initially sugarcane bagasse was subjected to a pre-treatment process with hydrolyzed acid to eliminate hemicellulose. Whole cellulosic fibers thus obtained were then subjected to a two-stage delignification process and finally to a bleaching process. The chemical structure of th...

In this study, untreated and treated jute fiber composites were investigated as candidates to replace glass fibers as reinforcement to produce structural composites with better environmental performance. The surface of the jute fibers was modified by drying and bleaching/drying treatments to improve the wetting behavior of the apolar polyester, imp...

The auto industry is compelled to improve its environmental performance, namely by making use of renewable materials and cleaner manufacturing processes with lower energy intensity, and at the end-of-life of the auto, recyclable products and materials are desirable specifications that need to be considered at an earlier design stage, i.e., promotin...

Components based on composites reinforced with vegetable fibers have awaked interest in various industrial fields. The thermal properties of fibers, matrix and composite define the temperature limits for application and processing of these materials. In this work, a thermal analyzer TGA was used to evaluate the degradation and thermal events of veg...

The search for materials from renewable sources such as vegetable oil-based polymers, polyurethane based on castor oil represents a promising alternative in researches. Using castor oil polyurethane as matrix for composites reinforced with lignin and cellulose from sugarcane straw is in tune with economical and environmental interests. The objectiv...

This work evaluates the technical performance and environmental impacts, when sugarcane bagasse is applied as reinforcement of polypropylene in a component instead neat polypropylene (PP). To achieve the goals of this study, the tensile and flexural properties and Life Cycle Assessment (LCA) as a function of fiber content were performed. In additio...

The improvement of environmental performance of products is the main focus for many companies. Although, methodologies are fundamental in the design process in order to introduce environmental inputs in the development, it has not been a comfortable practice for companies. In this context, this study is concerned with the development of procedural...

The use of natural fibers as reinforcement for thermoplastics has generated much interest due to their low cost, possibility of environmental protection and use of locally available renewable resources. In this work the mechanical and morphological properties of high density polyethylene/pre-treated and modified residues from sugarcane bagasse cell...

Accession Number: 35623798; Luz, Sandra M. 1; Email Address: sandra@debiq.eel.usp.br Gonçalves, Adilson R. 2 Del'Arco Jr., Antonio P. 3 Ferrão, Paulo M. C. 1; Affiliation: 1: Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal 2: Escola de Engenharia de Lorena/USP, Brazil 3: Comando Técnico Aeroespacial, Brazil; Source Info: 200...

This current work is concerned with the development of polypropylene composites reinforced with cellulose and cellulignin fibers attained from sugarcane bagasse. Moreover, the fibers were chemically modified by acetylating process and its effects on the fiber/matrix interaction were also evaluated. The chemical modification efficiency was verified...

The compression and injection molding processes were performed in order to evaluate the better mixer method for fiber (sugarcane bagasse, bagasse cellulose and benzylated bagasse) and matrix (polypropylene). The samples (composites and polypropylene plates) were cut and submitted to mechanical tests in order to measure flexural and tensile properti...

Composites utilizing vegetable fibers as reinforcement have attracted increasing interest of the scientific and industrial communities. Sugarcane bagasse and straw are renewable materials and when used as reinforcement in thermoplastic matrix can give origin to composite materials with low cost, low density and interesting mechanical properties. Th...

Composites utilizing vegetable fibers as reinforcement have demonstrated attracted increasing interest ofcrescent advantages from the scientific and industrial communities. Sugarcane bagasse and straw are renewable materials and when used as reinforcement in thermoplastic matrix can give origin to composite materials with low cost, low density and...

Sugarcane bagasse and straw can be converted into pulps, oils, controlled-release formulations, chelating agents, and composites. This article reviews bagasse and straw conversion efforts in Brazil. Laboratory-scale processes were developed aiming at the integral use of these biomass byproducts. Organosolv pulping and oxidation of lignin are the mo...

Sugarcane bagasse and straw can be converted into pulps, oils, controlled-release formulations, chelating agents, and composites. This article reviews bagasse and straw conversion efforts in Brazil. Laboratory-scale processes were developed aiming at the integral use of these biomass byproducts. Organosolv pulping and oxidation of lignin are the mo...

Sugarcane bagasse and straw can be converted into pulps, oils, controlled-release formulations, chelating agents, and composites. This article reviews bagasse and straw conversion efforts in Brazil. Laboratory-scale processes were developed aiming at the integral use of these biomass byproducts. Organosolv pulping and oxidation of lignin are the mo...

The objective of the present work was to obtain gypsum reinforced with natural fibers. Gypsum reinforced matrices were prepared from the admixtures of sugarcane bagasse, sugarcane straw and classified pulp of bagasse, at 1, 2, 5, 10 and 20 wt.% concentrations. Water to gypsum ratio was 0.7 for all preparations but 0.4 and 0.7 for pure gypsum. The r...

Caixa Postal 116, 12600-000 Lorena/SP; 2 Depto de Biotecnologia da FAENQUIL -adilson@debiq.faenquil.br; 3 Divisão de Materiais do IAE/CTA -delarco@iae.cta.br Mechanical and Morphological Properties of Polypropylene Reinforced with Cellulose from Sugarcane Bagasse The necessity of materials attending the economic and environmental aspects provide an...