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A presente investigação teve com objectivo principal estudar as correlações da actividade físicodesportivas com o autoconceito e o aproveitamento escolar de estudantes do segundo e terceiro ciclosde escolaridade com idades compreendidas entre os 12 e os 19 anos, verificando igualmente se os hábitos de exercício reflectem as recomendações do American College of Sports Medicine/American Heart Association. A amostra consistiu de 622 indivíduos (268 do sexo masculino, 354 do sexo feminino e 2 que não se classificaram por sexo). Avaliou-se o autoconceito através do Self-Description Questionnaire II (SDQ-II) e para o efeito recorremos à versão portuguesa de Gonçalves e Vasconcelos-Raposo. O aproveitamento escolar foi avaliados a partir do número de reprovações na escola. De uma forma geral conclui-se que existe uma correlação positiva entre autoconceito e actividade físicodesportivase uma correlação também negativa entre o autoconceito e aproveitamento escolar.

Sugarcane bagasse is an abundant agricultural residue derived from the sugar-alcohol industry, which is usually burned in boilers for power generation. However, this practice results in relatively low yields and ash production, requiring the investigation of novel methods of sugarcane bagasse conversion. In this context, gasification arises as a promising option: it is a thermochemical process that converts a wide range of carbonaceous resources into syngas, a gaseous mixture that mainly contains H2, CO, CO2, CH4 and light hydrocarbons, and can be applied in the generation of heat, power, and chemicals. Gasification can be held in different gasifier configurations, but special attention is given to fluidized beds due to advantages such as feeding flexibility and scalability, high heat and mass transfer rates, and high reaction rates. Despite the given panorama, there is a lack of data in the literature of sugarcane bagasse gasification in bubbling fluidized beds operating with steam and oxygen as gasifying agents. To address this subject, this work performed a simulation of sugarcane bagasse gasification in a steam-oxygen-blown bubbling fluidized bed based on Gibbsfree energy minimization using Aspen PlusTM. With the proposed model, a 24 factorial design was conductedwith the intent to study the influence of gasification temperature, pressure, biomass moisture content, and steam-to-biomass ratio (S/B) on syngas production. The obtained results have shown how different operating conditions and their interactions affect gasification exothermic and endothermic reactions and, consequently, compositions and performance indicators. Finally, the present work has demonstrated that sugarcane bagasse gasification is a potential and feasible process for clean energy production, contributing as an alternative for this agricultural waste use.

Renewable source biofuels are a promising alternative to fossil fuel and can be economic and environmentally viable when associated with effluent gas and wastewater treatment. This work proposes the study of lipid accumulation and microalgae cultivation using vinasse which is a residue from sugarcane bioethanol production. Besides being a largely produced effluent that requires bioremediation, vinasse is a carbon and nutrient rich source that could be advantageous as microalgae cultivation medium. Therefore, the objective of this research is to cultivate the microalgae strain Desmodesmus sp. in different types of undiluted vinasse medium (raw, raw recycled and biodigested) in a photobioreactor system. Cultivation was performed under different conditions varying: I) bubble agitation; II) temperature; III) light incidence; IV) flux of atmospheric air supplemented with CO2. Biomass concentration was measured by cell density, lipid accumulation was measured gravimetrically after solvent extraction, and vinasse biochemical composition was determined usingTOC-VCSN Shimadzu® analyzer. The levels of dissolved O2 and CO2 were monitored using O2 and CO2 electrodes, respectively. Raw vinasse with relative biomass concentration of 1.5 g L-1 showed to be preferred medium for high lipid accumulations and carbon consumption. The maximum lipid content of 24.48% wasobtained under heterotrophic, aerobic (0.05 VVM) growth conditions, at a temperature of 26 °C, without magnetic agitation and CO2 presence. However, for effluent treatment, better results were obtained under mixotrophic, aerobic (0.05 VVM) and bubble agitated growth conditions, at 26 °C of temperature. Recorded carbon reduction was 46.35%. As vinasse consists of an organic carbon and nutrient source, cultivation cultures are susceptible to contamination by other microorganisms. Therefore, further study is necessary to the use of Desmodesmus sp. microalga for either biodiesel production or bioremediation.

Future biomass conversion systems have to be developed using advanced technological routes in order to compete with fossil fuels, as well as to fulfill sustainability criteria. An attractive biomass feedstock for ethanol production is sugarcane, which is available in large amounts in several regions around the world. Although first-generation ethanol is a consolidated process, due to their large-scale production and tradition, there is still room for improved economic and environmental outcomes in the bioethanol industry. Bearing this in mind, this work presents a detailed process design strategy for biomass to ethanol production (1st-generation ethanol technology) from sugarcane. The simulation processes were performed using Aspen Plus® software focus on the annexed plant (production of bioethanol and sugar) and autonomous distillery(only bioethanol is produced) systems. Furthermore, a performance comparison in terms of the exergy efficiency and the destroyed exergy rate as a metric conversion of the processes are determined. Hence, the techno-economic bottlenecks in bioethanol production are attained using the exergy as an index. In addition, the sustainability aspects involved in the process design of the sugarcane biorefineries was discussed through the renewability exergy index. The results showed that the annexed plant has a reduction in the process irreversibilities rate of 6 % approximately, and in the average unitary exergy cost rate of 10 % approximately, in comparison to the autonomous distillery. Even though the proposed methodology is applied to 1G ethanol, it may well suited for several bioprocesses as a tool to help in taking decisions regarding design as well as operational policy definitions.

The use of bio-based resources for the production of added value products has become a key element of sustainable development. In this regard, biorefinery is a recognized approach to transforming renewable feedstocks into fuels, chemicals, and materials. However, the integration of chemicals production into current biorefineries is challenging. This route is the least developed and most complex of all biorefinery operations and bio-based chemicals suffer from direct competition with oil-based counterparts. Additionally, the overabundance of targets makes difficulty the decision making for companies. As such, there is a need to identify a core group of primary chemicals and secondary intermediates analogous to those in the petrochemical industry, including products with well-established value chains. To address some of these challenges, this work intends to contribute with ideas for the use of glycerol as a feedstock for polymers production. These polymers may be produced directly from glycerol or from some organic acid derived from glycerol. Such organic acids are in general flexible building blocks which may result in polymers for several applications, such as packaging materials and textile fibers, insulation foam, electronics and car parts. Among organic acids, succinic acid and lactic acid has a great potential to be used in the production of specialty polymers for medical implants because these materials can combine biodegradability with biocompatibility. Bearing this in mind, potential conversion routes of glycerol to lactic acid-derived specialty polymers are discussed in this work./div>

Despite their advantages when replacing fossil fuels, biofuels have faced some concerns related to their expansion within the so-called “food vs. bioenergy” debate. This debate relies on the premise that the use of food crops and/or the increase of land use for bioenergy production would affect food availability and price. Nevertheless, it is worth to mention that livestock production is the largest anthropic use of land resources worldwide. In Brazil, livestock production mainly consists of extensive management with low technology level, which results in a low average productivity. The intensification of this system would release pasture areas to expand cropland for biofuels production. In this way, the integration of sugarcane ethanol and livestock production would allow taking advantage of the synergies between both systems; for instance, using sugarcane agroindustrial residues as animal feed ingredients in feedlot systems. In addition, ethanol production from lignocellulosic feedstock (second-generation process) is also a possible solution towards a productive land use, since a larger amount of biofuels can be produced per crop area. This work focuses on the sustainability assessment of a first- and second-generation (1G2G) ethanol facility that produces animal feed using sugarcane by-products integrated to livestock production in feedlots. The Virtual Sugarcane Biorefinery (VSB) – a computer framework that simulates the entire production chain and assesses the sustainability impacts of different biorefinery alternatives/routes – was used in this work. This paper indicates that the integration of a future 1G2G sugarcane mill with intensive livestock system may be a feasible alternative. Regarding the economic performance, verticalization of a mill with intensive livestock is preferable when compared to extensive cattle production. Integrated scenarios also have environmental advantages, such as the production of more outputs using the same area, as well as more efficient technologies that may represent lower emissions. In addition, this paper revealed that it is possible to sustainably produce biofuels without displacing food crops or livestock production, which otherwise could advance, for example, in forest areas.

The Bio Based Press wrote “The production of levulinic acid is gaining momentum”. Today, researches are focusing efforts to convert biomass on new chemicals platforms, including levulinic acid (LA), which has gained increased attention for being an attractive platform for products with high added value. LA can be obtained through the acid hydrolysis of some types of saccharides such as glucose and xylose, the constituent unit of cellulose and hemicelluloses. In this work, three substantial steps to convert biomass, in this case sugarcane bagasse, in LA were investigated. Sugarcane bagasse was pretreated with acid (121 °C, 1.0 % w/v H2SO4, and 80 min) and alkali delignificated (80 °C, 0.5 % w/v NaOH, and 90 min reaction time) both with 20 % w/v of solids loading. Experiments were carried in a discontinuous reactor at different variations of temperature (160, 170 and 180 °C), acid concentration (3, 7 and 5 % w/v H2SO4), hydrolysis reaction time (55, 75 and 95 min) and substrate loadings (6, 8 and 12 % w/v). This research has demonstrated that LA production at 170 °C, 5% w/v H2SO4, 75 min and 6 % w/v of solids loading conditions achieved a LA yield of 55.00 ± 0.36 % and selectivity about 45.65 ± 0.26 %.

Hybrid short path evaporation (HSPE) is proposed as an alternative separation process with potentiality for recovery and concentration of thermally unstable molecules such as lactic acid. This work aimed to analyze the influence of HSPE process variables on the concentration of lactic acid from sugarcane molasses. Through 22 factorial experimental design, the influence of evaporator temperature (from 115 to 135 °C) and internal condenser temperature (from 13 to 22 °C) on lactic acid concentration and mass percentage of residue and distillate stream were studied. The results showed that it is possible to increase the lactic acid concentration greater than twice from fermentation broth by HSPE. In addition, the effect of each variable studied and interactions between them were demonstrated.

The gasification process may be utilized to transform the lignocellulosic material, in this case bagasse sugarcane, in three major products: coal, tar and gas (mixture of hydrogen, carbon monoxide, carbon dioxide and methane, mainly). The products have high potential as raw material for added-value fuels; among these fuels the hydrogen, which has lower capacity of environmental contamination (Anukam et al., 2016). In literature, most of the work covers two scale kinds of biomass gasification processes: a) Small-scale processes processing mass flow rate of the order of 10-1 kg / h, the most largely used kinetic data are the result of work done in this range. b) Large-scale processes, processing 102 - 103 kg / h of biomass. This fact has led to some phenomena, presented on the large-scale processing, which are not explained, because the kinetic in which the process is based on was conducted in a completely different scale and sometimes even the regime is not the kinetic one, mass transfer and heat phenomena are scale dependent and hence with completely different behaviours (Shen et al., 2017). In this context, this work presents a semi- pilot scale reactor, 2 kg of biomass/h as platform for investigation the main phenomena taking place in the process. Such a rig scale developed in house allows the collection of data in different operating conditions, combining ease of operation and more accurate measurements, typical of small scale, with the phenomenology of large-scale equipment. Taking this into consideration, the reactions that occur in the biomass gasification process in a reactor with a processing capacity of 2 kg / h biomass were evaluated. The operability of the equipment, heating rates and cooling the reactor, start-up time, evaluation of the collection system and quantification of samples were identified and evaluated. After setting the operability of the equipment, optimizing the gasification process with the objective of maximizing the gaseous fraction obtained was carried out through changes in the air / biomass ratio used with respect to the same relationship required for complete combustion; this ratio is defined as ER. Varying the ER ratio, gas fractions, tar and char obtained, as well as gas composition and the amount of water in the tar were determined, allowing to identify suitable operational policies.

Renewable energy is described in the political sphere as a means to reduce greenhouse gas emissions and simultaneously increase energy security, especially in the transport sector, which is dependent on oil products. Enzymatic hydrolysis is an intermediate step in the biomass conversion process into fermentable sugars. This step has to be favorable to produce high sugar yields and the resulting hydrolysate must be able to support fermentative organisms while they produce biofuels. In this investigation sugarcane bagasse was submitted to a chemical pretreatment with dilute sulfuric acid (121 °C, 80 min and 1.0 % v/v H2SO4) and then delignification with alkaline solution (80, 100 and 120 °C, 30, 60 and 90 min, 0.5, 1.0 and 1.5 % w/v NaOH) both with 20 % w/v of solids loading. The samples were submitted to enzymatic hydrolysis with 8.0% w/v solids loading (dry basis) considering 15 FPU (filter paper unit) and 33.0 CBU (beta-glucosidase unit) per gram of dry biomass. The fermentation was applied on the 0.5 % w/v NaOH, 80 °C, 90 min delignificated point. The enzymatic hydrolysis process favored the release of fermentable sugars, given the fact the values for the concentration of total reducing sugars increases with hydrolysis time. However, it is shown that after 24 h of hydrolysis occurs the maximum liberation of sugars. Results from fermentation process showed that YP/GLC for pretreated sugarcane bagasse was about 0.51 kgetanol/kgGLC and for the delignificated was 0.47 kgetanol/kgGLC. It was attained a process yield of 100 % for the pretreated sugarcane bagasse and 91.59 % for the delignificated.

The present work proposes, in the context of a Biorefinery, to assess the biochemical-thermochemical hybrid route through the recovery of the residual cellulignin from pre-treatment and hydrolysis of sugarcane bagasse and straw in an integrated first- and second-generation ethanol plant (1G2G plant), by means of residual cellulignin gasification in a thermochemical ethanol plant. In this assessment, a decentralized plant concept is considered, in which four first- and second-generation ethanol biochemical plants (1G2G biochemical plants) processing 4 million tonnes of sugarcane per year (4 MTC/y) each and producing first- and second-generation ethanol supply residual cellulignin for a central standalone feedstock flexible thermochemical plant, configuring an 1G2G biochemical-thermochemical ethanol hybrid scenario. As base scenario, four 1G2G autonomous plants with residual cellulignin burned in the boilers is selected. For the routes comparison, main technical, economic and environmental aspects of each scenario are assessed. Results showed an increase in total anhydrous ethanol production for 1G2G biochemical-thermochemical ethanol hybrid scenario, besides higher alcohols that are also produced in this scenario. An increase of capital investment is observed for the 1G2G biochemical-thermochemical ethanol hybrid scenario justifying the Internal Rate of Return (IRR) lower than the base scenario, yet with a positive net present value (NPV). Environmental results showed similar impacts for both scenarios.

Since sugarcane biorefineries are a large source of CO2 emissions, there is an opportunity of using or capturing this pollutant. An alternative would be to use mechanisms to capture, transport and inject CO2 into underground geological formations with the purpose of permanent storage of this gas, the so called Carbon Capture and Storage or CCS. Another possibility is to produce biodiesel from microalgae cultivated with CO2 to replace fossil diesel used in the sugarcane production chain. Environmental impacts using life cycle assessment of both technologies, CCS and biodiesel production from microalgae, integrated into first and second generation ethanol production plants were assessed. Biodiesel production from microalgae promoted reduction in all the assessed environmental impact categories, decreasing about 35 % of climate change impacts. CCS presented the highest climate change reduction transforming ethanol in a net carbon absorber. However, higher environmental impact in other categories are observed in this case.

The açaí seed is an abundant byproduct of açaí productive chain, Brazil`s northern region important fruit, especially in Pará and Amazonas states. However, it has been characterized as a hygienic-sanitary inconvenience to the region big cities, respectively Belém and Manaus. The use of this material to generate high added value products depends on better knowledge of its microstructure. This work aimed to analyse açaí seeds biomass using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) in order to better understand its structural and chemical changes during treatment stages. For this purpose untreated, treated with H2SO4 and treated with H2SO4 and subsequently delignified with NaOH açaí seeds were used. SEM photomicrographs comparison showed that treatment with H2SO4 resulted in partial disruption of açaí seed structure, which became more evident after NaOH treatment. The crystallinity index for untreated açaí seeds was 47.05%, reducing after the treatments. FTIR provided spectra in the region of 4000 to 400 cm-1. The used techniques allowed to observe significant structure changes caused by açaí seeds biomass treatment and provided information about microstructure of the untreated material.

In this work, a kinetic model considering the effect of temperature was employed to assess the dynamic behavior of an ethanol fermentation process. To calibrate the model, experimental data were obtained from batch cultures using cellulosic hydrolysate from sugarcane bagasse blended with sugarcane molasses at 75% and 25% in volume, respectively, as carbon sources. The kinetic model with its parameters is applied in the simulation of a continuous fermentation process for ethanol production. The system is a typical large-scale industrial process consisting of four fermenters attached in series and operated with cell recycling. Based on dynamic simulation of the process, a suitable Infinite-Horizon Model Predictive Control (IH-MPC) was applied to deal with the fluctuation of the sugar concentration in the raw material. The control objective is to maintain the outlet sugar concentration of the fourth reactor at a desired value, by manipulating the feed flow rate. This strategy was tested for both disturbance rejection (regulatory problem) and changes in the output reference (servo problem).

In this study, the ethanol fermentation of cellulosic hydrolysate produced from hydrothermal pretreatment of sugarcane bagasse, followed by detoxification and enzymatic hydrolysis was investigated. It was conducted on fermentability, and nutrient supplementation requirement. Fermentability was evaluated through ethanol fermentation with cell recycle for eight sequencing batches. In the first cycle, glucose was converted mostly to ethanol and cells without nutrients addition. In the following batches, nitrogen and phosphate supplementation to achieve a successful fermentation was required. The kinetics of cell growth, substrate consumption and ethanol production during fermentation were described using a mechanistic model. Specific ethanolproductivity of 1.34 kg/m3.h, yield of 90 % and cell viability of 93 % were obtained. Nutrient supplementation was assessed using a central composite design to investigate the effect of molasses, urea and diammonium phosphate (DAP) addition on productivity. Statistical analysis showed that only the effect of molasses addition was significant on productivity at 95% confident level.

A promising use of sugarcane bagasse is for cellulosic ethanol production. One step of this production is the enzymatic hydrolysis process. A residual stream from this process is mainly composed of lignin and some non-hydrolysed cellulose fibers. In order to extend the application of the biorefinery concept to second generation (2G) ethanol production, the residue generated in this process could be used as raw materials for new processes to obtain value-added products. Besides, fully utilization of the residues produced in the enzymatic hydrolysis process is a feasible method to reduce cost. Lignin has a potential to replace petroleum- based materials, which are increasingly scarce and expensive, in many industrial applications, such as phenolic resins. The original source, the extraction method used and the process by which lignin was stemmed change its physicochemical characteristics. Thus, the suitability of lignin as raw materials into value- added products can vary widely. Bearing all these in mind, it is necessary to characterize the material to be able to evaluate it in formulations of value-added products. In this work, a chemical characterization of Enzymatic Hydrolysis Residue Lignin (EHRL) was carried out aiming the use for resins. The EHRL was obtained from the sugarcane bagasse pretreated by hydrothermal process to 190 °C by 10 min with solid-liquid ratio of 1:10. Then, the enzymatic hydrolysis process was carried out using the 15 FPU/g dry biomass of cellulolytic complex (Celluclast® 1.5 L) and 10 UI/g dry lignocellulose of ß-glucosidase (Novozym® 188). The pretreatment and the enzymatic hydrolysis processes were carried out in batch reactor (Pope Scientific 350 L)pilot scale using the facilities of Brazilian Bioethanol Science and Technology Laboratory (CTBE). A chemical characterization of the EHRL allowed knowing better its features, before being applied in manufacturing of value-added products. By chemical characterization method, we found that the total lignin content is 47.3 %, cellulose content is 39.8 %, hemicelluloses content is 4.5 % and ash content is 8.4 % (w/w on dry matter) in the EHRL. An alternative to use the EHRL for manufacturing of composites has been considered. Since it could be used to partially replace petroleum-based phenol in synthesis of phenolic resins, it is interesting to evaluate the effect of the remaining cellulose fibers in the EHRL and as they could act as reinforcement in phenolic composites.

Microalgal biomass have a potential to be used as feedstock for biodiesel production because of high photosynthetic rates, high biomass production, faster growth in comparison to traditional feedstocks and to not be competitive with food production. In this paper, the growth and lipid content of three microalgae strains, namely Chorella vulgaris, Desmodesmus sp. and Desmodesmus brasiliensis, were studied during 9 days of mixotrophic cultivation. The laboratory scale experiments were carried out in BG-11 media enriched with 10 g/L glucose at initial medium pH of 7.5, temperature of 26 ± 4 °C and light flux of 62 µE m-2 s-1. The highest biomass concentration of 3.82 mg/mL was found in the Desmodesmus brasiliensis, followed with 3.64 mg/mL of Desmodesmus sp. and 3.32 mg/mL of Chorella vulgaris strain. However, the Desmodesmus brasiliensis had the lowest lipid content of 6%, followed with 13.2% of Chorella vulgaris, whereas the Desmodesmus sp. strain produced the highest lipids (19.45%).

In this work is presented a process with high lactic acid production as well as high sugar conversion and low by-products formation. The microorganism Lactobacillus plantarum uses preferably 6-carbon sugars. However, the xylose consumption occurs since the hexose concentration is not high. Lb. plantarum was shown to have a capacity for lactic acid production from cellulosic and hemicellulosic hydrolysates without detoxification. The results were similar to that using glucose, which is the source of carbon currently used by the lactic acid industry. Lactic acid is an organic acid with a hydroxyl and an acid functional group. It has an asymmetric carbon and it naturally occurs as two optical isomers, D and L lactic acid. Crystallinity and many other important physical properties such as rate of degradation, melting point and boiling point are controlled by the ratio of enantiomers used. Lactic acid production by fermentation has several advantages when compared to chemical synthesis, such as low temperatures, low energy consumption, better environmental concerns and high purity. Furthermore, by fermentation it is possible to obtain the optically pure lactic acid, while by chemical synthesis only the racemic mixture can be produced. Despite the wide variety of feedstock tested for the lactic acid production most of them have problems with price, seasonality, continuous availability for large- scale production, fermentation rate, the amount of contaminants present, yields of lactic acid, formation of by- products, location of lactic acid production plant due to both availability as logistics of transportation and use of it. Trying to find substrates that overcome some of these barriers, in this work is proposed the use of molasses from sugar industry, pentose and hexose from enzymatic hydrolysis of sugarcane bagasse aiming to produce lactic acid.

Tissue Engineering offers a new route for the reconstruction of new organs and tissues that have suffered trauma or injury. With this respect, the production of tridimensional scaffolds to allow cells to attach, migrate and proliferate is the base of Tissue Engineering. In this study, a polyurethane scaffold was synthesized in a batch reactor by the reaction of bio-based polyol extracted from Euterpe oleracea Mart. seeds (açaí berry), a renewable raw material present in Amazon Region of Brazil, and a polyisocyanate derived from hexamethylene diisocyanate. The chemical structure of the scaffold was characterized by using proton nuclear magnetic resonance spectroscopy, the distribution of average porosity and pore size was characterized by X- ray microtomography, the thermal properties were determined by thermogravimetric analysis and the biocompatibility was studied by in vitro assays. The results showed that the scaffold presents excellent morphological, chemical and thermal properties, with an appropriate porosity for cell attachment, cell growth proliferation, it also shows no inflammatory response, a good biocompatibility making it applicable as a new biomaterial for future applications in Tissue Engineering.

This study presents paleomagnetic results from Tancitaro volcanism in the Michoacan Guanajuato Volcanic Field, western Mexico, as a contribution to the time averaged field global database. Detailed paleomagnetic and rock-magnetic studies were carried out on eleven independent lava flows; 120 oriented, standard paleomagnetic cores were collected from Tancitaro volcano and surrounding areas. All sites were dated by means of 40Ar-39Ar (Ownby et al., 2007) as originating from 793 ka to present. Rock-magnetic experiments included continuous susceptibility and hysteresis measurements. Remanence is carried mostly by Ti-poor titanomagnetite of pseudosingle-domain magnetic structure. Eight out of eleven flows yield normal magnetic polarities while three sites yielded inconsistent paleodirections most probably due to lightning. Mean paleodirection from eight flows is Inc=39.5°, Dec=356.4°, k=29, α95=9.1° which corresponds to a pole position with Plat=84.4°, Plong=219.9°, K=33 and A95=8.5°, practically undistinguishable from expected Plio-Quaternary paleodirections, for the North American Craton. Paleosecular variation is compatible with other studies at the same latitude bands and with recent statistical models. The mean inclination falls within the uncertainties of the Geomagnetic Axial Dipole plus 5% quadrupolar contributions.

Este estudio presenta los resultados paleomagnéticos del Volcán Tancitaro, (perteneciente al Campo Volcánico Michoacán Guanajuato), en el oeste de México, como una contribución a la base de datos de promediados en el tiempo del campo global. Se realizó el estudio paleomagnético y de magnetismo de roca en once flujos de lava. Se colectaron 120 núcleos orientados en el volcán Tancitaro y sus áreas aledañas. Todos los sitios fueron previamente fechados por 40Ar –39Ar (Ownby et al., 2007,) y van desde 793 ka hasta el presente. Se realizaron experimentos de magnetismo de roca, curvas de susceptibilidad e histéresis magnética y en la mayoría de los casos la remanencia magnética fue por la presencia de titanomagnetita pobre en Titanio con estructura magnética de pseudodominio simple. Ocho de los once flujos de lava dieron polaridad normal, mientras que los tres restantes produjeron paleodirecciones inconsistentes y no se tomaron en cuenta para el análisis y se debió probablemente por efectos de rayos. La paleodirección principal obtenida de los ocho flujos es Inc=39.5°, Dec= 356.4°, k=29, αc95=9.1° lo cual corresponde a la posición del polo con Plat=84.4°, Plong=219.9°, K=33 y αc95=8.5° Esta dirección es prácticamente consistente con la paleodirección esperada del Plio Cuaternario, derivada del polo de referencia para el Craton Norteamericano. La variación paleosecular coincide con otros estudios de la misma latitud y con modelos estadísticos recientes. La inclinación media cae dentro de la incertidumbre del Eje Dipolar Geomagnético más 5% de contribuciones cuadrupolares. doi: https://doi.org/10.22201/igf.00167169p.2009.4.16

Synthesis gas (syngas) is mostly known by its use on ammonia and hydrocarbons (Fischer-Tropsch process) production. However, a less explored route to produce chemical products, among them alcohols and other oxygenates, from syngas is gaining attention over the last few years. In this route, an initial feedstock as biomass is firstly gasified to synthesis gas, which is reformed, cleaned, compressed and finally catalytically converted in a mixture of alcohols and oxygenated products that after separation steps attain sufficient purity to be sold. In this case of study, the commercial simulator ASPEN Plus v7.3 is used to evaluate the application of a Rh-based (Rh-Mn-Li-Fe/SiO2) catalyst in a small scale plant with processing capacity of 100 kmol/h of pure syngas. This plant, besides methane, water, and CO2 produces 8 oxygenated products: methanol, ethanol, propanol, butanol, acetic acid, acetaldehyde, methyl and ethyl acetates, being necessary 9 further separation or concentration steps in order to obtain the products in their desired purity. The main goals of this work were to design and optimize a process so as to produce alcohols and other oxygenates using syngas as feedstock. After conceiving the process, an optimization was performed, which started by evaluating the reactor conversion/selectivity in order to produce more add-value products. Then, the downstream separation processes were optimized searching for less energy consumption and recovering as much as possible add- value products. Lastly, we aimed at possible solutions and improvements concerning sustainability, feedstock and energy integration, and utilities consumption.

Enzymatic kinetic studies of celulignin material obtained from acid-catalyzed hydrothermally pretreated sugarcane bagasse at high-solids loading (S / 25%), acid concentration (A) equal to 1.0; 2.0 and 3.0% w/v and pretreatment time (tP) equal to 30; 90 and 150 min were carried out using the synergistic action of cellulase from T. reesei and cellobiase from Aspergillus niger. The kinetic experiments were carried out at 50 oC, 150 rpm and 3 h with substrate (water insoluble solids after pretreatment - WIS) loading range between 30 gsubstrate/Lsol and 100 gsubstrate/Lsol, and mixed with cellulase (at 5.0; 15.0; 30.0 and 60.0 FPU cellulase/gsubstrate) and ß-glucosidase (at 33.0 IU ß-glucosidase/gsubstrate) enzymes. A Michaelis-Menten dependence on the cellulase from T. reesei concentration and substrate concentration plots were obtained based on experimental data. The rate constant, Km and maximum reaction rate attainable, Vmax were determined to characterize the cellulase-catalyzed reaction. Results showed that the cellulase from T. reesei behavior was highly specific for each WIS fraction obtained under a combination of [A-S-tP] where Vmax varies greatly as enzyme (cellulase) concentration rises. For example, Vmax values when considered a substrate obtained at [1.0% w/v - 25% - 30 min] and [3.0% w/v - 25% - 30 min] using 5.0 FPU cellulase/gsubstrate(WIS) and [1.0% w/v - 25% - 90 min] and [3.0% w/v - 25% - 90min] using 60.0 FPU cellulase/gsubstrate(WIS) were 5.96±0.27 gGLC/LSOLh; 2.90±0.05 gGLC/LSOLh; 5.16±0.18 gGLC/LSOLh; 7.48±0.81 gGLC/Lh, respectively. Dependence on the Km of enzyme-catalyzed reaction exhibited a considerably variation with the substrate nature and the enzymatic kinetic conditions establishing that Km for the cellulase from T. reesei –substrate complex was between 54.81 gGLC/LSOL and 209.99 gGLC/LSOL.

Ethyl lactate is an environmentally bio-based solvent with a wide range of industrial applications. In this work, ethyl lactate was produced by synthesis using reactive distillation process. Through factorial experimental design, the influence of operating conditions as molar ratio ethanol: lactic acid, reboiler temperature and catalyst concentration on ethyl lactate were evaluated. A mathematical model was developed in order to describe the response of interest as function of operating conditions. The experimental results showed that the reactive distillation seems to be an alternative and simple energy-saving process with lower investment and operation costs to obtain ethyl lactate which normally requires a stage to the reaction and a stage to the reaction products separation. Each additional step in the downstream represents an increase in the operating and equipment investment costs.

The current development of technologies related to materials for science, biology and medicine is gaining a new impetus in order to give a better treatment to injured tissues and organs. In this context, biomaterials and biofabrication techniques are providing a healthier life to the population. However, to produce implant parts and devices, there is the need for biocompatibility and absence of toxic materials, which may preclude their medical application. To avoid this situation, Chemical Vapor Deposition (CVD) is presented as an attractive technique, since it can produce, in some case solvent less, polymeric biomaterials and uniform adherent films over substrates in just one single processing step. The development of CVD reactors has been extensively studied, but little is known about their fluid dynamic behavior and associated heat and mass transfer effects. The aim of this paper was to simulate a CVD reactor during the synthesis of poly 2-hydroxyethyl methacrylate (PHEMA), through of the release of the gaseous 2-hydroxyethyl methacrylate (2-HEMA) and initiators in a single step, completely dry, without the use of solvents or volatiles. The impact of operating conditions in the quality and characteristics of the deposited material was explored. A computational fluid dynamic (CFD) study was carried out to simulate velocity and temperature distribution on the vertical CVD. As a result, certain design aspects related to heat and mass transfer were addressed, which allowed to understand and to suggest modifications in the reactor design. These simulations were important to define a desirable temperature operation range aiming a uniform flow distribution in the reactor.

Ethanol production in Brazil is carried out through biological routes where yeasts are generally employed. For greater flexibility, ethanol production is linked to the sugar production. In this configuration, the main by- product of sugar production (molasses containing about 50 % wt in sugars) can be widely used for ethanol production. Nonetheless, due to strong ethanol inhibition, molasses dilution is necessary in order to maintain ethanol concentration in the broth below the threshold of toxicity at the end of fermentation. Hence, large amounts of water are added to the process resulting in higher costs of separation and plant design (since larger equipments are necessary). One way to solve these problems is couple fermentation to a continuous product removal technique such as in situ gas stripping fermentation process. This simple and inexpensive technique, which consists basically of a fermentor, a condenser and a pump for circulating gases, is used to remove volatile inhibitors continuously. In this work, in situ gas stripping on lab-scale was studied using ASPEN PLUS® V.7.3 aiming to evaluate the impact of sugar concentration in feed stream on the overall process. The gas flow rate was varied for three different levels of sugar concentration in the feed (20, 30 and 40 % wt).The main goal was to evaluate the sugar concentration ranges where more ethanol can be stripped compared with water, maintaining the ethanol concentration below the threshold of toxicity in the broth. Optimized sugar concentration were found after analyzing the following output variables: ethanol stripped (%), ethanol concentration in condensate (w/w), ethanol recovered (%), selectivity and ethanol mass fraction in the broth (w/w).

Molecular distillation process has been used to obtain an extended true boiling point (TBP) curve (above 565 °C up to 700 °C), compared with the results offered by traditional methodologies like ASTM D 2892 and ASTM D 5236. This separation process has the advantage of operating under conditions that reduce the thermal decomposition of the oil. In this paper, polynomials to represent the extended true boiling point curve up to 565 °C from molecular distillation data are proposed. The development is based on molecular distillation experimental results of 14 atmospheric and 5 vacuum oil residues obtained in Pilot and lab scale distiller in other works of the research group at Separation Processes Development Laboratory (UNICAMP). The experimental data were classified in seven different classes based on API density. In first instance, a database was built to perform an extension of the TBP curve of each oil, using the DESTMOL correlation to find the atmospheric temperatures that correspond to the distiller operation temperatures. The results of the three methodologies (ASTM D 2892, ASTM D 5236 and molecular distillation) were adjusted to a 3rd order polynomial as function of the accumulated mass percent. The coefficients were optimized using genetic algorithms. Finally, a variable analysis procedure was developed in order to determine the influence of the genetic algorithm parameters (population size and number of generations) in the obtained response and improve the average absolute deviation percent (%AAD). As a result, a third order fitting polynomial was found for every oil class, presenting %ADD lower than 3%.

Biodiesel production is currently a highly researched topic due to environmental issues as well as a possible biofuel to contribute with the energetic matrix regarding transportation. Among potencial alternative feedstock for biodiesel production microalgae appear as a possibility in view of its advantages in comparison to conventional crops, since they present high photosynthetic activity, exponential growth rates and high biomass productivities. In this investigation, the influence of two culture media (BG-11 and Guillard f/2) on the growth and lipid accumulation of the Desmodesmus sp. microalgae was assessed. Microalgal growth in BG-11 medium reached higher cell count in the considered time period and the microalgae presented higher lipid fraction in relation to the Guillard f/2 medium, thus being the most suitable medium for Desmodesmus sp. cultivation.

Higher alcohols production from syngas through chemical route has gained attention over the last decade because of characteristics such as: short-time reaction, abundant and lower price feedstocks, the use of lignin (a biomass component that is hardly used) and the almost complete conversion of the initial feedstock. In this route, cleaned and reformed synthesis gas (syngas), formed of carbon monoxide (CO) and hydrogen (H2) is catalytically converted into a mixture of alcohols that after purification can be used as fuel, solvent, or as feedstock for other processes. In this particular case study we use a Cu-based (Cu-O-ZnO-Zr-Fe-Mo-Th-Cs) catalyst, which consists of a modified methanol synthesis catalyst, so as to conceive, simulate, optimize, and analyze a small scale syngas-to-higher alcohols production plant (process capacity of 100 kmo/h of pure syngas). We assume that the WGS (water-gas-shift) reaction reaches equilibrium conditions and the alcohols production follows the ASF (Anderson-Schulz-Flory) distribution. The main advantage shown by this catalyst is the absence of water production, since all the water is consumed by the WGS reaction, on the other hand, the same reaction produces CO2 that can be recovered only coupling another process in order to produce more CO. The final product separation (methanol, ethanol, propanol, butanol and pentanol) is facilitated by the absence of water. After process design and optimization, an energy and yield analysis is discussed while pointing possible solutions and next steps regarding the sustainability of the process.

Ethanol production from lignocellulosic residues from agriculture, such as the acaí seeds, have a fundamental step, delignification. This step becomes is more effective when performed in combination with others pre- treatments, preferably with those that are able to remove the hemicellulose fraction, such as treatment with dilute sulfuric acid. The aim this work was perform the delignification of açaí seeds pretreated with dilute sulfuric acid and evaluate the enzymatic hydrolysis rate. The açaí sees were pretreated with 1 % sulfuric acid, 10% solids for 60 minutes at 121 °C. An experimental set 22 for evaluate delignification was performed and the experimental conditions were 1 % NaOH, temperature from 39.64 to 110.36 °C (+a; - a) and solids loading from 3.79 to 46.21 % (-a; +a). After delignification the liquid fraction was characterized for carbohydrate content, lignin and fermentation inhibitors (acetic acid, furfural and HMF). And solid fraction was also characterized for the carbohydrate, lignin and acetic acid. Both fractions were characterized via HPLC. After delignification, the resulting material was enzymatically hydrolyzed with an enzyme loading of 15 FPU/g of seed and 25CBU/g of seeds and 3% of solids and glucose concentrations were measured via HPLC. The results showed that the yield varied from 24 to 49% and delignification was effective in removing up to 89 % of this pre-treated material with dilute sulfuric acid lignin. The condition of 75°C and 3.79 % of solids was the condition that promoted higher enzymatic conversion with a value of 94.76%. It can be concluded that the conditions for delignification studied were effective in removing lignin and improve glucose release during enzymatic hydrolysis.

The aim of this work was to obtain experimental data in order to generate the kinetic model that showed the effect of the particle size on the performance of the pretreatment process. Data were obtained from the pretreatment kinetics process of sugarcane bagasse with dilute sulfuric acid in concentration of 1.0, 2.0 and 3.0% (w/v). The pretreatments were carried out at temperature of 121±1°C varying time and milling size, The studied times were 0, 15, 45, 60, 90 and 120 minutes and particle average diameter of 0.11, 0.25 and 0.50 mm. All the experiments were performed using a solid load of 15%.

In this work, sugarcane bagasse was processed by H2SO4-catalyzed hydrothermal pretreatment (CHP). CHP was performed under various solid loadings (SP) 10, 20 and 25 %, acid concentrations (A) 1.0, 2.0 and 3.0 % w/v and reaction times (tP) 30, 60, 90 and 150 min. The results showed that more than 60 % of the hemicellulose was removed. Cellulignin material was processed by enzymatic hydrolysis using a solid loading of 3.0 % w/v (on a dry basis) and by the action of cellulase from T. reesei and cellobiase from Aspergillus niger. Based on this experimental dataset, three Multilayer Perceptron Neural Network-MLPN models were developed (one for each level of acid concentration (A) in CHP) for predicting total glucose yield (GYield) as a function of solids loading (SP), pre-treatment reaction time (tP) and enzymatic hydrolysis time (t). The prediction by the model using the test dataset gave acceptable performance measures (mean absolute error, MAE, and residual standard deviation, RSD), equivalent to those obtained for the validation and training datasets. The dynamic models developed can be used to predict GYield during enzymatic hydrolysis of H2SO4- catalyzed hydrothermally (CHP) pre-treated sugarcane bagasse, which promote a successful hydrolysis process control.

It is clear that biofuels have a positive impact in the social, environmental and economic aspects of our world. In Brazil, ethanol is produced from sugarcane and is mainly used as a biofuel for cars. However, much research is being done in order to reduce the price of ethanol. With this goal in mind, pervaporation is being studied as a recovery process for ethanol from wine from fermentation, and to simplify the distillation step in order to reduce its production costs. More specifically, this research project studies ethanol separation by pervaporation from ethanol-water mixtures. The pervaporation was evaluated at 30 °C using a hydrophobic membrane of Polydimethylsiloxane (PDMS) for ethanol recovery, using ethanol concentrations characteristic of sugarcane fermentation. Keywords: Fermentation, ethanol, membranes processes, pervaporation.

This work is a review of the main chemical properties of aliphatic and aromatic isocyanates and their advantages and disadvantages when used as precursors for polyurethane (PU) synthesis, to be applied as biomedical polyurethanes. Isocyanates react quantitatively with primary hydroxyl groups producing urethane groups. The presence of urethane groups can promote the restoration of living tissues. Molecules with two or more hydroxyl groups reacting with molecules containing two or more isocyanate groups results in PU, therefore PU is biocompatible, with the condition they have no remaining isocyanate groups and if all the precursor molecules from PU do not have damaging groups. Furthermore, this report describes the synthesis reactions of isocyanates used industrially and their advantages and disadvantages, alternative process as well as alternative compounds discussed in current articles, as isonitriles, carbamates, and new routes as transcarbamylase, blocked isocyanates, non-isocyanates, in order to suit the environmental and safety standards.

The development of biomaterials for application in medicine is one of the great challenges of research in material science. The poly (a-hydroxy acids) are the principal biodegradable and bioresorbable polymers used in tissue engineering. Among the biomaterials (biopolymers) used in the medical field, the poly (lactic acid) (PLA) has received significant attention. It is produced from lactic acid, a naturally occurring organic acid that can be produced by fermentation. The attractive price and commercial availability of lactic acid are important reasons for PLA development. PLA and its copolymers are being used in biomedical area in the form of implants or devices due to its excellent biocompatibility and biodegradability. In this study, lactide was synthesized and Poly lactic acid produced. The objective of this study was to investigate the PLA production in laboratory scale. Characterization by FTIR of the lactide and PLA production was made to confirm the polymerization and a possible use as biomaterial.

Previous kinetic modelling for dilute H2SO4-acid hydrolysis of sugarcane bagasse operated using batch reactor led to conclude that hemicellulose conversion, about 75 % of theoretical, was possible to be reached using 1.0 % w v-1 H2SO4 solution, solid load equal to 20 % and 80 min of operation. The present study aims to expand the fundamental understanding of the kinetic involved in this process. A continuous process isothermally performed in a plug flow reactor at dynamic was proposed and studied. H2SO4-acidhydrolysis of 200 kg h-1 of sugarcane bagasse using 1.0 % w v-1 H2SO4 solution, solid load equal to 20 %,60 min and a reactor length of 1.30 m (with a cross-sectional area equal to 1 m2) at 121 °C resulted in yields of 59.70 % for xylose, 2.00 % for arabinose, 8.46 % for glucose, 8.42 % for acetic acid, 0.73 % for furfural, 0.12 % for 5-hydroxymethylfurfural and 0.00 % for levulinic acid which means more than 72 % of the hemicellulose (related to 30.99 % in the raw material) was easily hydrolyzed with similar inhibitors yields values when compared to process in batch configuration reported as: 8.43 % acetic acid, 0.96 % furfural, 0.16 % 5-hydroxymethylfurfural and 0.29 % levulinic acid. Hence, both reactors are equivalent in terms of the influence of the acid solution concentration and solids loading. However, plug flow reactor configuration reduces the time required to proceed with the H2SO4-acid hydrolysis.

With the aim of studying the fermentation of syngas, this work presents an integrated gasification with syngas fermentation process using the Aspen PlusTM. A reaction mechanism for the decomposition of sugarcane bagasse was used to represent the pyrolysis. The influence of operating conditions as gasifier temperature, oxidizing agents and gas composition in the fermentation were investigated for the production of ethanol by syngas fermentation. The simulation showed good results according to the validation with experimental data.

Ethanol competitivity can be enhanced when the total use of sugarcane portions is practicable, including bagasse and straw, through hydrolysis technology, in which the polysaccharides are processed to produce fermentable sugar and posteriorly ethanol. Among the problems of hydrolysate fermentation is the lowsugar concentration in the medium (when hydrolysis is performed at low solids loading), which leads to lowethanol concentration, increasing the energy requirement in distillation. This can be solved through the concentration of hydrolysates with molasses. Kinetics of a mixture hydrolysates - molasses changes significantly from that of molasses, due to presence of other sugars and inhibitors. Thus, the kinetic models developed for molasses are not useful to predict fermentation data for hydrolysates. Considering this, in this work, a kinetic model for fermentation of a mixture of sugarcane bagasse hydrolysate and molasses was developed. For this purpose, data from batch fermentations at temperatures of 30, 32, 34, 36 e 38 °C were used. The model for hydrolysates was based on kinetic expressions previously developed for molasses fermentation, with addition of a term considering acetic acid inhibition on Saccharomyces cerevisiae growth. Also, to describe the data for fermentations with hydrolysate, a parameter re-estimation was necessary. Due to the large number of parameters in the model, a re-estimation methodology was proposed, in which the most sensitive parameters were adjusted and the less sensitive were kept fixed, making the re-estimation easier. A parametric sensitivity analysis through Plackett-Burman designs was performed, using the software Statistica, by varying the kinetic parameters and calcullating their influence on the profiles of cell, substrate and ethanol concentrations. The model consisted of 13 parameters, of which 5 were considered as relevant on fermentation profiles (µmax, Pmax Yx, Yp/x and Xmax) and chosen to be re-estimated. Through the use of this methodology, an accurate model for second generation bioethanol production was developed.

This study aims to assess how Internal Rate of Return of the enterprise, Ethanol Output and Surplus Electricity vary according to changes in existing scenarios of an autonomous distillery, that is, a distillery producing ethanol and electricity, but not sugar. A simulation procedure using the Virtual Sugarcane Biorefinery (VSB) framework according to a screening design is used for this purpose. The VSB is composed of a set of computer-aided tools to simulate the sugarcane agricultural production system, its transport as well as the industrial processing. The sensitivity of operational variables, such as fermentation yield, steam consumption, boiler steam pressure, juice extraction yield, residual ethanol concentration in vinasse and alcohol content in wine were varied in a realistic basis, constrained by operational limits, which resulted in forty-five scenarios following a Central Composite Design (CCD). This design was used to describe ethanol production possible scenarios in autonomous distilleries in Brazil. This procedure has allowed evaluating scenarios with different technological configurations. The influence of these operational variables on the techno-economic parameters was studied through a screening procedure for statistical evaluation of results.

In this work, fermentation process was carried out using sugarcane molasses without pretreatment and Lactobacillus plantarum inoculum. The purification of the fermentation product was conducted by using the hybrid short path evaporation. The system allowed to employ lower temperatures of operation due to the use of vacuum and short residence time was achieved, avoiding the tendency of lactic acid decomposition. For tests were used: feed flow rate of 8 mL/min, stirring of 750 rpm, pressure of 1 kPa and it was varied the evaporator temperature from 30 to 170 °C. The experimental results showed 5 times higher the lactic acid concentration than the initial content in the raw material.

Production of chemicals and second generation ethanol from lignocellulosic material integrated to first generation sugarcane biorefineries presents potential for industrial implementation, since significant part of the infrastructure may be shared between both first and second generation plants. Additionally, chemicals from renewable resources have attracted increasing attention, mainly for their market prices (usually higher than commodities as biofuels) and potential for replacing oil-based products used as feedstock in the chemical industry. The production of chemicals through the alcoholchemistry route uses catalysts to convert ethanol into desired products according to catalysts activity and selectivity. One of the possibilities in the alcohol chemistry route is to use ethanol to produce n-butanol that can be sold as feedstock for the chemical industry and as drop-in biofuel for gasoline powered engines. Due to catalyst selectivity, this process generates also other chemicals, which can be purified to be sold as feedstock for the chemical industry. Previous studies have pointed out that the use of ethanol in a biorefinery to produce n-butanol presents good economic and environmental impacts. Nevertheless, results obtained for the economic return of the n-butanol biorefinery compared to autonomous ethanol plants were very similar, which can be unattractive for investors dealing with the high risks involved in a novel biorefinery process. In this work, the possibility of enhancing the financial and environmental impacts of n-butanol and other high value chemicals production integrated to a second generation sugarcane biorefinery is explored. Computer simulation is used to quantify the influence of technical parameters, including down-stream operations required to separate coproducts, adding value to the mix of products and commercial flexibility. Risk analysis is used to evaluate uncertain parameters such as the investments in n-butanol and second generation ethanol plants and the market prices assumed for the new products. Results obtained show that production of n-butanol and other high valued chemicals integrated to a first and second generation sugarcane biorefinery could be an economically and environmentally attractive alternative. However, the financial risk involved is high and hugely dependent on the selling prices of the new products of the portfolio investigated in this work, mainly n-butanol.

A model based on Artificial Neural Networks (ANN) to predict the concentration of ethanol, substrate and cells from secondary measurements (pH, turbidity, CO2 and temperature) was developed in this work. A second generation ethanol production from hydrolyzed sugarcane bagasse was considered as a study case. Experimental data were obtained from fermentation in the range of 30 to 38 °C with cell recycle. The fermentation feedstock is a mixture of molasses and hydrolyzated bagasse from the alkaline hydrogen peroxide pretreatment at 25 % of volume and 75 %, respectively. The accuracy of prediction of the ANN model is evaluated by its precision in describing experimental observations, and by the challenges involved in the use of online measurements. The model used to describe the fermentation provided a good prediction of concentration of cell, substrate and ethanol.

This work presents the synthesis of acrylic acid by hybrid route from sugarcane molasses fermentation and later acid lactic dehydration. Lactic acid was produced by sugarcane molasses fermentation using the Lactobacillus plantarum CCT 5731 bacteria in bioreactor BioFlo 415 at 37 °C. After of 46.4 h of fermentation 50.6 g/L of lactic acid was obtained with productivity of 1.1 g/L.h which was subsequently concentred to 152 g/L and stored to dehydration stage. Both commercial lactic acid and lactic acid obtained through fermentation stage were dehydrated by catalysts supported on basic zeolite (NaY) in a tubular reactor at 300 °C and continuous flow of CO2 (30 mL/min). The largest selectivity (25.7 %) for acrylic acid was obtained when the commercial lactic acid and KBr/NaY were used. When lactic acid obtained by fermentation a maximum acrylic acid selectivity of 16.7 % was achieved using KI/NaY. All chemicals species were characterized by high performance liquid chromatography (HPLC).

Efficient conversion of biomass into energy resources remains one of the biggest challenges faced by humanity in the search for a sustainable energy future. Bioethanol, the most important biofuel, currently produced from first generation feedstock like sugarcane may also be produced from lignocellulosic materials like sugarcane bagasse and straw, which are not a primary food source. Efficient technologies for production of lignocellulosic (or second generation) ethanol, however, are still under development, and challenges concerning its technical, economic and environmental feasibility remain to be solved. Integration of first and second generation ethanol production processes can be more economical, efficient and present lower environmental impacts than stand-alone second generation; thus, integrated first and second generation ethanol production can improve the feasibility of lignocellulosic ethanol and foster its industrial implementation. In this study the integrated production of first and second generation ethanol from sugarcane, including some of its technical, economic and environmental aspects are discussed. The biochemical route for second generation ethanol production, comprised by feedstock pretreatment and enzymatic hydrolysis, is taken as an example. Features of both first and second generation processes that are required to promote an adequate integration are discussed, providing guidance for development of experimental works, especially in second generation process.

The açaí seeds are an abundant byproduct of the chain of açaí and represent a significant source of lignocellulosic material for bioethanol production in the northern region of Brazil. In the present paper seeds of açaí were hydrothermally treated to overcome biomass recalcitrance for enzymatic hydrolysis. The effect of the hydrothermal pretreatment carried out with high solid loadings in the rates of sugars released was evaluated by subsequent enzymatic hydrolysis. The pretreatment used acid concentrations ranging from (0.5-1.5 %), solids loadings from 5 to 15 % (w/v) and time from 30 to 90 min at 120 °C under a pressure of 1.7 MPa. The enzymatic hydrolysis was carried out at a solid loading of 10 % DM. Hydrolysis was performed at 52 °C and pH 5.0 with an enzyme loading of 30 FPU of celullase and 50 CBU of ß- glycosidase for 72 h. The results showed that hydrothermal treatment can remove significantly hemicelluloses from seeds of açaí (80 %) and improve of yield monosaccharides released by hydrolysis enzymatic. Pre-treatment with 1.5 % sulphuric acid and 5 % solid content for 90 min at 120 °C was found to be the best condition for pre-treatment and conversion.

The major problem associated with the bioconversion of ethanol for industrial fuel purposes is the ethanol inhibition in the fermentation process. One way to solve this problem is couple fermentation to a continuous product removal technique. The gas stripping in situ removal process has a number of advantages over other techniques, for example: it is simple, inexpensive to operate and do not harm the culture. In this work, the feasibility of in situ gas stripping fermentation process was studied using ASPENPLUS® V.7.3. The process conditions were evaluated according to the existing laboratory scale design. The main process variables were investigated in order to achieve the best conditions to carry out an experimental plant, which is the planning of further work. The results show that such technique can lower ethanol concentration in a reactor making it below of inhibitory ranges. A correct choice of the optimized variables of the process provides a larger recovery of ethanol, contributing to the improvement and intensification of the fermentation process.

A fluidized bed reactor to gasify sugarcane bagasse was designed and built in order to produce syngas. A study of the effect of two variables -- ER ratio (defined as the ratio between the air flow introduced into the gasifier and the air stoichiometric flow required for complete combustion of the bagasse) and reaction temperature -- on the product distribution (syngas, bio-tar and char) and syngas composition have been analyzed. The ER ratio has a positive effect on gas production, increasing production when a higher ER is used. The char yield decreased at higher temperatures and yield of bio-tar remained almost invariant regardless the value of ER. The amount of bio-tar in the syngas was very small, but it was found that the bio-tar was almost water (> 95 wt% of water). The highest ER promoted the production of larger quantities of hydrogen and carbon monoxide, while reducing the amount of carbon dioxide.

Poly(lactic acid) or Poly(Lactide) (PLA) has been extensively used both in food packaging and in biomedical applications. In fact this material is a thermoplastic polyester, which is compostable and so it can be used as an alternative to PET for food applications. Moreover it is a biocompatible and bio absorbable material and for this reason is used in biomedical area. It can be used with hydroxyl apatite for the production of composite materials used as scaffolds in bone tissue engineering, or as drug delivery system. In this work bulk melt ring-opening-polymerization (ROP) of L-Lactide (cyclic dimer of lactic acid) has been studied. Starting from the kinetic scheme developed by (Yu et al., 2011) an isothermal model has been developed and validated with experimental data obtained in laboratory. Once kinetic constants were evaluated, a complete model of a batch reactor for PLA production for biomedical applications has been developed. Finally a PI temperature control has been implemented on the reactor, in order to satisfy process targets (MW of 100[kDa] and conversion of 95%) in the shortest possible time period.

Today there is a worldwide interest in the use of biomass as an environmental friendly renewable energy source. The depletion of fossil oil reserves, constant uncertainties as far as price is concerned, unsecured supplies, and environmental pollution are among the many energy problems, when the use of fossil fuels are considered. Greenhouse effect and its consequences on climate change is one of the drawbacks resulting from the extensive use of this kind of fuels. These problems require the development of new alternative fuels such as biofuels. In this way, the biomass appears as an attractive source for the production of fuels and chemicals due to its versatility, renewable nature and low environmental impacts. The available energy production processes from biomass can, roughly, be divided into two general categories, to know: thermochemical and biological processes. Pyrolysis, gasification, reforming and combustion are the four thermochemical processes and direct biophotolysis, indirect biophotolysis, biological water–gas shift reaction, photo-fermentation and dark-fermentation are the five biological processes. Alternative thermochemical via (pyrolysis and gasification) can be practically applied to produce hydrogen and syngas from many types of renewable feedstock and deserve special attention. Bearing this in mind, this paper gives an overview of these technologies for hydrogen and syngas production from biomass.