Desidratação/oxidação seletiva de metanol recorrendo a catalisadores heterogéneos para a obtenção de biocombustíveis (DME e DMM)

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Química e Biológica

Decarboxylative Generation of Carbenes for the Synthesis of N-Heterocyclic Carbene Copper(I) Complexes - Applications in the Oxidative Coupling of 2-Naphthols

Le présent mémoire décrit la synthèse et l’utilité de complexes Cu-NHC. En premier lieu, la synthèse de complexes de cuivre porteurs de ligand(s) de type carbène-N-hétérocyclique (NHC) via une génération décarboxylative de carbènes sera présentée. En effet, de précédents rapports font état de l’utilisation de carboxylates d’imidazol(in)ium en tant que précurseurs carbéniques sous conditions thermolytiques. Ainsi, la présente étude montre l’utilisation de ces espèces zwitterioniques pour la synthèse de complexes de cuivre(I) mono- et bis-NHC comportant divers substituants et contre-ions. Une seconde partie du projet se concentrera sur l’évaluation de complexes Cu-NHC en tant que catalyseurs pour la synthèse de 2,2’-binaphtols via une réaction de couplage oxydatif de naphtols. L’objectif de ce projet de recherche est d’étudier les effets de variations structurales de différents complexes Cu-NHC afin de construire un processus catalytique plus efficace. Les effets de la structure du catalyseur sur la réaction de couplage ont été évalués en variant son contre-ion, le nombre de ligands NHC se coordonnant au cuivre, ainsi que la nature des substituants du ligand.

Organizational excellence through quality governance

This paper provides an overview of an Enterprise Engineering method called IEM (Integrated Enterprise Modeling) and it describes the usage of SIX SIGMA approach for performance measurement of an enterprise. Based on these two instruments a methodology including procedure and tools is developed, which allows enterprises to define their adequate quality criteria for performance, to measure performance and quality and to derive reasonable actions to take for optimization. Determination of adequate quality and performance criteria and reasonable measures for the enterprise organization means “Quality Governance”.

El Outsourcing en la dinámica de sistemas hacia mercados extranjeros

Este trabajo recopila literatura académica relevante sobre estrategias de entrada y metodologías para la toma de decisión sobre la contratación de servicios de Outsourcing para el caso de empresas que planean expandirse hacia mercados extranjeros. La manera en que una empresa planifica su entrada a un mercado extranjero, y realiza la consideración y evaluación de información relevante y el diseño de la estrategia, determina el éxito o no de la misma. De otro lado, las metodologías consideradas se concentran en el nivel estratégico de la pirámide organizacional. Se parte de métodos simples para llegar a aquellos basados en la Teoría de Decisión Multicriterio, tanto individuales como híbridos. Finalmente, se presenta la Dinámica de Sistemas como herramienta valiosa en el proceso, por cuanto puede combinarse con métodos multicriterio.

Characterization of safe nanostructured polymeric materials

The addition of small quantities of nanoparticles to conventional and sustainable thermoplastics leads to property enhancements with considerable potential in many areas of applications including food packaging 1, lightweight composites and high performance materials 2. In the case of sustainable polymers 3, the addition of nanoparticles may well sufficiently enhance properties such that the portfolio of possible applications is greatly increased. Most engineered nanoparticles are highly stable and these exist as nanoparticles prior to compounding with the polymer resin. They remain as nanoparticles during the active use of the packaging material as well as in the subsequent waste and recycling streams. It is also possible to construct the nanoparticles within the polymer films during processing from organic compounds selected to present minimal or no potential health hazards 4. In both cases the characterisation of the resultant nanostructured polymers presents a number of challenges. Foremost amongst these are the coupled challenges of the nanoscale of the particles and the low fraction present in the polymer matrix. Very low fractions of nanoparticles are only effective if the dispersion of the particles is good. This continues to be an issue in the process engineering but of course bad dispersion is much easier to see than good dispersion. In this presentation we show the merits of a combined scattering (neutron and x-ray) and microscopy (SEM, TEM, AFM) approach. We explore this methodology using rod like, plate like and spheroidal particles including metallic particles, plate-like and rod-like clay dispersions and nanoscale particles based on carbon such as nanotubes and graphene flakes. We will draw on a range of material systems, many explored in partnership with other members of Napolynet. The value of adding nanoscale particles is that the scale matches the scale of the structure in the polymer matrix. Although this can lead to difficulties in separating the effects in scattering experiments, the result in morphological studies means that both the nanoparticles and the polymer morphology are revealed.

Automatic control of food manufacturing processes. 2nd edition

In the ten years since the first edition of this book appeared there have been significant developments in food process engineering, notably in biotechnology and membrane application. Advances have been made in the use of sensors for process control, and the growth of information technology and on-line computer applications continues apace. In addition, plant investment decisions are increasingly determined by quality assurance considerations and have to incorporate a greater emphasis on health and safety issues. The content of this edition has been rearranged to include descriptions of recent developments and to reflect the influence of new technology on the control and operations of automated plant. Original examples have been retained where relevant and these, together with many new illustrations, provide a comprehensive guide to good practice.

COMPOSITION OF SUPERCRITICAL CARBON DIOXIDE EXTRACTS OF PITANGA (EUGENIA UNIFLORA L.) LEAVES

The leaves of the Pitanga bush (Eugenia uniflora L.) are considered to be effective against many diseases. Extracts from Pitanga leaves have been found to show pronounced anti-inflammatory action and to have antimicrobial and antifungal activities, among other properties. In this work, extracts from Pitanga leaves were obtained by hydrodistillation and by extraction with supercritical carbon dioxide (SC-CO(2)) at three conditions of temperature and pressure. In the SC-CO(2) extractions also were collected the components that are lost with the CO(2) in the exit of the system using Porapak-Q polymer trap. All extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). Thirty-nine compounds were found in the extracts and twenty-six were identified. The main components identified in the extracts in decreasing quantitative order were: curzerene, germacrene B, C(15)H(20)O(2) and beta-elemene for hydrodistillation; C(15)H(20)O(2) and curzerene for SC-CO(2) extracts and 3-hexen-1-ol, curzerene, C(15)H(20)O(2), beta-elemene and germacrene B for SC-CO(2) extracts captured in Porapak-Q. PRACTICAL APPLICATIONS The natural extracts are a potential source of compounds possessing biological activities. They can be used in foods, pharmaceutics and cosmetics. Pitanga is an exotic fruit from Brazil and extracts from its leaves have been used against many diseases in Brazilian folk medicine. Supercritical extraction is an interesting process for the production of natural extracts because it is a clean process and the knowledge of composition of extracts is crucial for the identification of the probable active components.

High strain rate tensile properties of rapidly cured woven carbon fibre composites

Tensile tests at high speeds corresponding to automotive crash events were conducted to understand the dynamic properties of rapidly cured woven carbon fiber composites. The High Strain Rate (HSR) experiments were conducted on a servo-hydraulic machine at constant velocities up to a maximum of 25 m/s (82 ft/s). Results from HSR tests were compared with the static results to determine the rate sensitivity of the composite. A high speed camera was used to capture the failure at HSR. The tensile properties of rapidly cured laminate were compared to oven cured laminate to justify its productivity while maintaining the desired properties. The methodology used to achieve constant velocity during HSR tests is discussed in detail. The specimen geometry was specially designed to suit the test rig and to achieve high speeds during tests. All the specimens failed with linear elasticity until sudden brittle fracture. The Scanning Electron Microscopy (SEM) images of the fracture zone were used to identify the failure modes observed at static and high strain rates.

Carbon nexus: a strategic overview and research highlights

Carbon Nexus (www.carbonnexus.com.au) is a globally significant research facility at Deakin University focused on the manufacture and use of carbon fibre. Carbon Nexus represents a partnership between Deakin University and the Victorian Centre for Advanced Materials Manufacturing (VCAMM) and houses two production lines capable of manufacturing industrially relevant quantities of aerospace grade carbon fibre. The facility enables scientists to conduct research into the chemical, mechanical and nano-scale characteristics of new carbon fibre materials produced on site. There is a strong focus on evaluating these new carbon fibre products in composite materials, particularly composites cured using out-of-autoclave techniques. This paper will present an overview of the vision for Carbon Nexus as well as the technical capabilities of both the laboratory scale single tow line and the larger pilot line capable of producing up to 50 tons of carbon fibre per year. Both lines are fully operational and able to convert a range of polymer precursors into carbon fibre. They are representative of world's best practice for carbon fibre manufacturing methods and well suited to conducting energy efficiency studies. Highlights from recent research projects will focus on the effect of the surface treatment and sizing of carbon fibre on fibre-matrix adhesion in composite materials. In addition to this, results from studies of the effect of varying processing parameters on the structure and properties of oxidised polyacrylonitrile and carbon fibre will also be presented.

Craqueamento termocatalítico de óleo de girassol na presença da peneira molecular SAPO-5

The catalytic cracking of triglycerides presents itself as a possible alternative to the production of biofuels with low emission of pollutants. In this work were synthesized the SAPO-5, the catalysts for the cracking reaction of soybean oil is presented. The solids were powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG) and infrared spectroscopy (FTIR). The analyses indicated that the synthesis method has employed to obtain materials with high surface area and high acid. The soybean oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ºC in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. The products obtained in the cracking of soybean oil were analyzed by distillation, acid number, infra-red spectroscopy, density, viscosity, carbon residue, cetane number determination and characterization. The analysis of the products obtained in the presence and in the absence of the SAPO-5 permitted to conclude that all the solids tested presented catalytic activity in the deoxygenation of final products only at the second step of the cracking process

Obtenção de diesel verde por craqueamento termocatalítico de óleo de buriti (Mauritia flexuosa L.) sobre materiais nanoestruturados do tipo LaSBA-15

In order to obtain a biofuel similar to mineral diesel, lanthanum-incorporated SBA- 15 nanostructured materials, LaSBA-15(pH), with different Si/La molar ratios (75, 50, 25), were synthesized in a two-steps hydrothermal procedure, with pH-adjusting of the synthesis gel at 6, and were used like catalytic solids in the buriti oil thermal catalytic cracking. These solids were characterized by X-ray fluorescence (XRF), powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), infrared spectroscopy (FTIR), nitrogen porosimetry and ethanol dehydration, aiming to active sites identify. Taken together, the analyses indicated that the synthesis method has employed to obtain materials highly ordered mesostructures with large average pore sizes and high surface area, besides suggested that the lanthanum was incorporated in the SBA-15 both into the framework as well as within the mesopores. Catalytic dehydration of ethanol over the LaSBA-15(pH) products has shown that they have weak Lewis acid and basic functionalities, indicative of the presence of lanthanum oxide in these samples, especially on the La75SBA-15(pH) sample, which has presented the highest selectivity to ethylene. The buriti oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ºC in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. One the other hand, OL coming from second ones, called green diesel (GD), have presented low acid index, particularly that one obtained from the thermal catalytic process realized over LaSBA-15(pH) samples. The acid sites presence in these samples, associated to their large average pore sizes and high surface areas, have allowed them, especially the La75SBA-15(pH), to present deoxygenating activity in the buriti oil thermal catalytic cracking, providing an oxygenates content reduction, particularly carboxylic acids, in the GD. Furthermore, the GD comes from the second liquid fraction obtained in the buriti oil thermal catalytic cracking over this latest solid sample has shown hydrocarbons composition and physic-chemical properties similar to that mineral diesel, beyond sulfur content low

RHEOLOGICAL CHARACTERIZATION of SUSPENSIONS of SUCROSE CRYSTALS IN SATURATED SUCROSE SOLUTIONS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)