910 resultados para Sugar-alcohol production sector


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A quantitative and qualitative review of the cultural industries in Manchester at the end of the 1990s

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this work a detailed thermodynamic analysis for an extraction-condensation steam turbine capable to drive a 40 MVA electricity generator in a sugar-alcohol factory was carried out. The use of this turbine in the cogeneration system showed that its efficiency contributed to increase the power generation, although the condensation reduces the overall efficiency of the plant. Sensibility analyses were performed to evaluate the behavior of the overall energy efficiency of a plant with the extraction-condensation turbine in function of the boiler efficiency, the specific consumption of steam in the processes and the condensation rate in the turbine. It was observed that the plant efficiency is very sensible to the condensation rate variation and it increases when there is an increase in the demand of steam for processes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this work it was performed energetic and exergetic analyses of three thermal plants to assessment a cogeneration system in expansion of a sugar-alcohol factory. The initial configuration considered is constituted by a low pressure steam generator, single stage steam turbines for electricity generation and crusher, shredder and mills with mechanical driving. In the intermediary configuration, the low pressure steam generator was substituted by another which generates steam at higher pressure and higher temperature, the steam turbines for electricity generation were substituted by a multiple stages extraction-condensation turbine and the other steam turbines were maintained. The final configuration consists in the substitution of these last turbines by electrical motors. Thermodynamic analyses were performed to evaluate the equipment and the overall plants efficiencies to permit a comparison among the plants. Besides of this, some important parameters of the sugar-alcohol factories were calculated.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Includes bibliography

Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Energy requirements to produce ethyl alcohol from three different crops in Brazil (sugarcane, cassava, and sweet sorghum) were calculated. Figures are presented for the agricultural and industrial phases. The industrial phase is always more energy-intensive, consuming from 60 to 75 percent of the total energy. Sugarcane is the more efficient crop for ethyl alcohol production, followed by sweet sorghum and cassava from a net energy viewpoint. The utilization of sweet sorghum stems might increase the total energy gain from this crop to almost the same level as sugarcane. Cassava has a lower energy gain at the present state of agriculture in Brazil. Copyright © 1978 AAAS.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Mecânica - FEIS

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for bioethanol production creates a major competition with the food market in terms of land for cultivation, and this makes bioethanol from these sources economically less attractive. RESULT This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for bioethanol production via yeast (Saccharomycesbayanus)under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L -1 obtained from 10 g L-1 of lipid-extracted microalgae debris. CONCLUSION This productivity level (∼38% w/w), which is in keeping with that of current production systems endorses microalgae as a promising substrate for bioethanol production.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The baker s yeast Saccharomyces cerevisiae has a long tradition in alcohol production from D-glucose of e.g. starch. However, without genetic modifications it is unable to utilise the 5-carbon sugars D-xylose and L arabinose present in plant biomass. In this study, one key metabolic step of the catabolic D-xylose pathway in recombinant D-xylose-utilising S. cerevisiae strains was studied. This step, carried out by xylulokinase (XK), was shown to be rate-limiting, because overexpression of the xylulokinase-encoding gene XKS1 increased both the specific ethanol production rate and the yield from D xylose. In addition, less of the unwanted side product xylitol was produced. Recombinant D-xylose-utilizing S. cerevisiae strains have been constructed by expressing the genes coding for the first two enzymes of the pathway, D-xylose reductase (XR) and xylitol dehydrogenase (XDH) from the D-xylose-utilising yeast Pichia stipitis. In this study, the ability of endogenous genes of S. cerevisiae to enable D-xylose utilisation was evaluated. Overexpression of the GRE3 gene coding for an unspecific aldose reductase and the ScXYL2 gene coding for a xylitol dehydrogenase homologue enabled growth on D-xylose in aerobic conditions. However, the strain with GRE3 and ScXYL2 had a lower growth rate and accumulated more xylitol compared to the strain with the corresponding enzymes from P. stipitis. Use of the strictly NADPH-dependent Gre3p instead of the P. stipitis XR able to utilise both NADH and NADPH leads to a more severe redox imbalance. In a S. cerevisiae strain not engineered for D-xylose utilisation the presence of D-xylose increased xylitol dehydrogenase activity and the expression of the genes SOR1 or SOR2 coding for sorbitol dehydrogenase. Thus, D-xylose utilisation by S. cerevisiae with activities encoded by ScXYL2 or possibly SOR1 or SOR2, and GRE3 is feasible, but requires efficient redox balance engineering. Compared to D-xylose, D-glucose is a cheap and readily available substrate and thus an attractive alternative for xylitol manufacture. In this study, the pentose phosphate pathway (PPP) of S. cerevisiae was engineered for production of xylitol from D-glucose. Xylitol was formed from D-xylulose 5-phosphate in strains lacking transketolase activity and expressing the gene coding for XDH from P. stipitis. In addition to xylitol, ribitol, D-ribose and D-ribulose were also formed. Deletion of the xylulokinase-encoding gene increased xylitol production, whereas the expression of DOG1 coding for sugar phosphate phosphatase increased ribitol, D-ribose and D-ribulose production. Strains lacking phosphoglucose isomerase (Pgi1p) activity were shown to produce 5 carbon compounds through PPP when DOG1 was overexpressed. Expression of genes encoding glyceraldehyde 3-phosphate dehydrogenase of Bacillus subtilis, GapB, or NAD-dependent glutamate dehydrogenase Gdh2p of S. cerevisiae, altered the cellular redox balance and enhanced growth of pgi1 strains on D glucose, but co-expression with DOG1 reduced growth on higher D-glucose concentrations. Strains lacking both transketolase and phosphoglucose isomerase activities tolerated only low D-glucose concentrations, but the yield of 5-carbon sugars and sugar alcohols on D-glucose was about 50% (w/w).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O objetivo desta tese é analisar, orientar e indicar algumas formas de mensuração de resultados das ações ou programas na área de Gestão de Pessoas ao longo dos anos, bem como de novas tendências no setor de agroenergia. O trabalho procura também propor práticas de planejamento estratégico e, indicadores para as organizações com foco no desenvolvimento e nas mudanças previstas nas organizações, no mercado de trabalho, nos modelos de gestão e de negócios do segmento de produção de cana-de-açúcar para os próximos anos. No estudo são analisados as transformações organizacionais, novos desafios competitivos do presente e do futuro, e a forma como a área de Recursos Humanos nas diversas organizações do setor, tem acompanhado tal processo, verificando o impacto dessas ações em um contexto de mudanças nos processos da cadeia agrícola (mecanização do plantio, colheita,.dentre outros), da cadeia industrial (biorefinarias, etanol de segunda geração, gaseificação...dentre outros), e no desenvolvimento organizacional e humano como parte integrante de um programa de sustentabilidade das organizações. São abordados metodologias, sistemas e ferramentas de planejamento estratégico, e mensuração propostas por certos autores que visam a demonstrar o impacto das estratégias e as ações na Gestão de Pessoas em direção ao cumprimento das metas e objetivos das organizações, em um cenário de forte crescimento interno e global do mercado de bioenergia. Nesse cenário, expõe-se e discute-se como as empresas do setor sucroalcooleiro utilizam, na prática, essas metodologias e os indicadores de performance da área frente às necessidades, e indicam-se as melhores práticas e ferramentas que visam a facilitar os processos decisórios, o uso de métricas de Recursos Humanos para previsão e acompanhamento do Capital Humano, e a otimização dos recursos e dos investimentos frente aos novos desafios do setor. Embora já se notem várias iniciativas visando a tornar a Gestão de Pessoas um fator estratégico para as organizações da agroenergia, a pesquisa identificou que a área de Recursos Humanos está evoluindo nessa direção e pode contribuir de forma efetiva para a melhor performance e sustentabilidade dos negócios. Palavras chaves: Cana-de Açúcar, Estratégia Organizacional, Capital Humano