978 resultados para specific mass


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This study proposes to find a biodiesel through transesterification of rice bran oil with KI/Al2O3 checking the influence of two types of alumina (Amorphous and Crystalline) for conversion into methyl esters. The catalyst was synthesized by the wet impregnation method. Adding 30 mL of 35% KI(aq.) in 10 g of alumina, under stirring at 80 °C for 3 hours. The reaction conditions used in this study were optimized, with a molar ratio methanol:oil of 15:1, 8 h of reaction time and reflux temperature. The catalyst amount was varied in the range of 1 to 5 % wt. The solid catalysts materials were analyzed by: x-ray diffraction (XRD), thermogravimetry (TG), N2 adsorption/desorption, scanning electron microscopy (SEM) and basicity, for the identification of its structure and composition, verifying the presence of basic sites. The results showed that Al2O3(A) presents an amorphous structure, high surface area and a better catalytic activity, in relation to the catalyst synthesized with Al2O3(C) support that proved to have a more crystalline structure, having as well, a lesser surface area, enabling difficulties for the incorporation of active sites. The obtained biodiesel with 5% wt. KI/Al2O3(A) presented physicochemical properties within the standards specified by the Resolution No 7/2008 ANP and obtained the best reaction yield with 95.2%, according to quantitative measurement from the TG, which showed 96.2% conversion into methyl esters. It was furthermore found that with the increasing amount of the quantity of the catalyst in the reaction, there was also an increase in the ester content obtained. The specific mass and the kinematic viscosity were reduced with the increase of the amount of quantity of the catalyst, indicating an increase in the conversion of triglycerides

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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It was evaluated the energetic efficiency and operational parameters of a windrowing and prismatic baling, both from CASE NEW HOLLAND® operations in sugarcane vegetal residues (green leaves, dry leaves and tops) picked mechanically in green cane. The area belongs to COSTA PINTO MILL (COSAN® Group) which was harvested mechanically by combines in the State of Sao Paulo, Brazil. The geographic location of the area is: Latitude 22°40'30S, Longitude 47°36'38W and Altitude of 605m. The variety was RB 82-5336, planted in 1.40m row spacing, with 78t.ha-1 yield. The vegetal residues analysis obtained 69.93% of leaves, 21.44% of stalks fractions, 2.27% of tops and 6.36% of total strange matter. The vegetal residues values were: gross heat of 18.43MJ.kg-1, low heat of 17.00MJ.kg'1 and useful heat of 12.94MJ.kg-1. The vegetal residues average energetic potential was 342.48GJ.ha-1. The treatments were simple, double and triple windrowing. The use of the rake and prismatic baler to pick up the residues was viable. The simple windrowing treatment presented the best results: effective capacity of 83.06t.ha-1, fuel consumption of 0.18L.t -1 and 99.95% of positive energetic efficiency. The bales obtained in the treatment of triple windrowing presented the largest specific mass average of 221.11kg.m-3. The soil amount in the bales increased with successive windrowing. The baling operation in the triple windrowing treatment obtained better results, presenting the effective capacities of 20.29t.h -1 and 1.45ha.h-1 and fuel consumption of for baled in 1.37L.t-1. The high total energetic efficiency of 99.53% indicates that is technically viable the withdrawal of the vegetal residues.

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The objective of this study was to analyze the sugar cane vegetal residues collection, as well as determining its energetic potential, using a rake and cylindrical baler, both from NEW HOLLAND® under two different windrowing process (simple and double). The field tests were carried out in an area that belongs to COSTA PINTO MILL (COSAN® Group) in the city of Piracicaba, Sao Paulo State, Brazil. The geographic location of the area is: Latitude 22°4030'S, Longitude 47°3633'W and altitude of 605m. From the trash analysis, before the baling, the following average results were obtained: 69.93% of leaves; 2.27% of stalks fractions; 21.44% of tops and 6.36% of total strange matter. The estimated residues yield was 27.01 tons.ha -1 with a gross heat of 18.43 MJ.kg-1, low heat of 17.01 MJ.kg-1, useful heat of 13.32 MJ.kg-1, average moisture of 20.76% and an energetic potential of 494,875.09 MJ.ha-1. In the windrowing operations (simple and double) the averages of the 5 out of 13 analyzed variable presented differences between them in a 1% level of significance in the Tukey Test. The averages comparison of the results for bale's specific mass and the effective capacities (ton.h-1) e (ha.h-1) had been significant at a 5% level in the Tukey Test. The comparisons of the averages for the results had been significant to 1% level. The strange matter averages of the bales did not differed between them.

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Pós-graduação em Ciência e Tecnologia de Materiais - FC

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

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

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Pós-graduação em Engenharia Civil - FEIS

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Pós-graduação em Engenharia Civil - FEIS

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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A espécie Piper aduncum L. é uma planta de porte arbustivo, popularmente conhecida na região amazônica como pimenta-de-macaco. Dela, pode ser extraído um óleo essencial, rico em dilapiol, de grande interesse econômico pela sua ação inseticida e combate às pragas na agricultura. Esse bioinseticida surge como alternativa para substituir os inseticidas sintéticos, pois sendo de origem natural não causam danos ao meio ambiente e à saúde do homem. Neste trabalho, foram analisadas as propriedades físicas do óleo essencial de pimenta-de-macaco, obtido por destilação por arraste com vapor que apresentou valores médios do índice de refração igual a 1,516 e massa específica igual a 1,08 g/cm³. Estudou-se o processo de destilação fracionada do óleo essencial, visando concentrar o composto de interesse agregando maior valor econômico, o que viabiliza seu emprego na produção de novos produtos. Nesse processo o composto principal é obtido com elevado grau de pureza. Avaliou-se um modelo matemático para a concentração de dilapiol no fundo do balão de destilação, via análise de regressão, em função do tempo de operação, o qual ajustou muito bem os dados experimentais. A análise dos resultados permite afirmar que o processo de destilação fracionada pode ser empregado para separar os constituintes úteis de óleos essenciais. Isso só é possível, pois os óleos essenciais são constituídos por vários compostos orgânicos voláteis de pontos de ebulição e pressões de vapor diferentes, tornando a separação viável. O maior teor de dilapiol obtido experimentalmente pelo processo de destilação fracionada a vácuo foi de 95 %, operando-se nas condições de vácuo (40 mmHg) e temperatura média da coluna de 122 ºC, obtendo-se um rendimento médio do processo de 41 % (v/v).