Glass-ceramic material from the SiO 2-Al 2O 3-CaO system using sugar-cane bagasse ash (SCBA)

Brazil is the world's largest producer of alcohol and sugar from sugarcane. Currently, sugarcane bagasse is burned in boilers to produce steam and electrical energy, producing a huge volume of ash. The major component of the ash is SiO 2, and among the minor components there are some mineralizing agents or fluxing. Published works have shown the potential of transforming silicate-based residues into glass-ceramic products of great utility. This work reports the research results of SCBA use to produce glass-ceramics with wollastonite, rankinite and gehlenite as the major phases. These silicates have important applications as building industry materials, principally wollastonite, due to their special properties: high resistance to weathering, zero water absorption, and hardness among others. The glasses (frits) were prepared mixing ash, calcium carbonate and sodium or potassium carbonates as flux agents, in different concentrations. X-ray fluorescence was used to determine the chemical composition of the glasses and their crystallization was assessed by using thermal analysis (DTA/DSC/TGA) and X-ray diffraction. The crystallization kinetics was evaluated using the Kissinger method, giving activation energies ranging from 200 to 600 kJ/mol. © 2011 Ceramic Society of Japan.

Initial analysis from a Lidar observation campaign of sugar cane fires in the central and western portion of the S̃ao Paulo State - Brazil

The central and western portion of the S̃ao Paulo State has large areas of sugar cane plantations, and due to the growing demand for biofuels, the production is increasing every year. During the harvest period some plantation areas are burnt a few hours before the manual cutting, causing significant quantities of biomass burning aerosol to be injected into the atmosphere. During August 2010, a field campaign has been carried out in Ourinhos, situated in the south-western region of S̃ao Paulo State. A 2-channel Raman Lidar system and two meteorological S-Band Doppler Radars are used to indentify and quantify the biomass burning plumes. In addiction, CALIPSO Satellite observations were used to compare the aerosol optical properties detected in that region with those retrieved by Raman Lidar system. Although the campaign yielded 30 days of measurements, this paper will be focusing only one case study, when aerosols released from nearby sugar cane fires were detected by the Lidar system during a CALIPSO overpass. The meteorological radar, installed in Bauru, approximately 110 km northeast from the experimental site, had recorded echoes (dense smoke comprising aerosols) from several fires occurring close to the Raman Lidar system, which also detected an intense load of aerosol in the atmosphere. HYSPLIT model forward trajectories presented a strong indication that both instruments have measured the same air masss parcels, corroborated with the Lidar Ratio values from the 532 nm elastic and 607 nm Raman N2 channel analyses and data retrieved from CALIPSO have indicated the predominance of aerosol from biomass burning sources. © 2011 SPIE.

Soursop (Annona muricata L.) and sugar apple (Annona squamosa L.): Antioxidant activity, fatty acids profile and determination of tocopherols

Purpose: This study aims to analyze the soursop and sugar apple seeds as to its composition, to evaluate the antioxidant potential of seeds extract and characterize the oil extracted from them, regarding the fatty acids profile and content of tocopherols. Design/methodology/approach: To obtain the extracts, dried and crushed seeds were extracted with ethanol for 30 minutes, at a ratio of 1:3 (m/m, seed: ethyl alcohol) under continuous stirring at room temperature. Then, the mixture was filtered and the supernatants subjected to rotoevaporator at 40°C aiming to determine, by direct weighing, the yields of dry extracts. Findings: According to the results, the soursop and sugar apple seeds constituted significant sources of lipids, proteins and carbohydrates and can therefore be used in food and feed, and offer relevant antioxidant activity of phenolic compounds. The oil seeds are a good source of unsaturated fatty acids, especially oleic and linoleic acids and they have significant amounts of total tocopherol. Research limitations/implications: Implications are the identification of bioactive compounds extracted from seeds of tropical and subtropical fruits, and to prevent certain types of diseases. Practical implications: The information presented might be directly used for developing of functional foods such as fruits. Originality/value: The article tries to identify new source of compounds extracted from fruits. © Emerald Group Publishing Limited.

The assessment of the quality of sugar using electronic tongue and machine learning algorithms

The correct classification of sugar according to its physico-chemical characteristics directly influences the value of the product and its acceptance by the market. This study shows that using an electronic tongue system along with established techniques of supervised learning leads to the correct classification of sugar samples according to their qualities. In this paper, we offer two new real, public and non-encoded sugar datasets whose attributes were automatically collected using an electronic tongue, with and without pH controlling. Moreover, we compare the performance achieved by several established machine learning methods. Our experiments were diligently designed to ensure statistically sound results and they indicate that k-nearest neighbors method outperforms other evaluated classifiers and, hence, it can be used as a good baseline for further comparison. © 2012 IEEE.

Clastogenicity of landfarming soil treated with sugar cane vinasse

The addition of nutrients and/or soil bulking agents is used in bioremediation to increase microbial activity in contaminated soils. For this purpose, some studies have assessed the effectiveness of vinasse in the bioremediation of soils contaminated with petroleum waste. The present study was aimed at investigating the clastogenic/aneugenic potential of landfarming soil from a petroleum refinery before and after addition of sugar cane vinasse using the Allium cepa bioassay. Our results show that the addition of sugar cane vinasse to landfarming soil potentiates the clastogenic effects of the latter probably due the release of metals that were previously adsorbed into the organic matter. These metals may have interacted synergistically with petroleum hydrocarbons present in the landfarming soil treated with sugar cane vinasse. We recommend further tests to monitor the effects of sugar cane vinasse on soils contaminated with organic wastes. © 2012 Springer Science+Business Media B.V.

Quantification of uncertainties associated with space-time estimates of short-term soil CO2 emissions in a sugar cane area

The characterization of soil CO2 emissions (FCO2) is important for the study of the global carbon cycle. This phenomenon presents great variability in space and time, a characteristic that makes attempts at modeling and forecasting FCO2 challenging. Although spatial estimates have been performed in several studies, the association of these estimates with the uncertainties inherent in the estimation procedures is not considered. This study aimed to evaluate the local, spatial, local-temporal and spatial-temporal uncertainties of short-term FCO2 after harvest period in a sugar cane area. The FCO2 was featured in a sampling grid of 60m×60m containing 127 points with minimum separation distances from 0.5 to 10m between points. The FCO2 was evaluated 7 times within a total period of 10 days. The variability of FCO2 was described by descriptive statistics and variogram modeling. To calculate the uncertainties, 300 realizations made by sequential Gaussian simulation were considered. Local uncertainties were evaluated using the probability values exceeding certain critical thresholds, while the spatial uncertainties considering the probability of regions with high probability values together exceed the adopted limits. Using the daily uncertainties, the local-spatial and spatial-temporal uncertainty (Ftemp) was obtained. The daily and mean emissions showed a variability structure that was described by spherical and Gaussian models. The differences between the daily maps were related to variations in the magnitude of FCO2, covering mean values ranging from 1.28±0.11μmolm-2s-1 (F197) to 1.82±0.07μmolm-2s-1 (F195). The Ftemp showed low spatial uncertainty coupled with high local uncertainty estimates. The average emission showed great spatial uncertainty of the simulated values. The evaluation of uncertainties associated with the knowledge of temporal and spatial variability is an important tool for understanding many phenomena over time, such as the quantification of greenhouse gases or the identification of areas with high crop productivity. © 2013 Elsevier B.V.

Thermal behavior of renewable diesel from sugar cane, biodiesel, fossil diesel and their blends

Biofuels and their blends with fossil fuel are important energy resources, whose production and application have been largely increased internationally. This study focuses on the evaluation of the activation energy of the thermal decomposition of three pure fuels: farnesane (renewable diesel from sugar cane), biodiesel and fossil diesel and their blends (20% farnesene and 80% of fossil diesel - 20F80D and 20% farnesane, 50% fossil diesel and 30% biodiesel - 20F50D30B). Activation energy has been determined from thermogravimetry and Model-Free Kinetics. Results showed that not only the cetane number is important to understand the behavior of the fuels regarding ignition delay, but also the profile of the activation energy versus conversion curves shows that the chemical reactions are responsible for the performance at the beginning of the process. In addition, activation energy seemed to be suitable in describing reactivity in the case of blends of renewable and fossil fuels. © 2013 Elsevier B.V.

Multi-choice mixed integer goal programming optimization for real problems in a sugar and ethanol milling company

Goal Programming (GP) is an important analytical approach devised to solve many realworld problems. The first GP model is known as Weighted Goal Programming (WGP). However, Multi-Choice Aspirations Level (MCAL) problems cannot be solved by current GP techniques. In this paper, we propose a Multi-Choice Mixed Integer Goal Programming model (MCMI-GP) for the aggregate production planning of a Brazilian sugar and ethanol milling company. The MC-MIGP model was based on traditional selection and process methods for the design of lots, representing the production system of sugar, alcohol, molasses and derivatives. The research covers decisions on the agricultural and cutting stages, sugarcane loading and transportation by suppliers and, especially, energy cogeneration decisions; that is, the choice of production process, including storage stages and distribution. The MCMIGP allows decision-makers to set multiple aspiration levels for their problems in which the more/higher, the better and the less/lower, the better in the aspiration levels are addressed. An application of the proposed model for real problems in a Brazilian sugar and ethanol mill was conducted; producing interesting results that are herein reported and commented upon. Also, it was made a comparison between MCMI GP and WGP models using these real cases. © 2013 Elsevier Inc.

Energetic, ecologic and fluid-dynamic analysis of a fluidized bed gasifier operating with sugar cane bagasse

This work aims to study the thermodynamic, ecological and fluid-dynamic aspects of a circulating fluidized bed gasifier using sugar cane bagasse as biomass, in order to estimate a model of its normal operation. In the initial stage was analysed the composition of biomass selected (sugar cane bagasse) and its lower heating value (LHV) was calculated. The energy balance of the gasifier was done, being the volumetric flow of air, synthesis gas and biomass estimated. Also the power produced by this gasifier was theoretically estimated. Then the circulating fluidized bed gasifier was designed for operation with approximately 100 kg/h of processed biomass. Cross-sectional area of the reactor, feeder size, diameter of the exit zone of the gases and minimum height of the expanded bed were selected. Some bed gasifier hydrodynamic factors were also studied. The minimum fluidization velocity, fluidization terminal velocity, and average fluidizing velocity were calculated, in order to understand the fluid-dynamic behaviour of gasification of this fuel. It was obtained a theoretical model that can support a possible prototype of circulating fluidized bed gasifier biomass. Finally, there were studied the ecological aspects of the gasifier, through an overall methodology. Ecological efficiencies were estimated for two scenarios: first considering the carbon cycle and thereafter disregarding the carbon cycle. In both cases, it can be proved the ecological viability of the project. © 2013 Elsevier Ltd. All rights reserved.

Use of slag/sugar cane bagasse ash (SCBA) blends in the production of alkali-activated materials

Blast furnace slag (BFS)/sugar cane bagasse ash (SCBA) blends were assessed for the production of alkali-activated pastes and mortars. SCBA was collected from a lagoon in which wastes from a sugar cane industry were poured. After previous dry and grinding processes, SCBA was chemically characterized: it had a large percentage of organic matter (ca. 25%). Solutions of sodium hydroxide and sodium silicate were used as activating reagents. Different BFS/SCBA mixtures were studied, replacing part of the BFS by SCBA from 0 to 40% by weight. The mechanical strength of mortar was measured, obtaining values about 60 MPa of compressive strength for BFS/SCBA systems after 270 days of curing at 20 °C. Also, microstructural properties were assessed by means of SEM, TGA, XRD, pH, electrical conductivity, FTIR spectroscopy and MIP. Results showed a good stability of matrices developed by means of alkali-activation. It was demonstrated that sugar cane bagasse ash is an interesting source for preparing alkali-activated binders. © 2013 by the authors; licensee MDPI, Basel, Switzerland.

Occurrence of Cu and Cr in the sedimentary humic substances and pore water from a typical sugar cane cultivation area in São Paulo, Brazil

Purpose: The purpose of this paper is to study the interactions of sedimentary humic substances (SHS) from a sugarcane cultivation area with Cu(II) and Cr(III) and to evaluate the occurrence of these metals in the pore water and SHS. Materials and methods: For this study, the northwestern region of the State of São Paulo, Brazil, which is considered the region with the highest production of sugar cane in the state, was selected. Samples of sediment were collected from four sampling sites in the Preto, Turvo, and Grande rivers. The SHS and pore water were extracted from the sediment using the method suggested by the International Humic Substances Society and centrifugation, respectively. The complexing capacity (CC) of the SHS for Cu(II) and Cr(III) was determined by individually titrating these metals with an ultrafiltration system using tangential flow. The total concentrations of Cr and Cu were determined for the pore water, sediments, and humic substances with graphite furnace atomic absorption spectrometry and Zeeman background correction after an acid digestion, according to the methods described in US EPA Method 3050B. Results and discussion: The SHS from a site in the Turvo River, which is typically cultivated with sugarcane, possessed the highest concentration of Cu bound to SHS (25.0%), the largest CC (0.63 mmol Cu g-1 HS) and the highest concentration of this metal in the pore water (1.38 mg Cu Kg-1 sed.). For Cr, the SHS collected from a location on the Preto River dam had the largest CC (0.90 mmol Cr g-1 HS) and the lowest Cr content in the pore water (0.29 mg Cr Kg-1 sed.), indicating that there was an inverse relationship between the CC and the concentration of metal available in the pore water. Conclusions: Sedimentary humic substances might be one of the regulatory factors controlling the availability of Cu and Cr in the sediments found in a typical region that has been planted with sugarcane. Distinct behaviors were observed between the two elements investigated; higher CC and a larger fraction of Cu(II) were found in the pore water of samples originating from sugarcane crops. The opposite behavior was observed for the Cr(III) species. © 2013 Springer-Verlag Berlin Heidelberg.

Anthropogenic influences on Cd, Cr,Cu, Ni, Pb and Zn concentrations in soils and sediments in a watershed with sugar cane crops at São Paulo State, Brazil

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

Analysis of efficiency and rationality in a sugar-alcohol mill using hyperboloid a-load and potency

Brazil is the world's largest producer of sugar cane and which in the state of São Paulo concentrate the greatest amount of sugar cane field of the country. The sugar-alcohol sector has the capacity to produce sufficient thermal and electrical energy to be used in their process of production and commercialize of surplus in electricity distribution network. Therefore it is necessary to evaluate the energy efficiency and rationality within the mill. Accordingly this research proposed analyze the sugar-alcohol mill's sectors globally and individually, located in the west center of the São Paulo state, using the valuation methodology employed by the Agência Nacional de Energia Elétrica (ANEEL) in the industries that do not have systems of cogeneration. In this analysis, the hyperboloids of load and potency were applied based on the indexes of potency factor and load factor that allow estimate the efficiency and rationality. © 2013 IEEE.

The enzymatic recalcitrance of internodes of sugar cane hybrids with contrasting lignin contents

The recalcitrance in grasses varies according to cell type and maturation. The origin of the recalcitrance in different regions from sugar cane internodes with varied lignin contents was evaluated. The efficiency of enzymatic hydrolysis was correlated with the chemical, micromorphological and microspectrophotometric characteristics of the samples. The internodes of three sugar cane hybrids were dissected into four different fractions. The outermost fraction and the rind were the most recalcitrant regions, whereas the pith-rind interface and the pith were less recalcitrant. Cellulose conversion reached 86% after 72h of enzymatic digestion of the pith from the hybrid with the lowest lignin content. There was an inversely proportional correlation between the area occupied by vascular bundles and the efficiency of cellulose hydrolysis. High cellulose and low lignin or hemicellulose contents enhanced the efficiency of enzymatic hydrolysis of the polysaccharides. The critical evaluation of the results permitted to propose an empirical parameter for predicting cellulose conversion levels that accounts for the positive effect of high cellulose and low lignin plus hemicellulose and the detrimental effect of abundant vascular bundles. The cellulose conversion levels fit well to this calculated parameter, following a second order polynomial with an r2 value of 0.96. © 2013 Elsevier B.V.

Use of Moringa oleífera Lamarck leaf extract as sugarcane juice clarifier: effects on clarifed juice and sugar

The objective of this study was to evaluate the effect of Moringa oleifera Lam. leaf extract on the sedimentation of impurities in the treatment of sugarcane juice and the effects on sugar quality and on the clarified juice. The experimental design used was a 4x2 factorial arrangement with four replications. The main treatments performed included the extracted original sugarcane juice, the synthetic polyelectrolyte (Flomex 9076), the leaf extract, and a control. The secondary treatments consisted of the sugarcane varieties RB92579 and RB867515. The clarification process used was simple defecation, in which the flocculating agents and the juice, limed and heated, were poured simultaneously into a decanter. The microbiological and chemico-technological characteristics of the extracted and clarified juices were evaluated. The clarified juice was concentrated up to 60° Brix (syrup) and subjected to boiling in a pilot pan using seeds to perform the graining: The sugar was recovered by centrifugation and analyzed for microbiological and chemico-technological characteristics. It was concluded that the use of the Moringa oleifera Lam. leaves extract resulted in a better quality of clarified juice and sugar.